Getting gray background using white paper

Started Jun 26, 2013 | Questions thread
YonathanZ
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Re: Getting gray background using white paper
In reply to ChrisBurch, Jun 28, 2013

ChrisBurch wrote:

It's not a "lack of light", you have simply exposed the background paper so that it is within the dynamic range of your camera. You will only get pure white if the background is at or beyond the point of being over-exposed. Since you used automatic settings, your camera is trying to make everything in the image properly exposed including the background. You'll have to go to fully manual settings to get what you're looking for.

Since you're using a continuous light source,, you can either slow down your shutter speed or increase the ISO to get a brighter background. If you over expose too much it will flare into the pendant, so keep that in mind.

The biggest catch to increasing the exposure is that you need to get the white background brighter without blowing out the pendant itself. Since you only have one light source, you may find that hard or impossible to do. If so, you can fix in post by increasing your highlights in whatever editing program you use.

A better solution is to get a second light source and light up the background from behind (create a lightbox). That way you can crank up the backlighting without messing up the exposure on your subject. If you have a light tent, you have the translucent material to pull this off...it's just a matter of physically positioning everything to work.

You can also avoid having to focus stack if you use a higher f-stop and/or backing away from the pendant. Unfortunately that will make the photo even darker, so you'll have to increase the shutter/ISO even more to compensate.

Using a light tent, I was able to get a pure white background, but the subject is over exposed, it becomes dull looking. I wonder how I can truly separate the lighting of the background from the lighting of the subject.

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