ASTRO: REQ Diagnosis - 1 attachment

ASTRO: REQ Diagnosis
..
....I'm requesting diagnosis of the following image, i noticed
what i believe to be 'Coma' on the left of the frame in all the
images taken with the Pronto setup, in this image i also find
a 'Diagonal Banding or Stripes', i'm not sure if they are related,
but several questions come to mind..
...could they be related, is it possible that the objective
is not seated or not square to the optical path, could they be
products of reflection and/or flexing from my adaptors, the st4000
is pretty heavy but the pronto is also pretty stout but here again
i have no real reference.. as always TIA
..
IIIDaemon
www.GasRecovery.net

Joseph,

the "coma" could be due to the camera being tilted in the focuser. I have
similar problems with almost all of my telescopes if I use my QHY8 camer
(which has a larger chip than the ST4000).
I do not think that the "coma" is related to the stripes. Usually banding in
CCD images is caused by problems in the timing of the USB port, but then you
usually get vertical banding, not diagonal as in your image. Another source
of such artifacts could be the power supply to your camera, especially if
you were using a 12V to 110V converter on a battery.
Is the banding always at the same place or is it variable? If it varies
taking a series of images should average the bands out and it wouldn't be a
big problem...

Stefan

"Joseph Schmosovich" schrieb im Newsbeitrag
0...
ASTRO: REQ Diagnosis
.
...I'm requesting diagnosis of the following image, i noticed
what i believe to be 'Coma' on the left of the frame in all the
images taken with the Pronto setup, in this image i also find
a 'Diagonal Banding or Stripes', i'm not sure if they are related,
but several questions come to mind..
..could they be related, is it possible that the objective
is not seated or not square to the optical path, could they be
products of reflection and/or flexing from my adaptors, the st4000
is pretty heavy but the pronto is also pretty stout but here again
i have no real reference.. as always TIA
.
IIIDaemon
www.GasRecovery.net

Joseph Schmosovich wrote:
ASTRO: REQ Diagnosis
.
...I'm requesting diagnosis of the following image, i noticed
what i believe to be 'Coma' on the left of the frame in all the
images taken with the Pronto setup, in this image i also find
a 'Diagonal Banding or Stripes', i'm not sure if they are related,
but several questions come to mind..
..could they be related, is it possible that the objective
is not seated or not square to the optical path, could they be
products of reflection and/or flexing from my adaptors, the st4000
is pretty heavy but the pronto is also pretty stout but here again
i have no real reference.. as always TIA
.
IIIDaemon
www.GasRecovery.net


Diagonal banding usually means interference of some sort. Make sure
your USB line is well shielded and well away from any other line. If
the cable is longer than needed shortening it may help. Never go over 5
meters without amplifiers in the line. It can be in the computer as
well. In CCDSoft there's a box to check in setup that should be checked
labeled High Priority downloads. It can prevent internal USB
interference. I used to get some banding before I checked that box when
stretching the image beyond reasonable limits. Though it was vertical
not diagonal.

I don't know the Proto focuser but suspect it might be the cause. Are
you using thread on connection rather than a nose piece? Anything less
than threaded on connection will almost always cause this problem. As
can a focuser that can't carry the load.

Rick

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