[bull drinkwater]

I am courious as to whether a 6x7 lens would work on a full frame camera. what would be the crop factor and quality on the images.?

[drei3]

Which lens and camera? I don't see why it wouldn't work provided you have the appropriate adapter.

[bull drinkwater]

Which lens and camera? I don't see why it wouldn't work provided you have the appropriate adapter.

67 300mm f4 . and maybe 645 400mm f5.6 on the sony a-850.

[blackcloudbrew]

I've used my 6x7 and 645 lenses on my K5 a number of times. With a hypothetical FF Pentax camera with the right adapter yes it would work. The crop factor is a bit more complicated and I'll leave others to discuss that. However, my guess is that it would be 1. The image quality would depend on the lens. I used to think that MF lenses would be a solution to cheaper higher quality lenses. For a number of reasons, they aren't. They are good but not as good as a new lens with new coatings. IMHO.

[tuco]

No crop factor. A, say, 6x7 55mm mounted on a 35mm film/digital camera should have about the same FOV as mounting a 35mm format 55mm lens on one.

[indy]

I have a trio of smca lenses for a 645. I used an adaptor to mount the 35mm on my k7. Worked well but no better (image quality) than the Kpa 35mm I have. Also lost the A setting with the adapter.

[ElJamoquio]

I am courious as to whether a 6x7 lens would work on a full frame camera. what would be the crop factor and quality on the images.?

As others have said, there's no (different) crop factor.

On a FF, a 50mm lens is a 50mm lens.
On a APS-C, a 50mm lens is a 50mm lens.

Crop factor goes with the camera, not the lens.

Unless you already have the 6x7 lenses, though, it usually doesn't make sense to adapt them to smaller formats. 35mm stuff is about as cheap as it comes. There's a few exceptions of course.

[Pål Jensen]

A 300mm is 300mm lens regardless of format. A F:2.8 is F:2.8 regardless of format.
There is no crop factor. Any, say, 55mm lens will have the same angle of view on a 35mm(FF) camera regardless of what format the lens was originally designed for (as long as it is a larger format as a lens for a smaller format won't make an image that cover the whole frame, but thats another issue).

[desertscape]

The 67 300 Takumar does not have a tripod mount, so using that setup on a tripod with the camera screwed into the tripod would be a problem. The 300 EDIF has its own tripod mount and is better corrected.

[nightfly]

I use several 6X7 lenses on my K-5IIs with good results. The 75 f/4.5 Takumar easily resolves the full pixel resolution of the sensor, and wide open no less. The 55 and 105 are similar in this regard, but the 75 totally lacks in CA problems. The SMC 67 200 f/4 does very well when used in this manner as well. Sharp enough for digital, but made for 6x7 film. A bit awkward to use, but if you already own a 67 system it's worth the cost of an adapter and try them on. Good luck.

[bull drinkwater]

The 67 300 Takumar does not have a tripod mount, so using that setup on a tripod with the camera screwed into the tripod would be a problem. The 300 EDIF has its own tripod mount and is better corrected.

that's why I use a lens support. that's a great lens, but it feels like it weights a ton.

---------- Post added 06-17-14 at 01:55 PM ----------

A 300mm is 300mm lens regardless of format. A F:2.8 is F:2.8 regardless of format.
There is no crop factor. Any, say, 55mm lens will have the same angle of view on a 35mm(FF) camera regardless of what format the lens was originally designed for (as long as it is a larger format as a lens for a smaller format won't make an image that cover the whole frame, but thats another issue).

I thought that was the whole point of even talking about crop factors. the smaller size of the sensor captures a smaller portion of the image, giving the effect of a longer lens.with my sony a-850 I am using full frame lenses, when I switch between full frame and aps-c I see the difference. I don't deal with the technobabble, I just accept the fact that the central subject is filling the frame. to me that's a " crop factor".

[itshimitis]

Not having a dig here, I think the OP's underlying question was: How will the camera see the lens? A Nikon 7100 sees a Nikkor 50mm FX lens in the same way that a D800 sees a 75mm lens. How would the A850 see the 6 x 7 lens? Crop factor may not be strictly an accurate thing,but just a lot of people's way of simplifying so that it makes sense more easily.

[bull drinkwater]

i'm going to concede on this one. I have compared the fov between the 300mm 67 and a 300mm Minolta on my sony a-850 in both the full frame and aps-c modes. they were the same. I am courious to see if the 300mm 67 has better iq. the adapter was fairly cheap so it's no big loss.

---------- Post added 06-23-14 at 01:32 AM ----------

I concede on this one. in compareing the 300mm 67 to the Minolta maxxum 300mm, the fov was the same in the full frame and aps-c modes.the adapter was fairly cheap, so i'll be checking iq to see if it was worth the bother.

[OregonJim]

I thought that was the whole point of even talking about crop factors. the smaller size of the sensor captures a smaller portion of the image, giving the effect of a longer lens

If you want to know the crop factor between your 6x7 and full frame, it's 88mm/43mm or ~2x. So, a 300mm lens on FF will have a FOV comparable to 600mm on 6x7. It will not have the equivalent compression, however.

I think people got confused by your wording, as you asked about crop factor of the lens rather than the format.

[Pål Jensen]

I thought that was the whole point of even talking about crop factors. the smaller size of the sensor captures a smaller portion of the image, giving the effect of a longer lens.with my sony a-850 I am using full frame lenses, when I switch between full frame and aps-c I see the difference. I don't deal with the technobabble, I just accept the fact that the central subject is filling the frame. to me that's a " crop factor".

You asked about the crop factor when using a 6X7 lens on an FF camera. There is no crop factor. If you use a 200mm 6X7 lens on an FF camera it will have the same angle of view and the same DOF (at the same aperture) as a 200mm lens designed for FF.

When it comes to quality it depends on the lens. However, usually the best lenses for the system you are using are preferable. Eg. the Pentax FA645 45mm and the FA645 75mm are not as good as the 43 Limited and the 77 Limited, respectively, when all are used on a 35mm(FF) camera.