September 17, 2012

DIY lightbox projector

A cheap and effective way to accurately project drawings or photos for airbrush artists is explained in this blog entry. It has several advantages over traditional projection methods that involve art / tracers projectors and does not necessarily cost s ton of money. These advantages are:

  1. the drawings or photos are not heated by the projector's lamp that generates a lot of radiation heat which tends to deform the reference material, resulting in inaccurate or incorrect projection
  2. the image can instantly be made visible while the artist does not have to worry about maintaining the position of the photo / drawing relative to the surface (s)he is airbrushing on
  3. it is not necessary to trace the photo / drawing on the airbrush paper or canvas with a pencil. No pencil lines have to be erased later which is difficult or impossible to do with some types and brands of paint
  4. prints are used that give an accurate representation of the reference image
  5. the printed reference image can be made visible at any time it is necessary by the flip of a switch while the artist is never blocking a traditional projector's light beam

Below you see a drawing of the principle of the lightbox. I used an old drawing table that I bought cheap and mounted a wooden frame on top of that. Inside the frame I put an LED armature of four tubes that generates almost no heat at all. On the top and bottom edge of the wooden frame I mounted profiles in which I slide a glass plate (also bought second hand for a fair price) from the side. On the lower left of the left of thewooden frame I placed a switch with which I turn the LED lights on or off which allows me to see the print of the reference image whenever I need to see it.

Exploded view of DIY lightbox

In real life the set-up looks like is shown in the image below. The reference image is printed on several A4 papers that are taped together in the correct position relative to each other and onto the glass plate. On top of the prints, the airbrush paper is taped. Since the glass plate is mounted in profiles on the top and bottom of the wooden frame, the reference image - when wider than the LED armature - can be moved to the left or right by sliding the glass plate to whatever side will show the part of the reference image that needs to be seen.

LED lights off - reference prints taped to glass plate underneath airbrush paper

LED lights on - the reference image becomes visible through the airbrush paper

Airbrush in progress

Top light outside lightbox switched on when airbrushing

A note on the reference prints. I use Corel PhotoPaint to edit and print the reference images for two reasons:
  1. PhotoPaint has excellent filters that allow you to print the outlines or edges (two different filters) that saves a lot of ink when using an ink jet printer or toner powder when using a laser printer
  2. PhotoPaint offers an option in the print dialogue to print tiled pages, each of which contains a part of the image if it is larger than the paper size a printer is able to process
The tiled prints I tape onto the glass plate with transparent tape, positioning them to the relative correct position, using the narrow overlap areas PhotoPaint automatically makes the printer print. Using the PhotoPaint filters prevents my old HP 1010 laser printer from printing one huge black blob in which almost no detail can be distinguished. I have found this projection method to be more comfortable and far more accurate than the tracer projection I used before.

I placed the swith on the lower left hand side of the wooden frame, because I hold the airbrush in my right hand. It allows me to switch on and off the LED's to make the reference prints visible whenever I need to see them. On the right side of the lightbox I mounted the clips in which I hang my airbrushes. If I need several for a particul job, I can easily switch airbrushes without interrupting the spraying process.

The old drawing table cost me 40 Euro, the wood 10 Euro, the glass plate 15 Euro and the LED armature approximately 80 Euro (the only part I bought new). So besides being more effective, this construction was also cheaper than buying a tracer projector.