Simcoe Skies Astronomy

M92 - Globular Cluster

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M92
M92 Cluster - NGC 6341
First try on this Cluster

Magnitude: 7.5
Location: Hercules
Date: Sept 18/04
Exposures: 22 best of 65
Exposure length: 5 seconds
Amp on setting: OFF
Brightness: 100
Gain: 40

Notes: Annoyingly out of focus. After this, I read up on focusing and tried various solutions. I found the "dowel & diffraction spike" method to produce crisper images than a Hartmann mask.

M92
Another try
2nd Attempt about a week later

Magnitude: 7.5
Location: Hercules
Date: Sept 26/04
Exposures: 30
Exposure length: 6 seconds
Amp on setting: OFF
Brightness: 100
Gain: 40

Notes: Much better focus this time, although polar alignment was suffering (again). After enough of these, I concluded that my polar alignment was off because I was setting up on a wooden deck - and the redistribution of weight and deck "flex" when I walked away from the scope would instantly throw my alignment out (I could see the image shift around in the preview screen when I changed my location on the deck).

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	M92 Cluster - NGC 6341 First try on this Cluster Magnitude: 7.5 Location: Hercules Date: Sept 18/04 Exposures: 22 best of 65 Exposure length: 5 seconds Amp on setting: OFF Brightness: 100 Gain: 40 Notes: Annoyingly out of focus. After this, I read up on focusing and tried various solutions. I found the "dowel & diffraction spike" method to produce crisper images than a Hartmann mask.

	Another try 2nd Attempt about a week later Magnitude: 7.5 Location: Hercules Date: Sept 26/04 Exposures: 30 Exposure length: 6 seconds Amp on setting: OFF Brightness: 100 Gain: 40 Notes: Much better focus this time, although polar alignment was suffering (again). After enough of these, I concluded that my polar alignment was off because I was setting up on a wooden deck - and the redistribution of weight and deck "flex" when I walked away from the scope would instantly throw my alignment out (I could see the image shift around in the preview screen when I changed my location on the deck).