Has anybody adapted a Pentax 110 lens to mount on Pentax ASP-C sensor DSLR?

**goatsNdonkey** · 11-23-2016, 08:18 AM

If so, how did you do it, and how did it work? Please post pix of adapters needed & pix you took with the lens(es) mounted. Thanks.

I begin by suspecting that the registration is too far out in front of the sensor, meaning that no infinity focus would be possible, but I really don't know. On the other hand, if lens extension is part of the territory, do interesting close-up or macro photography possibilities come into play?

Another concern would be coverage, but a little lens would be more likely to cover an ASP-C sensor than it would full-frame, so maybe that isn't a concern, beyond a little corner vignetting with certain 100 lenses.

Anyway, somebody must have tried this. I searched for discussion threads about it and came up empty. So I thought I would ask.

**goatsNdonkey** · 11-23-2016, 08:57 AM

Well, dcshooter, maybe somebody has tried them for strictly macro purposes. That would be worth hearing about. They might even be capable of something surprisingly good reversed with more extension, verging on microscopy.

Pics I saw of them mounted on mirrorless cameras showed a fair amount of extension in the adapters, at least more than I would have expected, so reports from somebody who tried it with a mirror-ful dslr should clear up that question you raise.

Adam · 11-23-2016, 09:21 AM

Originally posted by goatsNdonkey

Well, dcshooter, maybe somebody has tried them for strictly macro purposes. That would be worth hearing about. They might even be capable of something surprisingly good reversed with more extension, verging on microscopy.

Pics I saw of them mounted on mirrorless cameras showed a fair amount of extension in the adapters, at least more than I would have expected, so reports from somebody who tried it with a mirror-ful dslr should clear up that question you raise.

You can use them on the Q

**goatsNdonkey** · 11-23-2016, 09:45 AM

Originally posted by Professor Batty

You could sacrifice a body cap to make an adapter. Here is a shot made with the 110 50mm f2.8 mounted on a piece of cardboard on a K-01, note the sharpness fall-off at the edges, probably due to curvature of field. It would be better stopped down with a washer. I tried it with the 18 mm and I only had about an inch distance between the front of the lens and the subject, the 24mm had a couple of inches. It works, sort of:

Thanks for posting the sample! I wonder if adding an aperture reducer would have cleared up some of the edge unsharpness?

While the price of the 18mm & 24mm 110s is appealing, perhaps the longer 110 lenses would have more flexibility for macro work--of course they would be in more competition with standard K-mount & m42 lenses that are very common in normal and short-telephoto lengths.

---------- Post added 11-23-16 at 10:52 AM ----------

Originally posted by dcshooter

. . . . FWIW, the difference in FFD between the 110 and K mounts is 18mm, which when dealing with those tiny lenses is a pretty significant amount, in the case of the wider lenses, taller than the lens itself.

The popular mirrorless formats, on the other hand, are in the 17-20mm range, so they have up to a full cm of leeway between the two. The 110 lenses are stuck right in the middle of the two formats.

Fascinating. I wonder if anyone has tried nesting one back inside the camera to get the registration correct? Mirror would have to stay locked up, meaning no viewfinder. Might be able to do it in my old Zenit B, but then I'd be asking the lens to cover full-frame--darn!

11-23-2016, 08:18 AM	#1
goatsNdonkey Site Supporter Join Date: Jan 2016 Location: Fulton County, Illinois Posts: 3,727	Has anybody adapted a Pentax 110 lens to mount on Pentax ASP-C sensor DSLR? If so, how did you do it, and how did it work? Please post pix of adapters needed & pix you took with the lens(es) mounted. Thanks. I begin by suspecting that the registration is too far out in front of the sensor, meaning that no infinity focus would be possible, but I really don't know. On the other hand, if lens extension is part of the territory, do interesting close-up or macro photography possibilities come into play? Another concern would be coverage, but a little lens would be more likely to cover an ASP-C sensor than it would full-frame, so maybe that isn't a concern, beyond a little corner vignetting with certain 100 lenses. Anyway, somebody must have tried this. I searched for discussion threads about it and came up empty. So I thought I would ask.

11-23-2016, 09:21 AM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Originally posted by goatsNdonkey Well, dcshooter, maybe somebody has tried them for strictly macro purposes. That would be worth hearing about. They might even be capable of something surprisingly good reversed with more extension, verging on microscopy. Pics I saw of them mounted on mirrorless cameras showed a fair amount of extension in the adapters, at least more than I would have expected, so reports from somebody who tried it with a mirror-ful dslr should clear up that question you raise. You can use them on the Q Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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11-23-2016, 08:57 AM	#2
goatsNdonkey Site Supporter Join Date: Jan 2016 Location: Fulton County, Illinois Posts: 3,727 Original Poster	Well, dcshooter, maybe somebody has tried them for strictly macro purposes. That would be worth hearing about. They might even be capable of something surprisingly good reversed with more extension, verging on microscopy. Pics I saw of them mounted on mirrorless cameras showed a fair amount of extension in the adapters, at least more than I would have expected, so reports from somebody who tried it with a mirror-ful dslr should clear up that question you raise.

11-23-2016, 09:45 AM	#4
goatsNdonkey Site Supporter Join Date: Jan 2016 Location: Fulton County, Illinois Posts: 3,727 Original Poster	Originally posted by Professor Batty You could sacrifice a body cap to make an adapter. Here is a shot made with the 110 50mm f2.8 mounted on a piece of cardboard on a K-01, note the sharpness fall-off at the edges, probably due to curvature of field. It would be better stopped down with a washer. I tried it with the 18 mm and I only had about an inch distance between the front of the lens and the subject, the 24mm had a couple of inches. It works, sort of: Thanks for posting the sample! I wonder if adding an aperture reducer would have cleared up some of the edge unsharpness? While the price of the 18mm & 24mm 110s is appealing, perhaps the longer 110 lenses would have more flexibility for macro work--of course they would be in more competition with standard K-mount & m42 lenses that are very common in normal and short-telephoto lengths. ---------- Post added 11-23-16 at 10:52 AM ---------- Originally posted by dcshooter . . . . FWIW, the difference in FFD between the 110 and K mounts is 18mm, which when dealing with those tiny lenses is a pretty significant amount, in the case of the wider lenses, taller than the lens itself. The popular mirrorless formats, on the other hand, are in the 17-20mm range, so they have up to a full cm of leeway between the two. The 110 lenses are stuck right in the middle of the two formats. Fascinating. I wonder if anyone has tried nesting one back inside the camera to get the registration correct? Mirror would have to stay locked up, meaning no viewfinder. Might be able to do it in my old Zenit B, but then I'd be asking the lens to cover full-frame--darn!