Archived posting to the Leica Users Group, 2001/11/14

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Subject: Re: [Leica] Re: High altitude question
From: Doug Herr <telyt@earthlink.net>
Date: 14 Nov 2001 09:57:48 -0800

On Wed, 14 November 2001, Jim Brick wrote:

> 
> Use a B+W KR3 filter. The higher you go, when there is clear blue sky, the 
> higher the color temp as there is less atmosphere (moisture & stuff that is 
> packed down at lower elevations). I've taken ton's of Leica photographs in 
> the Colorado Rockys and after the first roll, started using a KR3, and all 
> was well after that.
> 
> Please note, it is NOT UV that is causing the blue, it is simply a higher 
> color temp of the light. Your Leica lens has all of the UV filtering 
> built-in. You need to warm up the light, convert it back down to 5000-8000 
> Kelvin (from roughly 12,000 Kelvin) color temp. Use a KR3.
> 
> Jim
> 

Another method is to use Photoshop.  The advantages include making the *exact* color correction you need, and no filter factors.  Here's a good example of how not using a warming filter saved the photo (this .jpg matches the color of the original slide, an old Kodachrome X):

http://www.wildlightphoto.com/technique/bluepika.jpg

The Pika was lit by the deep blue sky at high altitude; even the sun had gone behind a cloud.  Since asking the Pika to wait until the cloud moved was pointless, I shot anyway, 1/60 sec @ f/4.5.  This was with a 300mm f/4.5 lens, leaning against a rock.  Since a warming filter works by reducing the cooler wavelengths, using the warming filter would have taken away more of the light than the nominal filter factor would indicate.  1/60 sec was slow enough; a slower shutter speed would likely have given me too much camera motion.

By using Photoshop I can make the nessesary color corrections:

http://www.wildlightphoto.com/mammals/pika.html

This photo has been one of my most successful, having been used in several books and magazines (including Audubon magazine) and has also been quite popular as a print.


Doug Herr
Birdman of Sacramento
http://www.wildlightphoto.com
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