Nikon/Zeiss Lens on 7D

[seanwin]

Hi Guys,

I'm looking at getting the 7D purely for film once its released here in Oz.

Question is my other cam is a XH-A1s with a brevis adapter. I use nikon lenses and a zeiss planar 50mm 1.4 (nikon mount).

I was wondering if getting an adapter to mount my Nikon lenses on the Canon 7D would make the quality bad or what the drawbacks are, if any.

I know many probably won't know since its not officially released, but has anyone tried it on the 5D?

I only ask because if it will still produce a great picture then I dont need to start another lens collection.

Cheers,

Sean.

[ydgmdlu]

Nikon-mount lenses adapt perfectly to Canon cameras; it's been done like forever. Since there are no optics needed in the adapters, there is zero loss in quality. You just need to be aware that a crop factor is involved that will narrow the FOV of all of your lenses.

[Rhys Day]

good idea to get one adapter per lens...and not the really cheap ones.

[squig]

I'm shooting with a full set of nikkor primes and some M42 mount pentax and russian glass on the MKII, some of the cheap adapters are a little loose but nothing a bit of gaff can't fix and when i say loose I mean 1mm of rotational play not loose like they're gonna fall off.

[seanwin]

Hey that great feedback thanks guys.

However I am new to the world of SLR filming so when you say "crop factor" is that due to using non-canon lenses or is that regardless of lens?

What is the crop factor about?

[Michael Olsen]

Two important things first.
Still Photography Cameras predominantly used film at one point. To emulate that, they now have Full Frame sensors. This is what the 5D MKII uses.

Cinema Cameras predominantly shoot on Super35mm film. This is roughly equivalent in size to an APS-C sensor. This is what the 7D uses.

Crop factor is a way of comparing the differences in Field of View based on different sensor sizes. Imagine this: put a 50mm lens on a 5DMKII (a camera with a Full Frame sensor) and take a picture. Now take the same lens with the same setting and put it on a 7D (a camera with an APS-C sized sensor) and take a picture. Even though you used the same lens, the two images will look different. The magnification will be the same, but the image from the 7D will only have captured the center of the image from the 5DMKII - it won't have the same FOV. Here's an example (this is not to scale).



The term crop factor specifically refers to a number which can be used to calculate the approximate FOV (in terms of focal length) of using a lens on a camera with a sensor smaller than Full Frame 35mm.

To illustrate, we take any given lens - a 50mm - and multiply it by a "crop factor". The crop factor for the 7D or any other APS-C sized sensor is 1.6.

50 * 1.6 = 80.

This means that, on an APS-C sensor, a 50mm lens will have the Field of View of an 80mm lens. It will not be an 80mm lens, however. It will not magnify the image any more than the 50mm, because any given lens will always project the same image. Instead, it simply has a slightly smaller field of view because the sensor itself is smaller.

We can use this for any sensor size assuming we know the crop factor. A 2/3" sensor has a crop factor of (very) roughly 4, meaning that with a 50mm lens...

50 * 4 = 200.

So a camera with a 2/3" sensor using a 50mm will only see the very center of the image. The image itself, however, will not be any more magnified than it would on a 1/3", 4/3", APS-C, APS-H, DX, or Full Frame sensor.

I recommend getting to know your camera. DPs who run film cameras don't bother with this - they know what lenses will look like on their camera. Instead of trying to compare everything to what it might look like on a Full Frame camera, simply get to know what it will look like on yours.

[Isaac_Brody]

Imagine this: put a 50mm lens on a 5DMKII (a camera with a Full Frame sensor) and take a picture. Now take the same lens with the same setting and put it on a 7D (a camera with an APS-C sized sensor) and take a picture. Even though you used the same lens, the two images will look different. The magnification will be the same, but the image from the 7D will only have captured the center of the image from the 5DMKII - it won't have the same FOV. Here's an example (this is not to scale).

I always find this example hilarious, as if you wouldn't adjust for the crop and move back to take the photo. I mean really, who would take a photo like that?

[mhood]

I ran out of room to move back with a 50mm on my D90 shooting a talking head in a typical office.

[Isaac_Brody]

So I take it you shot the interview like this?

[mhood]

No...I actually tilted up. lol