How to make a cheap light box
Posted 17 December 2010 - 01:04 PM
I just scratch built a first attempt at a lightbox. Results were unimpressive. I used white cardstock (flat sheet for a bottom, cylinder for the vertical aspect, with a 2x2 inch opening at the bottom for the camera, open on top for a desk lamp to shine into the cylinder). I have a flourescent bulb in there which I understand is not right, but my problem wasn't one of color balance (well yes, it was.. but I have a bigger problem), it was that the photo was extremely dark. Here are several pictures of a mini I was shooting to try it out and of the setup. I've got flourescent lights throughout the house, so with the intense light in the lightbox it appears I'm shooting in a dark room, but it's the middle of the day here.
What am I doing wrong?? Obviously the size is different than the tutorial... somehow I doubt that's the problem. That leaves the lightbulb and the materials. If it's the lightbulb that's easy enough to fix, but do I need to scrap the whole design and go get the cloth and all of that?
Posted 17 December 2010 - 01:41 PM
Currently I'm using a wacky and probably dangerous setup of three lights sans box (above light is precariously hanging off an easel) and still using the taping paper method (taped to easel at back of table) to avoid seam for backdrop. Not the sharpest tack method but works at the moment. Good luck!
Posted 17 December 2010 - 03:39 PM
BTW, how many watts of juice does that bulb use / how many lumens does it output?
Posted 17 December 2010 - 04:52 PM
11W 120V 60Hz
Either way I plan on upgrading the bulb - is a 60 watt bulb bright enough?
For starters I will make the cylinder larger in diameter and see how that goes, thanks for the tip!
Posted 17 December 2010 - 05:39 PM
1) Your light box design is pretty inefficient. The sides of the cylinder don't really reflect much light toward the figure and the direct light from above isn't in a very useful position. There's a reason most ghetto light boxes are designed for light to come in at least partly from the sides.
2) The bulb is pretty far from the figure. Light energy falls off as 1/distance^2, so if you halve the distance, you'll quadruple the light energy.
3) Your bulb is pretty anemic. Light fixtures specify wattage limits mostly because of heat dissipation issues (in the cord and in the shade). The heat you need to dissipate doesn't depend on the visible light output but rather on the total power pushed through the bulb. You can put a much brighter bulb in that fixture without problems.
4) As previously noted, of the limited light you do have from the bulb, probably 60% is being scattered outside the box.
5) Finally, and possibly most important, your photographs are quite underexposed. For stationary subjects, this doesn't really depend on how much light you have (so long as you have enough to see by.) Your camera is not exposing correctly for the available light. You need to manually raise the ISO, increase the aperture, decrease the shutter speed (increase the exposure time), or some combination of the above on your camera. If you can't do those, you'll need to use a darker (yes, darker) background to fool the camera into allowing more light onto the sensor.
Posted 17 December 2010 - 09:32 PM
I think my camera can adjust most of those things, so I'll look into that. I have redesigned the cylinder so that the whole lamp fits within the circumference, but I also have loads of cardboard and easy access to the materials to do it right, so I should probably just go ahead and scrap my lame design and do it right if I'm going to bother doing it at all.
Thank you all for the advice! I hope to have something worthy of a miniature soon.
Messed with the aperture setting and applied your statement about light "falling off" - I made sure the lamp was very close to the mini. The following three pictures are using the same energy saver bulb, and all I did was adjust the aperture and make the light closer - everything else is the same as the last photos I posted.
So now a SUPER thanks for all of the advice! Nearly there and I only made 2 fixes!
Posted 17 December 2010 - 10:48 PM
I plan on making one soon from a few old picture frames and some tracing paper. Not sure about the lights, I'm hoping maybe I can salvage some aquarium lamps from second hand shops.
Edited by Leader of the Rats, 17 December 2010 - 10:56 PM.
Posted 20 December 2010 - 11:26 AM
If your camera does not allow you to set white balance, try putting a very thin piece of pale-blue tissue paper between the lamp and the mini to act as a filter.
Posted 29 March 2011 - 07:46 PM
"Derek Schubert and John Bonnot are my MASTERS!"
Posted 19 August 2012 - 02:07 PM
Proud Member of WAMP
Posted 24 August 2012 - 02:55 PM
And this is my current work-in-progress, photographed using the light box.
Posted 27 August 2012 - 12:44 PM
Here's my current setup on my new (old) desk, so stuff is just tossed on the desk.
And the test run:
I just took a box, cut holes in the sides and tops and taped tissue paper to the holes. Put a lamp on each opening (you can't see the lamp on the left, really). Taped a sheet of palette paper to the back.
Posted 27 August 2012 - 05:48 PM
2) For a good exposure and color balance (if you're using automatic modes), use a light to medium gray backdrop.
3) If necessary, adjust your exposure and black point in post if you miss your exposure in camera.
Posted 07 October 2012 - 10:32 AM
And the light box just before I shot my latest WIP update:
I've also made several backdrops in GIMP using the airbrush tool to just place some random color at different pressures. Seems to work ok:
(This one was taken just after those two set up shots)
And one with another backdrop:
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