Pentax Pentax Macro mode (Pentax-A 70-210mm or Pentax-F 35-70) for negative scanning

Hi all,

I recently purchased a very cheap negative scanner on Amazon, and was pretty disappointed with the results. I found online a description of a process using DSLRs using 3D printed parts -- I'm intrigued by the idea - especially since I have a K-1, and the goal is to digitize film from Pentax cameras.

The question I have -- on the Pentax side, I only have the two lenses listed which have a 70mm "macro" mode. I'm confused if I can actually use these lenses for this purpose -- the minimum focus distance seems to be such that I can't fill the sensor with the negative.

Was just curious if I'm doing something wrong, or if that is in fact a limitation. I have an OM-system actual macro (bellows), but if I'm not mistaken M43 has a different aspect ratio, so I'm not sure that would be suitable for this purpose...

Thanks!
 
Location
Oregon Coast
Name
Andrew
First of all, I'll be interested to hear your findings if you use the K1 for film scanning. It really does seem like it would be a good candidate for it, especially with the hi-res mode. In fact, if you use the hi-res mode I would say you probably don't need to fill the entire frame with the negative. Even after cropping you would still have quite a lot of resolution to work with.

What I understand to be the biggest consideration with a film digitizing lens is whether its plane of focus is very flat, otherwise what's towards the periphery will be slightly out of focus, even while the center is in focus. Even very slightly out of focus, it will markedly decrease the effective resolution you can get out of the film. I experienced this using my Epson V550 flatbed to scan film - that scanner can't adjust its focus plane, and film doesn't want to lay perfectly flat on the glass, plus it is thick enough that the plane of focus is just enough out of whack that you get soft results.

Sorry for rambling. I guess you will only know by trying the lenses you have, in general the sharpness and other qualities of older Pentax zooms aren't ideal, but this is gear that's perfectly capable of surprising. I'd say, don't obsess with trying to fill the entire frame because you'll be wanting the sharpest and flattest focal plane, which will be more towards the center, and use hi-res mode and RAW to get as much detail as you can.
 

JensM

Top Veteran
Not sure about the lenses, as such but I am using a Nikon ES-2 Film Digitizer kit on the Oly 60mm macro.

Based on the Nikon parts being for two specified Nikon lenses, with a recommendation towards a 60mm, I had to tweak the set-up with some distance pieces to put the system together and not overfill the frame so to speak. For minor tweaks the Nikon "end-cap" can be slide back and forth to get the best result as to fill the frame.

Not a very Pentaxian answer, but there are possibilites, even with M43.
 
Not sure about the lenses, as such but I am using a Nikon ES-2 Film Digitizer kit on the Oly 60mm macro.

Based on the Nikon parts being for two specified Nikon lenses, with a recommendation towards a 60mm, I had to tweak the set-up with some distance pieces to put the system together and not overfill the frame so to speak. For minor tweaks the Nikon "end-cap" can be slide back and forth to get the best result as to fill the frame.

Not a very Pentaxian answer, but there are possibilites, even with M43.
That's actually one of the things I really like about this site -- while still appreciating the platform specific ones -- we can talk other systems :)

The 3D printed version of a digitizer kit of course you can easily modify the length so it can be customized to exactly your gear, which is cool. The downside is it doesn't really do anything about the light side -basically just recommends a flash. The kit seems to take that into account.

I played around with it last night - there are multiple possibilities. I have an OM Macro - bellows, that I have adapted currently to M43, and I was able to put the full frame of the negative in. Aspect ratio is slightly different, so it would partly need to be cropped, which is less than ideal, but is easy.

A suggestion on the Pentax forum was to put an extension tube on the 35-70 which should put more of it in frame, and then use high-res mode. I don't have any K-mount extension tubes, but it probably wouldn't be hard to get some - or I could probably print one.

In any case, black filament comes in today, looking forward to trying this out...
 

doobs

Regular
Location
Fairfax, VA
Name
Chris
Hi all,

I recently purchased a very cheap negative scanner on Amazon, and was pretty disappointed with the results. I found online a description of a process using DSLRs using 3D printed parts -- I'm intrigued by the idea - especially since I have a K-1, and the goal is to digitize film from Pentax cameras.

The question I have -- on the Pentax side, I only have the two lenses listed which have a 70mm "macro" mode. I'm confused if I can actually use these lenses for this purpose -- the minimum focus distance seems to be such that I can't fill the sensor with the negative.

Was just curious if I'm doing something wrong, or if that is in fact a limitation. I have an OM-system actual macro (bellows), but if I'm not mistaken M43 has a different aspect ratio, so I'm not sure that would be suitable for this purpose...

Thanks!
Would you please provide a source for the models to print parts from?

Thanks!
 

Brownie

Top Veteran
I've used factory made versions of that setup before and was not satisfied with the results. Now I use a copy stand, negative holder, Macro lens and a $20 LED light tablet from Amazon. Whatever method you use it's important to keep your light consistent. Same light, same distance, every time. I'd pick up one of the cheap light tablets and hang it on a wall, then set the camera up on a tripod pointing at the tablet.

Tip: take a photo of the lit table when you start and use that to set your white balance before processing.
 
So just a quick update - negative carrier is mostly done -- waiting on a belt (a few days), and then it should be complete. For grins, I tried the OM macro (80mm) on my E-M1 Mark II under a bit more controlled environment (negative in the carrier, telescoping tube at the minimum, distance extended to get it visibly in focus. Light is still a problem - I've got a light table coming also in a few days.

Not terrible - seems like the tube needs to be about 210mm. I'm printing this now. I think clearly the K-1 with an actual macro lens will be better for this application (it appears I can't adapt OM well onto PK). But besides a loss due to the aspect ratio difference, this seems OK for now...

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Thanks, to be honest - I'm kind of impressed. Still working on the details (200mm distance seems best -- focusing is a bit of a challenge), but I got this with no extra lighting and a whiteboard as the background.

This is tripod hires mode on the E-M1 Mark II -- I think f/16 13-second exposure x2. Obviously, got some cleaning to do with the lens and/or negative, but this is considerably more detailed than the lab print AND it's from a JPG. I can only imagine what the K-1 could do with this...

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Location
Oregon Coast
Name
Andrew
You're making me want to give it a try! If I went that route I might get the Lomography Digitaliza (or whatever the heck it's called). Turns out amongst the contents of a box of random odds and ends a friend gave me is a set of Pentax K-mount extension tubes. I'm really curious now to see if I could rig something up.
 
You're making me want to give it a try! If I went that route I might get the Lomography Digitaliza (or whatever the heck it's called). Turns out amongst the contents of a box of random odds and ends a friend gave me is a set of Pentax K-mount extension tubes. I'm really curious now to see if I could rig something up.
You definitely should. I'm going to be getting some extension tubes soon, and I can't wait to try out the K-1 with this. Considering I got good results even with a 2x crop sensor, I can only imagine how much better the K-1 will be. In fact, I'm navigating getting a Macro just for the purpose :)

The only hard part is getting a tube that connects to a filter thread, and is sufficient length to get the negative in the complete frame and focused. The OM Macro has a 49mm thread and the sweet spot was 200mm. I re-designed it a bit - the original tube wasn't long enough, and had a bayonet mount instead of a screw. I ended up separating the screw mount from the tube to make it easier to print.

For software, I think I'm going to go with this Negative Lab Pro plugin -- seems like it does a decent job :) But next adventure going to try the K-1 without extension tubes, but with Hi-Res and compare it to the E-M1.2...
 

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Well... Curiosity got the best of me :)

On the Pentax Forums, a gentleman did a test of the 35-70 in Macro mode with extension tubes (36mm total) on a Pentax APS-C camera. I'm waiting on extension tubes, but in the meantime, I thought I'd print one.

This is far from what the final quality would be. I made the tube, so it's probably not exact, and I didn't have a tube on the reverse end, so unwanted light came in. But I found with ~36mm of extension, I was able to get the entire negative into the frame, and a tube of only a few cm will be needed on the other side.

Edit: Found out that a prototype tube I created earlier is about the right size, so I was able to come up with near-optimal (for 3D printed parts) - 3D printed K-mount extension tube, Pentax FA 35-70 on Macro mode, approximately 50mm tube connecting to the negative carrier.

What's obvious to me - the K-1 will be great at doing this. 36mp, pixel shift. Maybe extension tubes won't be the best answer, but a real macro sure would :)

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Well, I'm convinced. This works. My light table came in, put together as controlled an environment as I could, and frankly, I'm super pleased with the results.

I'm going to:
- Replace the 3D printed extension tube with real tubes
- Buy a 49mm-82mm filter adapter (3D printed screws are less than ideal)
- Do a lot more film photography
- Memorize how to say "negatives only" in Italian. :)

Thanks for the inspiration!
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