Thread subject: :: Magnification

Posted by JariF on 23-01-2011 10:44


I use Konus Crystal-45 microscope for diptera and it works fine with specimens and larger genitalia. With 10x ocular I can get 45x magnification and now it seems to be too weak for genitalia of smaller flies. I'm thinking of buying new 20x oculars but will they be strong enough to study genitalis of Pipunculidae or Agromyzidae ? I do have a regular microscope with magnification from 100x upwards but as it's not "stereo" it's not practice to handle. Any tips will be wellcome.


Posted by ChrisR on 23-01-2011 11:58

I'm not really sure about the exact type/quality of that microscope but what you can see clearly depends a lot on the quality of the glass AND the power of the lights you are using. A powerful lighting system can make things a lot easier but a poor/weak light will make a good microscope perform badly :)

Posted by JariF on 23-01-2011 12:34

The microscope is good quality and lights are ok. The problem is the magnification. I don't know how strong it must be to see clearly all the deatails of Pipunculidae genitalia for example.

Posted by JariF on 24-01-2011 06:04

So no-one is using microscope for preparation :|

Posted by Nosferatumyia on 24-01-2011 10:41

I am using a compound microscope to take pictures of genitalia in tephritoid flies, which are a little larger than in Agromyzidae. In general, resolution of what you see, depends on the objective magnification, NOT eyepiece. I usually take pictures with x10 or x20 lens and x8 eyepiece. The lamp I am using is 1A halogene, which is enough to have 1/15 sec exposition at camera (which is the longest to avoid blur of trembling). The camera is a soapbox Nikon 50. This is the minimum self-made kit, which works for further combine of stack photos. When taking pix of the Agro phalli, it could be necessary to use X40 lens, and in this case the light beam is critical, indeed.

Posted by Christian Kehlmaier on 03-02-2011 10:24

JariF wrote:
The microscope is good quality and lights are ok. The problem is the magnification. I don't know how strong it must be to see clearly all the deatails of Pipunculidae genitalia for example.

Hi Jari,

It depends a bit on the genus you are looking at, but for Tomosvaryella or Chalarus a magnification of 80 or higher is recommendable.


Posted by JariF on 03-02-2011 17:16

Ok, I will buy new set of 20x oculars and will rise the highest magnification from 45x to 90x

Thank You


Posted by pjoris on 03-02-2011 17:49

I use sometimes 20x oculars (instead of the standard 10x oculars with a Euromex stereomicroscope) for smaller diptera/coleoptera, but as said: they don't increase resolution. I also have a 1.5x barlow lens (which you screw under the objective lenses), this seems to be a bit better/sharper than using 20x oculars. I don't know if your microscope takes barlow lenses ? Barlow lenses do reduce working distance however (in contrast to higher powered oculars).

To see small detail, I switch to my compound microscope (Nikon SE), with the same lighting as the stereomicroscope. This resolves much more detail (even at low magnifications, 40x - 100x), but depth of field is lower and you can't use it for preparation (unless you can think in mirror images). Good for photography using stacks as I noticed recently.


Edited by pjoris on 03-02-2011 18:00

Posted by zcuc on 12-05-2011 08:25

You must remember that the same magnification in compound microscope vs stereo is not the same since the focal distance is different i.e. With 40x magnification in stereo the focal distance it lets say 10cm but 40x in compound has a focal distance of lets say 1cm so the image at your eye will be much larger and detailed. I don't think there is a replacement for compound when looking at very small objects.
Also from my experience if the current magnification of the stereo microscope is not enough it'll probably will be a little better after another x2 but still too small.