I feel like a dill. I was in a rush last night and I did check the focus of the setup before I imaged – just forgot to remove the focus mask. As a result I took an hours worth of “focus mask stars of southern Pleiades”. I had a feeling something wasn’t right, but only went up to initially move the dome – but then stopped the imaging run to check the front of the scope - DER!!! Then I swapped the positioning as Cent A was coming out of the light pea soup over Newcastle. I then started to image it and then took 53 x 3minute shots of it. Yet to process anything but I am looking forward to my first NGC5128!!!
Not to worry David, looks like your focus was slightly out anyway. Take a look at the bahtinov stars. Your centre spike is just slightly to the right of center. Then if you take a look at the centaurus A image you will see slight black dots on the edge of the field.
When I use the mask I look at it at around 200% just so I get the focus really nailed.
Not to worry David, looks like your focus was slightly out anyway. Take a look at the bahtinov stars. Your centre spike is just slightly to the right of center. Then if you take a look at the centaurus A image you will see slight black dots on the edge of the field.
When I use the mask I look at it at around 200% just so I get the focus really nailed.
gee not much in it the focus waqs entirely from back of camera on 350D - havent got the PC fixed up yet. As for the other stuff it was as i said - raw unprocessed files
Bahtinof Grabber suggests you are off focus by 0.5 pixel. Not to bad but you should be able to get closer than that. A small shift in temp may change it further.
I think we have all done this simple mistake. I did 3 hours worth one night.
Bahtinof Grabber suggests you are off focus by 0.5 pixel. Not to bad but you should be able to get closer than that. A small shift in temp may change it further.
I think we have all done this simple mistake. I did 3 hours worth one night.
Well there is room for heaps of improvement – here is a very rough and noisy (very much pushed) image. Took all of lunch to stack – this was 3 minutes worth trying to get something to look at.
repro - trying to make a silk purse out of a sows ear LOL
That's a real cool shot IMO. The soft edges are only a slight field curvature which can be corrected but the center is pin sharp. Saw you bathinov shot and that was spot on too. Then I read Paul H.'s comment about focus being a bit off and I sadly realised that I had been kidding myself all this time: I'll never be able to focus.
Really nice, round, 0.5 pixel out of focus stars Dave
You did turn 5128 into one with the lot.
Looking at the original shot, your processing really did a great job.
Allan
Then I read Paul H.'s comment about focus being a bit off and I sadly realised that I had been kidding myself all this time: I'll never be able to focus.
Maybe we should ask Paul to volunteer a shot with one perfectly focussed for comparison.
been there, done that, have the tee shirt...
the focus waqs entirely from back of camera on 350D - havent got the PC fixed up yet. As for the other stuff it was as i said - raw unprocessed files
That's a real cool shot IMO. The soft edges are only a slight field curvature which can be corrected but the center is pin sharp. Saw you bathinov shot and that was spot on too. Then I read Paul H.'s comment about focus being a bit off and I sadly realised that I had been kidding myself all this time: I'll never be able to focus. 
