[dstructor]

I'm not looking for theories as much as actual trials & results

I plan on switching to Full Frame, that's why I plan to buy FF compatible lenses

So, Can i use Pentax K-lenses (ex: Rokinon 14 & 85mm) on Nikon body?
i know an adapter with a correction glass is needed, Does it exist? what about loss of quality & functionality?

Would it be better to use on Canon body? does an adapter exist? with or without AF capability?

Please let me know what you TRIED or if there was something to try

[DSims]

Using a Canon body is much better than using a Nikon body. You may have trouble finding many here who even bothered to try with a Nikon body, already knowing how significant the compromise is.

A number of people use K-mount glass on Canon bodies - perhaps you'll get some good responses on this one.

[Docrwm]

The registery depth makes that a no-go from all reports. Nikon has the longest registration distance of any of the major SLR manufacturers. This makes Nikon an almost universal donor to other SLRs but makes it impossible to adapt other SLR lenses to Nikon without optical correction. You can force fit a Nikon manual focus lens to Pentax but not the other way around.

[dstructor]

Okay, so what about Pentax-to-Canon adapters? What works best? (infinity focus + AF)

[Docrwm]

Okay, so what about Pentax-to-Canon adapters? What works best? (infinity focus + AF)

https://www.google.com/search?q=k-mount+on+canon+adapter#hl=en&tbo=d&q=+site...w=1680&bih=885

[interested_observer]

As others have posted the registration distance is the primary factor here. Nikon being the longest does not really permit a simple adapter. An adapter needs a corrective lenses to allow infinity focusing is necessary, but then you still have a manual lens (focusing and aperture). There are some simple adapters, however I would guess image quality increases with price.

• https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/96179-nikon-pe...does-work.html
• which adapter pentax lens to nikon body?: Beginners Questions Forum: Digital Photography Review
• pentax k-mount adapter
• https://www.google.com/search?q=nikon+pentax+adaper+lens&ie=utf-8&oe=utf-8&a...w=1366&bih=636
• Pentax Lens on Nikon - MacRumors Forums

On using a Canon body, things become much simpler. The registration distance works in your favor, and a simple adapter does work - still manual lens. However, this does have some problems of its own. Pentax Tak lenses are famous for being butchered by Canon folks, cutting off pins, etc. so to remove interference with the mirror lifting up.

You also have a wide array of other lenses, Contax lenses (Zeiss) and Leica lenses that can be used on the Canon body along with M42 lenses, through the use of simple adapters.

• CONTAX C/Y LENSES ON CANON dSLRs --- COMPATIBILITY DATABASE

[boriscleto]

Okay, so what about Pentax-to-Canon adapters? What works best? (infinity focus + AF)

You will not find an adapter with AF. If you buy a chipped adapter you will get focus confirmation. The aperture shield will hit the mirror of a Canon FF so surgery is required (either shaving the mirror or removing the aperture shield or even the aperture lever).

[dstructor]

You will not find an adapter with AF. If you buy a chipped adapter you will get focus confirmation. The aperture shield will hit the mirror of a Canon FF so surgery is required (either shaving the mirror or removing the aperture shield or even the aperture lever).

Removing the aperture lever means that 1) I can put it back & use it as it was & 2) Aperture control works via aperture ring, right?

[boriscleto]

Removing the aperture lever means that 1) I can put it back & use it as it was & 2) Aperture control works via aperture ring, right?

1. On some lenses yes. But you see a lot of Pentax lenses on eBay where the lever was cut off.

2. Yes.

[DSims]

I know some forum members use their Pentax lenses on Canon bodies - I think even Adam's done so. Perhaps one of them can chime in.

[vladimiroltean]

Hint: Rokinon also makes lenses in Nikon and Canon mount

[Lowell Goudge]

Aside from the system regestry issue where with Nikon, unless there are optical elements to correct it, you give up infinity focus, tenother issue so that you are dealing with MF only, and stopped down metering, if there is any metering at all.

Bottom line is that Pentax oldies are the most forgiving with respect to being able to at least meter with what ever you can mount, correctly or otherwise.

Also, canon FF cameras have a mechanical interference with the aperture activation lever on Pentax lenses, therefore even minimum mounting leads to lens modifications.

In my mind it just ain't worth it

[dstructor]

Aside from the system regestry issue where with Nikon, unless there are optical elements to correct it, you give up infinity focus, tenother issue so that you are dealing with MF only, and stopped down metering, if there is any metering at all.

Bottom line is that Pentax oldies are the most forgiving with respect to being able to at least meter with what ever you can mount, correctly or otherwise.

Also, canon FF cameras have a mechanical interference with the aperture activation lever on Pentax lenses, therefore even minimum mounting leads to lens modifications.

In my mind it just ain't worth it

Starting to feel this way too...

[Lowell Goudge]

Starting to feel this way too...

The only real way to do this is to swap mounts and pull some shims out to adjust the regestry distance. I have done this with a Minolta MD. Lens onto Pentax, and also a Nikon lens onto Pentax

[dstructor]

The only real way to do this is to swap mounts and pull some shims out to adjust the regestry distance. I have done this with a Minolta MD. Lens onto Pentax, and also a Nikon lens onto Pentax

care to elaborate? with mentioning different regestry distances plz