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Wednesday, September 6th, 2023

How to easy build a DIY UV Exposure Box with Dimmer and Timer

Lately I started with alternative printing techniques. Salt prints and als cyanotypes are something I want to learn more about. I did the first exposures with the sun and it turned out really well. But I couldn’t make always time during the day, beside that sometimes the sun moved to fast and I had the prints in the shade, or it even was to late for sun printing at all.

I got great results in the sun, but I just don’t have always time during the day

Thats when I looked at tutorials for UV exposure boxes. There are so many great tutorials with beautiful results everywhere. But all I found needed lots of time to build it and a dimmer and timer was not included in the ones I found. So I constructed one by myself, with as less as possible diy knowledge needed to build it. Even I am very confident with soldering and building stuff, I wanted to have a quick solution. Find the full tutorial in my latest video (Scroll down for the full material List)

I started with a 60x40x12cm Eurobox – you can use whatever box you need. Maybe even a nice wooden one.
With a utility knife I could easily cut through the box to make myself a door with a hinge. Thats a step you can easily skip. I only made it, so I can access the box, without lifting it up.
I used a little clamp and a piece of rope to hold the door in place when its opened.
To make the box more reflective, I used an aluminum tape. its easy to cut and easy to mount.
Now I mounted the led strips on the aluminum foil. Before that I drilled a hole for the cables in the box.
If you use the same sized box, be sure to always leave the same with as they led strip is between each lane. Don’t worry if you make a mistake, my led strips came easily off and I got them easily on again.
These are digital dimmers that have also a time included.
After you install the app, the dimmers connect automatically via bluetooth. They also group together as one single light. Now you can change the output power of the lights, or set two kind of timers. I like these a lot, because I can precisely write down the time I used and also write down the light intensity. Another cool thing is, that you can close the app and even if you set a timer before the dimmers will remember without a phone connection.
If you don’t want to use your phone, then you will like these. Simple on, off and dimmer function.
It may not be as symmetrical as some others, but it worked really well.
Thats the first print from a glass negative out of the UV box. I think it turned out pretty well.
One light strip should put out 36Watts of power. I measured only 2,2 Amperes. If I calculate that by 12 Volts I get 26.4 Watts. I already contacted the company who produces the strips, but didn’t hear back so far. I will let you know how this goes. I think the power supplies are a bit on the week side. But don’t worry to much about that, as you saw my print looked really well. I am just a curious person and wanted to know if they deliver what they stated on the packaging.
There you have it, a very easy diy UV box exposure unit build. Enjoy building it!

Here are the links to all parts I used:



Aluminum Tape:


Power switch

Germany or

Power splitter

Germany or

Analog Dimmer:


Digital Dimmer:


Led Strips

International: (discription says 60 Watt!!!)

Brushes for salt print or cyanotype


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  • Posted by Markus | Filed in cyanotype, darkroom, diy, salt print, uv box, uv exposure | 2 Comments »