MicrobeHunter.com Microscopy Forum

Hi,

Sorry if this is the wrong place to post, I did a bit of googling and I've looked at the manual I can find but I'm still lost.

I got a second hand microscope and the images seemed poor with the 40x objective. When I took it apart I found that part of the casing is damaged, big tool marks on the threaded ring and the inner side of the inner lens was dirty.

An example dodgy image (no plate): It is the splash of light upper right I'd like to get rid of but I've no idea where it is coming from. The "worm" more centre picture seems to be with all the objectives. It is a brand new CCD.

Given how heavy handed the original owner was taking it apart I don't really trust the order it was put back together. The parts are: in the order they came out (with lens downwards in all three cases). Anyone know it that is correct?

I'm a bit lost, any help appreciated.

Regards

Sam

If it's the old Amici lens design it would be difficult to tell which doublet goes in first just by looking at them. Might try both ways. In all cases the meniscus lens faces the sample.

Thanks Bram,

Is it safe to assume that they should go in lens first?

I double checked and the filth is on the larger lens inside the "cup".

Cheers

Sam

Since you actually found some schmutz on a lens and have cleaned it, why don't you try putting them back in the original configuration and see how that goes.

I'm very new at this so still googling how to clean these things. I saw something early on about dirt being hard enough to scratch lenses so needing to use a lot of fluid and let it air dry. Our water here is very hard so was going to get some distilled water.

I'm still puzzled how a bit of filth would make a big bright spot like that. I wondered if it was the broken holder but I can't seems a stretch for the light to creep in like that.

Thanks for your help, much appreciated.

I like two parts distilled water one part rubbing alcohol (70%) and a few drops of clear dish soap as my go to lens cleaner. It cuts the grease well, won't melt lens cement, and is handy.

Bright spots might be caused by reflecting light internal to the objective if the inflitrated oil or whatever is interfering with the AR coating. Who knows!

I wouldn't let it air dry. You want to sop the fluid up ir it will redeposit stiff rjght back on the surface.

Thanks Scaro,

I'm practising with cleaning slides, I'm surprised that using tissue to dry them doesn't seem to leave stuff behind.

Still very puzzled by the light coming in. Rotating the 40x doesn't seem to move the light so it is not the lens?