Hi guys, got a Bresser in maintenance for a friend. What can I say about it, well, it is better than what I started of myself with. The image is reasonable enough.
Anyway, the condenser struck my as weird. It looks like a normal Abbe (toplens marked 1.25). But it does NOT have the lower field lens and consequently does not deliver an NA higher than, say 0.45 or so. Which is fine for this thingy, no fiddling with the iris, always leave it open. But it diminishes the amount of light as well.
Is this simply a compromise, or is it possible that the lower lens fell out?
Thanks,
René
Hi René,
Which microscope is it, a picture would be nice. Anyway, I have never seen a case like this. Simpler microscopes often have a single lens build into the stage. I have also seen student microscopes with a fixed condensor containing only the bigger lower lens (eg Olympus HSA, some older Euromex models). But only a toplens marked with 1.25?? Looks like a failure. But then again, with those chinese microscopes, anything is possible............Best regards,
Rolf
This one, Rolf: http://www.bresser-online.nl/Webwinkel-Product-4993072/Bresser-Microscoop-Trino-Researcher-40x-1000x.html
It looks better than it actually is. Stage is ok, but focus is too coarse, lighting shows visually a hotspot at 40x and is barely intens enough at 400x. Objectives and oculars are pretty much ok. But the whole thing does not match up against e.g. a Lomo. But it does the job, so let's see how I can improve it.
Best wishes,
René
Hi René,
The illumination in a microscope is often a weak link and not only with no-name scopes. For instance, the 5 W (the "Taschenlampebirne") illumination of the Zeiss KF2 is a laugh and here also you don't have enough light with a 40x objective (especially with the 1.25x tube-factor). My KF2 ICS has halogen but the field of view was very unevenly illuminated. I had to optimise this by sticking frosted transparent paper underneath the condenser. I have been trying the Euromex BioBlue microscope in a shop a few times and it doesn' t have these problems, it gave a very nice homogenous and bright illumination. As far as chinese models are concerned, the Euromex is probably in a different league then the Bresser and it cost about the same. Best regards,
Rolf