Re: [APML] STV or ST7E for guiding?...

["Jeff Crilly" <jlcapml@sbcglobal.net>]

> Jeff - I have the same ST7E (using a 102mm Vixen achromat) and it is
> indeed a beast. I use the CCDSoft 5.0 that came with mine and it does
> subframes which totally nails the download hassle. It is great. Do you
> have that software? Maybe CCDOps has subframe downloads? (i.e. click and
> drag a box around the star you are going to use and it seems to figure
> it out - was a bit of trial and error but it worked and substantially
> speeded this up for me).

I am using CCDOps for guiding.  As far as I can tell it does subpixel centroiding
which is what the STV/237 does w/ the e-finder. (Btw, my understanding
is that the St-4 does not do centroiding.)

When guiding, CCDOps also does tiny subframes.  This is acceptable.

However CCDOps doesnt do subframes when calibrating -- it needs to
take 4 full frames (or is it 5?) and the download for those is a bit long.
The problem is that the first calibrate doesnt always work... CCDOps
seems to choose the brightest star in the FOV.. if that star is close
to the edge.. tough luck.. or if it moves out of the FOV, or if another
bright star moves in the FOV during one of the movements.  Hence, the
calibrate is a hit-or-mis operation... I end up doing it about 4 times
before its calibrated.

CCDSoft5 had problems with the G11.  The old "x-y simultaneous" bug
had crept back in to the shipping version of ccdsoft.  The bisque bros
fixed it, and got me a new version last summer.  However, I've just had
better luck (?) getting CCDOps to work for calibrating and guiding.

MaximDL/CCD is indeed much better for guiding.  I tried out the
demo, but at the time couldnt justify the $340.  I'm considering of
buying the new 4.0.

For now, I'll probably stick with the ST7E and work out getting a 
shorter guidescope.  I have a 200mm fl pentax screw mount lens that
I've used for wide field... this is one approach, or a shortube.
The issue is focuser -- it has to be rigid.. hence a stellarvue
or WO or tak would qualify.  The synta (what I'm using now --
80mm f/11) is ok, but even when "locked" its not rigid.

jeff

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