DIY Desktop Video Microscope

After seeing some of the amazing electronics repair work that people do on YouTube, I have been wanting to get a digital microscope. Trying to get by with these headset magnifiers is just not making the cut anymore. I will be using a computer (iMac 27") as my display, utilizing a standard webcam application. I have plenty of parts laying around to make one, so lets see how it goes!

All of these items I had on hand, mostly leftovers from other projects, nothing was purchased for this project.

1. Chemistry stand (base and pole)
2. 35mm Belows
3. SLR Camera Lens (50mm)
4. 1080p USB Webcam
5. DC PWM controller (12v)
6. 30" LED 12v strip lighting
7. 3 x SPST switches (or Binary Output Dial Push Wheel Switch)
8. Misc wires
9. Female DC power connector
10. 3D filament
11. thumbscrew (1/4-20 tri-wing)

Tools

1. 3D printer
2. 3D modeling software
3. Soldering tools (iron, flux, solder)
4. Screwdrivers

Parts to 3D print

1. Webcam holder
2. Webcam holder cap
3. Threaded lens mount
4. SLR lens mount Ring Light
5. Belows mount glide
6. Belows mount clamp
7. Ring Light controller box (2 pieces)

I have a cheap solder reflow box and I picked up an Aixum T3A micro soldering station from eBay for $80. But throwing in another few hundred dollars for a bi/tri-nocular is not in my budget. Being the DIY'er that I am, I thought about this for a while and fell back on some photography knowledge : the Reverse Macro lens. I have used these in photography as well as a set of belows for adjusting field of focus and macro photography. I have a few lo-res webcams for telescopes (no lenses attached) and thought I would try it with an old lens.

I 3D printed a lens cap style cone to attach the telescope webcam and the 50mm together, and to keep the extra light out. Not bad... but contrast was very poor. So I dug around and found a higher resolution webcam (1080p) with an attached lens.

While the 1080p camera does have an adjustable lens, it just does not get close enough. When adjusted correctly for focus, it is about an inch away from the keyboard, so no room to actually work on anything as well as a limited amount of zoom.

But using the 1080p with my reverse lens, I get much better contrast than the lo-res camera. This was handheld, so not as sharp of focus as desired. The cone attachment and the lo-res telescope camera have some room for adjustment. By moving the camera closer to the lens, you adjust the focus and zoom. With the 1080p camera, I had to disassemble everything and remove the built-in lens.

I abandoned the cone idea, and decided to use my Belows as it has a longer length of adjustment. It had canon mounts on both sides, so I removed those. I 3D printed pieces to connect the 1080p cam on one end, and lens threads to screw on the Nikon lens on the other end. A small cap to cover the 1080p camera is to block any stray overhead lights.

Of course a light ring will be helpful. I have some leftover flexible LED light strips from an illuminated shelving project, so I will use that. 3D printed a light ring with the Nikon F mount. I will have inner and outer ring strips in there as well. What it looks like all together.

Then I soldered in the light ring. Rather than go all out, I decided to have three options: inner ring, flat face, outer ring. There is a 12V PWM DC motor controller used as a dimmer. Then a Binary Output Dial Push Wheel Switch (mine has positions 0-6, I would have preferred 1-7, but whatever). This gives me the following options:

0 - off

1 - inner ring (6 inches of LED strip)

2 - Flat surface (12 inches)

3 - Inner + Flat (18 inches)

4 - Outer ring (12 inches)

5 - Outer + Inner (18 inches)

6 - Outer + Flat (24 inches)

So all 3 segments are never on at the same time. It is not a matter of limiting the power draw, but a limit of the switch I had on hand. I could have used an arduino, or some other logic controller, or 3 individual push button switches, but I went with this weirdo switch for now.

Some photos of pre-testing without the light ring and a proper mount completed. I will be using a chemistry stand (heavy base and 20 inch pole). Photo of the bolts I will be using for clamp on the chemistry stand rod.

I then tried an AGP card that I hope to repair in the future. Plenty of room between the lens and the materials for working on soldering projects.

I finished the 3D mount with a nice tri-wing knob on it so I can move it up and down the chemistry stand much easier. Completed assembly and all parts 3D printed (pic 3-7). Closeup of the light control... I had 3D printed the case to include external buttons, but they did not move far enough so I clipped them off. Back to using a toothpick or paperclip to push the buttons. I will likely just use it in 'mode 6' anyway. The light ring in mode 6.

Lets start normal wide (pics 1-3): 11.5 inches with the chemistry stand rod being about 20 inches long, and both mounts still on the chemistry rod.

Even wider (pics 4-7), it's a bit risky because only the bottom mount is on the chemistry rod. 17.5 inches

Closest focused zoom is about 2 inches (pics 8-10), not really enough room to solder around, but a good measure of max.

This is all manually controlled: camera height, focus, f-stop on the lens, light ring illumination. The only auto feature is the brightness in the 1080p camera itself.

Let me know what you think about this project!