For me works this the best
Important is by all this setting what is your field of view FoV. I have Newton 25cm F4 1000mm conform spec howeverafter solved the images it was actualy 1131mm becauso of the corrector i use and important is to know your Cammera specs also
Camera gegevens
40d
Chip size : 14.8mm x 22.2mm
Pixel Size: 5.7 x 5.7
Array Size: 3888x2592
5D Mark II
Chip Size : 35.8 x 23.9 mm
Pixel Size: 6.4 x 6.4
Array Size: 5616x3744
Via the following link you can calculate the FoV
http://www.skyatnightmagazine.com/field-view-calculator
For me means with the above specs a FoV of 1.12° x 0.75° ist degrees
with some torranace you can fil in the Low and Hig Scale
[operations]
restrict scale = 0
[local]
shell = C:\cygwin\bin\bash.exe --login -c "%s"
downscale = 0
configfile = /etc/astrometry/backend.cfg
scale_units = degwidth This means what your values mean in scale low and hi
scale_low = 0.4
scale_hi = 1.71
xtra = --sigma 70 --no-plots -N none -r --objs 100
Downscale setting doesnot work for me by local solving so i set this on zero in the ini file
By the way the index files you use can be found on cygwin C:\cygwin\usr\share\astrometry\data
I have 4107 => 4119 and the whole 4207 series
Top explianation can be found at http://www.lightvortexastronomy.com/tutorial-setting-up-and-using-astrotortilla-for-plate-solving.html
hoop it helps, I am very happy with the program
I use for Capturing APT 3.11, requested at ivo if he can create grid view zo this helps with precies movement of the stars when working on the L/R or UP/DOWN
http://www.ideiki.com/astro/ this program use also All Sky Plate Solver.