MicrobeHunter.com Microscopy Forum

Several posts have mentioned the critical nature of cover glass thickness. I have a box of 22x40mm labeled as "#1", so I measured a few to see how close they are to the recommended 0.17 inch thickness and got 0.06" on several. Can that be right? I compared to an automotive feeler gauge to be sure I was reading the micrometer correctly.

0.17mm = about 0.0067 inch.

Hmm the .17 on the objective is the size in mm. If you have something different on the objective then that is the size of cover glass you should use.

Sounds like a wrong reading to me, too thin even for a #0 coverslip let alone a #1. The oft-quoted 0.17 seen on objectives is the 'ideal thickness' of coverslips if thickness numer #1.5.

Here are the numbers,

The specification on the objective is for a cover glass being used over a very thin sample or smear. In reality the specification is a cumulative measure of the sample plus cover glass.

apochronaut wrote: ↑

Sun Sep 12, 2021 7:34 pm

The specification on the objective is for a cover glass being used over a very thin sample or smear. In reality the specification is a cumulative measure of the sample plus cover glass.

Yes: that is why I often use a # 1 (or #0) coverslide when watching pond samples: there is usually some ditritus material in the sample so it has some “thickness” on its own.

Brainless here. Must have posted that on a day when I thought "0.17" was inches and not mm. My apologies. Thanks for all the responses that cleared that up!