MicrobeHunter.com Microscopy Forum

Hi.

I’m so sorry for this weird topic
It’s here for a short time, I just want to find some help on here

After I watched with immersion oil I cleaned an objective with simple paper. 100x and 40 x too because it caught a little bit of it too.

Now, it looks like this. Is is scratched, what do you think?
And if yes, how much could it cost to repair it?

Hi

Hard to tell. Some of the mark looks like a partial fingerprint so it seems likely it's just dirt. What objective is it exactly?
You should only use proper lens tissue for removing oil. Also you should only wipe the metal part of the lens - not the lens glass itself. To remove oil from the glass part just use a corner of the lens paper to 'wick' the oil from the glass. Assuming the mark is removeable, use some lens tissue dipped in isopropanol to gently wipe the surface. Hopefully, that will remove the marks.

Louise

Hi,
I'm fairly sure that these are no scratches. My guess is that you have old gummed up immersion oil on the lens, it got sticky from cleaning but wasn't removed and a bit of paper tissue got stuck.
Do you have a loupe or stereo microscope to inspect the front lenses?

Bob

It that a cell phone photo taken through an eyepiece? Stuff on the objective is usually way out of focus. Could this be dirt on the condenser top lens you are focusing on?

hans wrote: ↑

Wed Apr 07, 2021 6:51 pm

It that a cell phone photo taken through an eyepiece? Stuff on the objective is usually way out of focus. Could this be dirt on the condenser top lens you are focusing on?

Yeah - that seems likely!
Louise

No.. after I turned it to 4x and to 20x it was gone..

Things in the ocular path may well not be seen at lower magnification but will be seen at 40 or 100x.
Loosen the objective so you can rotate it. Focus the objective and rotate the objective. If the smudge doesn't move the problem is not the objective.