ASTRO : M63 (sunflower galaxy)

And another try for M63.
8 x 180 sec
9 x 120 sec
7 x 90 sec
Stacked in Maximdl
Processed in CS
10"SCT
No auto guiding (working on it..)
Some vignetting occured but forgot to take flats...
Hope it doesn't show on your screen..

reg
Dirk

another nice one Dirk

Do you think the star shapes are distorted by tracking or collimation?


"D van den H" wrote in message
bel.net...
And another try for M63.
8 x 180 sec
9 x 120 sec
7 x 90 sec
Stacked in Maximdl
Processed in CS
10"SCT
No auto guiding (working on it..)
Some vignetting occured but forgot to take flats...
Hope it doesn't show on your screen..

reg
Dirk

Richard thx for the tips, in this image i really don't know. it looks like
only the upper left are effected..
Strange hey.

reg
Dirk

"Richard Crisp" wrote in message
t...
another nice one Dirk

Do you think the star shapes are distorted by tracking or collimation?


"D van den H" wrote in message
bel.net...
And another try for M63.
8 x 180 sec
9 x 120 sec
7 x 90 sec
Stacked in Maximdl
Processed in CS
10"SCT
No auto guiding (working on it..)
Some vignetting occured but forgot to take flats...
Hope it doesn't show on your screen..

reg
Dirk

D van den H wrote:

And another try for M63.
8 x 180 sec
9 x 120 sec
7 x 90 sec
Stacked in Maximdl
Processed in CS
10"SCT
No auto guiding (working on it..)
Some vignetting occured but forgot to take flats...
Hope it doesn't show on your screen..

reg
Dirk

For the short exposures you've gone rather deep. In my R model if the
collimation is correct for one side rather than the center then the
opposite side will get stars like you have in that corner. My
collimation seems temperature sensitive, winter is different than
summer. You likely don't have my temperature swings of 70C between
seasons. Also if focus is not exactly right the problem is accentuated.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Thx Rick, if i look at a single shot, it looks like a tracking error.
Other pictures don't show these assumed collimation error (which was my
first thought too)
I posted a single shot here as reference..

reg
Dirk

"Rick Johnson" wrote in message
news


D van den H wrote:

And another try for M63.
8 x 180 sec
9 x 120 sec
7 x 90 sec
Stacked in Maximdl
Processed in CS
10"SCT
No auto guiding (working on it..)
Some vignetting occured but forgot to take flats...
Hope it doesn't show on your screen..

reg
Dirk

For the short exposures you've gone rather deep. In my R model if the
collimation is correct for one side rather than the center then the
opposite side will get stars like you have in that corner. My
collimation seems temperature sensitive, winter is different than
summer. You likely don't have my temperature swings of 70C between
seasons. Also if focus is not exactly right the problem is accentuated.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

That looks a lot like a problem I had when I used the draw tube rather
than screwing on the camera using T treads. The nose would tilt a bit
when the screws to hold it in the draw tube were tightened so the camera
was no longer at right angles to the optical axis. The difference was
small but it showed in the stars. Once I went to a rigid system using
threads that wasn't a problem.

Rick


D van den H wrote:

Thx Rick, if i look at a single shot, it looks like a tracking error.
Other pictures don't show these assumed collimation error (which was my
first thought too)
I posted a single shot here as reference..

reg

Oke, i will investigate it Rick, thx for the tip.
reg
Dirk

"Rick Johnson" wrote in message
...
That looks a lot like a problem I had when I used the draw tube rather
than screwing on the camera using T treads. The nose would tilt a bit
when the screws to hold it in the draw tube were tightened so the camera
was no longer at right angles to the optical axis. The difference was
small but it showed in the stars. Once I went to a rigid system using
threads that wasn't a problem.

Rick


D van den H wrote:

Thx Rick, if i look at a single shot, it looks like a tracking error.
Other pictures don't show these assumed collimation error (which was my
first thought too)
I posted a single shot here as reference..

reg

"Rick Johnson" wrote
That looks a lot like a problem I had when I used the draw tube rather
than screwing on the camera using T treads.......

Rick, et al:

It's hard to believe how many little things like this have to work right
to get good images....... and that's *before* the atmosphere gets its chance
at messing with us!

George N