We have all seen these little shitters:
http://www.ebay.com/itm/8-LED-2MP-USB-Digital-Microscope-endoscope-2-0-Mega-Pixels-Magnifier-20X-800X-/310932077469?pt=LH_DefaultDomain_0&hash=item4864fefb9dI recently had one bestowed upon me, much like it, except it was a Celestron microscope and has zoom from 10x-150x. The stand itself was pretty horrid, and the working distances were absolutely awful. I could get slightly farther away, but the stand prohibited that, as well as the loss of a meaningful level of zoom. With this in mind, I first fashioned it a stand out 0.65cm*0.65cm(1/4"x1/4") pine, which is acceptably sturdy. reinforcement may be required. These stands are basically 3 pieces, the stand with a ball bearing, the arm, which is tightened by a screw in the middle, and another ball bearing on the microscope clamp itself. I simply took out the bottom stand and mounted the arm and the clamp on. This now allows for quite good movement. Next comes the lens:
I had a previous set of jewelers loupes:
http://www.ebay.com/itm/4pcs-Universal-Jeweler-Photography-Magnifying-Eye-Loupe-2-5x-5x-7-5x-10x-/121320944015?pt=LH_DefaultDomain_0&hash=item1c3f4ab18fNote that this ha 4 built in LED lights which are inadequate, however, if left in, will cause permanent glare from the sides of the lens. Remove this feature by unscrewing one of the nuts holding in the PCB, which is also the power supply for the LED ring.
With experimentation, I found that the best results were achieved using the 7.5x loupe directly force-fitted into the lip of the microscope, and this now allows for ~8cm of working distance with a good level of zoom. I find this perfectly adequate for SMD soldering, and if needed, the zoom knob can be used to zoom in or out, necessitating focus by adjusting the scope up or down. The primary problem now is that the sensor resolution is not adequate for this task. And yes, I can get 30fps out of the camera into a Microsoft capture program. Not bad for $30.
Photos below. Note that the picture with the screen looks weird because I did not have the light directly shining on it to prevent drastic autoexposure.