Almost fifteen years ago, I wrote an article about using an Intel QX3 microscope to take close-up pictures of a home etched printed circuit board (PCB). As I recently prepared to ship the QX3 away as part of The Great Internet Migratory Box Of Electronics Junk (TGIMBOEJ), I decided to see if a modern camera with a macro lens could outperform the toy microscope.
I paid $40 for the microscope at the time, and it is going to be pitted against $2000 worth of new technology (Panasonic GH4 with Leica 45mm macro lens). The microscope sensor has fewer than 0.1 megapixels (320x240). Yes, that’s right: one-tenth of a megapixel. In comparison, the Panasonic GH4 has 16 megapixels (4608x3456). So, the real question is whether the magnification of the optical lens in the microscope can be equaled.
The photographic target is an old crusty 3.4 cm wide x 4 cm tall circuit board that I etched at home. The surface is copper only, without a tin coating, silkscreen, or a solder mask. The photo below should be about life size on most desktop monitors. The point is: the target is small.
Old home etched PCB with a penny
Below, the Panasonic camera is zooming in on 7 mm wide area of text, along with a poorly drilled 30 thou hole in upper right. The thickness of the font line is 8 thou (0.2 mm). This is a great photograph for such a small area.
40kHz on home etched PCB
Now let’s see an old photo from the Intel microscope at 60x magnification. The color of the board looks different than real life -- but the shape of the damaged 'k' reassures us that we have the same target. The coloring difference is due to lighting, white balance, and possibly board aging.
QX3 partial k etch
Here’s the Panasonic with Leica 45 mm macro lens at the same crop. Notice the color, clarity, and magnification are better than the microscope.
PCB close up Leica 45mm
The Intel microscope goes to 200x magnification to inspect the crack in the letter 'H'.
QX3 broken H
The Leica lens on the Panasonic body has run out of magnification, although the details in its previous picture rival the 200x magnification in the microscope. Still, we can do better. I’ve switched to a Yasuhara 5x lens to take the following image of the broken H.
Broken H Yasuhara
Sliding over to the 'k', it’s impressive how the Panasonic GH4 with Yasuhara Nanoha x5 lens can resolve details smaller than 10 micrometers.
Closeup of cutoff k
Here is that poorly drilled hole.
Badly drilled PCB hole
And here are the fibers in the PCB substrate.
The verdict is in: Yes, a modern camera with a macro lens can outperform a fifteen year old toy microscope. If you’re interested in the setup and some technical details, turn the page.