I need help. Again... : )

[Simone]

Hi, I have this science assignment on standard microscopes, and I needed to know if any of you would know where I could find out which lenses and mirrors were used in a standard microscope. Also their exact functions and uses in the microscope? Does anyone know of a link, or links? Because I tried google, but I wasn't quite too sure what to type in the search engine, so I just wrote "types of lenses used in microscopes" and "types of mirrors used in microscopes" but I didn't really find anything. When I say lenses, and mirrors, I mean "convex" and "concave", or say, "biconvex" and "biconcave".


Thanks for your patience once again : )

[SteveS]

Hi Simone, I've got a really old, cheap telescope that I've dabbled around with.  It made me look into telescopes a while back, what's good, what's bad, etc.  So, from that perspective, I think you might have better luck searching for "microscope optics".  I did a quick search, one of the top links seems to be a decent overview of microscope lenses and how they function:

http://web.uvic.ca/ail/techniques/scope_basics.html

Hope this helps.....

[Simone]

Thanks so much! This answered every single one of my questions, I wasn't quite understanding the whole light path thing either and this cleared everything up,thank you so much!!!!!!!! I was ripping my head apart, because my friend was trying to explain all this stuff to me over msn (which did not work out).

[SteveS]

No sweat  :wink:

[Simone]

Although... I just hit a stop, how am I to know if one's a mirror, lens, biconvex  or biconcave? Because only two said lenses, which I thought was odd, because are there not many, many lenses and mirrors? Because not one said mirror, so then I got really confused. Heh, and um, which would be lenses, and which would be mirrors? Help again please?

[McQ]

Although... I just hit a stop, how am I to know if one's a mirror, lens, biconvex  or biconcave? Because only two said lenses, which I thought was odd, because are there not many, many lenses and mirrors? Because not one said mirror, so then I got really confused. Heh, and um, which would be lenses, and which would be mirrors? Help again please?

See if this: http://www.opticsforkids.org/resources/ ... Lenses.pdf

helps at all with your question. It might clear up a few things.

[Simone]

The link didn't quite work for me. It turned into a word file with some encoded stuff... Thanks though.

[Simone]

SteveS, um, so, if it doesn't say lens, and it doesn't say mirror either, do I just take it as a mirror? Seeing that some other parts say lens? Or better yet, does anyone know the exact amount of mirrors and lenses in a standard microscope? Does that make my question a bit less confusing?

[SteveS]

Hmm, I found the link and it looked good, but I didn't actually go through and try to analyze it myself.  Let me look it over....my telescope only has lenses because it's a refractor, although many have mirrors - named (appropriately) reflectors.

Okay - looking at it, the only place I can see that a mirror would be is in the base, just redirecting the light bulb's illumination from horizontal to vertical (pointing it to shine up at the specimen).  Everything else appears to either be a lense or a prism (the prism is bending the light into the eye tube).  At least, that's my take on it.

Again, hope this helps.....

[Simone]

but many of them seem to be bending, so would they all be prisms?  Sorry, I'm lost... Which parts would be the prisms or lenses? Because I need to be clear...  Sorry for bothering you so much...

Wait, wait, wait... which picture are you talking about exactly? The two long ones? Because I am... Or are you talking about the one directly bellow it?

[McQ]

but many of them seem to be bending, so would they all be prisms?  Sorry, I'm lost... Which parts would be the prisms or lenses? Because I need to be clear...  Sorry for bothering you so much...

Wait, wait, wait... which picture are you talking about exactly? The two long ones? Because I am... Or are you talking about the one directly bellow it?

Steve is right. However, Simone, many microscopes are different. Do you have a specific one you need to label, or are you doing an "in general" type of thing on microscopes?

The only mirror in the scope is at the bottom, as Steve described. The lenses also redirect light, so it appears to you in the picture that it is bending.

http://web.uvic.ca/ail/techniques/zeiss_wl.jpg

I just looked a my microscope and it is set up the same (generally) as the one in the diagram, except mine is a stereo microscope.

Again, hope this helps.

[SteveS]

Yes - the lenses will bend the light.  I think there is only one prism, which is the one that redirects the light into the eye tube.

I'm looking mostly at the picture that looks like a microscope (edit: The one McQ put a link to, a larger version).  It appears to me that in the light-path diagrams neither the mirror nor the prism is displayed --- I don't think they provide any imaging function (although in practice they could probably contribute to aberrations), so I'm thinking they aren't really a part of the imaging optics.  More functional to the design of the scope (so you don't have some ridiculously long tube you're trying to look down without impaling your eye - ouch).

Before going futher, let me point out I feel a little uncomfortable trying to speak authoritatively on optics - I took one class in optics, and that was like 15 years ago in college (damn, getting old!).  But, if I'm remembering right, the lenses will behave as:

1) Convex (or biconvex) will converge straight light entering it.

2) Concave (of biconcave) will diverge straight light entering it.

Actually, here's something better, I found a wiki article that is helpful.  In particular, if you scroll down to the "Imaging properties" section, you will see a drawing reminiscent of the one in the microscope article, which appears to be "bending" the light.  I think this is what the microscope article had in mind.  Here's the wiki link:

Argh, it's got a parenthesis in the name so it doesn't want to render in the url tag ... just copy and paste this whole string (not just the blue part) into your browser:

http://en.wikipedia.org/wiki/Lens_(optics)

McQ - you've got a stereo microscope?  That sounds like serious equipment....must be a fun toy?

[Simone]

but many of them seem to be bending, so would they all be prisms?  Sorry, I'm lost... Which parts would be the prisms or lenses? Because I need to be clear...  Sorry for bothering you so much...

Wait, wait, wait... which picture are you talking about exactly? The two long ones? Because I am... Or are you talking about the one directly bellow it?

Steve is right. However, Simone, many microscopes are different. Do you have a specific one you need to label, or are you doing an "in general" type of thing on microscopes?

The only mirror in the scope is at the bottom, as Steve described. The lenses also redirect light, so it appears to you in the picture that it is bending.

http://web.uvic.ca/ail/techniques/zeiss_wl.jpg

I just looked a my microscope and it is set up the same (generally) as the one in the diagram, except mine is a stereo microscope.

Again, hope this helps.

Well that's where I was questioning myself, because my teacher wasn't all that clear, and I hadn't much time to clarify it with her, seeing that I'm away at the moment (not in town) I was absent for her last class, and now it's due for the next. All she wrote was "microscope" so i just assumed a standard, simple, "microscope optique".

[Simone]

Actually, I just found this link, http://sps.k12.ar.us/massengale/images/microscope2.gif

but if you look in the tube, (between the four Lenses) there's a spot where, the light's rays become skinny, and then scatter, at that little say, "meeting point" is there anything there creating that "meeting point"? Or are those both mirrors, reflecting separate light rays towards each other?

[SteveS]

Ah - now this I think I can help with.  The "meeting point" is just the affect of the lenses.  The bottom lens, before the "meeting point", was a converging lens.  So, the light converges at the focal point, then diverges again after the focal point.  The next lens begans re-converging the light toward the eye-piece.  There is no additional optic at the "meeting point".

Edit: For additional clarity, the meeting point is the focal point of the last lens this light has gone through, that's all.