[Jonathan Mac]

My experience to date using a digital camera to copy negatives has been with the K-3 (handy as it has a "negative" filter so you can get an idea of how the negative will turn out, at least if it's B&W) and the 35mm DA Limited. The Limited has no problem focusing on the negative.

[ZombieArmy]

Any macro from pentax's lineup will do, you don't need a pricey one or even a 1:1. They're all sharp and will out resolve most film stock. What matters more is properly lighting and framing your film.

I'd recommend picking up an older light table, one with replaceable bulbs inside so you can get the color temperature to your liking. Personally I use a Logan desk top light box, which while not entirely uniform across the large surface is perfectly suited for slide copying. They should also be very cheap on the used market.


https://www.flickr.com/photos/135940736@N02/albums/72177720299961119 here's a test I did with it.

[pres589]

I do this same basic thing with a 105mm macro on an APS-C camera and I don't achieve 1:1 magnification due to working distance and the amount of negative I want filling the frame (I would rather leave some dead space around for cropping any rotation of the negative out as needed). Any 1:2 or greater macro from 50mm on up would be suitable for this in my estimation. The one question I have is if it's really desirable to have a fixed length tube setting the distance from the lens to the negative. I don't think I would want to create the tube before I've had a chance to evaluate distances using a negative and the lens+camera that will be used. I agree with Zombie that achieving full 1:1 resolution is not worth worrying about.

If I needed to buy a new lens for my setup I would probably go with a 50mm macro just to get the working distance down but really I'm just fine with my 105. The only reason I'd use a zoom is for a one-off copy of a print or printed document. For higher quality and repeateability I would stick with primes.

[dionhouston]

French Alps 1961 | Flickr here's a test I did with it.

Thank you! You are hitting precisely why I want to do this - there is simply nothing like film. I'd like to shoot more, but frankly it's quite costly / not as good if I'm going from prints.

I do this same basic thing with a 105mm macro on an APS-C camera and I don't achieve 1:1 magnification due to working distance and the amount of negative I want filling the frame (I would rather leave some dead space around for cropping any rotation of the negative out as needed). Any 1:2 or greater macro from 50mm on up would be suitable for this in my estimation. The one question I have is if it's really desirable to have a fixed length tube setting the distance from the lens to the negative. I don't think I would want to create the tube before I've had a chance to evaluate distances using a negative and the lens+camera that will be used. I agree with Zombie that achieving full 1:1 resolution is not worth worrying about.

If I needed to buy a new lens for my setup I would probably go with a 50mm macro just to get the working distance down but really I'm just fine with my 105. The only reason I'd use a zoom is for a one-off copy of a print or printed document. For higher quality and repeateability I would stick with primes.

The fixed-length tube is definitely for convenience and repeatability. The nice thing about the project - the negative adapter is a separate part from the tube, and everything is 3D printed, so I can make the tube however long I'd like, or replace it with a telescoping tube. The part I'm skeptical about - you all hit it. The project shows the guy using a flash on what appears to be a whiteboard. That just seems like it's not enough. I did a rough test under uncontrolled circumstances and it didn't work well at all -- it's all about light

In any case, I've printed the main part of the negative holder, most of the remainder is printing now, and then just a couple of gears. Then it's figuring out the length of the tube (I'm going to start with the 35-70 in macro mode). Hopefully, I'll have a better test by the end of the weekend.

[Not a Number]

Most of the vintage slide duplicators and indeed the current one from Ricoh/Pentax flash is aimed directly at the diffusion screen on the film/slide holder. Some of them even have an extension rail with a flash shoe on the rail.

[dionhouston]

Well...

I printed the negative holder -- pretty solid actually, I'm impressed. I'm now printing the gears that keep it in place, and then I need some hardware to come in, but that's going well.

Curious about your opinions about my most recent tests -- the pictures. The one where I'm holding a negative is the closest I could get it and still focus (it actually auto-focused). That's maybe 1:3? Do you think extension tubes will help enough with that?

The second picture is with the gear. The orange tube is the original for a Sony 90mm Macro. My guess is mine would have to be about 20cm to work -- that's a mighty long tube

Otherwise -- hmmm. An OM->K Mount adapter is about the same as an old 50mm Macro...

[othar]

That's maybe 1:3? Do you think extension tubes will help enough with that?

I suspect it is closer to 1:4.

As promised have I done some testing of my own today:
The image in the upper left was made with the original K-3 (APS-C) + SMC Pentax-M Macro F4 50mm @f5.6.
The image in the lower left corner was made with the K-3 + SMC Pentax-F Zoom 35-70mm + 36mm Extension Tube @f8
The crops where made from the upper part of the tree close to the middle and from the lower left edge of each image.



A dedicated macro lens like the M 50mm f4 lens is certainly more desireable for negative scanning, but the F 35-70mm lens in combination with some extension tubes is still a viable option on a tight budget (depending on how big you are planning to print the images afterwards)

---

Last edited by othar; 08-07-2022 at 10:33 AM.

[dionhouston]

I suspect it is closer to 1:4.

As promised have I done some testing of my own today:
The image in the upper left was made with the original K-3 (APS-C) + SMC Pentax-M Macro F4 50mm @f5.6.
The image in the lower left corner was made with the K-3 + SMC Pentax-F Zoom 35-70mm + 36mm Extension Tube @f8
The crops where made from the upper part of the tree close to the middle and from the lower left edge of each image.

A dedicated macro lens like the M 50mm f4 lens is certainly more desireable for negative scanning, but the F 35-70mm lens in combination with some extension tubes is still a viable option on a tight budget (depending on how big you are planning to print the images afterwards)

Thanks for doing that! That was very thorough, and far more scientific

I can see that the extension tubes definitely soften the image, but that may be acceptable. In fact, I wonder how much can be gained back by using Topaz Lab's SharpenAI.

You've given me options...

[The Jannie]

I use a concoction of old and new. I had an Olympus 35mm scanner I couldn't use because it was SCSI, I don't use a desktop and no other software available.. Waste not, want not. I removed most things except the negative carrier which is nice and stable. I use 50mm Minolta E-Rokkor in a classic ( but shortened for coverage ) BPM bellows, the Olympus holder fixed to the end and my Kr or K5 doing the hard work. Like most DIYs, it would be expensive to set out from nothing but I already had the scrap scanner and the bellows: I'm nothing if not cheap!

[dionhouston]

So did an experiment - Based on Othar's comment I made a makeshift extension tube -- 36mm. That was sufficient to put the complete negative in frame on the K-1.

The big thing I noticed - extension tubes (and I think by extension) a real macro would require a significantly smaller tube on the other side -- my guess is a few centimeters instead of the 20 I have with the M43. And between pixel shift, and a larger sensor, for sure the final results will be good.

This picture is a bit soft - I'm not sure how much it is the extension tubes, how much the picture, and how much the focusing ("focusing" is manually moving my camera on a dark background). Looking forward to more!

[Erich_H]

FWIW, with the M42 (2nd) version of Macro Takumar, I'm using a 27mm extension tube to get slightly higher magnification than 1:1

[dionhouston]

This (or similar)


amazon.com : 58mm Macro Reverse Adapter Ring for Pentax K PK mount : Flash Adapter Rings : Electronics?tag=pentaxforums-20&


and a 50mm manual lens on APS-c would (possibly) likely perform well in a static copy set up and be quite affordable since you can use any brand glass with suitable filter size. While you don't have to have a dedicated light source/shooting stage having one or being able to maintain a set-up for large batches takes a lot of work out. It's mechanical copy work. Aperture is set for max DoF before lens diffraction kicks in, say f8 and exposure generally will vary on film bases only. Need to (re)focus is dependent on reliability/stability of your set-up and flatness of film.

So this is something I'm going to try. I have a Pentax-M 50/1.4 I'm going to try this with, just to see if it gets me something better than the 35-70 without buying a new lens

I was trying to figure out how to get a tube out of a reversed lens, but then I realized it's a rear lens cap, minus the cap, elongated. That should be 3D-printable

[dionhouston]

This (or similar)


amazon.com : 58mm Macro Reverse Adapter Ring for Pentax K PK mount : Flash Adapter Rings : Electronics?tag=pentaxforums-20&


and a 50mm manual lens on APS-c would (possibly) likely perform well in a static copy set up and be quite affordable since you can use any brand glass with suitable filter size. While you don't have to have a dedicated light source/shooting stage having one or being able to maintain a set-up for large batches takes a lot of work out. It's mechanical copy work. Aperture is set for max DoF before lens diffraction kicks in, say f8 and exposure generally will vary on film bases only. Need to (re)focus is dependent on reliability/stability of your set-up and flatness of film.

Thought you'd like to know I took your suggestion - got great results with a Pentax-M 50/1.4. I designed a part that is essentially a reverse PK->82mm adapter, then just connected to a tube. It didn't quite fill the frame - I have extension tubes coming, and I'll do a final configuration, but at this point, I'm thinking going this way and skipping a "true" macro. Thanks!

[JohnMc]

What's your light source? The sharpness across the plane looks variable. I don't know where you were exposure/aperture wise or if there's a way to flatten the film any more with your holder. Looks like you're making good progress and will soon set yourself up for a lot of scanning hours. )

[dionhouston]

What's your light source? The sharpness across the plane looks variable. I don't know where you were exposure/aperture wise or if there's a way to flatten the film any more with your holder. Looks like you're making good progress and will soon set yourself up for a lot of scanning hours. )

Yeah, definitely a work in progress. The light source is a small light table (the one the camera is on in the photo). That one I may have taken on battery which is dimmer. But the problem is figuring out the right distance. I'm finding it quite difficult to focus on a negative, and the K-1 seems to as well - it's not giving me the beep thing it generally does when it's in focus.

So bit of a trial by error. I've made some more progress though. Think I'm pretty good on the length - 78mm. We'll see with the latest prints...