I have finished my Light Tent - DPChallenge Forums

Promaster 28-200mm f/3.8-5.6 XR IF

07/09/2010 03:09:05 PM · #1

I just finished hooray! It only cost about 6 dollars total. ~~Pics~~

Message edited by author 2010-07-09 15:16:12.

atupdate

Pentax K-R

07/09/2010 03:13:12 PM · #2

Originally posted by jvaughn94:

I just finished hooray! It only cost about 6 dollars total. Pics

Can't see the picture, as Photobucket is asking me to login.

Tim

Canon EF 28-135mm F/3.5-5.6 IS USM

07/09/2010 03:15:53 PM · #3

1

2

Test Shot

kleski

Canon EOS-7D

07/09/2010 03:25:53 PM · #4

So surprising what a cardboard box and some tissue paper(or sheet)can do for lighting. I built one of these years ago and it's a great cheap way to diffuse light.

07/09/2010 03:32:02 PM · #5

Yes but I can't out how to set the white balance. Guess I'll have to break down a read the manual.

07/09/2010 07:53:03 PM · #6

Gah. Does anybody know how to set the white balance for a light tent. I keep getting bluish background color.

jfriesen

Panasonic LUMIX GH5

07/09/2010 07:57:58 PM · #7

Sure, it's easy.

First, take a picture of a piece of white paper under your lights.
Then, go to your camera's menu and select "custom white balance".
Then, select the image of the white paper you took and hit "OK".

But, I would highly advise reading the manual anyway...there is tons of good info in there.

Message edited by author 2010-07-09 19:58:25.

07/09/2010 08:03:42 PM · #8

Ok so does this look right?

07/09/2010 08:04:56 PM · #9

Originally posted by jvaughn94:

Gah. Does anybody know how to set the white balance for a light tent. I keep getting bluish background color.

Not sure how you do it with your camera (but there is likely a way). If you photograph a known white or neutral gray card (the seamless paper you are using might work, too) you should be able to fix it in post with a white-balance eye dropper correction. As long as you don't change your lighting sources from shot to shot, you should be able to fix it once and then "sync" it (I think that is the Lightroom terminology) or Lift/Stamp (Aperture) or Copy (iPhoto) the adjustment to other images.

There should be a way to set a custom white balance in your camera--this would also entail photographing a grey card, etc. I noted that it looks like you are using two different kinds of light sources (mixing incandescent and fluorescent, maybe?) If you can make sure to use the same on each side (those home depot clip lamps are cheap enough) and the same bulbs it will be easier. Your diffuser can still alter the color of the light some, so correcting the WB will still be needed, but matching light sources will help (especially if you move one further away than the other for any reason--that would change the ratio of tungsten to fluorescent as soon as you do it).

07/09/2010 08:06:17 PM · #10

This looks a little greenish to me, especially on the left side. Are your light sources identical?

07/09/2010 08:07:29 PM · #11

I am using the same kind of bulbs. The problem may have been in the distance anyways I posted the image above after correcting it in lightroom. Seems good to me.

07/09/2010 08:12:54 PM · #12

also, when you take the pic of just the white in your box, try to set your exposure so you don't have blown highlights, and you want an even tone across the image.

07/09/2010 08:19:06 PM · #13

If I used the same bulbs in two different kind of lamps would that have this effect?

07/09/2010 08:59:02 PM · #14

Originally posted by jvaughn94:

If I used the same bulbs in two different kind of lamps would that have this effect?

I guess it depends on how evenly and matched the lighting is falling on your diffusers. You could take shots with only one on, one off, then reverse, shoot again, see if the falloff looks the same, the level (keep the exposure the same). If one looks overall brighter or darker, or the illumination top to bottom, side to side looks different, then it could be. Remember the inverse square law here, your lights are close to the diffusers, so small differences can really matter. Your diffusers are close to the subject, so small differences can really matter.

ETA: I just looked again at the two set-up shots. In those, it seems that the lighting pattern on the diffusers is very different. If you go down to HomeDepot, etc., get two matching clip on lights (~6 bucks each) and two matching daylight balanced florescents, then you can match them exactly (same distance from diffusers.

Message edited by author 2010-07-09 21:13:42.

07/09/2010 09:58:02 PM · #15

I just did a WB eyedropper to make the version on the right.

BTW, since your matching light bulbs are in different lamps, not only do the illumination patterns on your diffusers make a difference, but the color of the reflectors can affect things, too. If the clip light is a silver reflector, and the reading lamp has an white or not-quite white reflector, that will also play into it.