Saturday, January 9, 2016

Every Mistake In The Book!

I made my bloggin' buddy Ken laugh a few weeks ago when we exchanged e-mails a few weeks ago, talking about rising in the predawn hours to observe Comet Catalina. I told him that: "Of course, to me personally, 5am is a time that exists only theoretically, as I'm usually observing the back of my eyeballs about then... The thought of getting up at 3, driving an hour, setting up gear (in the dark and cold!) to photograph a comet doesn't seem as attractive as back in the Hale-Bopp days 20 years ago when I would do it a couple days a week."

Well, here it is a month later, I've still not seen Catalina, though I blame most of that on the spate of rain and clouds we've enjoyed lately. But recently, I've taken to step outside the predawn hours when "nature calls" to check on the planetary conjunction. This morning was the last chance to see Venus and Saturn less than the moon's-width apart for the last time, and when I ducked out at 6:05, I could see it through a hold in the clouds!

Now I take lots of images to support this blog - over 1700 in December alone, mostly for the Kitt Peak sunset chasing trips, and that doesn't count the hundreds more taken with my secondary camera of Melinda's.  But at 6 in the morning with my sleep-addled brain, I was making every mistake in the book as the inexorable movement of the clouds blocked my view!

Image Stabilization and Spagetti-Os!
Everything finally set - oh-oh...
Diving for the tripod and camera went fine, kit lens - check. Mount in the kitchen before stepping out into the 36.4F morning temperature. Step one is to frame and focus. I could see bright Venus in the viewfinder - looked pretty good to me - go to "Live view" to fine-focus - nothing... Lengthen exposure to make the image brighter - nothing. Evidently it was just out of focus enough to not make Venus visible. A twist of the focus ring and finally there it was. Took an 8 second exposure - a little underexposed. Doubled ISO to 800, and exposure to 10 seconds - better! Turn on long-exposure-noise-reduction, and take another - looks out of focus! Another - tadpole shaped stars! Drat - hadn't turned off image-stabilization! While helpful for hand-held exposures, from a tripod, step number 1 or 2 should always be to turn off IS! Fumble for the switch in the dark - step inside for a flashlight, turn it off and expose again - cloudy! The moment was gone, clouds cover the area, so I pack up and head back to a warm bed.

This morning I look at the results. The image that looked out of focus was actually stars that looked like Spagetti-Os!  The IS had "hunted" and completed a full circle during the 10 second exposure! The best exposure was that shown above, the second taken before noise-reduction was turned on. Total time from first image to last was only 5 minutes, before the clouds moved in... If I had only known what I was doing! Just another demonstration that astrophotography is a little different animal than normal imaging!

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