Re: [APML] My first light shots with Canon 20Da

["Richard Crisp" <rdcrisp@earthlink.net>]

I have about 7 or 8 different computers I regularly use for one thing or 
another and none of them have managed color. I can also tell you that an 
astro image will look different displayed on each of them.

It might look really good on one and look terrible on three or four of them 
and sort of so so on the others.

my view is that if you aren't running a color calibrated/managed system, you 
have no clue what the colors are or are supposed to be.


----- Original Message ----- 
From: "Chuck Vaughn" <aa6g@aa6g.org>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Monday, September 12, 2005 12:42 PM
Subject: Re: [APML] My first light shots with Canon 20Da


>  Alan,
>
>> Blues seem to be more white, among other little things. Does
>> anyone have an explanation of why this is?
>
> I've certainly noticed the same thing. Believe it or not I processed  that 
> m31 to get it to be more yellow in the middle and more blue at  the outer 
> edges. This was taken with the unmodified 20Da so the Ha  response is way 
> down which is probably why the nebulas aren't even  pink. Now that it is 
> modified I'll see what happens.
>
> OTOH, tricolor TP shots of M31 and M33 show nebulas as mostly white  with 
> a hint of pink. I think the bright red nebulas you see in some  shots come 
> from the addition of H-a data.
>
> If you care to dig deep in the APML archives, years ago Brad Wallis  was 
> asked what color M31 would be if you could see it. he said it  would be 
> mostly gray with a bit yellower in the middle and a bit  bluer in the 
> outer arms, not the bright yellow/orange and blue you  typically see.
>
> Here's a question we need to ask ourselves:
>
> If the 20D takes normal daylight balanced images that look  satisfactory 
> to our color seeing eyes, why would a shot of M31 with  the same camera 
> not produce an image balanced the way it appear if we  could see it in 
> color through a telescope? I believe the inescapable  answer is that it 
> does take the image correctly and Brad was right.
>
> When we see something presented in a certain way, we become  conditioned 
> to it and any other presentation we judge as wrong. We're  conditioned to 
> seeing a certain presentation of M31 based most likely  on how a few 
> people initially processed it; old yellow stars in the  middle and young 
> blue ones in the arms so it must be bright yellow  and blue.
>
> I've got a couple of very old M31 images taken on Konica films and 
> processed and printed in a photo lab and they're all sort of a gray- 
> magenta color. Yet on the same roll nebulas look completely "normal."
>
> Another thing to consider is if the foreground star colors appear  correct 
> in the image, orange, yellow and blue, how could the color of  the galaxy 
> be wrong?
>
> I've pretty much given up on what color these objects are supposed to  be 
> and look at the quality of the image overall.
>
> Chuck
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