Quote:
Originally Posted by multiweb
Well you have tilt in your field so sort that one out first, tick that box and move to the next item.
Yeah but nah... do it visually with a Bath mask and make sure you're spot on zoomed at 400%. Then insulate your tube so you keep focus. I assume you have a MEF or other (micro focuser) on that scope right?
As I said I had a look at your raw files and I can't see much wrong with them. My feeling is that you're not 100% in focus. If you are then there's something else.
PS: get rid of that tilt adaptor as well for testing.
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1. I'm still not convinced that it is tilt as the radial pattern looks fairly even in the corners to me. (Once again, I'm happy to be proved wrong on this. I'm just not seeing any convincing arguments here).
2. I wouldn't have thought that focusing with the Bath mask would be more accurate than using the auto focuser, no worries though I can give this a shot. I have one that should fit the FSQ. It does beg the question though which is that if this was an issue, what is wrong with the auto focusing? Note that I also tried 'manually' focusing by moving the stepper motor through the focus zone in small increments until the best focus was achieved.
3. I have the Feather Touch posi drive focuser on this OTA. I has a step size of 2.3 microns which equates to 26 steps per critical focus zone for this OTA.
4. We will have to disagree on the quality of the raw files. To me they are not up to the quality I would expect to the extent that I would not bother attempting to process the data.
5. There is also an issue with registering images from this OTA which have been taken pre and post meridian resulting from the elongation of the stars in the image. This will take longer to explain so I will post a separate reply on that one.
6. The Gerd Numen M68 tilt adapter is a solid unit which comes with good recommendations from others that have used them. I specifically purchased this one as the ZWO tilt adapters have a very poor reputation. The general advice is that small pixel full frame sensors are always going to show up any foibles in the image train, particularly tilt, which I why I included one in the image train.
Thanks Marc, I hope you don't mind me challenging some of your responses. I appreciate the input and am just trying to nut my way through this
Best,
Rodney