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07-24-2015, 03:05 PM   #1
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Possible to use short flange lenses on the k-01 with modification?

I'd post this in the k-01 sub forum but that place is less active than a graveyard. I was thinking since the k-01 has the benefit of a mirror box with no mirror, I was wondering if anyone has physically modified/used small lenses to mount them within the camera itself to allow it to focus to infinity?

07-24-2015, 03:19 PM   #2
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Probably because it has no viewfinder, you'll find an obstruction near the top of the box. I have lenses with somewhat protruding rear elements when focused at infinity (like the Yashinon-DX 50/1.7) that will work in a mirrored body like the K-5 (just barely -- the mirror nearly hits it) that won't work in the K-01 because it bangs into an obstruction that is open space on the SLR bodies...
07-24-2015, 03:24 PM   #3
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QuoteOriginally posted by ZombieArmy Quote
I'd post this in the k-01 sub forum but that place is less active than a graveyard. I was thinking since the k-01 has the benefit of a mirror box with no mirror, I was wondering if anyone has physically modified/used small lenses to mount them within the camera itself to allow it to focus to infinity?
Nothing to do with the camera mirror or no mirror, it is the lens property of k-mount, which has a flange (or registered) distance from the sensor. K-mount and some other camera mount are very close (with fractions of mm). However, some people have suggested that Pentax should create a new mount (that has shorter registered distance), but that is not the k-01.

There are some reasons why the registered distance are important from a lens design perspective. Canon lenses, the shortest distance among major brands, generally exhibit heavy barrel effect on most zoom and wide-angle lenses.
07-24-2015, 03:33 PM   #4
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QuoteOriginally posted by aleonx3 Quote
Nothing to do with the camera mirror or no mirror, it is the lens property of k-mount, which has a flange (or registered) distance from the sensor. K-mount and some other camera mount are very close (with fractions of mm). However, some people have suggested that Pentax should create a new mount (that has shorter registered distance), but that is not the k-01.

There are some reasons why the registered distance are important from a lens design perspective. Canon lenses, the shortest distance among major brands, generally exhibit heavy barrel effect on most zoom and wide-angle lenses.
I'm aware... But what I'm saying is since the k-01 has no mirror to flap up and down could you modify a lens so it's physically inside the camera so it IS the correct flange distance?

07-24-2015, 03:45 PM   #5
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QuoteOriginally posted by ZombieArmy Quote
I'm aware... But what I'm saying is since the k-01 has no mirror to flap up and down could you modify a lens so it's physically inside the camera so it IS the correct flange distance?
Theoretically yes, but practically almost improbable as there is not a whole lot of room inside the mount and not even worth the effort.
07-24-2015, 03:56 PM   #6
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Register distance depends on the lens design, which is made for a certain mount. I think some Canon shooters use old adapted lenses that would interfere with the mirror, so they have to take photos in mirror lockup mode. The other problem with adapting is the mount size, which is why Pentax K can go into Canon DSLRs, but Canon lenses cannot easily be adapted for Pentax K, even though they have the same register distance. Well, one of the Canon mounts does, at least, they have a couple

I remember a case where someone used a lens like that in K-01, but the problem was that since it was so close to the sensor, the angle of incidence of the light was too steep, so there was a purple vignetting. Maybe its mentioned in this thread: https://www.pentaxforums.com/forums/138-pentax-k-01/205155-lets-see-your-new-k01.html
But I think it had a thread of its own, as well.

The main problem is that nobody is making such adapters, as far as I know, because its too much of a niche. And making one yourself is difficult, because the tolerances are so tight. This is why those small mirrorless mount cameras are so popular now - they have a small register distance to begin with, so you can easily mount lenses with small register distance, and to adapt lenses with longer register distance, you just add an adapter with the correct amount of space.

Edit: Here are the threads for that lens adapted to K-01! Yashinon 21mm!: Here and also more here and finally on this site: http://imgur.com/a/TCRG0
Also, while looking for it, I found this thread, which you might find interesting: https://www.pentaxforums.com/forums/22-pentax-camera-field-accessories/96884-...sions-lba.html

Last edited by Na Horuk; 07-24-2015 at 04:14 PM.
07-24-2015, 04:13 PM   #7
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QuoteOriginally posted by Na Horuk Quote
Edit: Here are the threads for that lens adapted to K-01! Yashinon 21mm!: Here and also more here and finally on this site: Yashinon-DX 1:3.3 f=21mm Yashica - Album on Imgur
Also, while looking for it, I found this thread, which you might find interesting: https://www.pentaxforums.com/forums/22-pentax-camera-field-accessories/96884-...sions-lba.html
That's incredibly cool! Great link, thank you
07-24-2015, 04:19 PM   #8
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QuoteOriginally posted by ZombieArmy Quote
that place is less active than a graveyard.
But don't you guys keep graveyards pretty lively?

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