From: sc02492 (sc02492_at_antispamdomain.not)
Date: Wed Nov 26 2003 - 08:16:27 EST
Greg, definite improvement- keep up the good work. As for Photoshop
CS, I'm seriously thinking about upgrading, if only for the 16 bit
layers feature. I will continue to use ImagesPlus for raw
conversion, calibration, alignment, and background compensation- the
program is excellent and IMO a "must have" for anyone doing digital
astrophotography. But I'm too fixed in my old habits and still use
Photoshop for subsequent processing. I currently do my initial
curves and levels adjustment in Photoshop 16 bit mode, but once I'm
done with these rough adjustments, I move into layers mode, which
unfortunately requires 8 bits. Are all layers functions in CS
compatible with 16 bits(including selective color, etc.)?
Could you provide an update regarding Photoshop CS once you've had a
chance to use it for a while?
Steve
--- In digital_astro_.at._yahoogroups.com, <gregharp_.at._s...> wrote:
> Steve, Raoul, Dennis, Tony, et al,
>
> Thanks for the pointers. I am definitely seeing some improvement
doing
> things similar to what you have suggested.
>
> http://www.pbase.com/image/23638231
>
> This image is made up of several layers (16-bit layers! Woohoo!).
At the
> bottom of the stack is the original image, of course. On top of
that is a
> copy with a feathered layer mask revealing just the nebulosity.
Adjustment
> layers (hue/saturation, levels, and color balance) are associated
with that
> layer to tweak the color and intensity.
>
> Above that are two layers of just stars, selected from the original
using
> the magic wand and copied into their own layers. These both have
levels
> adjustment layers associated with them. In the case of the dimmer
stars,
> the levels are set so that they are mostly no longer there. This
layer in
> particular also has a layer mask applied that keeps it from
affecting the
> nebulosity.
>
> I could probably play with this image for a long time.
>
> In fact, I just did some more. :)
>
> http://www.pbase.com/image/23638557
>
> That image is the previous image with an additional layer of the
nebulosity
> that has been processed using the Median filter. The blending mode
for this
> layer was set to "Lighten" and it was placed above the normal
nebulosity
> layer. The result is a much smoother and even brighter
nebulosity. I'm
> probably getting a little close to "cartoonish" in terms of the
look but I
> am just sort of playing at this point.
>
> Thanks to everyone.
>
> Ok, that's my new personal best, at least until I work on it some
more. :)
> I also have some wide field shots of the belt and sword of Orion
that I'm
> still playing with.
>
> Regarding Photoshop CS, there are several reasons I decided to go
ahead and
> upgrade:
>
> 1) RAW conversion for the 10D is now built in vs having to hack
Camera RAW's
> D60 filter. Also, there are quite a few more tweaks available in
the
> handling of RAW files including (interestingly enough) easy
adjustments for
> vignetting, etc. While I don't plan to use Adobe's RAW conversion
for
> astrophotography, I prefer it to anything else I have used for
development
> of RAW files for terrestrial photography.
>
> 2) Need I say it again: Layers (and may other features, including
some of
> the stock filters) now work with 16-bit images! I'm such a layers
addict
> (the above image has 10 layers) that I've been working strictly in
8-bit
> mode once I get to Photoshop. While we all know that the output
devices
> we're using (be they monitors or printers) are limited to 8 bits
per color
> per pixel, as we all know from astro image processing it's still
much better
> to work in 16 bits for as much of the process as possible. This
will be as
> big a boon to my terrestrial photography as it will to my
astrophotography.
>
> 3) CS has a live histogram that updates as you make changes. In my
case,
> this will mean I will begin using Curves more often, as a lack of
feedback
> in the form of a histogram has always been my main problem with
them.
> However, I haven't developed the habit yet.
>
> 4) There are quite a few new user interface features or
improvements upon
> old ones like the file browser, better automation/scripting, etc.
>
> I like it...
>
> --Greg
>
> > -----Original Message-----
> > From: sc02492 [mailto:sc02492_.at._y...]
> > Sent: Wednesday, November 26, 2003 2:09 AM
> > To: digital_astro_.at._yahoogroups.com
> > Subject: [digital_astro] Re: How do I process this?
> >
> >
> > Greg, nice shot of a difficult area. Here's a suggestion that
you
> > may already know about, but I'll mention it for others as well.
The
> > problem with these kind of shots is star bloating when you try to
> > enhance faint areas using curves. It's sometimes possible to
> > selectively enhance the nebula, without affecting the stars, by
> > using a simple Photoshop technique:
> >
> > 1. Use the magic wand to select most stars.
> > 2. Use the lasso tool on "minus" mode to remove any selected
areas
> > that inadvertently involve large sections of the objects of
interest
> > (the nebula in this case).
> > 3. Use "Select", Expand (about 6 to 8 pixels), and then Feather
> > (about 4-6 pixels). This will make a smooth transition between
the
> > stars and the background.
> > 4. Here's the trick- go to select and choose "inverse". Now you
> > have isolated only the nebula/sky areas, excluding the stars.
You
> > can make any adjustments you need (curves, selective color,
filters
> > like unsharp mask, etc.) without affecting the stars too much.
> >
> > Either way, I think you will benefit from a filter as well, as I
> > think Raoul mentioned. Finally, could you let us know how much
you
> > like the new 16 bit Photoshop?
> >
> > Steve
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