Re: [APML] A few more barn door shots

["Eric Z. Beard" <ericzbeard@yahoo.com>]

Here's a link to a picture of the mount:

http://members.aol.com/IC4703/equipment.html

I have a small finder mounted, but I actually feel better about the 
alignment when I just sight down the hinges.

The reason I went from getting maybe three or four round star shots per 
roll to getting round stars in practically every shot is a little 
embarassing: I assumed that given the inherent inaccuracy of a barn door 
mount, counting in my head for a few minutes would be adequate: wrong! 
Now I have an analog wristwatch attached to the back of the mount - I 
crank it manually, and once I started watching the seconds hand, I 
realized I have a tendency to rush through it.  I didn't post any of the 
5 minute exposures, since they were all wrecked by dew, but the stars 
were still good, so next time I'll stick to f/2.8 and shoot from 4-6 
minutes.

Anybody know of an easy/cheap way to keep dew off the lens while 
shooting without adding much weight to the setup?

As far as getting the images on CD when they are developed, I asked 
about the resolution and I couldn't get a good answer.  Cramming 24 
shots onto a CD means I can't possibly get better than 600dpi.  What I 
really need to do is break down and get a negative/slide scanner.

Thanks for the tips!

EZB

Jerry Lodriguss wrote:

 >
 > Hi Eric,
 >
 > Those shots look pretty good. The barn door tracker seems to be working
 > very well. Why don't you post a shot of it? Are you driving it by hand or
 > with a motor? How are you polar aligning it?
 >
 > I'm guessing that you scanned the prints from WalMart with the HP 4400c
 > flatbed scanner?  You might want to check into having the images
 > digitized
 > when they are developed. I think Walmart offers this service, but I don't
 > know how high of a resolution they offer.  You will get better quality
 > that
 > way for images you display on the web because they will be digitized
 > directly from the original negatives and you won't lose quality and
 > dynamic
 > range by going the additional generation of the print.
 >
 > Looking at your images in photoshop, I think you can improve them by
 > re-setting the white point on them in Levels. You are not using all of
 > the
 > available dynamic range. The stars are not as white as they can be. For
 > example, Vega, the brightest star in the picture of Lyra and Hercules,
 > reads only 191,177,177 for the pixel values in the red, green and blue
 > channels. They should be 255,255,255.
 >
 > Jerry
 >
 >
 >
 > At 10:59 AM 6/29/2003 -0700, you wrote:
 > >I finally got the tracking figured out, so almost all
 > >my shots feature round stars now, but the dew killed
 > >me on this roll.  Also, I found that shooting at f/1.8
 > >causes some annoying vignetting.  I used Kodak Max 400
 > >Versatility this time.  Here are links to the shots
 > >that came out Ok:
 > >
 > >http://members.aol.com/NGC5195/20030625/sagittarius.html
 > >http://members.aol.com/NGC5195/20030625/scorpius.html
 > >http://members.aol.com/NGC5195/20030625/mars.html
 > >http://members.aol.com/NGC5195/20030625/lyr_herc.html
 > >http://members.aol.com/NGC5195/20030625/beta_oph.html
 > >
 > >EZB
 > >_______________________________________________
 > >Astro-Photo mailing list
 > >Astro-Photo@seds.org
 > >http://seds.org/mailman/listinfo/astro-photo
 >
 >
 > The book "Photoshop for Astrophotographers" is now finished!
 >
 >   Go to: http://www.astropix.com/PFA/PFA.HTM
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 > _______________________________________________
 > Astro-Photo mailing list
 > Astro-Photo@seds.org
 > http://seds.org/mailman/listinfo/astro-photo
 >


_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo