Macro lens for copying

I have been scanning transparencies and negatives, both 35mm and 645 but the process is very slow and I have thousands to go at!
Pentax have a 50mm f2.8 macro and a 100mm f2.8 macro, which would be best for my purpose?
What height on a copy stand would be needed?
In film days a 50mm lens could be used reversed with extension tubes, if I remember rightly, but I assume that this is not practical with digital?
What size of lightbox would be OK, does an A4 size have any advantage over an A3? Any other sizes?
Thanks in Advance.

Reversing a lens for close-up/macro does work with digital and can be fun if you like tinkering. However, it is a relic from the days when true macro lenses were rare. It's now far easier to use a modern macro lens.

If you're looking at the latest versions of Pentax macros, the 50mm macro has an aperture ring, the 100mm doesn't. Both will of course work normally on Pentax digital cameras. If you're ever tempted to reverse the lens, though, having an aperture ring gives you the ability to change the aperture when reversed.

I've copied slides with the 50mm and the camera mounted on a Novoflex macro rail with their slide copier attached to the end and backlit slides. It worked. But the 100mm macro would have worked too if I'd had it. The only difference would have been a slightly longer working distance with the 100mm.

Good luck. Whatever method you use will take time - lots of it!

Steve

I have scanned film with my Pentax K-5iis and a Vivitar 100mm f2.8 macro lens. The Vivitar macro is made by Kiron and is very good. This Kiron made macro was produced under different brands/names (link) and can often be found for little money. I paid £10 for mine at a local second hand shop. I also have Pentax A50/2.8 and A100/2.8 macros, but have yet to use them for film scanning.
With the K-5iis and Vivitar macro set up I have scanned both 35mm and 6x7 medium format film. When scanning 35mm film I have achieved good results with one shot scans. I have experimented with scanning 6x7 medium format film by taking several shots from different areas of the negative and used stiching software (Affinity Photo) to combine these shots. Stiching six or nine shots from a 6x7 negative have resulted in a very high resolution scan. There is really no limit how high resolution scan one can achieve by taking multiple shots and stiching. Compared to using a dedicated film scanner, "scanning" with a digital camera is very time consuming. Further, one has to be extremely careful with uniform exposure, colour balance and keeping the camera parallell with the film, especially if you uses the multiple shots and stiching method.

I use a small Kaiser lightbox (Slimlight Led 12,5x10cm) and 35mm film holders from my Minolta film scanners. The 6x7 film holder I use is made by Plustek.

Addendum:
Ten years ago I started to scan my father’s Kodachrome collection, comprising maybe 1000 dias. For this job I purchased a Minolta Scan Dimage 5400 film scanner. I scanned the Kodachromes as TIFF and at highest resolution. The Minolta scanner can scan four slides in succession. While scanning these Kodachromes I tried to combine scanning with other activities, and had some success for instance working on preparing my teaching job, marking tests and reading. Sitting around waiting for the scanner to "do its thing" is the epithome of waisting time, so for me to survive 1000 Kodachromes I had to find other activities to make it meaningful.

If I had to scan a large collection of negatives or slides again I would probably opt for a decent film scanner, it is less work than camera duping.

There is the option of the Valoi easy scan 35, they also have options for 120 film.
Pricey but depending on the amounts you want configure to digital.
A Pentax 100mm DFA macro is what I am using and learning currently with a cheap Lidl wardrobe light box 5000K
Its working for my needs but that is possibly of no help to your good self.
A 100mm macro seems to be the recommendation from most who have tried photographing slides or negatives via a light box and then editing later.Tripod of coarse and exact positioning in live view and zoned in for the best possible clear focus.
The 100mm will frame pretty much bang on for 35mm film negatives or slide film, if one has level plane of view in both fields correct and the film negative is correctly laid flat for the backlight.
The easy scan Valoi makes this a doddle apparently but I don't have one.
Best of Luck

If they are mounted I use a pixl-latr. I bought a Kaiser lightbox as a light source and I have a 1960s Pentax IIIP. I use a K50 macro lens but it doesn't get close enough so I use an extension tube. Once set-up I can copy slides very rapidly: drop the slide into the holder, fire the camera, then move on to the next. I have an Epson V750 which will scan 12 slides at a time but this is faster.

Heres a frame of my Niece over thirty years ago Kodak colour 200 converted to B@W in edit
DFA 100 mm macro using a simple light box

I bought an Epson Perfection V370 scanner for scanning scores of old slides I had. When used with the Epson software it can scan several negatives and several mounted slides as well as several photos at once. Loads of options in the software to change from negative to positive film as well as in scanner photo editing. I dont know if Epson have a patch to make it work in Windows 11 but as long as I installed an Epson software patch it worked fine on Windows 10.

Here's a link to a forum discussion from 6 years ago, a little off of your exact topic but related, you might find it interesting.

link

Regards
Mike

Here are some more links to threads (on other forums) discussing camera "scanning":

https://www.dpreview.com/forums/thread/4148599
https://rangefinderforum.com/threads/scanning-with-a-digital-camera.164014/

I have used PANAGOR ZOOM SLIDE DUPLICATOR for my 35mm transparencies. Attach it to the camera, hold it against light source and click !!

Thanks for all the suggestions everyone, food for thought!

https://www.amazon.co.uk/JJC-Negative-Digitizing-Copying-Restore-Accessories/dp/...

Just add an LED light panel and a macro lens. They also sell this kit with their own light which fits together with the rest of it but I can't see it on Amazon UK.

Just avoid flatbed scanners like the Epson V series as they're terrible for scanning negatives, producing very soft results in my experience.