Stitching scans or not???

[AdamD]

Hi all. I'm not sure if this is the best section for this post, I'm sure it will be move if not....

My question to you is, when scanning your negatives, in particular DSLR scanning, what are the advantages of taking multiple photos of your negative and stitch them all together into one very large megapixel photo?

I can maybe see this being helpful for 35mm because you are starting with a small image on its own, but generally speaking, why should I take the time to take, say 6 images of my negative? Other than having a larger file to make super massive prints from, what are the advantages?

I don't believe you'll get more color control or anything better, but hence my question. I just don't know...

Thanks!!

Adam

[Peter De Smidt]

The only reason is to increase resolution. What determines that is how big you might want to print. When I started with dslr scanners, my camera only had 10mp, which meant the stitching was required for medium-sized prints. There are many much better quality cameras now, and so the need for stitching is greatly reduced. A simple 3-exposure stitch is easy to do with a sliding negative carrier.

[Sasquatchian]

The problem with DSLR scanning of 35mm is that just in order to get a full frame copy you need a great quality 1:1 macro. If you want to stitch for a larger file you need something that give you a higher magnification, which introduces all sorts of other problems into your equation, like, when putting extension tubes on even very good macro lenses, the optical performance at the edges of the frame can be substantially reduced, plus the overall alignment of whatever "system" you've set up gets more and more critical the closer you get, and, on top of that, the effects of diffraction creep in sooner - and destroy detail. The stitching part is easy and works well. It's the shooting part that is actually quite difficult to get right. This has no effect on color at all. And then, there's the question of how much inherent detail is contained in your neg. With color negs there is rarely any benefit going above an effective resolution over 2000 ppi while some black and white negs like T-Max100 can hold detail up to 6000 or greater ppi in a scan.

[Peter De Smidt]

The problem with DSLR scanning of 35mm is that just in order to get a full frame copy you need a great quality 1:1 macro. If you want to stitch for a larger file you need something that give you a higher magnification, which introduces all sorts of other problems into your equation, like, when putting extension tubes on even very good macro lenses, the optical performance at the edges of the frame can be substantially reduced, plus the overall alignment of whatever "system" you've set up gets more and more critical the closer you get, and, on top of that, the effects of diffraction creep in sooner - and destroy detail. The stitching part is easy and works well. It's the shooting part that is actually quite difficult to get right. This has no effect on color at all. And then, there's the question of how much inherent detail is contained in your neg. With color negs there is rarely any benefit going above an effective resolution over 2000 ppi while some black and white negs like T-Max100 can hold detail up to 6000 or greater ppi in a scan.

I agree. Alignment, exact focus, freedom from vibration all become much more important, and harder to achieve, when going up in magnification. If you don't have a lens who's optimum range is in the magnification you're thinking of using, then think twice.

When I was working on my semi-automatic dlsr scanner, about 5years ago now?, I tested my best lens at 5x magnification, a Nikon Measuring Microscope 5x lens, versus a Rodagon D F/4 at 1x. The 5x scan obliterated the 1x scan with a high resolution chrome on glass test slide, but with the best film/lens combo I had, 35mm Kodak Technical Pan developed in TD-3, a 16 lbs. tripod, my Nikon 105AF Macro, mirror lock-up, and an ideal subject, neither option showed more subject detail. The resolution with that system is much higher than with a large format camera. Since I couldn't tell the difference no matter how far I zoomed in with Photoshop, I concluded that going above 1x with that lens and camera was not worth it, especially for medium and large format.

[Jody_S]

I stitched all my 11x14 shots because I don't have a scanner that will do that format. It was relatively painless, automated.

[AdamD]

This all makes a TON of sense and I'm glad I actually was "thinking" the answer in my mind and it was correct!!! Yippie.

Very interesting about when scanning higher than 1:1. That makes sense too, but I really don't think I'm going to do much if any of that. The 35mm scanning and photo editing is more for learning so I'm more accurate when working with 4x5 and don't waste 4x5 film as I learn.

Good stuff. Thanks!!

[Sasquatchian]

Adam - There's another thing I've done experimentally with DSLR scanning, and mind you, I've got two Howteks in my studio, but, copying larger film I've tried and been very successful using a Canon 5DSR and Canon's spectacular 135mm f/4 T/S-E Macro, which focuses to 1/2 life size. It's extremely sharp and very well corrected and have used it shifting up, center and down to make a combined 100 mp effective scan with the Canon. Of course that's a $2500 or something like that lens, but what a lens it is. The new 90mm T/S-E is a better macro lens than the Zeiss Milvus Makro I also own, but it ain't f/2, so they both have their place. Waiting for the Novoflex I bought last year to get back from Deutschland from being fixed. Who know if I'll ever get it back now. But there are lots of options for this.

[sanking]

When I was working on my semi-automatic dlsr scanner, about 5years ago now?, I tested my best lens at 5x magnification, a Nikon Measuring Microscope 5x lens, versus a Rodagon D F/4 at 1x. The 5x scan obliterated the 1x scan with a high resolution chrome on glass test slide, but with the best film/lens combo I had, 35mm Kodak Technical Pan developed in TD-3, a 16 lbs. tripod, my Nikon 105AF Macro, mirror lock-up, and an ideal subject, neither option showed more subject detail.

Peter,

Some may may not be aware but there are two flavors of the Apo Rodagon D, the f/4 variety that is optimized for 1:1, and the f/4.5 version that is optimized for 2X. Both are superb lenses for scanning with high resolution digital cameras. These lenses typically come with M42 thread and require the use of either extension tubes or bellows, but both are relatively inexpensive options with manual focus control compared to modern macro lenses, which is totally OK for me in digitizing film.


Sandy

[Peter De Smidt]

I have both versions, but I ended up preferring the 1x f/4 for my use. They're terrific lenses.

[wattsie]

Peter,

Some may may not be aware but there are two flavors of the Apo Rodagon D, the f/4 variety that is optimized for 1:1, and the f/4.5 version that is optimized for 2X. Both are superb lenses for scanning with high resolution digital cameras. These lenses typically come with M42 thread and require the use of either extension tubes or bellows, but both are relatively inexpensive options with manual focus control compared to modern macro lenses, which is totally OK for me in digitizing film.


Sandy

The 2X is optimised for 2X for enlargement so for picture taking (ie camera scanning) it would be 0.5X (the reciprocal of 2X). Rodenstock literature has the 2X lens designed for 1.2X to 2.5X for projection (enlargement) purposes and 0.8X to 0.4X for taking (camera scanning) purposes. Just in case that's helpful for anyone. I'm just getting set up to use a Panasonic S1R (with pixel shift) with extension tubes, a modular focus unit and Rodagon APO D 75mm (1X) and 120mm lenses to scan from 35mm through to 4x5. Planning on stitching 3 shots of the 4x5 similar to what Sandy sounds like he is doing. Kaiser copy stand with a leveling head attached for easier alignment, Kaiser slimlite plano light source (so far) and using a Versalab Parallel (laser alignment) from the darkroom days to align (still available). So far so good, but I'm still testing the set up. Lots of helpful experience to leverage from this forum - thank you.

Jason

[Peter De Smidt]

Jason, you can use these lenses normally or reversed. The 1x isn't very good at other magnifications. The 2x/.5x is a bit more versatile.

[wattsie]

Jason, you can use these lenses normally or reversed. The 1x isn't very good at other magnifications. The 2x/.5x is a bit more versatile.

Thanks Peter. I’d heard that about the 1x and so only intended that for 35mm. I was planning on using the 2x and 120mm for larger formats.

[Pere Casals]

My question to you is, when scanning your negatives, in particular DSLR scanning, what are the advantages of taking multiple photos of your negative and stitch them all together into one very large megapixel photo?


Adam, let me add that one of the drawbacks DSLR scanning faces is format not matching.

A DSLR is ideal to scan 35mm as both the DSLR and the film frame are 3:2 aspect ratio.

Larger formats contain much more informtion and format is not matching, not only the DSLR shot is not able to take all information a 6x7cm frame (157MPix effective for a 6x7cm tmax 100 shot) has...

https://www.onlandscape.co.uk/2011/12/big-camera-comparison/

...beyond not being able, only a fraction of the sensor pixels are used because aspect ratio is different. All this is even worse for LF. As mentioned, by stitching crops enough you may get all resolution you may want. If you want 10.000 dpi effective this possible with a dslr scanner with an smart setup.



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189049


Here it is explained that using a ($35) reversed enlarger lens you can get insane quality if your setup is smart, say 9000dpi effective with a 3x3 mosaic in 35mm film.

https://www.largeformatphotography.info/forum/showthread.php?151265-9000-dpi-effective-DSLR-scanner&p=1490213&viewfull=1#post1490213


Some people had pitfalls when trying to scan x3 or x5 magnification... but just about applying from basic optic knowledge you to make an smart setup that's very easy to focus: a kid's game as with the reversed lens you have (say) x5 more DOF in the sensor plane.

To be smart at x5: use a "focus unit" lens like an enlarger lens, internal focusing of regular shooting lenses makes the lens more expensive for the same peformance. Use an enlarger lens also to have a very flat field focused plane. Use it reversed . Fix well camera and focus by elevating more or less the lens the reversed lens for a total precision, this is the smart setup for high performance.

For LF this is not necessary, best choice is a cheap Epson V850 flatbed (or a used V700), it has no problem and performance is atonishingly good for the LF sizes.