View Full Version : Lightbox attempts...why?
0ozma
13th of November 2008 (Thu), 17:21
Just built a DIY lightbox from one of the ideas over in that thread. Using two 500w lamps and white foam core.
Why do these pics not appear very sharp? The background doesn't seem very white either even though I set the Custom WB from it. EXIF is attached. Used on-camera flash as I don't have a shoe mount flash yet. I also used a steady tripod and a 50mm 1.4
http://farm4.static.flickr.com/3227/3027804591_2f993e56eb_o.jpg
http://farm4.static.flickr.com/3290/3028639238_5a14be700d_o.jpg
Thanks for any input you guys can give.
edit: just realized it was on AV by looking at EXIF. oops.
0ozma
13th of November 2008 (Thu), 17:39
Reshot with a much higher F # and manual mode... How does this look? Still not happy with the white background :(
http://farm4.static.flickr.com/3201/3027837771_91bab33268_o.jpg
Slight curves, contrast and brightness adjustment with a tiny bit of sharpening. Is this normally what people do?
http://farm4.static.flickr.com/3036/3027846459_7212436ea0_o.jpg
DrFil
13th of November 2008 (Thu), 18:39
the first couple just look underexposed. i've experimented with 500w lamps and realized that they're just not enough. they don't put out nearly as much light as strobes will. i ended up just getting a 430ex and it works wonderfully. i also have a sunpak 383 and that also works really well for less than half the price (just looks antiquated). it's hard to go cheap with lighting.
Robert_Lay
13th of November 2008 (Thu), 20:50
When you made your Custom White Balance shot, did you also use flash? If not, that's your problem.
Also, in my opinion, it may give better result to use a gray card instead of a white card for the Custom White Balance shot.
Last but not least, is there any chance you forgot to set it to the CWB when you took the actual shot?
I wouldn't put any time into examining a posted image for sharpness unless you were posting a full detail 100% crop. That's about the only way that we viewers can see the full detail that you have in the image. Examining a down-sampled, highly compressed jpg is not very useful.
0ozma
13th of November 2008 (Thu), 21:11
Here is a 100% crop of the claw from above. It just doesn't seem in focus although I made sure to center focus right in the middle of it.
I did use flash when setting the custom WB. I did change the setting in the camera. Thanks
http://klphotog.zenfolio.com/img/v6/p105151770-5.jpg
Robert_Lay
14th of November 2008 (Fri), 21:46
Well, there's got to be a first time for everything!
Bill Boehme
14th of November 2008 (Fri), 22:07
Regardless of how the white balance was set or how much light is used, the camera's metering system tries to make the overall average exposure approximately equal to middle gray. That means that when you take a meter reading and include a large part of the white background, you are forcing it to be exposed as gray rather than white. When shooting with a high key background, get the camera really close to the object being photographed so that it completely fills the viewfinder and then take a meter reading (assuming that its brightness is about mid exposure level -- otherwise use a gray card for setting exposure). Use that exposure setting for the shot, but make sure that the white areas are not blown out. Lighting is tricky because the color of the object being photographed will always color the background to some extent. Likewise, light that reflects off the background can wash out details in the item being photographed. Getting the right amount of background lighting will take some experimentation.
Mark1
14th of November 2008 (Fri), 23:05
It looks like you are following what the meter says. As explained above the meter wants to make everything gray. So It underexposes the image to try to make it gray. Use the meter to get the settings it wants. Then OVER expose by 2 stops and start there to dial it in. This will make the white a lot whiter.
By over exposing having a 500 watt light is overkill. With the camera on a tripod and the subject not moveing. You can shoot in just about any light. I have shot tabletop before with 3, 22 watt compact flourescent bulbs. Came out fine. But it was like a 1/3 second shutter speed. The key to getting the light right is to get the light to bounce all arround the box. So I would not use the flash as it is probably trying to overpower the 500's Plus the 2 lights are different colors...big pain to ballence in post.
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