On the imaging front, I built a simple beam splitter to experiment with illumination through the lens. It's a small cardboard box painted black to absorb reflections with a 45° angled half-mirror inside and a hole in one wall.
The half-mirror is a piece of a "mirror" protection foil for smartphone displays. These foils are supposed to make the screen reflective when the LCD is blank but still be transparent enough for normal use. It probably isn't exactly 50% reflective and 50% transmissive, but whatever, good enough for us.
![](https://www.eevblog.com/forum/projects/decapping-and-chip-documentation-howto/?action=dlattach;attach=1046672;image)
The box goes on top of the lens. Light is supplied through the hole in the side, bounces off the mirror downwards, passes through the lens back and forth and passes through the mirror to be observed from above. Half of the entering light passes through the mirror and is dumped on the wall and half of the light from the lens is reflected back towards the illumination source, but 25% efficiency is not the end of the world.
I tried it in combination with my favorite HD webcam lens, a lousy VGA webcam lens and a 10x biological microscope objective. A few sample images follow.
The webcam lenses have enough magnification that one can simply use them as a loupe and look directly into the lens. Magnification is good enough for low density analog ICs and with the HD lens and with some squinting I can even follow the super-die-shrunk Chinese LM358 chips. The first two images show how the two lenses perform on a TI NE5532 die. My camera couldn't capture the full field of view visible with naked eye and the image turned out a bit dark, but it gives a glimpse of the resolution available with the HD lens.
The third image is the same but with the 10x microscope objective. Magnification is very low. This lens could only possibly be usable for photography, i.e. projection onto a camera sensor at a sufficiently far distance, or as part of a compound microscope with an additional eyepiece lens. Go figure
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)