Microscope for entomology

derekmc · #1 (**permalink**) 02-09-2009, 08:01 AM

Morning everyone -

Just a very quick question, but I've been thinking for some time about buying a microscope to help with identification of smaller arthropods (including water beetles) and general study of their anatomy. I've seen a non-zoom model that I'm quite taken with, but it comes in two models - 15x/30x and 20x/40x.

This isn't a field I know too much about, and I'm not sure which one would be most appropriate for entomological use. The higher powered one is tempting, but it might be too specialised for the sort of use I have in mind. I might find it focuses on too small an area, or have too little depth of field, to be of much use.

I'm sure some of you must have more experience with using microscopes. Any thoughts on this? Or would I be better paying the extra and going for a zoom microscope?

Unfortunately I don't think I'll have a opportunity to visit the Amateur Entomologists Open Day at Kempton Park to allow me to try the microscopes in person.

Thanks for the help.
Derek

Phil Whiley · #2 (**permalink**) 02-09-2009, 08:38 AM

Hi Derek.
This depends on how much you think you will use it and how much you are willing to spend - it can become an expensive hobby

I use a few different microscopes, mostly old ones (collecting antique scientific instruments is one of my hobbies). For this work I would say go for the lower power. If your budget permits, I would go for a binocular microscope preferably with built-in illumination and separate lenses on a rotating turret, which would let you start with a couple of lenses (say 5x and 10x) and add better or higher power lenses later (remember the eyepieces also magnify the image - 10x eyepeices are fairly standard). Try Brunel microscopes, they have quite a good selection, including thier own brand models which are quite good; they also occasionally have ex-display/second hand models, and sometimes also sell second-hand lenses and eyepeices. They also offer good advice.
Regards
Phil

JonSadler · #3 (**permalink**) 02-09-2009, 09:05 AM

To follow up on Phil's comments. You get what you pay for in optics and a decent microscope will cost a good few hundred (similar to fast glass for the photographers!). To look at smaller finer structures (punctuation and microsculpture) on beetles or other small insects you'll need up to around x40 . Zoom scopes are excellent because they are very flexible but they cost more (especially if you want good optics). I'd go for 2-3 objectives at various magnifications - it will be cheaper. Don't buy without trying, unless you are sure you can return the scope for a full refund.

The other thing you'll need is a good light source. A cold source is best. It will need to be quite intense and if it allows you to vary the direction of light that will help also.

Some of the natural history stores that emphasise moths are likely to be a good starting point for looking for models, as Lepidopterists frequently need to look at genitalia to identify micro moths (and some macros). I have seen and used a lot of microscopes as part of my work and it pays to get the best you can afford. Bad optics make identifications much more difficult. At the cheaper end the suppliers frequently advertising in British Wildlife sell good microscopes. I cannot remember their name and guess I shouldn't list on the forum anyway.

Regards
Jon

derekmc · #4 (**permalink**) 04-09-2009, 08:23 AM

Thanks for the help, guys. It's been greatly appreciated!

I take your point about the lower magnification. It's something that hadn't occured to me, but it makes a lot of sense. As you say, I can increase the magnification of an existing microscope with supplementary eyepieces, but I can't do anything about reducing the power of a non-zoom microscope if the image only shows a tiny fragment of the specimen, or have too little depth of field to be of any practical use.

Funnily enough, Phil, the one I was looking at is from Brunel Microscopes (the company you recommend). It's one of their BMX range - they do two models for the same price with twin objectives in a rotating turret (BMX3 is 15x/30x, and BMX4 is 20x/40x). Lighting is an important issue, but this range seems to be pretty well equipped in that regard. It was just a question of my getting the right magnification. Your comments have persuaded me that the BMX3 is the way to go.

I'd have preferred to try the 'scope beforehand, as you recommend Jon. As I mentioned in the original post, that doesn't seem possible, but your point is a valid one. I've checked with the supplier and Brunel Microscopes will offer a full refund provided I return it in 14 days.

I think we can consider this one closed. Thanks again. Hope I can return the favour sometime!

Derek