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Photography Question 
Justin G.
BetterPhoto Member Since: 7/13/2004
 

Red filter lesson needed.


I've been using a red filter lately on my monochrome work and was talking with one of my instructors about using it on Pan F Plus and he was saying something about watch out and see if the film is sensitive to red light or not. This greatly confused me and I was wondering if anyone could give me a lesson on red filters and monochrome negatives. I simply thought it was used to increase contrast, but is there more? Thanks.

.justin.


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10/1/2005 4:45:15 PM

 

BetterPhoto Member
  Red filters will brighten red reflected light and darken its complimentary colors which are blue, cyan and green. So a red filter will darken a blue sky, leaving the clouds virtually untouched because they are brighter and there is much more light coming from them than the sky or shadows. One word of advice. Find a uniformly lighted and colored surface. Meter it straight and then meter it again through the filter you will be using. mark the difference in exposure stops for quick future reference. Also a couple of graduated neutral density filters are nice and handy to have in your array of photographic equipment.


Walrath Photographic Imaging
http://home.comcast.net/~flash19901/wsb/html/view.cgi-home.html-.html


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10/1/2005 8:19:25 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  Chris check out my Door of Judgement photo. It might look familiar if you visit downtown Dover much. lol. Thanks for the help.


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10/1/2005 8:30:00 PM

 
Michael H. Cothran   Justin - it's sort of like penicillin. The right amount will cure you, and too much will kill you!
Some film, such as Kodak's Technical Pan, is highly sensitive to red, meaning that it reacts to light without a filter about the same as a "normal" film would with a red filter attached. I believe this is what your instructor was referring to. By adding a red filter to a film sensitive to red would be an overkill, and the results would probably be way too much contrast.
Michael H. Cothran
www.mhcphoto.net


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10/1/2005 8:35:37 PM

 
  It does, Justin. I was a jury foreman in there in 2003. Nice photograph.

Walrath Photographic Imaging
http://home.comcast.net/~flash19901/wsb/html/view.cgi-home.html-.html


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10/1/2005 8:37:17 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  OOOH ok I see. So do you think most of these Pan films are probably sensitive to red, and average consumer films aren't??? I'm going to try and look at the Ilford's Pan F Plus tech data and see if I can read it.


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10/1/2005 8:51:42 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  Do you guys know what wavelength red is??

This link shows on the first page the wave length chart and the sensitivity and if I remember right the lower wavelengths around the 300 and 400 are red right? I just don't know how to read the chart.


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10/1/2005 9:00:24 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  For anyone else (and Mike and Chris) here's a great site that shows color wheel theories. In the middle it shows the complimentary colors and like chris said, the comp. of red IS blue, cyan, and green! (not saying I doubted you, I just needed a visual!) Cool stuff, thanks Chris and Mike.


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10/1/2005 9:05:10 PM

 
Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
gregorylagrange.org
  red has longer wavelength than blue.


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10/2/2005 4:32:30 PM

 
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