Why did my Star Pix turn out this way???

Maybe some of you night sky photographers can help me out a bit. Last night I went to a local observatory to see a meteor shower - didn't see much but it was a nice night. Anyhow, I took my e500 along with my 14-54 and my 7-14 lenses, along with a tripod. I set it up, aimed it at the sky and shot. I used a 2 sec mirror lock-up and tried a 60 sec exposure - I don't have the remote, so no bulb mode right now.

I did get some shots, but why did the stars turn out in various colors - not white like they looked and there sure is lots of noise. I had NR on. These were shot at iso 400.

This one was 7mm, F4.5, 60 Sec, MF. (just re-sized and saved for web in Adobe)



This one was 13mm, F13, 60 Sec.



Also - how do you MF when it's so dark you can't see? I went by the guide on the lens and set to infinity.

You can tell I'm new to this

Hello,

First things first. You need to turn on noise reduction, because you're getting a lot of thermal noise. The dark frame subtraction on long exposures works well.

It turns out that stars are many different colors, many of which only show up in long exposures. I expect (but have not yet proved) that noise reduction software would work well on high ISO astro images.

Something else that I haven't tried but may help is to pack the camera in an ice bag. This might reduce the ambient temperature experienced by the sensor, further reducing the noise.

Best of luck,

--
Archer in Boulder, CO

Oh, and for focusing, two tricks.

1. Focus during the day, and then lock it down.

2. Use the magnified view to check your focus, and adjust accordingly. This one is easier if you use a telescope instead of a lens.

A third:

use live view on an E-330. I'm starting to think that a new body is in my future. Maybe in several different senses ;-).

--
Archer in Boulder, CO

But unfortunately a lot of it is very difficult to see with the naked eye. Stars burn at different temperatures and these different temperatures cause differences in the colors of the stars. The problem is that in our eyes form a picture using rods and cones. Rods are sensitive to light and cones are sensitive to color. At night, the rods take over and most stars just look white. It takes a very bright star to show color. The best example I know of is Orion's Belt. It is made up of two bright stars on either end, Rigel and Betelguese. Rigel glows blue-ish, white and this juxtaposition makes it very easy to tell, even with the naked eye, that Betelguese is reddish in color.

Camera's, with their long exposure, are wonderful at picking up the hidden colors of the sky. Take a look at this, admittedly poor, picture of the Orion Nebula taken with the E-1:



You can see the Nebula glows a beautiful purple while the stars around it are all sorts of other colors. The Nebula isn't even visible to the naked eye and requires a telescope for us to see it directly.
--
Tarek
http://focusonlife.net

Just FYI - I actually did have my NR turned ON - just double checked.

tchatila said:

The best
example I know of is Orion's Belt. It is made up of two bright
stars on either end, Rigel and Betelguese. Rigel glows blue-ish,
white and this juxtaposition makes it very easy to tell, even with
the naked eye, that Betelguese is reddish in color.

Click to expand...

You've got the colors and constellation (Orion) right, but have the stars a bit out of position. Betelgeuse is toward the top left, and Rigel bottom right. Neither are on his belt.

Ref:
http://en.wikipedia.org/wiki/Orion_%28constellation%29
http://www.astro.wisc.edu/~dolan/constellations/constellations/Orion.html

--



E-Three-Hundred/DZ Fourteen-Fifty-Four/DZ Fifty-Two-Hundred/FL-Fifty
E-Ten/C-Twenty-One-Hundred-UZ/E-One-Hundred-RS/D-Four-Hundred-Z
Oldma-cdon-aldh-adaf-arm-EI-EI-O

julric01 said:

I did get some shots, but why did the stars turn out in various
colors - not white like they looked and there sure is lots of
noise. I had NR on. These were shot at iso 400.

Click to expand...

I think you should use ISO 100. No reason not to. It will help with the noise.

--
Brian
http://www.photosig.com/go/users/userphotos?id=6797
http://www.myfourthirds.com/folder.php?id=1605

Try ISO 100 and open your aperature up.

These were taken last night with the E-500 and 14-45, using lens reset to get infinity focus. ISO 100 F3.5, 8 minute exposures on both using bulb with remote. Definitely turn on noise reduction (dark frame subtraction), couple that with ISO 100 and you will get better results.

These are not the best night sky photos, my first shot at this long of exposure.





--
William
http://www.waninglight.com - my playground

Thanks =)
--
Tarek
http://focusonlife.net