These are very rigorous tests with a Silicon wafer, so testing particularly for flat field and resolution into the corners on a 61MP Sony ARIV. He rated both highly but the 105mm was slightly better. That’s me paraphrasing from memory so best to have a look at the reviews.
Vlad Serebryany also compares the 70mm Sigma with the highly regarded 75mm Apo-Rodagon f4.5 2x:
They can depend on distance and aperture settings of a lens. And while a lens might look perfect at 1:1 and f/8, it might be less than ideal under different conditions. However, I can’t say how these lenses fare in this respect, but you might find some info about it or simply buy one and be content. Assuming all other characteristics to be the same, a decision could easily be based on purchase price.
It’s a bit late for this but it might be of intrest?
This is a slide my partner Gabrielle took on Kodachrome 40 with her Nikon FM just after we stepped off this De Havilland Twin Otter at Tenzing-Hillary Airport Lukla in The Himalaya in 1987.
It’s “very” hand held, we were both a lot shaken by the flight and landing.
Anyway, the top enlargement was taken with a Sony FE 90mm Macro G OSS in 2021-08 and the lower with a Sigma 105mm f2.8 DG DN Macro in 2022-05. Both on my Sony a7C.
I had just bought the Sony Macro before I read Robert O’Toole’s review after which ran out and I bought the Sigma.
You can see quite obviously the chromatic aberration at the building and window edges on the Sony shot.
I have not modified the pics so the exposure is a bit different.
@Harry
If you’re still interested I will post some “collimated vs diffuse” comparisons in the Suggested backlight sources for scanning film thread. They don’t really shed any new light on the subject!
For those using APS-C sensor cameras, I can recommend the fully manual, metadata-free 7 Artisan 60mm macro II, the non-extending model 2 that is. Got one at a sales price of about 130 USD. Easily worth the money and easy to focus with focus peeking.
I don’t have a @VladS reference, but got an impression with this setup:
In analog times, we said that condenser lighting was “better” for B&W while diffuse was for colour. It had to do with the silver halide crystals and the film mask, but I don’t remember that detail any more.
In one of my test setups (show it), I moved the LED panel closer and farther away from the negative and noticed, that the far-away panel gave a similar effect like condensed light. While more directed light made captures look more crisp, it also made dust and scratches stand out more clearly.
Interesting, I see your 2020 rig was pretty configurable, how far away did you need to go to get this improvement in detail? Currently with my ‘copy box’ my film is only 28mm above a suitably masked CS-Lite but I have wondered if I might contrive to get a little farther away. That said at 24MP APS-C I doubt it’s going to show a clear difference.
The length of the rods allowed captures of up to 6x9 medium format, in which case, the negative was close to the backlight. For 135 film, the distance to the backlight is wider. This means that I got crisper captures for small negatives and less crunchy captures for 6x9. The difference was noticeable, but Lightroom’s structure tool was able to compensate that - in both ways.
Now to your question: differences were noticeable as soon as the backlight moved away, but the maximum distance is reached, when the backlight diffusor gets smaller than the negative as seen through the lens. From that distance on, you’d need a larger backlight and the effect of directing light would be partially compensated. Exposure times get longer too and if you keep the light outside of a box, more light means more light in your eyes…
Thanks, I’m careful to mask my panel so that the aperture is only just larger than that ‘seen’ through the lens when capturing a full frame with some rebate. To me that is making the effect of the light source less diffuse than if it was close to the negative so that is I think going to help however far away the panel is, even though it isn’t anything like a collimated light source of course.
I haven’t done any comparisons with a greater distance than 28mm or indeed closer but I personally think that moving the panel away from the film is an advantage for a number of reasons, but it does need to be masked off accordingly for each format. The major retail holders from Valoi and NS hold the film very close to the panel of course.
