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Posts Made By: Mike Clemens

March 8, 2008 09:55 AM Forum: DVDs and Music and Books That You Recommend

ummmm

Posted By Mike Clemens

Amy Winehouse is kind of awesome on this
http://www.youtube.com/watch?v=0KnBVJfXHx8

March 17, 2008 10:45 PM Forum: CCD Imaging and Processing/Solar System

ST237 filters

Posted By Mike Clemens

This ST-237 sure is refined compared with that blasted Toucam. What is a good CHEAP filter wheel assembly that does the job? I dont mind flicking between filters with a thumbwheel. I don't know squat about what threads are on the ST-237, what models of what screw onto it, etc. What works or doesn't work because this is not a ST-237A. Basically, I know nothing. Looking for any guidance. Thanks!

March 24, 2008 10:02 PM Forum: CCD Imaging and Processing/Solar System

single EOS DSLR shot of moon

Posted By Mike Clemens

From the other week, single frame. This was a 1 second exposure through clouds.

March 31, 2008 11:00 PM Forum: CCD Imaging and Processing/Deep Sky

Juniors First Planetary

Posted By Mike Clemens

NGC2392 (Eskimo Nebula) through the TEC200/9.

This is my first calibrated image.
ST-237, 40 frames of 20 unguided seconds each.

Calibrated with a single dark exposure, since I don't know what the hell I am doing. Next time I will average darks and do them at the same temp of the exposure etc... etc...

April 3, 2008 10:30 PM Forum: Equipment Talk

My new pier.

Posted By Mike Clemens

This is great, it's ready to go.
I mounted the fasteners exactly the way
you guys told me to. I'm going to go
out and fasten the pier plate on it right now!

April 4, 2008 08:15 AM Forum: CCD Imaging and Processing/Deep Sky

coolest sky toy

Posted By Mike Clemens

The picture analyzing star matching software demo'd at the very end of this astrophotography presentation is awesome!

http://www.youtube.com/watch?v=7vf50StbXG8

April 12, 2008 07:40 PM Forum: CCD Imaging and Processing/Deep Sky

NGC under the moon

Posted By Mike Clemens

This is quite a big galaxy. I wanted an NGC to do in color but I think I'll keep looking for one that fits the sensor. I think Skytools will let me search by size and altitude. This is 14x5 minutes from last night.

April 16, 2008 06:54 PM Forum: CCD Imaging and Processing/Deep Sky

good exposures

Posted By Mike Clemens

Whats the goal? For example, in a good exposure, how much brighter will the arms of a spiral galaxy be than the background brightness? Whats a good workable signal?

I have seen estimates that say my optimum sub-exposures should be 6 minutes long for my camera. At 6 minutes I certainly have signal showing through. I measured background brightness versus object brightness for several sessions of capturing M51, and depending on sky brightness that night, the average of a galactic spiral arm would be 20% to 50% brighter than the average background counts. Still, at 6 minutes these counts are pretty low. How much is appropriate?

When combining images, wouldn't the "Sum" method cause the good signal to progressively lift away from the sky background, whereas "Average" would result in a reduced-noise but extremely low magnitude signal with the same ratio of brightness to sky background?

And, which way is up and why is the sky blue...

April 17, 2008 07:36 PM Forum: CCD Imaging and Processing/Deep Sky

R, G and B

Posted By Mike Clemens

It becomes progressively harder to reduce noise as I move up the frequency spectrum. Is that normal? It's easier to get a clean red than green, and green is easier than blue. Is this all normal?

Is this noise difference due to sensitivity differences in my sensor yielding lower signal as I move up in frequency?

Will my TEC200ED be poorly spherically corrected in blue and thus soften all blue exposures?

Do you think my L exposures would be improved by filtering out UV/infrared?

April 20, 2008 08:19 PM Forum: CCD Imaging and Processing/Deep Sky

M57 shallow sky

Posted By Mike Clemens

M57 is fun... this thing is so bright I want to try imaging it at f/18 on the TEC200.

Here is M57 unguided, with only 2 exposures of 90" for each of RGB.

If this is possible in under 4 minutes per channel, I think spending a couple hours on it with the FFC for f/18 would probably be amazing.