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Old Feb 8, 2012, 2:41 PM   #1
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Default Seeing Red - Space Attack

Reds are hard for digital cameras!

I don't think this is exactly what the challenge is about, but thought it would fit if you stretch things a bit. It IS red, all red. I wouldn't have thought of this picture (it was taken several years ago), but someone someplace else asked about using a Hoya R72 filter, and this is one of my pictures taken using mine.

For those that aren't familiar with the Hoya R72 filter, it looks almost black when you look through it. It blocks most visible light, except for some deep reds and reflected infrared light. Most modern cameras have a strong anti-infrared filter over the sensor, which helps digital cameras correctly capture red objects. I know that the camera I was using this day has a fairly weak anti-IR filter (especially by today's camera standards), and so will record a fair amount of reflected IR light.

Most people who shoot using this filter will process their pictures either by converting them to black and white (which I normally do) or by swapping the red and blue channels, which gets the sky a (false) shade of blue. I did that originally with this picture, but someone objected to having the red rocks of Sedona portrayed as blue, so I re-did the processing and left it with the mostly red coloring. There's two other issues that you can see in this shot - the first is that there's a certain amount of light leakage through the viewfinder, the reason for the orange in the sky, I think (the reason why a number of dSLR cameras come with a viewfinder cover, something most people promptly lose or toss out). The other is why I named the picture "space attack" - the lens flare looks like some sort of alien weapon.

If anyone is interested in the false color version, it is at: http://mtngal.zenfolio.com/p780316653/e19f3c1f3 .

I know, this is a sideways look at the color red.
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Old Feb 8, 2012, 4:54 PM   #2
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I have a Cokin IR filter. I am not sure if is the same number as yours or not but the characteristics match your description. I have shot a few photos using it but, in all cases, I converted the image to BW. I think the false colors, especially in plants and trees are more spectacular in BW.

Now, to the current challenge, I don't this this image works as far as trying to determine how well your camera is capturing reds.

Thanks for showing us the image, anyway.

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Old Feb 8, 2012, 7:49 PM   #3
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Like Calr said doesn't address his challenge. Remarkable use of the filter tho.
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Old Feb 9, 2012, 6:37 PM   #4
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That's a neat filter and in this case, it produced an interesting effect between the sky and the vegetation. But, I see no red, just orange and some sort of pink (if my monitor is calibrated at all).

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