DSLR Film Scanning

[Stevo711]

Can anyone out there help me? I keep reading that I need a macro lens with a 1:1 magnification ratio if I want to scan negatives with a DSLR. I have a Canon 24-70 2.8L Macro lens with a magnification ratio of 1:3.45. Since the 4x5 negative is so much larger than a 35mm negative, why would I need a 1:1 dedicated macro lens? Since I can fill the frame with a focused 4x5 negative, what else could I hope for? Isn't my 24-70 macro more than enough to get great detail out of a whopping 4x5 negative?

[lenicolas]

Your lens would be fine, it’s just that you’d get a bigger file if you could get closer and stitch several shots.

Unless your dslr has very low resolution, 1:1 is overkill for 4x5.
When “scanning” 4x5 I only get so close that the short side of the negative fills the long side of of my dslr, and then I stitch 4 shots to get the length of the negative. 106mm/36mm that’s roughly a 1:3 ratio, and with a 45mp dslr the resulting image is a little over 8.000x10.000 ; plenty of resolution for any print size.

1:1 would produce huge files that would be slower to process, and introduce problems with depth of field and film flatness.

[Stevo711]

Your lens would be fine, it’s just that you’d get a bigger file if you could get closer and stitch several shots.

Unless your dslr has very low resolution, 1:1 is overkill for 4x5.
When “scanning” 4x5 I only get so close that the short side of the negative fills the long side of of my dslr, and then I stitch 4 shots to get the length of the negative. 106mm/36mm that’s roughly a 1:3 ratio, and with a 45mp dslr the resulting image is a little over 8.000x10.000 ; plenty of resolution for any print size.

1:1 would produce huge files that would be slower to process, and introduce problems with depth of field and film flatness.

Oh my God! You have no idea how much time I have spent on the internet researching trying to get an answer! Thank you soooo much! I just joined this forum last night. Not sure exactly how everything here works so I hope you get this reply. Wish I thought of it sooner. Happy New Year my new friend!

[Stevo711]

Oh my God! You have no idea how much time I have spent on the internet researching trying to get an answer! Thank you soooo much! I just joined this forum last night. Not sure exactly how everything here works so I hope you get this reply. Wish I thought of it sooner. Happy New Year my new friend!

[Willie]

Scanning? Use a scanner.

You are just looking at normal Copy work, same as has been done for decades.

[CreationBear]

Isn't my 24-70 macro more than enough to get great detail out of a whopping 4x5 negative?

As always, a lot will depend on your personal needs and infrastructure. If your short zoom gives you files you're happy with, excellent--however, many people make a distinction between lenses that have a short minimum focusing distance and "true" macro lenses that are designed to be sharp across the frame. (I.e., the reproduction ratio--whether 1:1 or occasionally 1:2--won't be as important as whether the lens provides a sharp image of a flat object from corner to corner.) It will probably come down to your preferred kind of output whether you need an optimized lens: if you're mostly sharing images on the Web, probably not; if you're printing large, you might be introducing slop that negates the potentialities of a well-exposed and focussed 4x5 negative.

On the upside, in the Pentax ecosystem at least, it's often possible to find legacy "true macro" lenses that work well for the kind of copy work we're talking about for not a lot of money--Canikon might be another story!

[neil poulsen]

Versus a zoom 24-70mm lens, all be it "macro", I would think that a 35mm, fixed focal length, macro lens would be preferable for DSLR scanning. A zoom lens is prone to chromatic aberration and barrel/pincushion distortion that could negatively impact the scan.

For example, I have a Sigma 100mm macro Canon mount lens that could be used. This lens does not have internal focus. So focusing this lens at 1:1 extends the barrel of the lens a substantial distance.

As an comment, I would never purchase a lens with internal focus, since depending on the magnification, focusing can alter the actual focal length of the lens.

[sperdynamite]

The advantage of getting the 1:1 macro lens is that it'll be meant for doing this kind of work and thus be well suited to the task. A 24-70 zoom even at a middle aperture will IMHO be not high performance enough.

A very popular lens for scanning is the 70mm ART macro from Sigma. It's wildly sharp, not terribly expensive, and will all you to fill the frame with a piece of film from 35mm to 8x10 on a copy stand. Stitching is always an option but IMHO that's sort of like ordering a 60" proof. You can always re-scan the film at higher resolution later. It does help that I use a pixel shift camera which creates a very large file in one bite.

[CreationBear]

Stitching is always an option but IMHO that's sort of like ordering a 60" proof.

Excellent, I was meaning to ask you: IIRC, you were using an Panasonic S1 (~24 MP with pixel shift) for a while--if you did a one-shot "scan" of a 5x7 negative with it, how big of a print do you think the file would support?

At any rate, my working theory is that 5x7 is the new sweet spot for a hybrid workflow--hopefully you're finding the same.

[sanking]

Excellent, I was meaning to ask you: IIRC, you were using an Panasonic S1 (~24 MP with pixel shift) for a while--if you did a one-shot "scan" of a 5x7 negative with it, how big of a print do you think the file would support?

At any rate, my working theory is that 5x7 is the new sweet spot for a hybrid workflow--hopefully you're finding the same.

I have been digitizing my archive of 5X7 negatives since last December with an a Sony a7r iv with 16 shot pixel shifting. This gives an image file size of about 19000 X 12000 pixel at 350 ppi with one shot. The resolution with this approach is about 50 lpi, which is about what you can get with an Epson V750 or V850, and this allows a vey large print of about 50X35" at 350 ppi from the 5X7 negative. The results don't quite match up to a drum scan, but for this format it is plenty good enough.


With three-stitch using 16 shot pixel shifting I get file size of about 28000 X 19000 pixel, which allows print size of about 80 x 55" at 350 ppi. Unfortunately the work flow with three or more shots with 16 shot pixel shifting is rather challenging as the processing takes a long time in computer due to the large file sizes, but in image quality it beats my drum scanner, and takes a lot less time.

Sandy