Here is a project, I made for pure curiosity. I wanted to know, is it as simple, as I thought it is.
The main idea was to make a slide projector, that could project 35mm slides with flash and old lens.

I started this project this project by making 3d model with necessary dimensions, to use it as a guide.

Here are the necessary supplies:

• A lens, preferably with manual aperture(I used old helios 58mm)
• Macro extender ring, or some kind of lens adapter, for the lens.
• Flash(I used my trusty YN-560 III)
• 35mm Slide Mounts
• A few pieces of plywood(I used some scraps from old fruit box)
• 1/4″ to 3/8″ adapter tripod screw(I suggest to buy these in bulk, because they are really useful in DIY photo projects)
• Transparency paper(preferably for laser printer)

The most important thing, to make the projector work, is precise flange distance, between lens and film plane. In my case, I used m42 lens, that have 45.46 mm flange distance. Precise flange distance is necessary; to make the projection focusable, like camera.

When it comes to distance between film and flash, I made it roughly same length as flange distance. It worked totally fine, with slight vignetting, that I fixed by pulling out built-in wide-flash adapter.
Other than that, the design and dimensions of the thing are open to interpretations. In my case, I made the back of the projector, so I have a tight fit for the flash.
In future, I may add a velcro strap, for safety.



Now, when the projector is finished, I have to make some projections. Sure, It is possible to project slide film, as well B&W negatives, but it is cheaper, to print them.
For this you will need transparency paper, used for transparency projectors.
Next, you will need to create some patterns on print them. Also, you can download some free patterns from Good Light Mag here: DOWNLOAD PATTERNS

After printing them, I had cut cut them in the size of slides and voilà!

So, we have the projector and slides. Now, does it work?
Here are some quick test shots I did in my basement:


In the end, here are my thoughts and recommendations:
It really works! I was surprised, that it was that easy to make. It will surely become useful tool in my proverbial camera bag.
Some suggestions. It is a good idea to use wide angle lens, like 28mm, if you intend to use the projector indoors. When it comes to transparencies, I suggest to use transparencies, made for laser printers, because they are made for higher temperatures.
That is pretty much it, for now. If you have any questions and/or suggestions – comment section bellow.

Update 26.04.2016: Here is recent photo made with this projector. https://flic.kr/p/FvZU5f