Re: [APML] Horsehead and Pleiades testshots with 6x9 camera/OAG and BRC

[Matt BenDaniel <matt@starmatt.com>]

Loke,

You're putting in a lot of time in AP, aren't you? But I guess I'm
"calling the kettle black". <g>

These are excellent images.  It's very impressive how quickly you're
getting this new setup working.

You're stacking a lot of PPF frames, but the grain is still evident (or
is just compression artifacts).  Have you considered doing tricolor TP
at f/5?  That's slower than you're used to, but still a lot faster than
what most others have.  Also, can you upload higher quality JPEG?  I see
compression artifacts.

Looks like it needs a bit of collimation; the stars halos aren't
symmetric.

The Pleiades shot is nice and deep.  I love the diffraction spikes!  I
don't care what SOME people say. <g>  Again, JPEG compression
artifacts.  Also, some vignetting.

The horsehead shot looks a little dark to me, or maybe just vignetted.

The color balance in both shots is superb. You have an excellent eye.

> From: <tan@home.com>
> >
> > Just got the chance to try out the Mitsuboshi 6x9 camera with OAG on a
> > Tak BRC250. Here are shots of the Horsehead and Pleiades Nebulas which
> > are cropped from a full 6x9 frame:
> >
> > Horsehead:
> > http://www.starryscapes.com/nebula/horsehead.html
> >
> > Pleiades:
> > http://www.starryscapes.com/clusters/pleiades.html
> >
> > These were processed rather hastily and should be considered work in
> > progress.
> >
> > A single full frame of the Horsehead (1 hour exposure) can be seen here
> > for those interested. The large version is really large so beware of
> > long downloads. The small version suffices if you want to check out
> > illumination. The larger version is better for seeing stellar spot sizes.
> >
> > Small 178kB version:
> > http://www.starryscapes.com/tmp/hh2_small.jpg
> >
> > Large 903kB version:
> > http://www.starryscapes.com/tmp/hh2.jpg
> >
> > As can be seen, there is vignetting at the very edge of the corners.
> > This could be attributable to some form of obstruction, but this is only
> > a guess. Since it is rather small, I do not think this to be critical.
> > Also noticeable is some gradual light dropoff.
> >
> > I have not empirically measured the stellar spot sizes of this
> > combination but I can tell they are small. Please judge for yourself.
> > Also noticeable is the fact that there is somewhat of a degradation of
> > spot sizes towards the edge of the 6x9 field.
> >
> > Anyway, I thought this information might be of interest to someone.
> >
> > Loke
-- 
Matt BenDaniel
http://starmatt.com

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