Re: Re:[APML] orion mosaic

["D. Kodama" <kodama@alumni.caltech.edu>]

Wei-Hao,

Fantastic mosaics!  It's amazing to me that you can turn out these mosaics
while pursuing a PhD!

It's interesting that the Witch Head shows up quite well in your R-channel
shot.  Most people reproduce that as an almost pure blue object, but for a
long time I've felt that wasn't quite accurate.   It could be that they
are trying to color-balance the background and losing the red because of
so much h-alpha emission in the general area.

When registering the components of a large mosaic covering a large part of
the sky, what are you using as an overall registration reference?

Dave Kodama




> Hi,
>
> Thanks for the comments from everyone.
>
> Robert, how do you think about this:
> http://www.ifa.hawaii.edu/~wang/misc/Orion__R.jpg  ?
> I enhanced the R channel to to bring out the faintest H-alpha light in
> this image.
> The "standard version" in the webpage had relatively little curve
> stretch.  This is
> to preserve the full dynamical range of this field, instead of
> emphasizing the depth.
>
> One of the difficulties I had when flat-fielding this image was that
> there is H-alpha
> emission almost everywhere.  This made the identification of "background"
> regions very difficult and tricky.  Indeed, I believe some large
> scale, faint H-alpha
> emission was removed from the image by my imperfect flat fielding.  This
> is the
> main limiting factor of how deep I can go.
>
> The crowded star field in the upper left is part of Milky Way.  See this:
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/WinterMilkWay2003.htm
>
> Cheers,
>
> Wei-Hao
>
> ps, My US visa doesn't allow me to make money outside the campus.  So
> there
> won't be any commercialized posters from me in the near future, I guess.
>
> --
> ________________________________________________________________
> 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
> ________________________________________________________________
> _______________________________________________
> 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