A USB digital microscope that I bought from www.dx.com turned up today. I wanted something cheap to inspect soldering and PCBs, and at $30 dollars I didn't have much to lose.
The specs say the sensor is 2.0 Mega Pixels, but I can't get anything above 480x640. Might be a driver issue, but as the included CD was blank and there is no website to download drivers the from, I'm stuck with it. Doesn't worry me, I was fully expecting problems. 480x640 is fine for my purposes.
To focus the scope you manually turn a small black wheel on the side of the case. There is also a button on the camera to take snapshots, which doesn't work. I assume it would work if had the right drivers, but I prefer to trigger the snapshot from the computer. This eliminates any movement of the camera that may blur the picture. The on-off switch controls a ring 8 LEDs around the lens that are used to illuminate the subject.
It comes with a stand that is pretty much useless, which is what I had expected from reviews of similar products.
|Microscope with stand|
There isn't much to say, it does what I want and I'm happy with it. As expected the product isn't great, but it gets me the results I want at a price that I'm happy to pay.
A few sample shots are shown below to get an idea of the results. Using a ruler as a test shot I was able to determine that there are about 100 pixels per mm or 2.5 pixels per mil which agrees with the track sizing on a couple of the PCBs imaged.
It also looks as if the images are a little over exposed. I may have to perform some adjustments there.
|Surface Mount Resistor|
|Australian Five Dollar Note|
|Back of Australian 2 dollar coin|
|Metal Ruler with 0.5 mm Markings|
|Soldermask, Track, and Pads|