Hello everybody,
USB microscopes can be really fun and may even be sufficient for the task at hand but everthing written on the box should be taken with a containership-load of salt.
Here is an article that explains some of the principal constraints
http://www.msscweb.org/public/articl...nification.pdf
My guess the optical magnification of most inexpensive usb-microscopes is in the range of 20x-30x.
Another concern is the Depth of Field which is likely very small. Again, these things are fun might be sufficient for what Gav wants to achieve.
I personally own a Lomo MBS-10 microscope that i use regulary for hobby purposes. The thing is build like a tank and has good optical components. Still I don't get much more out of it than 100x. I wouldn't even dare to compare it to the modern scientific microscopes found at most universities.
@Gav: Don't buy any microscope if you don't plan to use it regulary.
Best Regards,
Thilo