In another thread, someone was asking for recommendations for illuminated magnifiers. Back in January I decided to buy a whole bunch of inexpensive illuminated and nonilluminated magnifiers, in hopes of finding the right combination of (1) magnification strength, and (2) sufficient illumination to take to shows (venue lighting is usually horrific for close examination).
Here are the ones I tested:
http://www.amazon.com/gp/product/B0..._o04_s00_i01
Cost: $9.94
Magnification: 4x
This one is probably my runner up. Very even lighting, large field of vision (about 2.5 inches in diameter). Larger than the others. Not quite enough magnification for my needs.
http://www.amazon.com/gp/product/B0..._o05_s00_i00
Cost: $24.95 + $7.95 S&H
Magnification: 5x
Large 3-inch lens. The design works well, however (1) the illumination is not as bright as it needs to be, (2) it's quite bulky, and (3) it uses a CR2032 watch battery, which might be tough to locate depending on where you are.
http://www.amazon.com/gp/product/B0..._o00_s00_i00http://www.amazon.com/gp/product/B0..._o01_s00_i00

Cost: $6.44 and $6.95
Magnification: 10x and 15x
I lump these two together as they were a complete and utter waste of time and money. The chromatic aberration and distortion is so bad as to be unusable. Avoid like the plague!
http://www.amazon.com/Ultra-Optix-D...p/B001QKHEI4
Cost: $14.94 + $6.95 S&H
Magnification: 4x
(Check your local Hobby Lobby. It will be cheaper). This one, despite it being nonilluminated, is actually VERY cool! The "light gathering" constructon actually does pull in a fair amount of ambient lighting. I find myself using this at home more than I expected, as I can control the lighting conditions. Probably not a good choice for your only magnifier on the road.
http://www.amazon.com/gp/product/B0..._o04_s00_i00
Cost: $10.06
Magnification: 12x claimed, 8x actual
Winner! Even though the magnification isn't quite what it is claimed to be, it works very well. There is a bit of distortion at the perimeter, but since it is a 1.25-inch lens, it still provides more useful view area than most loupes. The two LEDs are quite powerful. It is also quite comfortable in the hand, and fairly compact at about 4 inches in length. This has become my go-to magnifier both at home and on the road.
For close-up work, I use the following:
http://www.dealextreme.com/p/30x-21...52279?item=1

Cost: $4 shipped
Magnification: 30x/60x claimed, approx. 15x/30x actual.
GREAT little device!! I've been reselling these locally and everyone who I show it to loves it. It's compact, opening it automatically turns the light on and closing it automatically turns it off. The larger 30x (15x actual) lens is 0.75 inches in diameter, and the smaller 60x (30x actual) is about 0.375 inches in diameter.
It has both a white LED and a UV LED. Has a carrying strap built in.
Too high magnification and small of a lens to use for regular examination, but for checking varieties, silk papers, flyspecking, etc., it is WONDERFUL. I use the hell out of it, and if I beat it to heck or lose it, hell it was only $4 shipped! Because the lead time on shipping from China is several weeks, I usually order several at a time and keep one in reserve just in case.
The watch batteries (it takes 3, one set included and installed) are dirt cheap on
ebay.
Seriously, I cannot recommend this one enough.