Re: [APML] New Images

["Stuart Heggie" <stuart.j.heggie@sympatico.ca>]

Wei-Hao, they are incredible! I simply MUST get to the top of a mountain soon!

Beauty in things exists in the mind that contemplates them.

Stuart
http://www3.sympatico.ca/stuart.j.heggie/Stuart.J.Heggie/
Flesherton, Ontario, Canada

----- Original Message ----- 
From: "Wei-Hao Wang" <whwang@gmail.com>
To: "APML" <astro-photo@seds.org>
Sent: Wednesday, August 04, 2004 5:43 PM
Subject: [APML] New Images


> Hi,
> 
> I had processed a few images from last month.  Here are the links and
> some more comments.
> 
> IC 1396
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/ic1396.htm
> The IC1396 nebula is in the center of this two-frame mosaic, i.e, it's at the
> edge of each individual frame where the image quality isn't that good.  In 
> the future, maybe I can take another frame center at IC1396 to improve
> the details.
> 
> M 31
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/m31-2004.htm
> Before I stacked the 4 exposures, I registered and calibrated them in Registar.
> The calibration makes them have roughly the same color and contrast, which
> makes easier the comparison of their S/N.  I measured their S/N in the 
> shadow region and use the square of S/N as weights.  These weights were
> asigned to each image when they were combined in Registar.  This optimizes
> the S/N of the final image.  Interestingly, if the the weight of the
> Provia 400F
> 2-hour exposure is 1.0, the weights of the Centuria 400 1.5-hour exposures 
> are all about 0.25.  Thie means, a single exposure of 2 hours on Provia 400F 
> (push 2) has higher S/N than combining 3 1.5 hour Centuria 400 exposures.
> 
> I guess this is the best I can do on a 4-in telescope.  I could make it better
> by adding more exposures.  But the investment of time is so huge that this
> is not worth doing.
> 
> M8, M20
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/m8_m20-2004.htm
> This is not very impressive.  This picture was just to fill the time gap
> between two objects.  I randomly chose an easy object that was high
> enough on the sky.  The slide comes out very well but I couldn't 
> reproduce what I see on the slide to the monitor.  
> 
> Sco-Oph Region
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/sco-oph.htm
> Although the faint nebulas do come out, their colors look kind of "flat".
> The sky on this day wasn't very transparent.  Humidity was also higher than
> usual.  Probably these are why the colors are not as impressive as I hoped.
> 
> Comments are welcome.
> 
> Cheers,
> Wei-Hao
> 
> -- 
> ________________________________________________________________
> Wei-Hao Wang  :)
> 
> Institute for Astronomy at University of Hawaii
> 
> Address:                       
> 2680 Woodlawn Drive         Personal Website:
> Honolulu, HI 96822             http://www.ifa.hawaii.edu/~wang
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