Cropping to match 16mm film

[DanielS]

Hi all,

I'd like to start by saying that I'm new to ML, and wasn't sure if this belonged in the hardware section or elsewhere.

In preparing to shoot a short film with my Canon 7D, I've decided to invest in some new vintage primes. While doing research, I've been made aware of the fact that lenses need to be matched to sensor/film size as well as to the mount of the body. That is to say, if a lens was intended for use on a 16mm film camera, but is mounted on a 35mm film camera, a part of the actual lens will likely be in the frame. On the other hand, if a lens made for use with 35mm film is mounted on a camera that uses 16mm film, there will be no lens in the frame, but instead, a large portion of what the lens captures will transcend the borders of the actual film and not show up at all. In hindsight it all seems pretty obvious, and should have occurred to me earlier.

Anyway, I'm assuming the same principle applies when shooting digitally, as a sensor, much like film, is what captures the light from the lens. Now, an APS-C sized sensor (the one in my 7D) is 22.2mm wide, meaning it falls between the dimensions of 16 and 35mm film. Cropping the sensor by 1.3875x would make it 16mm wide, meaning I'd be able to buy lenses made for 16mm film and they'd work perfectly and look as they were intended to

Now, is it possible to crop the sensor to such a specific degree with ML?

Thanks for any responses and cheers for now.

[dmilligan]

It's not just the size of the image circle (crop size) that is important, but also the flange focal distance. The lens may have been designed for a camera with a different ffd than what you 7D has. Which would potentially make it impossible to bring certain things into focus (e.g. impossible to focus at infinity). https://en.wikipedia.org/wiki/Flange_focal_distance

You can currently use raw video to crop to different sizes, and record in "crop mode" which samples every pixel in a crop of the center of the sensor, thus avoiding the aliasing and other artifacts caused by the line skipping your camera does in normal video mode.

[Oswald]

You can use eos M and c mount lenses work. Body cost around 120e.

[dfort]

... Now, an APS-C sized sensor (the one in my 7D) is 22.2mm wide, meaning it falls between the dimensions of 16 and 35mm film. Cropping the sensor by 1.3875x would make it 16mm wide, meaning I'd be able to buy lenses made for 16mm film and they'd work perfectly and look as they were intended to

Now, is it possible to crop the sensor to such a specific degree with ML?

Wrong! 

First of all are you talking 16mm or Super16mm? Even though the film is 16mm wide, the image area is less because of borders and sprocket holes. Then there is the flang to sensor distance as dmilligan explained and finally you can't crop with ML to that specific degree though you can change the aspect ratio. In other words you can make it look like it was shot in 16mm but you will have a hard time adapting lenses made for 16mm cameras to your 7D. Oswald mentioned that the EOSM can use C-mount lenses. Here's a topic that goes into that in more detail.

[DanielS]

Thanks for all the responses.

Dfort: It doesn't really matter if I was talking about 16 or super 16. I was simply asking if you could crop by a specific amount to match the dimensions of a certain type of film, be it 16, super 16, 8 or super 8. But you did also mention that this isn't possible, so much obliged.

Dmilligan: I previously had no idea what flange focal distance was, so that's just another reason why I would probably have ended up with an array of completely incompatible lenses  . I found this link that may prove useful if anyone ever wants to buy vintage lenses and are unsure of compatibility --> http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html.

Once again, thanks a lot for the help.