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  • s 10:34 PM on 130215 Permalink | Reply
    Tags: cine, ,   

    film is not necessarily about WHAT you see – but it’s almost more an exercise in what you DON’T or CAN’T see. The best Directors and DPs show you only what is relevant to the story and never introduce a random shot or character if they can at all avoid it. I’ve always preached that a director or photographer should INCLUDE elements in a frame or shots that add to the story, and EXCLUDE elements or shots that detract from it.
     
  • s 9:55 PM on 130215 Permalink | Reply
    Tags: , cine, ,   

    Lenses : Cine vs Still 

    zoom

    – : http://matthewduclos.wordpress.com/2011/10/07/why-cinema-lenses-cost-so-much/

    Basically, everything boils down to two categories; usability and image quality. Obviously there are other factors involved such as production quantity, but that is usually tied into image quality.  Again, the question is, why is a cinema lens so much more expensive than a still photo lens? Cinema lens prices increase exponentially as the quality increases. For this demonstration, the top of the price spectrum will be represented by the Angenieux 24-290mm Optimo, and the bottom will be represented by the Nikon 18-55mm kit lens. Some would expect a few test shots with some text overlaid on them similar to that of most online lens reviews (mine included), but this really doesn’t show much beyond very basic image quality. To be honest, with todays manufacturing processes and techniques, the overall image quality in the center portion of each example lens, would probably be fairly similar. That doesn’t mean that the next big feature film is going to go out and shoot on a Nikon 18-55mm, but it also doesn’t mean that an 18-55mm Nikon isn’t going to produce good results. This is where the usability of each lens comes into play. For example, the entire core, focus, zoom, lock rings, and housing of the 24-290mm Optimo are machined from billet aluminum. The only part of the Optimo that isn’t made of high quality aluminum is the mount… Because that is made of stainless steel. Comparatively, the Nikon 18-55mm does in fact have an aluminum core, but everything else is plastic and brass, which can be good. It keeps weight and production cost down to a minimum, but is devastating to mechanical accuracy and precision. It doesn’t mean that the Optimo is the better lens for every situation. I wouldn’t want to lug a 25 lb. lens around Disneyland to snap pics of the family with Mickey Mouse. This leads me to the fine details such as stability and accuracy. Cinema lenses are not auto focus and traditionally require a trained focus puller to nail focus in any given shot. This isn’t done by peering through the viewfinder or pressing a button. It’s accomplished by taping out the distance to the subject and then dialing in the measured distance on the lens’ focus scale, which means those marks better be accurate or someone is losing their job. Focus mark accuracy isn’t really a concern on still photo lenses since 99% of users simply depress the shutter button half way and let the cameras auto focus do the work. The other 1% of users who focus manually for still photography, usually look through the viewfinder, pick a subject and adjust the focus ring until it looks sharp, still no need for focus mark accuracy. Nobody sets up their SLR, tapes out the distance, adjusts the lens to that distance and snaps away. It’s just to realistic.

    Speaking of focus, image shift and breathing are two more features that are critical in motion picture lenses, but not so much in still photo lenses. Let’s take our 18-55mm Nikon lens, put it on a camera, look through the monitor and rack focus or zoom. The whole image jumps around and loses focus because the components used inside the lens are very light-duty and left very loose to allow the tiny little drive motors to auto focus the lens for you. Comparatively, our 24-290mm Optimo is built with solid aluminum components that are precisely fitted and adjusted to keep everything as tight as possible. This keeps everything extremely smooth and accurate. If you adjust focus or zoom, the image should stay dead center and solid. This kind of performance requires extremely tight tolerances during machining and a very high level of care during assembly. Focusing with just about any still photo zoom lens will create a “breathing” effect that is simply an optical design characteristic. There is no adjustment for this flaw within the lens. It’s part of the optical-mechanical design and is taken into consideration during the development of a lens. Breathing is a bad thing in cinema because it really pulls the audience out of the scene. It changes the field of view of the lens and appears as though the lens is zooming in and out during even a small focus pull. This is why cinema lenses are designed not to breath and add substantially to the cost in order to do so. Tracking is somewhat related to breathing as it can really ruin ascot if not calibrate. Tracking is the movement of the image relative the the sensor/film, while zooming. Ideally, zoomed all the way in, an object in the very center of the image should stay in the exact same position on the sensor/film throughout the entire zoom range. Most cinema lenses include internal adjustment to calibrate tracking while still photo lenses aren’t concerned since you can simply re-compose before each shot.

    Another common characteristic of still photo zooms is their speed, or maximum aperture. Take our 18-55mm Nikon for example, again… The maximum aperture is f/3.5 which isn’t too bad. But as soon as you start to zoom, it looses light and stops all the way down to an f/5.6. Modern SLR cameras can easily compensate for this with automatic adjustments to exposure with the shutter speed or ISO. The 24-290mm is comparatively very fast at T2.8 and maintains its maximum aperture throughout it’s entire zoom range. Mostly because it’s an annoyance to think about adjusting setting from shot to shot and trying to match everything, but also because it would look horrible if the aperture started to close down in the middle of a shot, ruining the lighting, look and feel of a scene. Okay, there are plenty of still photo lenses that maintain a constant aperture. In fact, most of the major pro lenses will do this easily. But these are usually a fairly short zoom range. Do the numbers… Take the 14-24mm Nikkor, a great lens with a constant f/2.8 aperture, the zoom range is only 1.7x. The 24-70mm, a 2.9x. And the 70-200mm, a 2.8x zoom. Those three lenses are Nikons current crop of pro zoom lenses. The Angenieux 24-290mm maintains the same constant T2.8 aperture throughout it’s 12x zoom range. That’s almost unheard of in still photo lenses. These couple of characteristics can be lumped into the optical quality of the lens but also effect the usability. Another usability concern for motion picture lenses is their durability. Granted, if a cinema lens is dropped, it’s almost certain that it’s thrown completely out of whack and would require re-calibration, they are built like tanks. The same can not be said for our little 18-55mm Nikon friend. However, there are a lot of modern still photo lenses that are built to endure relentless usage and can really take a beating. All of these details are very minor on paper. It’s when you really get into the nitty gritty and use the lenses on a daily basis that you realize the differences can be substantial. Kind of like looking at two different cameras on paper. Each camera has a 3″ LCD screen, shutter speed, aperture, and ISO adjustments, an SD card slot, compact and portable, and includes a strap! One is a Leica, the other is a Kodak. Both are great cameras, but they are clearly meant for different purposes and clearly have a cost difference. The same logic applies to still photo lenses and cinema lenses. I like to think of it this way: Still photography offers a moment of interest. Cinema demands sustained attention.

    0 : http://www.fredmiranda.com/forum/topic/1104890

    Compared to stills lenses, cine lenses:
    have much more rugged mechanics, with thicker barrel walls, etc. Reliability is more important, and low weight less important, than for stills lenses. Greater mechanical stability is also needed for mounting accessories on the lenses.
    have standardised housing dimensions as far as reasonably possible. This allows accessories such as matte boxes and lens motors to fit all lenses in the range, and means the lenses within a range are easier to work with, since the position of the focus and iris gear is the same across all lenses.
    have toothed rings for attaching motors or other focusing and iris-control devices. On many modern cine lenses, these rings don’t move when the lens is focused.
    are made so that the image remains perfectly still when the focus ring is rotated, with no tilt, rotation, or shift from mechanical play.
    have stepless iris controls for smooth adjustments while filming.
    have more iris blades, for a rounder aperture when stopped down.
    have a much longer focus-ring rotation, with distance marks (witness marks) calibrated for each lens, and many more witness marks than stills lenses. This means you can measure the distance to a subject with a tape measure, and then focus precisely by scale for that distance. The distance marks are sometimes placed on interchangeable (or reversible) rings, with metric or imperial units (rather than both). So if the focus puller prefers to work in metres, he or she won’t be confused by irrelevant feet markings, and vice-versa.
    have larger and brighter markings (sometimes fluorescent) for better legibility on dim sets.
    have more precise colour matching across the lens range.
    are often faster, e.g. the Master Primes are T1.3.
    sometimes have less breathing. Really high-end lenses, like Master Primes, have practically no breathing (they were introduced with t-shirts saying “Breathless!” to make this point). The Master Primes achieve this with a dual floating-element design: the lens zooms while focusing to compensate for breathing. Mechanically, this is achieved with the use of machined cams rather than helicoid threads, which has another advantage: less variation in focus resistance in hot and cold temperatures.
    have typically less distortion, again to a greater extent at higher price brackets.
    have less vignetting at low f-stops.
    have greater resistance to flare, principally by sacrificing compactness while adding large stray-light baffles inside the barrel (and other light traps). Greater efforts are also made to eliminate the formation of ghost images, by adjusting the curvature and placement of the lens elements at the design stage. Obviously this has the knock-on effect of making aberration correction more difficult, which increases the design effort and manufacturing cost because the aberrations must nonetheless be corrected to a very high level.
    have service-friendly features such as easy-to-change front and rear elements, interchangeable mounts, back-focus adjustment features, etc.

    1 : http://matthewduclos.wordpress.com/2010/04/29/still-vs-cine-lenses/

    One might assume that a lens is a lens and you can simply adapt any lens to suit ones needs. This is usually a matter of changing or adapting the mount just so the square peg fits in the square hole. The fact is that still lenses and chine lenses are very different and can’t always be interchangeable. Still lenses are defined (in my opinion) as lenses that were designed and built for use with an SLR still camera whereas a cine lens would be one designed and built for use on a motion picture (movie) camera. I’ll go over why the two aren’t interchangeable and what can be done to reduce the differences between the two. Modern still lenses are designed for two things… Speed and ease of use.

    Nikon 85mm f/1.4 modified with focus gear for a follow focus and an 80mm front for common motion picture accessories. This particular lens also had its manual aperture de-clicked for smooth, seamless rotation.

    Manufacturers are always looking for a way to make the auto focus faster and simpler and over the past several decades this has been accomplished by making the focus components lighter and looser in order to make actuations easier for the tiny motors found in the lens or camera. The often plastic mechanics move in very loose, dry, and all together sloppy methods. The same can go for the zoom mechanics in a still zoom lens. This isn’t an attempt to make it easy for a motor, but just a fact of mass production at low cost. This isn’t a bad thing for a photographer taking still photos since the camera focuses nice and quick and then stops all adjustments when the photo is snapped at a fraction of a second. Another issue is that many new still lenses are abandoning manual aperture control rings for several reasons. The camera can control the aperture with no problem and it makes manufacturing cheaper. Lastly, still lenses continue to use focus distance marks, for the most part. But still lenses aren’t calibrated very well and the marks are often just a general guess rather than a reliable reference. Again, not a big deal if you are just depressing the shutter half-way to activate autofocus that doesn’t care what the distance is.All of these “issues” are only issues if you attempt to use still lenses to record motion. With the loose, easy mechanics, the image rendered by the lens on the film plane will jump around and jiggle if you try to adjust focus or zoom while recording. Nothing takes you out of a piece of art more than a jolt of motion similar to that of my moms video tapes of my school parade from 1990. Then there is the zoom. If you try to zoom or out while recording, forget it. Because still lenses aren’t calibrated and don’t hold focus, your picture will go from tac sharp to mush in a few millimeters. The lack of an aperture ring can be neglected since it’s still adjustable in the camera, but not always adjustable while recording. And even when a nice camera allows aperture adjustment while recording, you’re looking at adjustments in half or third stop increments that will simulate the exposure compensation that my phone exhibits.. Not pretty. There are a few other snags with still lenses that can be circumvented. The difference in standards is small, but detrimental. Still lenses don’t utilize external gears for use with a follow focus. Many people have turned to aftermarket add-on gears that simulate a focus or zoom gear. These can be garbage… Some of them use a block or clamp that interrupts the rotation and limits the user to a certain range.

    The closest alternative… Zeiss 85mm f/1.4 ZF, a prime lens that come so close to being a cine prime. With a solid aluminum housing and metal components it’s a great compromise.

    That just about sums up a majority of the modern still lenses for motion use but alas, there are a few remaining still lenses that are fairly well suited for motion. The first that comes to mind is the Zeiss ZF series lenses. They are completely manual lenses that feature a nice, solid metal construction that eliminates the common image shift and focus loss. And then there are older manual lenses from back when auto-focus was just a myth. But those are hard to find in good condition. That’s about as close you can get to a chine lens with a still lens. The major aspects that make chine lenses more expensive and higher quality are things like build faulty and materials. The tolerances used for designing and making a chine lens are much tighter than a still lens. The components in a chine lens are almost always metals and alloys. The mechanical designs have become extremely complex to avoid the dreaded image shift and to maintain proper calibration even with the severe abuse of modern Hollywood users. For example, a chine zoom will be a para-focal lens (maintains focus throughout zoom range) whereas still lenses can be vari-focal since you just refocus and snap the photo. This is important with a cine lens because the distances referenced on the focus scale are critical to the cinematographer and/or focus puller. These marks must be dead on every time or someone is going to have a heck of a time doing their job.

    A true motion picture lens, a Zeiss 85mm Ultra Prime T1.7 provides all the features one would need for shooting motion picture material. With a proper PL mount and superb design it stands tall against still lenses. However, its price tag stands out almost as much as its quality.

    2 : http://www.dvxuser.com/V6/content.php?103-Why-We-Need-Cinema-Lenses

    Color MatchingMany variables exist that effect the way a lens reproduces color. These variations are usually slight in nature, but important all the same. It is a well known fact that photography lenses are not designed to be color matched. Why would they? Color matching is another perfect example of why cinema and photography lens designs differ based upon how they are used. A photographer works with single independent images. A photograph is taken with one lens, it does not matter if other lenses in the photographers kit have unique characteristics. However, the cinematographer works with multiple shots woven and juxtaposed together to create an illusion of continuous time. When cutting between a medium-close up and an extreme close up, one can’t have the medium shot look neutral-cool and the close-up suddenly have a warm/pink tone. The inconsistency will either consciously or subconsciously weaken the illusion and possibly awake the viewer to the fact they are watching a contrived work of fiction. Cohesion of the image is incredibly important and the illusion must live on. Of course a modern day digital intermediate color-correction session can fix just about any lens color rendering inconsistency. Unfortunately such a process takes time and money. If one were to shoot an entire feature with mismatched lenses, there would be two choices: either release the film with bad color timing, or spend the money and effort to fix it in post. Color timing sessions can be well over hundreds per hour. There is enough work to be done in post. Matching lenses in post color correction when they could have simply been matched on set, is the last thing a production needs to spend money on.

    Chromatic Aberration
    Chromatic Aberration, also called CA, is the optical occurrence when a lens fails to bend all wavelengths if light equally. Light is made of many different wavelength frequencies that create the colors we see. A lens must capture incoming light then bend and straighten it to fall upon the film/digital sensor plane as straight as possible. When the optical elements within a lens bends the light, they can consequently act as a very mild prism and separate some wavelengths from others. These offset wavelengths will fall just slightly off from their counterparts resulting in a color fringing in the image. This is why aberration is a thin line of color. The color can change depending on which frequency the elements offset. As discussed above in the vignetting section, wide angle lenses have very extreme field of views. These lenses must take incoming light from very radical angles of incidence (thus more radical angles of refraction), and bend them toward the film plane without allowing any wavelengths to be slightly offset creating CA. Thus, chromatic aberrations are often found on the edges of wide angle lens frames.

    Front DiameterCinema lenses are often used in tandem with a mattebox system. Unlike photography lenses, which use screw on filters and built in lens hoods, cinema lenses use a mattebox to keep extraneous light from flaring the lens and to hold filters in front of the lens. By using a mattebox, a lens can be changed much faster without having to remove and reattach filters. However, when using a mattebox, it is extremely important to keep light from entering the mattebox from behind, thus either a bellows ring, doughnut ring, or clip-on back must fit perfectly around the lens front. By having a lens set with matched front diameters, the previously listed devices need not be switched out for different sizes, thus the lens change needs no additional actions. This saves time and reduces the amount of support gear needed.

    Weight
    Although rare and extremely difficult, some select cinema lens sets have many focal lengths with similar or the same weight. Usually these are lenses in the typical range of lengths, as very wide or telephoto lenses have lens designs which often make them heavier in nature. Having similarly weighted lenses can help when the camera is on steadi-cam, a remote servo-head, in handheld mode, or any other delicate mounting operation when balancing the camera is very important.

    Focus/Iris Ring Placement and Gears
    Cinema lenses are designed to have geared focus and iris rings placed at the same point on the barrel for all focal lengths. Doing so saves the camera assistant time when changing a lens, as the follow focus module nor any FIZ motors will require being adjusted after every lens change, thus further saving time on every lens change. Additionally, photography lenses typically do not have geared focus or iris rings. They are textured as to provide a nice grip for the photographers hand, but are not geared as cinema lenses are. Geared focus and iris rings are a must if to be used with a professional follow focus or remote follow focus system.

    http://1.bp.blogspot.com/-_mmc7X19Ny…tachment-6.jpg

    Zeiss Ultra Speeds is a great example of what is likely one of the most consistent lens sets in regards to physical build. Every lens between 16mm and 100mm is exactly 143mm in length, have a 93mm front diameter, and matching geared focus and iris ring positions. All lenses are consistent T-stop of T/1.9, and six focal lengths within the 24-85mm range have the exact same weight of 2.2 lbs.

    http://1.bp.blogspot.com/-nNfeWMG5Z_…tachment-7.jpg

    Zeiss ZE Canon lenses, a pretty nice photography lens set, is an example of how photography lenses are built for different types of use. Each lens is streamlined to be as small and light as possible, paying little attention to set uniformity. This particular lens set has different sized front diameters, different lengths, and dissimilar ungeared focus/iris ring placement.

    When a lens is changed, the 1st AC will likely have to adjust the mattebox placement on the rails, exchange the bellows ring/back plate/doughnut, slightly adjust the follow focus, and require a greater re-balance on steadicam. This is not a big deal, as it’s simply more work for the AC, but it can cost time over the course of a day. If lens changes are often, this can add up quite quickly, especially in on bigger films.

    If this wasn’t enough, many wonderful photography lenses no longer have an aperture ring! Manufacturers have moved the aperture ring from a physical and tactical ring on the lens to an electronic and internal function. For many lenses, the photographer must now use the camera to communicate with the lens and control the aperture electronically. On a cinema camera this immediately disqualifies the lens for use on most digital cinema cameras, as many do not have the means to communicate with a lens electronically. There are systems such as the Birger mount, which address some of these issues and does so quite well. If using internal aperture photography lenses on a cinema camera, this adapter seems to be the only sane option.

    http://4.bp.blogspot.com/-stp9hVpbnx…8-usm-lens.jpg

    Where is the aperture ring?!

    Focus Barrel Rotation & Distance Witness Markings
    A photographer does not need to worry about pulling focus smoothly or tracking a subject accurately at all times. A photographer must quickly find his subject and snap the photo. He can freely focus in front and behind the subject, narrowing in his focus. His hand is on the barrel and his eye through the lens. He cannot see the lens markings on the barrel, nor does he need to. He finds focus by eye and releases the shutter on an intuitive moment. The cinematographer cannot do this. Maybe if shooting docu-style, this can be a semi-acceptable method of focusing, but for all general purposes, one does not want to call attention to the camera, and focus hunting during a shot is an effective way of doing so. The cinematographer must accurately and discretely use focus to manipulate and direct the viewers eye. The camera assistant must follow the performances of the actor and/or the movement of the camera to keep the subject in focus. He cannot hunt for focus during a shot, and thus needs assistance from the lens in order to help him accurately track his target. This assistance comes in the form of many accurate witness markings on the barrel.

    Photography lenses typically have short focus throws. One can go from close to infinity focus in a simple twist of the wrist. This is helpful when needing to focus quickly on a moments notice, as many field photographers do. However, short focus throws make it difficult to gently track a subject and increases the possibility of overshooting a target. The focus distance markings on a photography lens are often few in number, only generally accurate, and are without actual witness mark lines.

    Modern cine lenses typically have a 300*+ barrel rotation. Cinema lenses are usually larger in size (for optical reasons) thus tend to have a long 300*+ rotation (300* rotation on a tiny lens can be less travel than a smaller rotation on a bigger girth lens). On high quality cinema lenses, each lens is custom engraved to ensure focus witness marks are as accurate as possible. Modern cinema lenses also have two focus scales, one for each side, so the camera assistant does not have to flip the lens in order to pull from the other side of the camera.

    Build Materials
    It can be argued whether photography or cinematography conditions are the hardest on equipment, (it’s cinematography btw) but there is little argument that cinema lenses are typically better built. Cinema lenses are built for the most rigorous of production demands. They are made from machined metal and are designed to operate from sub freezing temperatures to dangerously hot climates. They can be easily serviced, repaired, and modified. The most typical of cinema lens mounts, the PL and PV mount, are amongst the most strong, sturdy and temperature resistant designs.

    http://3.bp.blogspot.com/-GnSbeC3KDm…kes4primes.jpg

    Cooke S4 lenses are made from machined anodized aluminum built to operate in conditions
    from -13° to 131° fahrenheit. They are not threaded lens barrels, but instead use a cam system,
    which eliminates the need for lubrication, such as grease.

    Linear Iris in T-stops
    Cinema lenses do not have ‘clicked’ iris rings like many photography lenses, thus one can set the aperture to land at any value between stops. Most modern PL lenses have linear iris rings, with every third of a stop marked. Because cinema lenses are in T-stops, achieving precise and matched exposures with different lenses is as easy as setting the iris ring. Photography lenses, often have clicked iris rings, meaning they must settle on one stop or another. Trying to split a stop will result in the lens likely trying to settle one way or another. If the photography lens does not have a clicked aperture, it will likely be rated in f/stops and without sub-stop markings.

    T-stops Vs F-stops
    Cinema lenses are rated in t-stops, ‘t’ for ‘transmission’, instead of the familiar f-stops found on photography lenses. T-stops are values which represent the true amount of light passing through the lens. Each lens is tested and marked for their T-stop values. An F-stop is simply a formula. It calculates the amount of light that should pass through a lens based on the focal length divided by the entrance pupil. Thus it’s decently accurate except for one thing… it does not take into account the light lost from passing through the glass elements inside the lens! Thus there is always a varying degree of light loss from one lens to another. With F-stop lenses you are always playing within a margin of error.

    Matching Maximum Aperture & Iris Assembly
    Cinema lens sets are designed and built to have matching maximum apertures. This feature isn’t as important as it is helpful, but if a lens set does not have matching maximum apertures, it is the responsibility of the cinematographer to work within the least common denominator among his lens set, or he will find himself switching to a lens that cannot support the working exposure he has already set with his lights. However, the iris assembly is different and arguably more important to the image. When shooting semi-stopped down, on a long lens, and with shallow depth of field, the shape of the iris aperture can be defined in the out of focus elements commonly referred to as lens bokeh. Lenses with matching iris assemblies will provide matching out of focus bokeh shapes. Cooke S4’s and Cooke Panchro/i’s use the same iris assembly design, thus if you were to use them together, they would not only be color matched, but would produce the exact same bokeh renderings at matched apertures. Having a lens set where one lens has a triangular iris assembly, another hexagonal, another octagonal, and another with 12 blades, will result in very different bokeh shapes. If consistency is the goal, this could prove problematic.

    Lens Breathing
    When one changes the focus of a lens, the optical elements inside shift in concert to bend the incoming light from the corresponding distance to a focal point upon the sensor. When the optical elements inside the lens reposition themselves during the focus rack, they can slightly alter the field of view of a lens, which will appear similar to a very slow and mild zoom. This is called lens breathing. In photography, breathing is not important what-so-ever. Besides changing the composition by arguably negligible amounts, breathing is not seen in the image. To eliminate breathing, the lens design must be changed to account for the optical effect, thus eliminating breathing is not a priority of photography lens manufacturers.

    In cinema, tracking focus within a shot, or racking focus from one subject to another is a very common practice, thus cinema lenses take great strides to eliminate breathing. Not long ago, to eliminate breathing all together, Zeiss created a Dual-Floating Element design for their Master Primes. This design will be recognized at the 2012 Oscars with an Academy Award for Scientific and Technical Achievement.

    Barrel Extension
    As explained with lens breathing, when a lens changes focus or zooms, the optical elements inside adjust and shift. When designing lenses, it is often easier to allow the lens barrel to extend forward, in order to accommodate the shifting elements. Many photography lenses, when focused or zoomed, extend their barrel forward as the optical elements shift. Because cinema lenses have connected follow focus gears and a mattebox, telescoping lens barrels are not ideal, thus cinema lens designs provide for internal realignment. All shifting and repositioning of optical elements happen silently and unnoticeable inside of the lens housing. Everything remains as is.

    Barrel telescoping can be from zooming or focusing. Typically barrel telescoping is worse from zooming, however poorly designed prime lenses can exhibit troublesome barrel telescoping when focusing a great distance across the barrel. Typically the issues arise when the lens pushes against the mattebox or the geared focus ring falls off the follow focus.

    http://2.bp.blogspot.com/-5JGgdtfuhr…oom-Lenses.jpg

    http://3.bp.blogspot.com/-oKiTaaLm99…with-Hoods.jpg

    Despite lens hoods being added, one can see the telescoping nature of some photography zooms.
    (images from www.the-digital-picture.com)

    Consistent focus and exposure throughout zoom range
    Cinema zooms almost always carry exposure from one end of the zoom to the other. As an example, take the legendary Angenieux Optimo 12x zoom. It is a perfect T/2.8 from 24mm all the way to 290mm. Coupled with the other impressive optical and mechanical features of this lens, it’s no surprise the thing is the size of a military shell. There are many photography zooms which hold maximum exposure throughout the zoom range, but there are photography zooms which forsake this feature in order to accommodate lens design within a small/light housing and low price. Yuck.

    http://3.bp.blogspot.com/-cd6EevfFG7…cture%2B33.png

    Angenieux 24-290mm T/2.8 Cine Zoom

    Page Three: Mechanical Requirements
    Conclusion
    At the end of the day, a wonderful film can be made on photography lenses or cinema lenses. However, because these two mediums are very different in nature and thus the needs of photographers and cinematographers are very different, using photography lenses for cinema purposes is simply adding possible issues and concerns to an already full plate.

    The same goes for using cinema lenses to take photographs. Using a Master Prime to take a photograph would be equally ridiculous. First of all, the lens is 8″ long and weighs about 5lbs. Additionally, handheld photography is not the same as handheld cinematography. One has the luxury of taking the weight on the shoulder… the other is all taken to the wrist. Now imagine having to carry several of these lenses around for a photo-journalism assignment. Not quite appropriate for the context of use. Focusing quickly would require multiple twists of the lens barrel, and likely lost time trying to reel in the focus, perhaps missing the spontaneous moment of the photo.

    Thus, just as photography, there are types of videography that also may not benefit from cinema lenses. If shooting a documentary, wedding, or event videography that involves long hours of handheld shooting in spontaneous/unpredictable environments, perhaps a very lightweight photography zoom might be a more appropriate tool despite some shortcomings.

    The design points described in this writing are the ideal design points of a modern day cinema lens set. However, not all cinema lens sets contain all of these attributes. Vintage cinema lenses and new lower cost cinema lens sets do not attain all of the above. Just as that is true, the same goes for photography lenses. There are photography lens exceptions to where some lenses exhibit attributes of cinema lenses. For instance, Zeiss ZM’s have f/stop markings for 1/3 stops on the barrel.

    http://4.bp.blogspot.com/-FR-HuLJH8j…0/zm15-pic.jpg

    Zeiss 15mm f/2.8 ZM (Leica Mount) with 1/3 stop mapped f/stop scale

    Shoot a film with the best optics available to the production. Learn the strengths and weaknesses of that lens set and go about doing what is necessary to utilize those strengths and minimize the weaknesses. Cinema lenses simply allow for less weaknesses and more strengths, leaving the burdened mind of the cinematographer to other things. It’s a luxury well worth having.

     
  • s 9:49 PM on 130215 Permalink | Reply
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    Anamorphic format is a term that can be used either for: the cinematography technique of capturing a widescreen picture on standard 35 mm film, or other visual recording media, with a non-widescreen native aspect ratio; or a photographic projection format in which the original image requires an optical anamorphic lens to recreate the original aspect ratio. It should not be confused with anamorphic widescreen, which is a very different electronically based video encoding concept that uses similar principles to the anamorphic format but different means. The word “anamorphic” and its derivatives stem from the Greek words meaning formed again, due to reshaping the image onto the film or recording media.

    HistoryThe process of anamorphosing optics was developed by Henri Chrétien during World War I to provide a wide angle viewer for military tanks. The optical process was called Hypergonar by Chrétien and was capable of showing a field of view of 180 degrees. After the war, the technology was first used in a cinematic context in the short film Pour Construire un Feu (To Build a Fire) in 1927 by Claude Autant-Lara.[1]
    In the 1920s, phonograph and motion picture pioneer Leon F. Douglass also created special effects and anamorphic widescreen motion picture cameras. However, how this relates to the earlier French invention, and later development, is unclear.[2]
    Anamorphic widescreen was not used again for cinematography until 1952 when Twentieth Century-Fox bought the rights to the technique to create its CinemaScope widescreen technique.[1] CinemaScope was one of many widescreen formats developed in the 1950s to compete with the popularity of television and bring audiences back to the cinemas. The Robe, which premiered in 1953, was the first feature film released that was filmed with an anamorphic lens.
    [edit]DevelopmentThe development of anamorphic widescreen arose due to a desire for wider aspect ratios. The modern anamorphic widescreen format has an aspect ratio of 2.40:1, meaning the picture width is 2.40 times its height, (technically it is 2.39:1, but it is known professionally as 2.40:1 or “two-four-oh”). Academy format 35 mm film (standard non-anamorphic full frame with sound tracks in the image area) has an aspect ratio of 1.37:1, which is not as wide (or, conversely, is taller). In non-anamorphic spherical (flat) widescreen imaging, the picture is recorded on film so that its full width fits within the film frame, and substantial film frame area is wasted on portions that will be matted out by the time of projection, either on the print or in the projector, in order to create a widescreen image in the theater (Figure 1).
    To make full use of the available film, an anamorphic lens is used during recording. Up to the early 1960s, three major methods of anamorphosing the image were used: counter-rotated prisms (e.g., Ultra Panavision), curved mirrors in combination with the principle of Total Internal Reflection(e.g., Technirama), and cylindrical lenses (lenses curved, and hence squeezing the scene being photographed, in only one direction, as per a cylinder, e.g., the original CinemaScope system based on Henri Chrétien’s design). Whatever the method used, the anamorphic lens leaves the image on film looking as if it had been stretched vertically. This deliberate geometric distortion is then reversed upon projection, resulting in a wider aspect ratio on-screen than that of the frame as recorded on film.
    An anamorphic lens consists of a regular spherical lens, plus an anamorphic attachment (or integrated lens element) that does the anamorphosing. The anamorphic element operates at infinite focal length (so that it has little or no effect on the focus of the prime camera lens onto which it is mounted), but still nevertheless anamorphoses the optical field. When you use an anamorphic attachment, you use a spherical lens of a different focal length than you would for 1.85:1 (one sufficient to produce an image the full height of the frame and twice the width), and then the anamorphic attachment squeezes 2x horizontally. Specialized reverse anamorphic attachments existed that were relatively rarely used on projection and camera lenses to expand the image in the vertical space (e.g., the early Technirama system mentioned above), so that (in the case of the common two-times anamorphic lens) a frame twice as high as it might have been filled the available film area. Since a larger film area needed to be used to record the same picture, quality was increased.
    The distortion introduced in the picture must be corrected when the film is played back, so another lens is used during projection that either expands the picture back to its correct proportions or (as in the case of the now defunct Technirama system) squeezes the image vertically to restore normal geometry. It should be noted that the picture is not manipulated in any way in the complementary dimension to the one anamorphosed (horizontally squeezed or vertically stretched).
    It may seem that it would be easier to simply use a wider film for recording movies; however, 35 mm film was already in widespread use, and it was more economically feasible for film producers and exhibitors to simply attach a special lens to the camera or projector, rather than investing in a new film format, along with the attendant cameras, projectors, editing equipment and so forth.
    Cinerama was an earlier attempt to solve the problem of high-quality widescreen imaging, but anamorphic widescreen eventually proved to be more practicable. Cinerama preceded anamorphic films, but consisted of three projected images side-by-side on the same screen: the images never blended together perfectly at the edges, and it required three projectors; a 6-perf-high frame, which required four times as much film; and three cameras (eventually just one camera with three lenses and three streaming reels of film and the attendant machinery, which presentedsynchronization problems). Nonetheless, the format was popular enough with audiences to spur studios to the wide screen developments of the early 1950s. A few films were distributed in Cinerama format and shown in special theaters. Anamorphic widescreen was attractive to studios because of its similar high aspect ratio (Cinerama was 2.59), without the disadvantages of Cinerama’s added complexities and costs.
    The common anamorphic widescreen film format in use today is commonly called Scope or 2.35:1 (the latter being a misnomer born of old habit; see “2.35, 2.39 or 2.40?” below). Filmed inPanavision is a phrase contractually required for films shot using Panavision’s anamorphic lenses. All of these phrases mean the same thing: the final print uses a 2:1 anamorphic projector lens that expands the image by exactly twice the amount horizontally as vertically. This format is essentially the same as at the time of CinemaScope, except for minor technical developments.
    There are artifacts that can occur when using an anamorphic camera lens that do not occur when using an ordinary spherical lens. One is a kind of lens flare that has a long horizontal line usually with a blue tint and is most often visible when there is a bright light, such as from car headlights, in the frame with an otherwise dark scene. This artifact is not always considered to be a problem. It has come to be associated with a certain cinematic look and is in fact sometimes emulated using a special effect filter in scenes that were not shot using an anamorphic lens. Another common aspect of anamorphic lenses is that light reflections in the lens will be elliptical rather than round, as they are in spherical cinematography. Additionally, wide angle anamorphic lenses of less than 40 mm focal length produce a cylindrical perspective, which some directors and cinematographers, particularly Wes Anderson, use as a stylistic trademark.
    Another characteristic of anamorphic camera lenses is that out-of-focus elements tend to be blurred more vertically. An out-of-focus point of light in the background will appear as a vertical oval rather than a circle. When the camera shifts focus, there is often a noticeable effect where elements appear to stretch vertically when going out of focus. However, the commonly cited claim that anamorphic lenses produce a shallower depth of field is not entirely true. Because of the cylindrical element in the lens, anamorphic lenses take in a horizontal angle of view twice as wide as a spherical lens of the same focal length. Because of this, cinematographers will often use a 50 mm anamorphic lens when they would otherwise use a 25 mm spherical lens, a 70 mm rather than a 35 mm, and so on.
    A third characteristic, particularly of simple anamorphic add-on attachments to prime lenses, is “anamorphic mumps”. For reasons of practical optics, the anamorphic squeeze is not uniform across the image field in any system, cylindrical, prismatic or mirror-based. This variation results in some areas of the film image appearing more stretched than others. In the case of an actor’s face in the center of the screen their faces look somewhat like they had the mumps, hence the name for the phenomenon. Conversely, at the edges of the screen actors in full length view can become skinny-looking. In medium shots, if they walk across the screen from one side to the other, they increase in apparent girth. Early Cinemascope presentations in particular (usingChrétien’s off-the-shelf lenses) suffered from it. The solution was to link the anamorphic squeeze of the add-on adapter to the focus position of the prime lens, so that as focus changed the anamorphic ratio changed along with it, resulting in a normal-looking geometry in the area of interest on-screen. In early prismatic systems such as Panavision’s Ultra-Panavision system, the angle of counter-rotation between prisms was linked by a mechanical system to the focus ring of the prime lens. In later cylindrical lens systems, the change in aspect ratio required between focus positions was achieved by combining two sets of anamorphic optics in one: a robust “squeeze” system coupled with a slight expansion sub-system. The expansion sub-system was counter-rotated in relation to the main squeeze system, all in mechanical interlinkage with the focus mechanism of the prime lens. The combination of squeeze and expansion changed the anamorphic ratio to the extent required to minimize the effect of anamorphic mumps in the area of interest in the frame. Though these techniques were regarded as a fix for the anamorphic mumps, they were a compromise. Cinematographers still needed to be careful with their framing of the scene so that effects of the change in aspect ratio were not readily apparent. The first company to produce an anti-mumps system was Panavision in the late 1950s.
    While the anamorphic scope widescreen format is still in use as a camera format, it has been losing popularity in favor of flat formats, mainly Super 35 mm film. (In Super 35, the film is shot flat and can then be matted and optically printed as an anamorphic release print.) There can be several reasons for this:
    An anamorphic lens can create artifacts or distortions as described above.An anamorphic lens is more expensive than a spherical lens.Because the anamorphic-scope camera format does not preserve any of the image above and below the scope frame, it may not transfer as well to narrower aspect ratios, such as 4:3 or16:9 for full screen television.Film grain is less of a concern because of the availability of higher-quality film stocks and digital intermediates, although the anamorphic format will always yield higher definition than the non-anamorphic format.

    The aperture of the lens (theentrance pupil), as seen from the front, appears as an oval.

    Anamorphic scope as a printed film format, however, is well established as a standard for widescreen projection. Regardless of the camera formats used in filming, the distributed prints of a film with a 2.39:1 theatrical aspect ratio will always be in anamorphic widescreen format. This is not likely to soon change because movie theaters around the world don’t need to invest in special equipment to project this format; all that is required is an anamorphic projection lens, which has long been considered standard equipment.
    Other widescreen film formats (commonly 1.85:1 and 1.66:1) are simply cropped in vertical size to produce the widescreen effect, a technique known as masking or matting. This can occur either during filming, where the framing is masked in the gate, or in the lab, which can optically create a matte onto the prints. Either method produces a frame similar to that in Figure 1, and is known as a hard matte. Many film prints today have no matte, though the film is framed for the intended aspect ratio; this approach is called full-frame filming, since most spherical 4-perf cameras retain the silent gate. In these, the film captures additional information that is masked out during projection using an aperture mask in the projector gate, and is known as soft matte. This approach allows filmmakers the freedom to include the additional picture in an open matte 4:3 transfer of the film and avoid pan and scan, by protecting the frame for 4:3.
    [edit]2.35, 2.39 or 2.40?One common misconception about the anamorphic format concerns the actual width number of the aspect ratio, as 2.35, 2.39 or 2.4. Since the anamorphic lenses in virtually all 35 mm anamorphic systems provide a 2:1 squeeze, one would logically conclude that a 1.375:1 full academy gate would lead to a 2.75:1 aspect ratio when used with anamorphic lenses. Due to differences in the camera gate aperture and projection aperture mask sizes for anamorphic films, however, the image dimensions used for anamorphic film vary from flat (spherical) counterparts. To complicate matters, the SMPTE standards for the format have varied over time; to further complicate things, pre-1957 prints took up the optical soundtrack space of the print (instead having magnetic sound on the sides), which made for a 2.55:1 ratio.
    The initial SMPTE definition for anamorphic projection with an optical sound track down the side (PH22.106-1957), issued in December 1957, standardized the projector aperture at 0.839 × 0.715 inch (21.3 × 18.2 mm) (aspect ratio 1.17:1). The aspect ratio for this aperture, after a 2x unsqueeze, is 2.3468…:1 which rounded to the commonly used value 2.35:1. A new definition was issued in October 1970 (PH22.106-1971) which specified a slightly smaller vertical dimension of 0.700 in. for the projector aperture to help make splices less noticeable to film viewers. Four-perf anamorphic prints use more of the negative’s available frame area than any other modern format which leaves little room for splices; as a consequence, a bright line would flash onscreen when a splice was projected and theater projectionists had been narrowing the vertical aperture to hide these flashes even before issuance of PH22.106-1971. This new projector aperture size, 0.838 × 0.700 inch (21.3 × 17.8 mm), aspect ratio 1.1971…:1, made for an un-squeezed ratio of 2.39:1 (and commonly referred to by the rounded value 2.40:1 or 2.4:1). The most recent revision, from August 1993 (SMPTE 195-1993), slightly altered the dimensions so as to standardize a common projection aperture width (0.825-inch, or 21.0 mm) for all formats, anamorphic (2.39:1) and flat (1.85:1). The projection aperture height was also reduced by 0.01″ in this modern specification to 0.825 × 0.690 inch (21.0 × 17.5 mm), aspect ratio 1.1956…:1 (and commonly rounded to 1.20:1), to retain the un-squeezed ratio of 2.39:1.[3] The camera’s aperture remained the same (2.35:1 or 2.55:1 if before 1958), only the height of the “negative assembly” splices changed and, consequently, the height of the frame changed.
    Anamorphic prints are still often called ‘Scope or 2.35 by projectionists, cinematographers, and others working in the field, if only by force of habit. 2.39 is in fact what they generally are referring to (unless discussing films using the process between 1958 and 1970), which is itself usually incorrectly rounded up to 2.40 (instead of the correct 2.4). With the exception of certain specialist and archivist areas, generally 2.35, 2.39, and 2.40 mean the same to professionals, whether they themselves are even aware of the changes or not.
    [edit]Lens makers and corporate trademarksSee also: List of anamorphic format trade names
    There are numerous companies that are known for manufacturing anamorphic lenses. The following are the well known in the film industry:
    [edit]OriginationPanavision is the most common source of anamorphic lenses, with lens series ranging from 20mm to a 2,000mm anamorphic telescope. The C-Series, which is the oldest lens series, are small and lightweight, which makes them very popular for steadicams. Some cinematographers prefer them to newer lenses because they are lower in contrast. The E-Series, of Nikon glass, are sharper than the C-Series and are better color-matched. They are also faster, but the minimum focus-distance of the shorter focal lengths is not as good. The E135mm, and especially the E180mm, are great close-up lenses with the best minimum focus of any long Panavision anamorphic lenses. The Super (High) Speed lenses (1976), also by Nikon, are the fastest anamorphic lenses available, with T-stops between 1.4 and 1.8; there is even one T1.1 50mm, but, like all anamorphic lenses, they need to be stopped-down for good performance because they are quite softly focussed when wide open. The Primo and Close-Focus Primo Series (1989) are based on the spherical Primos and are the sharpest Panavision anamorphic lenses available. They are completely color-matched, but also very heavy: about 5–7 kilograms. The G-Series (2007), Panavision’s latest anamorphic lens series, performance and size comparable with E-Series, in lightweight and compact similar to C-Series.Vantage Film, designers and manufacturers of Hawk lenses. The entire Hawk lens system consists of 50 different prime lenses and 5 zoom lenses, all of them specifically developed and optically computed by Vantage Film. Hawk lenses have their anamorphic element in the middle of the lens (not up front like Panavision), which makes them more flare-resistant. This design choice also means that if they do flare, one does not get the typical horizontal flares. The C-Series, which were developed in the mid-1990s, are relatively small and lightweight. The V-Series (2001) and V-Plus Series (2006) are an improvement over the C-Series as far as sharpness, contrast, barrel-distortion and close-focus are concerned. This increased optical performance means a higher weight, however (each lens is around 4-5 kilograms). There are 14 lenses in this series which goes from 25mm to 250mm. The V-Series also have the best minimum focus of any anamorphic lens series available and as such can rival spherical lenses. Vantage also offers a series of lightweight lenses called V-Lite. They are 5 very small anamorphic lenses (about the size of a Cooke S4 spherical lens), which are ideal for handheld and steadicam while also giving an optical performance comparable to the V-Series and V-Plus lenses. In 2008 Vantage introduced the Hawk V-Lite 16, a set of new lenses for 16 mm anamorphic production, as well as the Hawk V-Lite 1.3x lenses, which make it possible to use nearly the entire image area of 3-perf 35mm film or the sensor area of a 16:9 digital camera and at the same time provide the popular 2.39:1 release format.Joe Dunton Camera (JDC): Manufacturer and rental house based in Britain and North Carolina, which adapts spherical lenses to anamorphic by adding a cylindrical element. Its most popular lenses are adapted Cooke S2/S3, but they have also adapted Zeiss Super Speeds and Standards, as well as Canon lenses. JDC was purchased by Panavision in 2007.[1]Elite Optics, manufactured by JSC Optica-Elite Company in Russia and sold in the United States by Slow Motion Inc.Technovision, a French manufacturer that, like JDC, has adapted spherical Cooke and Zeiss lenses to anamorphic. Technovision was purchased by Panavision in 2004.Isco Optics, a German company that developed the Arriscope line for Arri in 1989.

     
  • s 9:21 PM on 130215 Permalink | Reply
    Tags: , , cine, ,   

    Picture Profile : Prolost Flat 

    http://prolost.com/flat

    Start with the Neutral Picture Style

    Set Sharpness to zero—all the way to the left
    Set Contrast all the way to the left
    Set Saturation two notches to the left
    +
    In the slideshow below, you can see one example of sharpening using the After Effects Unsharp Mask effect, with an Amount of 120 and a Radius of 1.1.
    A light pass of noise reduction from something like Magic bullet Denoiser II not only cleans up some compression artifacts, it also can promote your 8-bit footage to higher color fidelity by interpolating new, high-bit-depth pixels. So your HDSLR processing pipeline should look like this:

    In a 16 or 32bpc environment…
    Reduce noise
    Visual effects, if any
    Color correct
    Sharpen
    Add back some noise/grain to taste
    Titles or graphics, if any
    WHAT ABOUT HIGHLIGHT TONE PRIORITY?

    Highlight Tone Priority is an optional method Canon uses to capture more highlight detail by “pushing” the ISO one stop. The result is one extra stop of highlight detail (roughly), coupled with one extra stop’s worth of noise (also roughly).
    When I first posted about Prolost Flat, I recommended using HTP for bright scenes with difficult highlights. But since then, I’ve completely stopped using it. The benefits don’t tend to outweigh the risks. And by “risks,” I mean that you might leave HTP on and shoot a bunch of raw stills, and wonder why they don’t look as nice as they should in Lightroom. Unlike other settings discussed here, HTP does affect raw stills. Oops.
    I leave my cameras in Prolost Flat all the time, even for stills. If find that the flat preview image gives me a better sense of the actual raw “negative” that I’m capturing. The only thing you have to get used to is that it’s easy to underexpose slightly if you judge exposure by the preview image, as the Prolost Flat preview looks a touch brighter than most default raw processing.

     

     

     

    prolostFlat_01_1000

     
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