MicrobeHunter.com Microscopy Forum

I'm curious if anybody can comment on the photo-optical benefits of high end coverslips vs lower cost coverslips. I'm looking to order the more expensive #1.5 Schot coverslips listed as .16 to .19 mm thickness, but not sure if my camera will see an improvement. I understand that the DPlan objectives on my Oly scope have the .17 rating and that for pondwater applications, I should wick out the excess water so the subject is as close to the underside of the glass as possible when using the .17 higher end coverslips. I have no qualms with my $.06 glass, just wondering if I would see an improvement with the $.24 variety. Is the cost difference only due to manufacturing consistency?

Thanks in advance.

Bschnitzer wrote: ↑

Mon Oct 23, 2023 6:56 pm

I'm curious if anybody can comment on the photo-optical benefits of high end coverslips vs lower cost coverslips. I'm looking to order the more expensive #1.5 Schot coverslips listed as .16 to .19 mm thickness, but not sure if my camera will see an improvement. I understand that the DPlan objectives on my Oly scope have the .17 rating and that for pondwater applications, I should wick out the excess water so the subject is as close to the underside of the glass as possible when using the .17 higher end coverslips. I have no qualms with my $.06 glass, just wondering if I would see an improvement with the $.24 variety. Is the cost difference only due to manufacturing consistency?

Thanks in advance.

Probably due to difference in quality control. Cheap coverslips are often stained white or fogged, look ugly, and can be restored (not always) only by labor-intensive cleaning. High quality coverslips can be cleaned and reused (depending on the mounting medium). 24 cents are reasonable for a really transparent slip, in addition to the thickness issue.

At above NA 0.65, you may see difference.

If you use thick water mounts, try to use thinner cover slips towards the 0.15mm end to reduce spherical aberration introduced by thick water mounts.

If your mount is perfect (with subject immediately under cover slip without minimal water / mountant / air gap in between), then 0.17mm cover slips are ideal.

If your mountant is slightly too thick, then overall thinner cover slips would produce better images at high NA.

Edit: I did an experiment previously and measured how thick a good water mount would be. I squeezed out most water under cover slip, before I felt it was too thin (so thin that a live protist would be crushed); I got a depth of about 0.02mm; so 0.15mm cover slip would work well for water mounts.

Charles Krebs uses a micrometer to measure his cover slips and select them based on his applications. He also uses thinner covers for water mounts.

For live protists, if you want to see natural behavior, you are actually better off to use a thicker water mount and sacrifice some image quality. If your protists are pressed to a death choke, you may get a decent and stiff “corporate portrait”, but not an interesting (hunter vs prey) story, you know.

0,06$ means a pack of 100 is already at 6$. This is a not cheap for basic coverslips. Maybe you can find a different supplier with better prices and selection.
Zeiss offers square cover slips of tight tolerance with a thickness of 0,17 +/- 0,005mm. As mentioned above these will only improve image quality for objects that are eally close to the lower surface of the cover slip.
With oil immersion a thin coverslip plus the right layer of oil gives about the same result as a perfect cover slip with a little less oil layer.
I once bought chinese cover slips that were up to 0,25mm thick which is really too much.