I was recently gifted a barely-used microscope that came with everything but the instruction manual.
I was hoping someone could answer some very basic questions, to help me get the most out of what I have.
1. One of the objective lenses (pictured below) has a retractable spring-loaded tip, and the stage can raise far enough to touch it. I thought maybe this meant it was an emersion lens, but from what I found online it should say either “oil” or “water” on it if that were the case. Is it emersion capable anyway? Or just meant to directly touch a (dry) slide cover? Or retractable for some other reason? (I don’t want to ruin it by trying something it’s not meant for.)
2. The eye piece on the left has additional markings down the side that look like measurements (pictured below) and I have no idea why. Can anyone explain?
3. More generally, do certain eyepieces pair best with certain objective lenses, or is it just about mixing and matching to find the right magnification?
4. Finally, it has a light above and a light below. Am I correct in thinking that the light below is only for translucent things like very thin slices of plant material, and for everything else, use the light above?
1 No, the objective should not be immersed and should not deliberately be brought to touch the slide cover. It is spring-loaded so that you don’t accidentally break the lens by ramming it into a slide e.g. while trying to observe something that is too thick for its working distance. The other objectives are not spring-loaded because they have a much larger working distance, so there will be plenty of air between them and the slide to avoid such accidents.
3 Probably not with a basic scope I would imagine. Btw note that with the numerical aperture of your objectives using the 25x ocular compared to the 10x will not get you very much useful extra resolution at all, at the expense of a much narrower field of view.
4 The light below is for translucent things, but you will probably want to mostly use that one and prepare things as slides. A lot of things are translucent if squashed or cut thinly enough. Transmitted light can be focused so you can get much more light coming into the objective which you need to be able to see things at high magnifications.
I’d look really carefully for any text/numbers anywhere on the scope (possibly small print). It seems a bit unusual to have a microscope without any identifying information on it, but I may just be used to using scopes from a couple of companies that do this. Even without a logo, any other information can be informative. For example, googling “40/0.65 160/0.17 objective” gives you more general information about this even without knowing what company it’s from. Doing this confirms that it’s a dry objective. You may be able to find a serial or catalog number elsewhere on the scope. I’d post/search any alphanumeric information hidden anywhere on the microscope. A picture showing more of the scope may also help to identify it.
One more general piece of advice that addresses your first question is that the objective should never directly touch the coverslip, regardless of whether or not it is an immersion objective (these are designed to have the objective touch a drop of water/oil on top of the coverslip, but not to touch the actual coverslip). The easiest way to damage/ruin an objective is to be looking through the eyepiece trying to focus and not paying attention to the distance between the objective and the coverslip. If you zoom “too far” and your plane of focus has already passed through the sample, but you keep focusing deeper trying to find it, the objective will hit the coverslip. The spring helps cushion this to prevent it from breaking, but it may still scratch it. If the objective lens presses the coverslip and you move the slide/stage without noticing, you will be scraping your objective lens along the surface of the glass coverslip.
Thanks to your suggestion on googling parts separately, I just found out the weird looking “eye piece” is not an eye piece, but a Barlow lens that goes beneath an eye piece for additional magnification. That explains why I couldn’t see anything looking through it alone!
And I appreciate the additional warning to be careful about not touching the objective to a slide.
I agree it’s weird there are no markings anywhere on the body of the scope, but have gone over it three times now. Maybe that’s something only name brands do. This is probably from some obscure Amazon-only brand no one has heard of, but I’m actually surprised how clear and focused it can get.
I think my questions have been answered now, thanks everyone :)
