GFX100s scanning - lens choice and image stitching

[David Mackovic]

Hi everyone !

I need help with choosing the right lens/lenses for GFX100s for scanning 120 and 4x5 film. My colleague already has Flextight X5 but would like another more portable setup and also futureproof.

What I have in mind so far : Negative supply Pro line carriers+stand+light source - purely out of convinience as the budget is quite unlimited
But the lens is biggie for me - I was suggested to Pentax/Mamiya 645 macros with extension tubes, is that a good option ? What would be the best, never mind the budget, choice ?

And second question regarding this - for 120 film can i get away with single exposure or do i have to stitch from multiple ? Same goes for 4x5 - would one capture be enough ? 2 or 4 captures and stitch ? Im asking this because Im not familiar with image stitching and i cant imagine the consistency. If someone has a sample image i can pixel peep at would be amazing !

Thanks a lot for your input.
David

 

[koraks]

What is "enough" depends on how much resolution you need in the scans. There's no single answer to fit every use case.
Personally, given the 100mpix resolution of the GFX100s I would be fine with a single capture for all film formats and not bother with stitching.

 

[thinkbrown]

The gfx100s can also do pixel shift which can yield up to a 400mp image on paper. I can get (brief) access to a gfx100s ii through a family member who has one at work, and I've been meaning to try it out. They've got the 120mm macro on it which permits 0.5x magnification, so a 6x7 frame should just about cover the frame. If/when I get around to it I'll see about posting some samples.

 

[loccdor]

But the lens is biggie for me - I was suggested to Pentax/Mamiya 645 macros with extension tubes, is that a good option ? What would be the best, never mind the budget, choice ?

If digitizing 6x4.5 frames, you'll want a lens that is optimized for macro around 1:1. If you ever need more magnification than that, reversing the lens may be a good option.

For a really good 4x5 that you want to print huge, I'd consider stitching 2 frames. Otherwise I wouldn't stitch with such a powerful camera.

Neither of the native Fuji macros do 1:1 without tubes so they probably aren't optimized for that magnification.

The Pentax, Mamiya, and Hasselblad 120mm f/4 macros are all well-regarded. Some of the Hasselblad ones need extension for 1:1, I'd avoid those.

Though I haven't tested any of these lenses, I'd probably go with the Pentax SMC FA 645 120mm f/4 Macro, personally. I use a Pentax SMC D FA 50mm f/2.8 macro for film digitization (mostly 35mm) and have been very pleased with field flatness, low flare, and sharpness.

 

[loccdor]

If someone has a sample image i can pixel peep at would be amazing !

Warning, large 118 MP file - made with 6 hand stitched full frame 35mm images on a 6x6 (because my auto stitching software failed). I could have made it better by making sure the planes were a little more parallel - my copy stand sags a little bit, pitching the camera down slightly, which I should have adjusted for using the rubber feet on my negative holder. It's a CZJ Sonnar 180mm f/2.8 @ f/5.6 on Kentmere 400, with an orange filter.

You'll want to use carriers that have glass to hold the film flat if you do image stitching. Although with 4x5 the greater DoF may allow you to get away with it.

https://live.staticflickr.com/65535/54763843046_aeea0aae40_o.jpg?s=eyJpIjo1NDc2Mzg0MzA0NiwiZSI6MTc2ODMxNzQxNCwicyI6IjA3Y2Y3MTg3ZGFlMTNhNTJmODYzMTcyMWYxYWY3MDA5ZGE4NGYzNmIiLCJ2IjoxfQ

 

[TheFlyingCamera]

I do digicam scanning with a Fuji xt5. I've done the pixel shift thing for giggles and it really just creates super bloated files that you don't need unless you know you're planning to print billboard sized. As to lenses to do camera scanning with on the GFX, I've been advised that one of the best is the Pentax 120mm Macro for the Pentax 645. You'll still want to get one with the life-size module, and a set of extension tubes.

 

[runswithsizzers]

But the lens is biggie for me - I was suggested to Pentax/Mamiya 645 macros with extension tubes, is that a good option ?

I agree, the lens is a biggie. If you are determined to use a GFX100s, then I would start by finding out what adapters are available. No point in deciding you want to use lens "x" if there is no adapter available to mount it on your GFX100s. Is there an adapter available which allows you to mount a Pentax 645 lens on a GFX100s?

Actually, the first place I would start would be with a Fuji brand macro lens made to mount on your GFX100s. Fuji makes excellent lenses, so I would be looking at third party lenses only if Fuji does not make a lens suitable for your purpose. And for your purpose, you want something that will focus close (1:1), has a flat field, and good sharpness, including the corners.

Given the abundance of pixels provided by the GFX100s, I would be happy with a single shot, but for 120 film (if 6x6cm), I might consider two overlapping shots rather than "waste" the pixels that are not used when shooting a square subject with a rectangular sensor.

 

[runswithsizzers]

The sensor on the Fuji GFX100s is 43.8mm wide × 32.9mm tall. The image area of a square 120 negative is 56mm x 56 mm, so to fill the height of the Fuji sensor with a 120 negative requires a magnification of 32.9/56 = 0.59x. If you want to fill the width of your sensor (two shots, stitched), then you'll need a magnification of 43.8/56=0.78x. In either case, the lens should be able to focus greater than 0.5x (1:2), but will not need to focus as close as 1x (1:1).

It looks like the most suitable lens in the Fuji line would be the FUJINON GF120mm F4 R LM OIS WR Macro. That lens focuses to 0.5x, so it would need an extension tube to provide enough magnification to fill the sensor of a GFX100s with an image of a 120 negative.

One other possible benefit of using a Fuji lens compared to a third party lens might be software lens correction? When a Fuji lens is used on a Fuji camera, I believe a certain amount of correction for things like vignetting, barrel/pincusion, etc. are applied by software? I expect some lenses need more corrections than others, but I don't know anything specific about the FUJINON GF120mm F4. Nor do I know if that lens has a flat field. But if I was interested in digitizing film with a medium format Fuji camera, these are questions I would be looking for answers to.

 

[Ardpatrick]

What about an enlarger lens on a bellows or helicoid set-up?

 

[runswithsizzers]

What about an enlarger lens on a bellows or helicoid set-up?

I think that could be a good solution. We know most enlarger lenses are optimized for a flat field of focus and good sharpness at certain magnifications.

I started out using an enlarger lens on a bellows when digitizing 135 and 120 film with my Fuji XT-1, and I thought the results were pretty good.

I don't know if Fuji makes a bellows or helicoid in the G-mount. If not, then we are back to the question of what adapters are available.

 

[loccdor]

A wide variety of adapters are available: https://fotodioxpro.com/collections/fujifilm-gfx-adapters

 

[michaelbothager]

I am using a GFX 100s with a Novoflex bellows/Schneider lens setup - highly recommended. Pricewise it is in the same range (here in Denmark) as the GFX 120 Macro, but optically better.

Novoflex Adapter Fuji G-Mount Camera to BALPRO 1 (FUGPRO)
NOVOFLEX 25MM EXT TUBE FOR BALPRO (PRO25 )
NOVOFLEX Universal Bellows (BALPRO-1)
Schneider Kreuznach Pyrite 4.4/90mm w/PRO A flat plate (PRO-PYRITE90-F)

 

[Ardpatrick]

You can definitely get an F-mount to GFX adapter because I’ve seen F-mount lenses used on the GFX. As locodor says there are lots of adapters from Full-frame to GFX. An 80mm or longer enlarger lens would easily cover the sensor. The means of focus (bellows or helicoid) would need figuring out. It’s definitely the best ‘bang for the buck’ route.

My own Dslr slide scanning experiences with enlarger lenses and macros is never fully settled but the current king of sharpness (and convenience as an aside) is my micro-Nikkor 105mm AF-D. It’s close with an Apo-Rodagon N 80mm but the Nikon has it. I recently purchased a Fujinon EX 90mm enlarger lens from Kumar which comes with a big reputation for macro. But I haven’t yet ordered the right adaptor to use it on my bellows.

 

[thinkbrown]

My own Dslr slide scanning experiences with enlarger lenses and macros is never fully settled but the current king of sharpness (and convenience as an aside) is my micro-Nikkor 105mm AF-D. It’s close with an Apo-Rodagon N 80mm but the Nikon has it.

That's interesting, because I found the micro nikkor 105mm af-d great for medium format but seriously lacking for 35mm. I switched to using a Minolta CE Rokkor 80mm enlarging lens on bellows which outperforms it handily.

 

[Ardpatrick]

That's interesting, because I found the micro nikkor 105mm af-d great for medium format but seriously lacking for 35mm. I switched to using a Minolta CE Rokkor 80mm enlarging lens on bellows which outperforms it handily.

That’s interesting too. I think there is a lot going on - focus (in-)accuracy, lens sample variation, etc. As I said above - it’s never settled. I have the Fujinon to test as well as a variety of recently received Schneider Componon’s etc. The Minolta is highly regarded by the Delta website too. I think I might have a Minolta 50mm somewhere.

For 35mm duping using a bellows the 105mm is not the easiest to work with. I use a micro Nikkor 60mm which works very well on the bellows and is adequate optically.

I love the Micro-Nikkor 105mm. I bought it as a display model in-store at B&H in the late 90’s and it’s probably been my most useful ever lens acquisition, alongside a Rodagon 150mm enlarger lens used in the darkroom.

But I digress - the Micro-Nikkor 105 isn’t suitable for the OP’s purposes because it may not have sufficient image circle to cover the GFX sensor. Hence the advice to look at enlarger lenses for Medium format film in the range 75 - 105mm.

 

[David Mackovic]

Thanks for many replies !

As for the lens:
My own current setup for 135 and 120 is Sony A7R4+ Enlarging Nikkor 75mm + bellows and the results are fine, it is very easy to use.

For the GFX I was considering similar setup because I dont need Autofocus and enlarging lenses are probably better at this kind of imaging anyway, all that flat plane sharpness and stuff. I will connect it with bellows and extension tubes possibly if needed. They also have good image circle so no problem on larger sensor. Now which one ? There will be mostly 4x5 and ocasionally 120 films so mainly optimised for 4x5 film.

I know there is no right answer but consider this discussion as a widening of my knowledge about this topic which i know actually very little abut
Thanks guys !

 

[runswithsizzers]

@David Mackovic -- I am guessing there are relatively few Photrio members who have actual experience copying 4x5 film with a Fuji medium format camera(?), but I could be wrong. So it may be up to you to try out various setups and then tell us what works the best. ;-)

A few random observations which may be useful:

When your bellows is fully retracted, it is going to have some minimum thickness. Add to the bellows, the thickness of two adapters on either end, and there is a minimum extension for your working bellows. Depending on the focal length of your lens, in some cases this minimum extension can provide too much magnification.

In other words, if the focal length of your lens is too short, and your minimum extension is too long, then your magnification may be too high -- and your image will not fit on your sensor without cropping. The solution is to use a longer focal length lens.

There are formulas that can be used to calculate camera-to-lens, and lens-to-subject distances for given focal lengths and magnifications, but it is often difficult to apply these formulas with enough precision to be certain a given combination will work without actually trying it.

One fairly common size of enlarging lens mounting threads is M39, but there are others, so you want to be sure what thread you are getting when buying enlarging lenses so you can find the appropriate adapter.

Generally speaking, less expensive enlarging lenses have 4 lens elements, and the better ones have 6 elements in 4 groups. Here is a list of some of the many enlarging lenses you can choose from: https://www.photocornucopia.com/1061.html

There is a website called coinimaging.com that discusses both macro and enlarging lenses. (the website is of the HTML-3 era, so be patient) He makes the point that most lenses perform best at a given magnification, and he has done testing to see what magnification is optimal for a given lens. Here are a few of his test results: https://coinimaging.com/Lens_tests.html?

Good luck! And I am looking forward to seeing your results.

 

[Ardpatrick]

@David Mackovic -- I am guessing there are relatively few Photrio members who have actual experience copying 4x5 film with a Fuji medium format camera(?), but I could be wrong. So it may be up to you to try out various setups and then tell us what works the best. ;-)

A few random observations which may be useful:

When your bellows is fully retracted, it is going to have some minimum thickness. Add to the bellows, the thickness of two adapters on either end, and there is a minimum extension for your working bellows. Depending on the focal length of your lens, in some cases this minimum extension can provide too much magnification.

In other words, if the focal length of your lens is too short, and your minimum extension is too long, then your magnification may be too high -- and your image will not fit on your sensor without cropping. The solution is to use a longer focal length lens.

There are formulas that can be used to calculate camera-to-lens, and lens-to-subject distances for given focal lengths and magnifications, but it is often difficult to apply these formulas with enough precision to be certain a given combination will work without actually trying it.

One fairly common size of enlarging lens mounting threads is M39, but there are others, so you want to be sure what thread you are getting when buying enlarging lenses so you can find the appropriate adapter.

Generally speaking, less expensive enlarging lenses have 4 lens elements, and the better ones have 6 elements in 4 groups. Here is a list of some of the many enlarging lenses you can choose from: https://www.photocornucopia.com/1061.html

There is a website called coinimaging.com that discusses both macro and enlarging lenses. (the website is of the HTML-3 era, so be patient) He makes the point that most lenses perform best at a given magnification, and he has done testing to see what magnification is optimal for a given lens. Here are a few of his test results: https://coinimaging.com/Lens_tests.html?

Good luck! And I am looking forward to seeing your results.

Excellent points. I would add another challenge. Pretty much every available enlarger lens is a used lens - at least a decade old. Lenses have been handled differently - some have been dropped etc. So when buying used, sample variation from one Rodenstock apo-xx to the next is potentially quite variable. I think realistically it’s necessary to try out lenses before assuming this lens is better than that lens etc. The best way to find the best lens is to test lenses against each other on the same subject. Even at that focus technique matters etc. So it ends up being quite a bit of work - I have multiple 80mm, plus a 90 & a 105mm enlarger lenses, as well as the micro-Nikkor 105mm. I haven’t tested them all yet.

 

[MattKing]

Excellent points. I would add another challenge. Pretty much every available enlarger lens is a used lens - at least a decade old. Lenses have been handled differently - some have been dropped etc. So when buying used, sample variation from one Rodenstock apo-xx to the next is potentially quite variable. I think realistically it’s necessary to try out lenses before assuming this lens is better than that lens etc. The best way to find the best lens is to test lenses against each other on the same subject. Even at that focus technique matters etc. So it ends up being quite a bit of work - I have multiple 80mm, plus a 90 & a 105mm enlarger lenses, as well as the micro-Nikkor 105mm. I haven’t tested them all yet.

One big advantage with enlarger lenses is that you can easily do a useful initial test by mounting them in an enlarger and visually check how well they image grain in a glass mounted negative enlarged to a big size.

 

[Ardpatrick]

One big advantage with enlarger lenses is that you can easily do a useful initial test by mounting them in an enlarger and visually check how well they image grain in a glass mounted negative enlarged to a big size.

If you have an enlarger, of course. But you can't do a side by side comparison that way. If you've shot the same image with different lenses on a Dslr you can do very precise comparisons, without whatever variables there might be between an enlarger set-up and a Dslr capture setup.

 

[runswithsizzers]

Warning, large 118 MP file - made with 6 hand stitched full frame 35mm images on a 6x6 (because my auto stitching software failed). I could have made it better by making sure the planes were a little more parallel - my copy stand sags a little bit, pitching the camera down slightly, which I should have adjusted for using the rubber feet on my negative holder. It's a CZJ Sonnar 180mm f/2.8 @ f/5.6 on Kentmere 400, with an orange filter.

You'll want to use carriers that have glass to hold the film flat if you do image stitching. Although with 4x5 the greater DoF may allow you to get away with it.

https://live.staticflickr.com/65535/54763843046_aeea0aae40_o.jpg?s=eyJpIjo1NDc2Mzg0MzA0NiwiZSI6MTc2ODMxNzQxNCwicyI6IjA3Y2Y3MTg3ZGFlMTNhNTJmODYzMTcyMWYxYWY3MDA5ZGE4NGYzNmIiLCJ2IjoxfQ

When I try to look at your link, I get an error: "Invalid signature, 403"

 

[MattKing]

If you have an enlarger, of course. But you can't do a side by side comparison that way

Understood - but you can at least quickly detect the sort of problems that arise from damage, mishandling or incorrect (re)assembly.

 

[Ardpatrick]

Understood - but you can at least quickly detect the sort of problems that arise from damage, mishandling or incorrect (re)assembly.

Very true.

I find myself using my Dslr capture setup to 'preview' negs I've processed, when I'm not inclined to deal with mixing up chemicals for darkroom proofing. Superficially it seems much 'faster' and simpler. In practice, the Dslr capture set-up is fiddly, and what with various stages of 'post-production' involved in arriving at a positive, I'm not sure it is faster than quick proofing on 8 x10 RC paper prints. It's about the same. If I wanted to make 'A4' inkjets from the Dslr captures, the digital process would certainly take longer than just producing 8 x 10's printed direct from the negs. But I guess you do save paper and chemicals.