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Putting the FULL FRAME confusion to bed
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  • @shian

    It's easy. Use google:

    replace bold letters w/ keywords site:personal-view.com

  • Is there a way to get a better search function for the site? Cuz I can almost never find what I'm searching for. If I don't favorite it or bookmark it, it just gets lost somehow.

    I'll try. But can't do all at the same time. :-)

  • Sorry, VK, I searched and could not find one, otherwise I would have posted there.

    Is there a way to get a better search function for the site? Cuz I can almost never find what I'm searching for. If I don't favorite it or bookmark it, it just gets lost somehow.

    @pundit @sam_stickland after my meeting with Panavision, it is my understanding that the sense that a large sensor=shallow DOF is misleading. It is not a function of the sensor but of poor lens choices, and having to drastically change the distance between the subject and the lens to get the desired framing. DOF comes strictly from the lens (it's distance from the subject and the aperture) and there is zero difference between the DOF of a lens whether it's image is projected on a small or large sensor because the flange distance doesn't change...ever. If it did, you would be unable to focus the lens properly, and all of your barrel markings would be off. So you do NOT get a more shallow DOF with a larger sensor. You get more shallow depth of field by choosing the wrong focal length for the shot, and having to move closer to your subject, thereby reducing the DOF. Which EVERY Cinematographer/ Photographer should already know is a complete NO-NO! People will get fat distorted faces.

    In fact, it is also a myth that there is a more shallow depth of field on longer lenses. It is an optical illusion that comes from the lens compression magnifying the objects in both foreground and background. But if you use a DOF calculator, and some simple math you'll find that while maintaining the same frame size, DOF does not change between f2.8 on a 50mm and f2.8 on a 200mm. The in focus range and bokeh are exactly the same, but the images that are blurry are magnified so they seem to be more out of focus. (and before somebody loses their shit over this - http://www.film-and-video.com/dofmyth.htm)

  • @shian

    Thanks for posting.

    But. I though that we already have sensor crop topic :-)

    I have a dream. One fucking sensor crop topic....
    Buried in the Mount Doom... Sorry, it is from other thing :-)

  • Just remember, the ablecine af100 sensor size is smaller than the GH2's 1.85 16:9 crop.

  • Wide apertures on a full frame sensor can mean ridiculously shallow depth of field.

    I never thought about this before, but this must be even more of an issue on 65mm+ film? e.g. IMAX or Showscan. Do they counter this with more sensitive film or just lots more light?

  • Please correct another small error: the sensor in the BM camera will be smaller than the rest, closer to Super 16.

  • @B3Guy excellent link!!!!!!!

  • Better yet, just play around with this for a bit. so much becomes clear, and its actually kinda fun: http://abelcine.com/fov/

  • this might help

    image

    and a link to the full image for all the details http://blog.abelcine.com/wp-content/uploads/2010/08/35mm_Digital_Sensors_2012MAY.jpg

    35mm_Digital_Sensors_2012MAY.jpg
    800 x 1035 - 164K
  • @MarkV I wouldn't say "stupid", but they are not designed with a Cinema sensor in mind. They are designed for the 5D and D800, and any future "full framed" cameras that might arise. You'll want to use Cinema Lenses on the RED.

    The CP.2s will be cropped just like Nikon and Canon and all other still picture lenses would.

    They are EXCELLENT lenses, but not true cinema lenses.

  • Oh wait. So am I doing a stupid thing when I'm buying whole CP.2 set (that is - as you said - designed for full frame 5D) for RED camera? How the image will behave in this case?

  • @Sangye yes that is correct, but your crop factor statement is indicative of the confusion I'm talking about. FUCK THE 5D and the D800, they are not Cinema cameras. They are not "the standard" they should never in any way be used as the standard by which we determine what lenses to use in regards to cinema cameras, ONLY in regards to the "full frame" cameras, which no cinema camera is. (The only exception might be large format IMAX and 70mm type cameras which require special lenses.)

    I only put this together because a producer was killing himself trying to find a 9mm Cooke lens to shoot wide shots, and I was like... we don't need it. An 18mm will be fine.

    @cbrandin Sorry, I was unaware that the D800 was "full frame" (fixed it in the post)

  • I hate "crop factor" term.

    Super35 is not a cropped system. M43 is not, either.

    Canon EF-S is a cropped system because it shares the same mount with Canon EF. EF-M is rumored to be announced next Monday. I bet Canon fanboys would call it a cropped system.

  • The use of the phrase 'Full Frame' was a very clever marketing ploy by Canon designed to create a sense of 'small sensor' inferiority complex amongst non Canon 5D owners. Of course that campaign, however flawed in its terminology, has been a resounding success for Canon. I've lost count how many times I've been asked if my APS-C Pentax K5 is a 'full frame' camera.

    There are some benefits of a 'full frame' camera in still photography ie larger brighter optical viewfinder and a wider equivalent field of view for landscapes etc but the advantages probably diminish for video. Wide apertures on a full frame sensor can mean ridiculously shallow depth of field. Check out the amount of mis-focused 5D MK2 videos on YouTube for proof.

    You will find many DSLR video shooters assume the Canon 5DMk2/3 equates to 35mm film and nothing other than a 'full frame' DSLR can approximate the cinematic look of film. Of course APS-C sensors and are closer to Super35 than a 5D but try to explain that to a one eyed Canon 5DMK2 owner and you probably won't get very far.

  • See Focal length & Sensor Size & FOV diagram. http://www.cambridgeincolour.com/forums/thread10103.htm#post114447

    Two lenses having same focal length might cover different image circles. The difference in image circles makes them having different FOV. The FOV calculation is where the confusion is coming from... and I don't think it's important. All I need to know is which focal length is good enough for my work. e.g. 35mm focal length on GH2's 16:9 ratio without using anamorphic lens is good enough for medium shot. Of course YMMV.

  • The D800 has a full-frame sensor.

  • I believe you are mistaken when you say that a 50mm "still lens" on a 5D "is the equivalent of a 50mm PL mount lens on all other cinema cameras in terms of Field of View". It is not. Focal length is an absolute measurement of the optical dynamics of the lens elements, and is not relative to the size of what the image is being projected on to. I have never heard of a lens manufacturer labelling their lenses according to full frame equivalence. When they say that a lens has a focal length of 50mm, they mean that it is 50mm... not that it would create a field of view on a camera sensor of X by X dimensions equivalent to what 50mm looks like on a 36x34mm sensor.

    Crop factor is very relevant if you're accustomed to how lenses look on a 36x34mm sensor. And if you want to use your GH2 to get a perspective that looks like how 18mm looks on a 5D, yes you will need a 9mm lens.

    That being said, I agree that "full frame" is a misleading phrase. There are many sensors smaller than that, and some sensors larger than that. There's nothing particularly special about 36x34mm, other than that it became a convention in still photography