Hello Bob,

I've just downloaded the PinPoint trial, as I may want to upgrade to it for use with MaxPoint and/or CCD AutoPilot. I've run into some problems.

Short Version: I found an anomaly in scale sizes when solving with GSC, and could not get USNO A2 solves to work at all. I will buy the product if I can get USNO A2 solves working.

Details: Since I've had trouble "hitting the target" and want to get into automation of mosaics, I am testing Pinpoint full version on XP with 2 GB RAM, and (though not yet relevant), MaxImDL Suite (with MaxPoint), CCD Autopilot, Focus Max, all on a CGEM mount and a QHY8L color CCD that is 7.8um pixels square, an APS-C chip that is 23.65mm x 15.72mm, and 3032x2016 in pixels. The scope I used to take my test shots with is an EdgeHD 9.25 @ 2350mm @ f/10. That means my FOVI (according to TheSkyX) is 34.60 arcminutes x 23.00 arcminutes. This *should* be a scale of roughly 0.684 arc-seconds per pixel, in both X and Y (depending on where I have my primary locked down).

Here's what I have run into thus far, attempting to plate solve some raw subs near NGC 6888 from August 11. I know the actual location (in J2000) from TheSky.

Problem 1:

GSC 1.1 works. It solved an image (in 55 seconds -- it had to do a spiral, since there was some doubt as to the exact location) and gave me:

1179 image stars found
(doing spiral search)
444 catalog stars found
Solved using 46 of max 500, RMS residual is 0.01, order = 4
Solution took 55.4 seconds
Centerpoint RA = 20h 17m 22.589s Dec = 30 17' 00.08"
WCS: Roll = -4.40 HScale = 0.554 VScale = 0.890
PA = 184.403
FWHM = 1.18 arcsec
Zeropoint = 19.12 (1 sec.)

Now, I know this solve is correct (it nailed the RA/Dec of stars I inadvertently shot while trying to hit NGC 6888, the Crescent Nebula -- I missed by a couple fields of view, even with a Celestron Precise Goto!), and it also correctly nailed my position angle (which I know from a PEMPro run that session). However, why does it think my HScale and VScale are so clearly different than the known values? Why aren't they symmetrical, since I have square pixels?

Note that the frames I am using were inadvertently shot with a RED filter, but I still have "R" selected as Color Band in PinPoint Solver. Guiding was not great -- there is some 30-40% eccentricity in the stars according to CCD Inspector.

Problem 2:

I was doing the above in Test Mode (no WCS), and when I had to provide the RA and Dec (it wasn't in the header), I made sure "write data to FITS" was unchecked. However, it was altering my original FITS files, at the end of the solve (whether successful or not). I know it was the end, as I could watch the timestamp change in realtime, in Windows Explorer. Should it be modifying my masters, if I've asked it not to?

Problem 3:

I tried to switch to USNO A2.0 for epoch accuracy. I have not yet had a single successful solve on an image using A2, despite giving it many different additional guided frames from the same run, giving it the exact center as reported above by GSC-ACT (20.2974 RA, 38.2767 Dec). I have tried both scales of both 0.684, and using the scales as reported by the GSC run, to no avail. I've tried letting it do a 5x5 mosaic @ 120 seconds per field with 40% expansion. Took almost an hour. Nada.

I have used the Catalog checker to confirm that my USNO A2 catalog is in good order. It is.

Problem 4:

At some point during one of my USNO A2 attempts, I got a Runtime Error:

-2147220451 (8004041d)
The property has not been set: TargetRightAscension

I have a screen shot of this if you need it.

My primary concern is to get USNO A2 solves working. If I can do that, I'm buying the product. If I can't, I would imagine that PinPoint LE that comes with MaxPoint would be sufficient for my needs.

I can provide sample FITS images if you need them to test on your own, but for now, here is just one of the FITS headers (note that I appear to need to update my MaxIm scope definition -- the true Focal Length is 2350, and Aperture is 235 since I upgraded to an Edge HD recently).

SIMPLE = T
BITPIX = 16 /8 unsigned int, 16 & 32 int, -32 & -64 real
NAXIS = 2 /number of axes
NAXIS1 = 3040 /fastest changing axis
NAXIS2 = 2016 /next to fastest changing axis
BSCALE = 1.0000000000000000 /physical = BZERO + BSCALE*array_value
BZERO = 32768.000000000000 /physical = BZERO + BSCALE*array_value
DATE-OBS = '2011-08-11T06:57:25' /YYYY-MM-DDThh:mm:ss observation start, UT
EXPTIME = 300.00000000000000 /Exposure time in seconds
EXPOSURE = 300.00000000000000 /Exposure time in seconds
SET-TEMP = -10.000000000000000 /CCD temperature setpoint in C
CCD-TEMP = -10.446927826179945 /CCD temperature at start of exposure in C
XPIXSZ = 7.7999999999999998 /Pixel Width in microns (after binning)
YPIXSZ = 7.7999999999999998 /Pixel Height in microns (after binning)
XBINNING = 1 /Binning factor in width
YBINNING = 1 /Binning factor in height
XORGSUBF = 0 /Subframe X position in binned pixels
YORGSUBF = 0 /Subframe Y position in binned pixels
IMAGETYP = 'Light Frame' / Type of image
SITELAT = '40 20 22' / Latitude of the imaging location
SITELONG = '-75 59 36' / Longitude of the imaging location
JD = 2455784.7898726850 /Julian Date at start of exposure
FOCALLEN = 2032.0000000000000 /Focal length of telescope in mm
APTDIA = 203.19999694824219 /Aperture diameter of telescope in mm
APTAREA = 29252.214751229785 /Aperture area of telescope in mm^2
EGAIN = 0.50000000000000000 /Electronic gain in e-/ADU
SWCREATE = 'MaxIm DL Version 5.15' /Name of software that created the image
SBSTDVER = 'SBFITSEXT Version 1.0' /Version of SBFITSEXT standard in effect
OBJECT = ' '
TELESCOP = ' ' / telescope used to acquire this image
INSTRUME = 'QHYCCD QHY8L'
OBSERVER = ' '
NOTES = ' '
FLIPSTAT = ' '
SWOWNER = 'Jeffrey Woods' / Licensed owner of software
INPUTFMT = 'FITS ' / Format of file from which image was read

Thanks for any feedback you can provide.

Jeff Woods
Reading, PA