RE: [APML] Blending images: taking the best from both

["R. Scott Ireland" <ireland@gate.net>]

Using layer masking techniques in Photoshop would probably be the most
elegant way to achieve this.  One could "paint" away the brighter sky
background with as delicate a touch/brush as you wished, and this should
make the boundaries easier to work than a cut and paste technique.

If Picture Window has something comparable to layer masks, then that would
probably be the way to go.

Scott

website:  http://www.rsiphotos.com/
email:  ireland@gate.net

> -----Original Message-----
> From: owner-astro-photo@seds.org [mailto:owner-astro-photo@seds.org]On
> Behalf Of Jeff Ball
> Sent: Wednesday, March 13, 2002 7:00 PM
> To: Astro-Photo
> Subject: [APML] Blending images: taking the best from both
>
>
> I don't know if I am going to word this properly or if a technique
> already exists to do this.  I reviewed my comet Ikeya-Zhang shots with
> Fuji Provia 400 and they look good.  I shot from 15 minutes to 7
> minutes.  Driving in the car today, I thought how nice it would be if I
> could take the high signal from the 15 minute shot and the dark
> background from the 7 minute shot in a combine function.  I sent the
> slides away for scanning so I have not had a chance to work on them yet.
> I know I may run into problems when using curves to bring down the sky
> glow in the 15 minute exposure.    I am afraid I will cut out some of
> the comet tail that is just above the sky glow.  PW allows you to modify
> the amount of the input image in a combine, but, AFAIK, it does not
> permit you to selectively pick a part of the luminosity to take from
> each of the input images.  Can this be done with any current software?
> Can software be written to do this?  For instance, have the PW interface
> with the varying amount of percentage input of the image, but also have
> a histogram where one could select the points along the histogram to
> include in the combine function.  If I am thinking correctly, if this
> were available, one could find the point where the sky glow begins to
> overcome the faintest details and set the histogram combine point there.
> I do plead ignorance to many enhancing techniques and software
> capabilities.  Please excuse this post if this technique is covered
> elsewhere.  If it is, could you please put me on the right track.
> Thanks.
>
>
> Jeff Ball
> www.astro-photography.com
> Ohio Valley Astronomical Society
> www.ovas.org
>
>
>
>
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