Lens Comparisons

[Graham]

Three Macros and a Scanner compared on both Full-Frame and APS-C at 24MP.

Digitising Cameras: Sony Alpha 7C & Sony Alpha 6400 both 24MP.
Subject: Kodachrome 64 Slide taken with Nikon FM + 28mm f2.8 AI-s lens in Jaipur India1988:
Hand-held and most subjects moving, yet serves as “real-world” sample.
Light Source: Negative Supply Mini - 97 CRI 28mm below. Ambient light above excluded.
Focus separate on both centre and edge targets.
ARW files developed and exported to JPEG (Best Quality) in “Affinity Photo” target crops were flipped but have no alteration/resizing other than posting here.
Overall image (Sigma) below is flipped and does have shadows lifted 25% prior development.

Comments:
40 year old Micro-Nikkor had elements cleaned and iris freed.
Edge target sharpness deteriorated with apertures wider than f8. Nevertheless amazing!

Scanner Nikon 7ED had less contrast, revealing shadow detail, however, had uneven illumination. Was sharper at Full-Frame than APS-C , I tried reversing it without success.

Sony FE 90mm (Optical Steady Shot - Off) exhibited chromatic aberration, more so at Full-Frame, otherwise good.

Sigma 105mm DG DN had very slight pincushion distortion (see top & bottom edges of overall photo above), also slight vignetting wider than f5.6. Excellent.

Will do higher resolution “Full-Frame” tests if I get such a camera!

[Harry]

Excellent, a lot of work to present your results like this.

[VladS]

Amazing work! The results on vignetting are fascinating. Could you assess the light fall-off in terms of exposure stops for those lenses? Do you still observe any noticeable fall-off when the lens is stopped down to its optimal working aperture?

Regarding resolution, have you tried using a USAF 1951 chart to measure the difference between the center and corners? Vlad’s Test Target would be incredibly useful here—it essentially places the USAF 1951 pattern across the entire surface of the film frame. (A shameless plug for my product!)

[Graham]

@Harry and @VladS Thank you both. I think only the Scanner Nikon I could measure, the others seem only slight. The three macro fall-off tests were at their optimal apertures, although could be used at f8 which most likely would improve fall-off, the Scanner can’t stop down (easily). The macros most likely improve with stopping further down but diffraction starts. It was interesting to me to see also colour difference!

I do have your wonderful USAF chart and I have posted the Sigma previously but can’t remember which thread? At 24MP all the lenses here would perform much the same. I might do an addenda using the chart at 24MP? But it really needs to be at higher resolution. My test initially, was to choose which lens to carry on using for dynamic range, and sharpness.

[Harry]

Very good to present the vignetting like that, not often shown, if ever. It does certainly show up as a possible issue with the Nikon scanner lens, particularly for colour negative of course but I’d say for transparency as well, correction of some sort required.

Robert O’Toole was distinctly unimpressed with the Sony 90mm lens in his 2020 1:1 tests, finding that it exhibited a lot of CA if he opened it in Capture One and so neutralised the built-in corrections, it didn’t make it through from the APS-C pre-test. Wondering whether you did something similar here?

https://www.closeuphotography.com/1x-test-2020

[Graham]

@Harry When opening the full-frame ARW file in Affinity Photo, the “Sony 90mm Macro Lens Profile” did not improve the chromatic aberration, however, the “estimate from image” profile in Affinity Photo cleared it up. Good news for Sony 90mm owners! The other lenses did not have profiles at the time, the Sigma may have now?

A friend gave me the Scanner Nikon so I was keen to compare it having read favourable comments about scanner lenses here and reading Robert O’Toole and Daniel Knop’s reviews. I think they must be suited to higher magnifications and “line-sensors”? I used a Nikon Coolscan LS1000 in the 90’s a lot, and was never happy with the sharpness. Although you could select a focus point, I felt it was never grain sharp over most of the image. I put this down to lack of depth-of-field and film curvature, at the time. My friend also has a Minolta DiMage 5400 lens, he might give me as well, which I will compare.

[Harry]

Thanks, as you say, amazing what the Micro-Nikkor can do, especially when you can see its construction side by side with the Sony & Sigma.