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