[ikon.st]

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I tried searching but couldn't find anything conclusive, so please forgive me if this is been discussed before (recently?).

Is there an adapter for a7r, with which I can use pentax K mount lenses and use the entire 36mp (not cropped 24mp)?
If not what is the best K to E out there that is reasonably priced?

[stevebrot]

There are adapters and if the original lens was designed for 35mm film you should not have to use the cropped setting. As for quality/price/features, you might want to send a private message jogiba or hinman. I believe that they both use K-mount lenses on Sony FF cameras.


Steve

[osv]

there are probably half a dozen pk-nex adapters out there.

even the dirt cheap adapters can work well... i found a $10 adapter on ebay, that had a black lens mount area, that really cut down on light leakage at the lens to adapter joint.

don't fall into the trap of thinking that you have to pay $200 to get a usable adapter.

[ikon.st]

There are adapters and if the original lens was designed for 35mm film you should not have to use the cropped setting. As for quality/price/features, you might want to send a private message jogiba or hinman. I believe that they both use K-mount lenses on Sony FF cameras.


Steve

Thanks Steve. Does this mean, I can buy one of those K to Nex or E mount adapter and when used with FA or DFA lenses I should be able to shoot without cropping?

[interested_observer]

I'll just drop in a comment here - that lenses with an aperture ring work best, since there is no way for the camera body to control the aperture automagically, as that is going to have to be a manual operation. Just my 2 cents...

[stevebrot]

Thanks Steve. Does this mean, I can buy one of those K to Nex or E mount adapter and when used with FA or DFA lenses I should be able to shoot without cropping?

The short answer is yes. The adapter question is a little deeper however. That is why I suggested a PM to those who actually know. Here are the pitfalls as I understand them:

• Quality of machining, inter-flange distance is critical
• Aperture ring support for those lenses that lack them
• Potential for light leaks. The machining of the mount faces is critical.

I personally don't think this is a situation where "cheap on eBay" is a good option, though it might work for some. Both of the users I suggested above should be able to offer guidance. I know Hin personally and know that he is a helpful kind of guy.


Steve

[ikon.st]

The short answer is yes. The adapter question is a little deeper however. That is why I suggested a PM to those who actually know. Here are the pitfalls as I understand them:

• Quality of machining, inter-flange distance is critical
• Aperture ring support for those lenses that lack them
• Potential for light leaks. The machining of the mount faces is critical.

I personally don't think this is a situation where "cheap on eBay" is a good option, though it might work for some. Both of the users I suggested above should be able to offer guidance. I know Hin personally and know that he is a helpful kind of guy.


Steve

Thank you !!

[Na Horuk]

Yes, keep in mind the aperture thing! Some lenses are really great, but if you are stuck with wide open aperture,.. (this depends on adapter btw, not sure what exists with K to FE adapters)
What this basically means is, that instead of buying a DA 50mm f1.8 (no aperture ring) or FA 50mm (has aperture ring, but you don't need to pay for AF if you can't use it), you can instead get a Pentax M 50mm f1.7. Cheaper, optically excellent, and you don't pay for features you won't use.

Another thing is that DA lenses are made for "crop sensor", but many still project a full frame image circle. There is a thread with Pentax lenses tested on full frame/film.

[hinman]

On Amazon, I got something like these

http://www.amazon.com/Fotodiox-Adapter-Aperture-Control-E-Mount/dp/B005ORIS4...+k+to+sony+nex

http://www.amazon.com/RainbowImaging-Pentax-E-Mount-Camera-Adapter/dp/B00406...+k+to+sony+nex

I bought the brand by RainbowImaging. The above adapters will work for FA and DA lenses. My copy with Lock/Open ring on the adapter has about 5 stages of aperture control that can be used with DA lens. Not all DA lenses will work in FF non-crop mode, it varies depending on the individual lens and if the lens opening cover the full image circle on the FF sensor.

For FA type of lenses that has an aperture ring, I prefer simpler adapter without the Open/Lock ring on the adapter and they usually cost less.

There are some adapters that are better built and they cost more and I have a copy of Kipon adapter with an aperture ring but I dislike the adapter without any marking on Lock/Open. Some adapter work better than other with tight fitting and proper alignment on markings. I will suggest to choose one that is black in interior over chrome/silver in the interior.







A picture of the Kipon PK/DA to E adapter -- I don't recommend highly on this Kipon adapter as it has no markings on Open/Lock but the good thing on this adapter is a tiny bit better build than the other. The cosmetics may appeal to you and if you don't mind to spend a bit more on an adapter, the Kipon is one of brands to consider.

You see the above that has a Pentax FA 43mm f/1.9 mounted on the Kipon adapter sitting on the right next to a Contax Zeiss Planar 45mm f/2.0 mount on a TechArt AF adapter for the E mount.

The most costlier adapter is the Novoflex, which I don't have a copy, but others prefer its quality over the others

http://www.amazon.com/Novoflex-Adapter-Pentax-NEX-Cameras/dp/B00429Z7X0/ref=...entax+k+to+nex

Cheers,
Hin

[ikon.st]

On Amazon, I got something like these

Amazon.com : Fotodiox Lens Mount Adapter with Aperture Control, Pentax K Lens to Sony NEX E-Mount Camera : Camera & Photo

Amazon.com : RainbowImaging Pentax DA lens to Sony E-Mount NEX-3 NEX-5 Camera Mount Adapter : Camera & Photo

I bought the brand by RainbowImaging. The above adapters will work for FA and DA lenses. My copy with Lock/Open ring on the adapter has about 5 stages of aperture control that can be used with DA lens. Not all DA lenses will work in FF non-crop mode, it varies depending on the individual lens and if the lens opening cover the full image circle on the FF sensor.

For FA type of lenses that has an aperture ring, I prefer simpler adapter without the Open/Lock ring on the adapter and they usually cost less.

There are some adapters that are better built and they cost more and I have a copy of Kipon adapter with an aperture ring but I dislike the adapter without any marking on Lock/Open. Some adapter work better than other with tight fitting and proper alignment on markings. I will suggest to choose one that is black in interior.






A picture of the Kipon PK/DA to E adapter -- I don't recommend highly on this Kipon adapter as it has no markings on Open/Lock but the good thing on this adapter is a tiny bit better build than the other. The cosmetics may appeal to you and if you don't mind to spend a bit more on an adapter, the Kipon is one of brands to consider.

You see the above that has a FA 43mm f/1.9 mounted on the Kipon adapter sitting on the right next to a Contax Zeiss Planar 45mm f/2.0 mount on a TechArt AF adapter for the E mount.

The most costlier adapter is the Novoflex, which I don't have a copy, but others prefer its quality over the others

Amazon.com : Novoflex Adapter for Pentax K Lenses to Sony NEX Cameras : Camera Lens Adapters : Camera & Photo

Cheers,
Hin

Thank you very much !!

[jogiba]

Amazon.com : Fotodiox Lens Mount Adapter- PK-NEX, Pentax K/PK Lens to Sony Alpha Nex E-mount Camera Adapter, fit Sony NEX 3, Nex 5, NEX-VG10 : Camera Shutter Release Cords : Camera & Photo
Amazon.com : Fotodiox Lens Mount Adapter with Aperture Control, Pentax K Lens to Sony NEX E-Mount Camera : Camera & Photo

[ikon.st]

Amazon.com : Fotodiox Lens Mount Adapter- PK-NEX, Pentax K/PK Lens to Sony Alpha Nex E-mount Camera Adapter, fit Sony NEX 3, Nex 5, NEX-VG10 : Camera Shutter Release Cords : Camera & Photo
Amazon.com : Fotodiox Lens Mount Adapter with Aperture Control, Pentax K Lens to Sony NEX E-Mount Camera : Camera & Photo

Thank you

[osv]

The short answer is yes. The adapter question is a little deeper however. That is why I suggested a PM to those who actually know. Here are the pitfalls as I understand them:

• Quality of machining, inter-flange distance is critical
• Aperture ring support for those lenses that lack them
• Potential for light leaks. The machining of the mount faces is critical.

finding a good adapter is the problem.

here are two overpriced novaflex adapters that have serious light leaks:
Bad light leak with Novoflex R adapter: Sony Alpha/NEX E-mount Talk Forum: Digital Photography Review

again... expensive does not necessarily mean better.

here is what a black lens mount adapter looks like... this is canon fd, if you can find it in pentax mount, get it, because that black cuts down on the reflectivity.
Canon FD FL Lens to Sony NEX 3 NEX 5 5c NEX 5N NEX 7 6 NEX VG10 E Mount Adapter | eBay

a hairband around the mount joint can also help.

be aware that sony has a free warranty fix for any a7r mounts that leak light.