Thank you, Thomas! Lothar sent me some circular coverslips and Musou Black. "Gluing" the coverslip resulted a tad tricky, but after several attempts I got it done. Here is the first result with the Nikon Plan Apo 20 and 153mm tube lens at about 15X on sensor. Yoma sabina scales: https://images2.imgb...

Great work as usual.

Beautiful flower and excellent result. Maybe a tad oversharpened (looking at the crops), but detail is great nevertless.

Interesting subject as usual. Well done!

Very nice work!

As I understand it... High NA objectives are optimised for a certain coverslip thickness AND for focussing at a certain distance behind it - usually zero. On a scope, as you focus deeper into the mount and further from the underside of the coverslip, spherical aberration kicks in (haze and loss of ...

Betty,

yes, I'm aware the coverslip I'm using is not the best/optimal quality and that might be affecting the result.

I had (have) Thorlabs 1.5H coverslips (170 ± 5 µm), but I'm unable to find 'em.

I guess I'll have to buy some quality coverslips and re-test the objective.

- Macrero

It's pretty much the same in all of Europe. Then the courier asks for another 6-18€ for delivery because it was such a burden to automatically calculate your taxes and import duties during shipping... (especially when they didn't calculate the correct value to begin with and you had to send them al...

have you tried to blacken the edge of the coverslip? Otherwise I think the coverslip collects al the light from your flat illumination and causes the haze. No, I haven't tried that. Will try it later today and will report back if that solves the issue. Edit: blackenning the coverslip's periphery di...

Thanks for the clarification, Hristo! Have you ever used such an "unbranded" 1501-9398 20x Nikon with good results? Or if not, do you expect they could give good results by your refocussing method? I ask since they are cheaper than the branded ones... after all we disadvantaged Europeans have to pa...

Excellent Thank you! Awesome details and very nice lighting! Was "the weird Nikon" used here one of those Nikons from a gene sequencer, designed to be used with the thicker glass of a flow cell, just labelled with a number like 1501-9398? --Betty Thank you, Betty! No, it's the "branded" one, correc...

Sorry, I got lost. What is the objective you tested? Nikon Plan Apo 20/0.75. The one pictured above. Btw, I just realized the piece of coverslip has a small crack, so maybe that's the reason for the low contrast and haze :-k I'll change it, but I'll leave it for tomorrow, it's been a long day. Edit...

Ok, I'll let bygones be bygones, so back on topic: today I got the coverslips a friend sent me, since I was unable to find mine. Glued a small piece on front and did a quick test with 105mm tube lens on MFT sensor. Curiosly, with the coverslip I get much lower contrast and kind of haze :? However, r...

Lothar, I don't want to be annoying, but I'll make another attempt to make it clear: Afaik, it was assumed that a high-NA, coverslip-corrected objetives are simply inusable with no-coverslip. This thread shows that you can use use such objective with no coverslip getting more than aceceptable (to sa...

So my debunking thread got debunked? :| I'm afraid yes Well, I don't think so. Of coarse, it's always better to use the objective as intended (with coverslip in this case), but the point is that you can use a high-NA, coverslip-corrected objective with no coverslip with more than good result , outr...