Crazy Lab

It’s a third version of digital microscope I build. The first version used sensor and electronics from old webcam, it was useful for inspecting PCBs but the frame rate (15fps @ vga) was too slow to use it for smd soldering. It was very tricky to aim with the soldering tip, because the tip position on the screen was not the real one due the latency.  The second version used analog monochrome camera module I bought by pollin.de, the response time was acceptable for soldering and  but i figured out that monochrome picture is not very useful for detecting solder bridges and other defects. 

While searching for gifts for christmas I found some good offers for Logitech webcams and decided to buy also one for my microscope. The webcam I used is HD webcam 270 (15EUR in special offers on Logitech germany) and the performance is very good for this price.

What I also used is an old m42 lens, m42 lens cap, bellow  and tripod. The advantage of this setup is the possibility to quick exchange lenses (to achieve different magnification ratios) or to replace the webcam sensor through DSLR. But if you don’t have bellow or different lenses, you could also use two pipes sliding tightly in each other as replacement.

The first step is disassembling the webcam. Pill off the cover, loss some screws, unsolder the grounding cable… nothing special.

The next step is mounting of the camera sensor pcb on the lens cap. I used two long m2 screws (actually too long, but i found nothing suitable in my junk box), spacers and some foam pads for insulation.

And finally assembling everything together:

Time to test the new lab tool :D

The picture quality is good, response time acceptable. One problem is the old lens wich probably has no antireflection coating and the light bounce between lens and sensor, this causes a color cast in the middle of the picture.    But overall performance is very nice.

I can even take a video…

I think, the biggest advantage of this microscope is the big distance between lens and observed object. It allows me to work comfortable underneath it without touching the lens with solder iron. Or to film burning stuff without damaging the microscope ;)