High NA 2.5x pushed to 5x VS 5x

[Macro_Cosmos]

An objective with an NA of 0.21, at 2.5x pushed to 5x compared to a native 5x with an NA of 0.14.
Results were as expected.

I bought this for a measuring device at the lab, it's not needed anymore, they prefer that 5x.
Nikon Z6, only the centre is presented here. CMH200, coaxial epi-illumination.



Would be great if we can have spoiler tabs for larger images! Here's full resolution:
https://live.staticflickr.com/65535/501 ... 4803_o.jpg

Biggest difference is how the letter B is rendered. The letter requires an NA of about 0.2 for its lines to be fully resolved.

This is only the centre. The borderline and corners of the 2.5x are unusable due to its smaller image circle (field number should be a better term?).
This objective will work nicely on a smaller sensor.

[Scarodactyl]

This is pretty cool--what sensor size are you using? The qv isn't really a 2.5x in microscope specs though so it's sort of cheating. I think I've read thst normal QVs don't quite measure up to the m plan apos, but the HR variant seems like a real winner. I only have a normal '1x' and I like it, but on a 180mm olympus tube lens the edges don't perform amazingly on aps-c. This is much nicer.

[Macro_Cosmos]

This is pretty cool--what sensor size are you using? The qv isn't really a 2.5x in microscope specs though so it's sort of cheating. I think I've read thst normal QVs don't quite measure up to the m plan apos, but the HR variant seems like a real winner. I only have a normal '1x' and I like it, but on a 180mm olympus tube lens the edges don't perform amazingly on aps-c. This is much nicer.

This is a fullframe crop of the centre. The APS-C and FF corners as you've indicated, are very bad.
My post wasn't concise enough, I'll edit it to reflect the test scenario. It was posted at like 4am or so, I should be in bed.

So far, I've tried the 5x NA0.28 and this 2.5x QV-objective. They hold up quite well. The 5x when pushed to 10x on a 200mm tube lens (ITL200 in my case), is pretty close to a native 10x M Plan Apo from Mitutoyo in terms of CA and resolution. There is however rather extreme field curvature and uneven illumination (ie, not flat field corrected). These objectives are definitely apochromatic though, even though there's no label to reflect it.

They are used on Mitutoyo's expensive measuring microscopes. I know someone who actually has this device. I might ask him about the tube lens embedded within, and if I may borrow it.
According to a friend in this field, the QV-objective's aberrations can be fixed with a dedicated custom 100mm tube lens and will work nicely on APS-C. Funny enough, this 2.5x pushed to 10x will of course retain its 0.21 NA, not far behind that of a 10x M Plan.

My 2.5x has a bit of separation around the edges of one of those I assume, cemented doublets. Typical Mitutoyo. Looks new but has some funky internal issues.
Oh here's something interesting: https://www.edmundoptics.com/f/infinitu ... ses/15093/

- Color-Matched for all Infinity Corrected Objectives
- Compatible with Full-Frame 35mm Sensors
- Maintains Perfect Parfocal Performance
- Requires One Objective and Adapter for Use

[Bakwetu]

I have a Mitutoyo QV 5x/0.28. Using it with a Canon 100mm macro as tube lens it vignettes hard in the corners, but using it as a 10x with Canon 70-200 at 200mm, there is only a slight vignetting similar to how the photos vignettes when I use a true Mitutoyo 5x/0.14. Since the QV also has the same NA as the Mitutoyo 10x, isn't likely that the QV series are just pushed down objectives?

[Macro_Cosmos]

I have a Mitutoyo QV 5x/0.28. Using it with a Canon 100mm macro as tube lens it vignettes hard in the corners, but using it as a 10x with Canon 70-200 at 200mm, there is only a slight vignetting similar to how the photos vignettes when I use a true Mitutoyo 5x/0.14. Since the QV also has the same NA as the Mitutoyo 10x, isn't likely that the QV series are just pushed down objectives?

This is confirmed to be untrue. They are different objectives with different behaviour and design goal. The 5x NA0.28 HR isn't a pushed down 10x. Characteristics are entirely different.

I have to also revise what I said above. For a flat subject such as wafers, it took me 50 exposures at 5um to capture everything. The corners are actually not bad at all. I think it's because of the extreme field curvature causing the objective to perform very unordinaryily. Vignetting is present, extreme compared to MPlans. I would guess this is why the friend of mine said specific correction is required to use this lens for our purposes, can't just slap it onto a 100 or 200mm TL and expect it to perform.

[Macro_Cosmos]

Here's 2 wafer shots:




You can see the distortion in the second image, visible amounts of it! Details are staggering for a 2.5x objective, it's pretty scary actually.
Visible vignetting too. These are uncropped fullframe exposures. The corners aren't good, but the 5x EO objective I use is considerably worse in the corners.

Here's full resolution:
Nikon Z6, 24MP BSI, w/ OLPF

https://live.staticflickr.com/65535/501 ... 5779_o.jpg
https://live.staticflickr.com/65535/501 ... 60f1_o.jpg