On 1/24/2012 1:48 PM, Collin Brendemuehl wrote:
Believe me, as someone who has magic-wanded out more backgrounds that
I care to admit... it works really well SOME of the time. Other times
you a messing around with the magic wand sensitivity setting to keep
it from grabbing portions of your object.
Bruce is correct. Your images are seriously underexposed. The light
table should be white. It's the same principle as shooting something
on a snow bank. The meter will make the snowbank 18% grey and
underexpose the subject. That's what you've got here. You'll save a
lot of work in post if you expose correctly. Either get off automatic
to manual or use exposure compensation.
Also, if you have photoshop you may find that working with levels or
curves (to define your "white") will save you a lot of time with the
magic wand. Trust me, you don't want to rely on the magic wand.
Darren Addy
Kearney, Nebraska
I am shooting in Manual mode.
Yes, the Magic Wand has been useful. So many circular objects are more easily
cut with the oval selection tool.
As to the exposure, I only saw that on a couple of shots, obvious on the #3
with the PL. I took it off and have not put it back on.
Shots #1& #2, once separated from the background (about 10 seconds of work)
displays the detail perfectly for the customer's application. The sense of being
underexposed went away with the image on a different background -- pure white.
The paper should not be all white, but perhaps white-er than it is. I will be
adding some reflectors in the next day. Still, the boss is more than happy
with the results achieved.
Tomorrow I will put up one of the better, later pics with improved exposure.
Since you are shooting in manual mode (and I presume RAW), until you get
the system dialed in, why not try some shots where you keep cranking up
the exposure?
I would suggest two variations on "expose to the right":
1) simply looking at the histogram, this will probably put the table
just under clipping.
2) Expose to the right based on the object and let the table clip.
The histogram should be bi-modal. There should be a peak for the table,
and one for the object. When you expose to the right, ignore the the
bump for the table and just keep increasing your exposure until the
object itself is exposed to the right.
This, of course, has issues if there are sections of your object that
are close in albedo to that of the table. The alternative would be to
put your subject on a dark background, do your test shots to expose to
the right and set your exposure, then remove the dark background, and
let the exposure of the table fall where it may.
I do hope that you are keeping a notebook with good notes on your
different lighting setups. Once you get things dialed in, you should
have some base settings that are very close to perfect, and will
probably be good enough for most of your subjects.
Sincerely,
Collin Brendemuehl
"He is no fool who gives what he cannot keep to gain what he cannot lose"
-- Jim Elliott
--
Larry Colen l...@red4est.com (from dos4est)
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