Comparing macro lenses using MTF - invitation, take 2

Lou Jost · Post by **Lou Jost** » Wed Dec 18, 2019 5:33 am

I thought it was a scanner lens, but I can't remember why I thought that.

dickb · Post by **dickb** » Wed Dec 18, 2019 6:50 am

Lou Jost wrote:I thought it was a scanner lens, but I can't remember why I thought that.

Maybe because it has Kodak Imagelink Scanner Camera Module Assembly written on it?

Lou Jost · Post by **Lou Jost** » Wed Dec 18, 2019 7:09 am

That's probably why!!!!!

mawyatt · Post by **mawyatt** » Wed Dec 18, 2019 7:36 am

Miljenko,

Thanks for all the lens testing, I've been following your efforts and per recommendation have a Componon-S 2.8/50 which I'll try with a Nikon 100mm as tube soon after I finish up with the Piezo Stage efforts, although a strobe light project with sub-millisecond levels PW control is still lingering.

Would the Xenoplan 1.4/23 work with a old 50mm (Nikon D type) and have coverage for at least an APC sensor?

Best & Happy Holidays,

Miljenko · Post by **Miljenko** » Wed Dec 18, 2019 2:45 pm

mawyatt wrote:Miljenko,

Thanks for all the lens testing, I've been following your efforts and per recommendation have a Componon-S 2.8/50 which I'll try with a Nikon 100mm as tube soon after I finish up with the Piezo Stage efforts, although a strobe light project with sub-millisecond levels PW control is still lingering.

Would the Xenoplan 1.4/23 work with a old 50mm (Nikon D type) and have coverage for at least an APC sensor?

Best & Happy Holidays,

Hi Mike, thank you for appreciating my MTF tests, there will be many more if only my repaired heart continues ticking as reliably as it does now.
Decision on which magnification I'll test at comes from experience (previous trials and errors to be precise). For 23mm lens I decided to go straight to 3x as I believe it can't do 2x. Maybe I'm wrong. I don't have Nikon lenses at hand any more except for 4/200 AiS but I do have some other 50mm lenses like Tominon 4.5/50 and Componon-S you mention so I can do quick & dirty test for you at 2.2x. Consider that a Christmas present!

Happy holidays, Mike.

kaleun96 · Post by **kaleun96** » Thu Dec 19, 2019 3:18 am

dickb wrote:Nice to see the Xenoplan 23/1.4 (4.0) performing nicely here. Just to confirm, you used the fixed aperture version with its aperture unmodified, right? I was/am intending to drill out the fixed f/4.0 aperture to its optimal aperture for this use. When I tested this some time ago f/2.8 and f/4.0 vied for optimum performance, but this was on my previous relatively low megapixel setup. I should redo the test properly. Robert suggested using the lens without aperture and placing a stop between it and the tube lens.

I drilled it out to 10mm or so and sharpness decreased noticeably, though I didn't get around to posting the results. You may be right that Robert's suggestion is the way to go.

Don't the MTF charts for this lens show optimal performance close to f4 anyway?

It's been one of my favourite lenses for awhile now. You can also buy it from the seller's website for cheaper, like $18 or something.

Miljenko · Post by **Miljenko** » Fri Dec 20, 2019 1:11 am

kaleun96 wrote: Don't the MTF charts for this lens show optimal performance close to f4 anyway?

Well, yes, but at lower magnifications (1x to 2x). If you push it to 3x or 4x probably the sweet spot is around f/2.8 due to diffraction.

Miljenko · Post by **Miljenko** » Fri Dec 20, 2019 1:18 am

ray_parkhurst wrote:...corners were really degraded, far more than the 11% reduction in MTF numbers would indicate. The 40WA is also showing significant light falloff in the corners, even on APS-C.

This resolution discrepancy is probably due to sample difference and/or aperture setting. And as for light falloff since there were many lenses I tested in the past with good resolution but terrible light falloff making them close to unusable, I'm considering introduction of light falloff measurement on all the following lenses. The procedure is simple and Imatest has that function built in so this would not be much additional work.

ray_parkhurst · Post by **ray_parkhurst** » Fri Dec 20, 2019 4:36 pm

Miljenko wrote:
This resolution discrepancy is probably due to sample difference and/or aperture setting. And as for light falloff since there were many lenses I tested in the past with good resolution but terrible light falloff making them close to unusable, I'm considering introduction of light falloff measurement on all the following lenses. The procedure is simple and Imatest has that function built in so this would not be much additional work.

Could be related to sample difference, but both my samples perform the same. I shot with the 80RR wide open (f4), and no aperture between the lenses. Did you either add an aperture or stop-down the tube lens?

I've never seen a lens with large light falloff which showed good resolution in the corners. I've always thought of those as mutually exclusive, but perhaps there is some combination of factors which allows them to coexist?

I did finally check my 3M 8.05x lens, and it is indeed a very decent performer. I saw some corner degradation on APS-C, but not too bad, and central sharpness was very good. It also had pretty low CAs.

Along with the 8.05x lens I also received a 7x, two 9x, a 13x, and a 26x. I decided to check the 26x first, and was glad I did. It seems to be an amazing lens! It is for sure apochromatic, with that "sterile" look, similar to the Printing-Nikkors, that seems to come from perfect color accuracy. It covers APS-C pretty well down to 5x, with just a little degradation in the corners (but not for CA). At 7.5x it is great across APS-C, and at 10x it is perfect. It has excellent field flatness as well. I need to check it against my 10x Mitty to see how good it is there, but it has already won a place of honor. I'll be interested now to see how the 7/9/13x lenses perform.

edited to add: I tested the 8.05x with the 120G, but the 26x as a finite.

Miljenko · Post by **Miljenko** » Mon Dec 23, 2019 2:02 am

ray_parkhurst wrote:Did you either add an aperture or stop-down the tube lens?

I have stopped it down to f/4.7. Just enough to raise total resolution but not enough to introduce light falloff which starts at f/5.6.

ray_parkhurst wrote: I've never seen a lens with large light falloff which showed good resolution in the corners. I've always thought of those as mutually exclusive, but perhaps there is some combination of factors which allows them to coexist?

If the tube lens is the one producing light falloff (I call it shading in such cases) there is no resolution drop necessarily at the edges since it primarily depends on taking lens.

ray_parkhurst wrote: I decided to check the 26x first, and was glad I did. It seems to be an amazing lens!

You are one lucky son of the gun, Ray to catch that collection. I'm watching closely Ebay for such finds, but have seen 8.05x only once after I bought mine.

Macro_Cosmos · Post by **Macro_Cosmos** » Mon Dec 23, 2019 6:15 am

Lou Jost wrote:That's probably why!!!!!

I thought it was a scanner lens too due the text, but the performance was just not good. Tried to look up "Kodak Imagelink" and didn't find any useful results at first glance, I didn't bother to go any deeper.

enricosavazzi · Post by **enricosavazzi** » Tue May 19, 2020 7:34 am

Macro_Cosmos wrote:
Lou Jost wrote:I have that Kodak scanner lens, it was sold for a very few dollars (maybe $10) by Surplus Shed. It would be the winner in any weight per dollar lens contest. If I recall correctly (and I may not be recalling correctly), it had lots of longitudinal CA in my tests, but maybe there is some range of m where it works better. It looks and feels like it should be good for something!
It's also pretty soft. Centre is alright but the corners degrade very fast.
The lens itself has beautiful blue/purple coatings, it's quite nice. I would guess the lens is used for IR, although one can't be sure... information is scarce.

My impression (based only on the "look" of the lens and its mount) is that it is a lens from a pre-digital photocopier, so very large image circle (across an A4 or A3 page) and reasonably flat field, but rather poor resolution in lpi (although it may "accidentally" have a good center resolution at some non-optimal magnifications, at the price of field curvature). I had one, but did not find a practical use for it.