I did 25x300 of Christmas Tree, is the Rosette near, as in the bottom right corner I have a donut shaped occurance, which, if it was Rosette, I would have thought it would have come out more pronounced.
Also, whe stacking with my flats, the image is black & I cannot get anything out of it, so thinking I have a flats problem
Also, down the left side of the stacked image, I have a black line, about 1/2" in & a 1/4 inch black rectangle at the top. On the Right side, there is a black rectangle bottom right.
I did restack a couple of times, Mark, but it is still there & I had to crop the sides. All these problems I have never had before.
I have done a few tests on desktop, results:
If I stack 25x300 Lum in DSS, I get the line & black rectangles
If I stack 25x300 plus flats & flat darks, it only uses 1x300 Lum. Hence why I cannot get anything out of it.
Have you got a Flat marked as a Dark ?
Sounds like DSS is seeing a particularly bright frame and averaging out the rest accordingly.
Sort of sounds logical :oops:
Well, this is a 3x300 stack from Stairs Farm
Things in common= dedicated 0.8 FR/ ED80 & clip in filter
(http://farm5.static.flickr.com/4032/4438254524_0404baee1c_b.jpg)
It is clear that rotation has taken place over the course of the imaging session - DSS will tell you how much it had to de-rotate each frame to align the stars.
This happens when polar alignment is slightly off - the subs will rotate around the guide star.
Mark
Mark I stacked again & info for each sub was:
1/ 0 8 0 1 angle 0 0
2/ 65 3 56 7 0.5
3/ 0 0 0 0 0.0
are these the figures you mean?
Also , would this be the answer to the prog only stacking 1x300 when using the flats?
Thanks Mark
Hi Fay,
I got something similar to this when I did stacking in DSS when I was doing unguided imaging (only mine was a lot worse than that with black steps and several lines as the frames rotated). I agree with Mark that the box and line is where a frame has shifted.
No idea why it only stacked one luminance frame, but that also happened to me once in DSS, I never got to the bottom of that.
Carole
Hi Fay, I have have the same doughnut in the corner of my frames. Thought it must be amp glow.
Duncan, I thought you had a donut as well!
Yes,Fay. Those are the figures I mean.
Dunno why it only stacks one frame when using darks/flats. Is there a "quality threshhold" parameter somewhere, I wonder?
Doughnut at bottom right of a 350D frame is amp glow. Here's an example: http://www.markshelley.co.uk/Astronomy/Projects/mkiiframeafter.jpg
To combat this, you should take darks immediately after imaging - while the CCD is still warm.
Mark
I have got 100% ticked for quality, did not do darks just flats/ flat darks
Hi Fay, I would use 80-90% in the quality box so DSS uses only the best lights.
Ok, I know why only one light frame was being stacked when using flats & flat darks.......i was selecting the flats & dark flats in the wrong order................
Glad there was a simple explanation.
I've never taken a flat dark in my life. I would guess that they're only required if you are using a dim light source (hence long exposure) for your flats.