Pentax SMC 67 300 mm F/4.0 on a Nikon

[kalasinman]

This is a 67 lens. If I attempt to determine proper flange to chip distance, and I use an adapter, would not the distance be the same from the flange of the Nikon side of the adapter as a Nikon lens/

[Horwig]

I'm using pentax 67 lenses, and good they are too. I use a Canon adaptor off ebay, works well. If you need to know the various flange distances, they are all here.

http://www.graphics.cornell.edu/~westin/misc/mounts-alphabetical.html

Huw

[kalasinman]

Huw, thanks for the very interesting and informative chart. This confirms my suspicions that the rather long adapter for the 67 Pentax should work perfectly for the Nikon F mount.

The eventual goal of this project is to mount a QHY9 (don't own yet) to a 300mm camera lens for wide field. In the mean time I will use a modded Nikon DSLR.

A bit torn between several old lenses, the nikon 300mm f/4.5 (and ED version), the Sigma APO 3oomm f/4.5, and the Asahi Opt. 300mm 67 f/4 ( not a -A or -M).

I am sure each is reasonably sharp, but the CA and field flatness are the issues.

Also a bit concerned that the APC sensor is going to waste enough of the image circle to increase the sub exposure time.

Of course there isn't any data, so mind can churn along unfettered by facts

[Horwig]

I've been using an M* version of the Pentax 67 300 lens, that's the ED version with internal focusing, both on my Canon 5D, and starlight expess h35 cameras.

The field flatness is impressive, and with the ED lens, no CA worth talking about. But the ED version does go for quite a bit more than the other less corrected 67 lenses on ebay.

I've just splashed out on an FSQ, so my lens will have to go soon to pay for the new toy.

Huw

[kalasinman]

I like the last one a lot. Just what I aim for. You use FF DSLR and I have an APC. Although the sensor is a little bigger than the Canon APC, I think the crop of the sensor could give me good results , even with non ED. I will go for the later Pentax SMC version.