kirkster501

When it works, SGP is great. When it throws a wobble it can be very frustrating and the formal "support" is almost none-existent. There are many things that trip it up. I am in process of moving to NINA but we are so short of clear nights of late that I don't want to waste time learning new software!

Yeah, thanks Steve, maybe I need to lower my expectations and it is just bad seeing.

Yeah, that's the problem mate, readjusting back to reality.

Hi all, I noticed that PhD2 (2.6.9) seems to be much more fussy about its guide stars and even a very high, almost imperceptible, haze that is very light will set it off chirping and force a sequence abandon in SGP or NINA. It's so fussy now that if we were to wait for the desert skies it seems to expect then we'd never image anything in the UK. Is there a way to tell it to be more tolerant - or to tell SGP or NINA to be more accepting of what it is being fed from PhD2???? I must surely have something set wrong since I set this new PC up. I never recall it being so bad before. I am forever in sequence recovery mode even with very, very light haze passing by that used to go unnoticed by PhD. Thanks, Steve

Hi all, Got an infuriating issue. I'm on the way for a perfect "V" autofocus and then the very last sample will suddenly go down wrecking the autofocus and forcing it to rerun. Often requires three complete AF runs and sometimes abandons it. Any thoughts as to why this is happening please? I've messed with my step size, number of samples, backlash etc Sometimes it works perfectly. When it has a wobble It is always the last sample to the left This one just about worked. Is there a way to set the tolerance in SGP? I am moving to NINA shortly so I am sure SGHP is cursing me...! Thanks, Steve

It is a night and day difference. The quality of the subs is in a different league altogether and faint detail is not washed out by the LP. LP filters can only do so much, despite the claims on their wavelength charts. Even with NB some LP leaks into even very tight bandpass filters, even 3nm ones.

I used the SplitCFA on the master flat, equalised the levels of each and recombined with MergeCFA. This makes a more "aggressive" flat. I did a test preprocess to a final master of CFA adjusted flat and the regular flat and compared the two. I looked at the pixel by pixel levels of the two final outcomes all over the image at about forty places. There is no difference at all.

Wow, what a great job and well done. Much of what you discuss could be applied to other scopes too.

...clouded over after four subs this time 🙄 Boy you need patience to be an astronomer in the UK......

I've not finished the pic as yet, it was just a quick blast at a process in light of my earlier issues. Acquiring this data has proved extremely frustrating. At the moment it is a total of about 45 x 180s subs, acquired in five or six sub separate occasions through the clouds. It just keep clouding over all the time. It's out again capturing now to add to this 45 count hopefully before it either clouds over (again) or disappears over my roof at about 11 O'clock.

..so as Olly said, the flats were OK. I was expecting them to show much more vignetting than they do. Just shows how wide the flat field is on the FSQ85.

Very quick and dirty process. I did all the preprocessing manually and a quick stretch and colour boost. But it looks OK and no vignetting.

....I'm very much learning CMOS OSC processing but making progress, little step by little step.

I used the SplitCFA process to split the master flat into the four channels, linear fitted them to the weakest channel then reassembled them in MergeCFA. It gives a more "flatlike" flat I found as per my top post because this then equalises the intensity of the different types of light from the flat panel.

I am going to try again Olly but finished my lunch now so back at work I will look again later on. Thanks mate. Are the numbers above with the first flat or the "CFA flat" ?

Thanks Olly. Yes, maybe I am expecting to see too much of a fall off. I have measured it and it is about 20% even though it does not look like that here. Also, should not stretch the linear flat at all for display purposes. The histogram is not as the left anyway with a flat frame! My bad.

.... they don't look "enough" like a flat although there is a fractional amount of the vignet towards the corners. But I expected a lot more. Yes Olly, already doing a stretch but a very low one. We'll work it out Dave! , It is indeed somewhat different preprocessing CMOS than CCD.

This is a display issue I think with SGP and CFA images with a brighter object. Obviously a real image is very much fainter than a flats panel. I'm looking into it. The individual flats are grey - as should be expected - but they look wrong and not like a flat. Unless I am mistaken and the vignetting is less than I think. Scope is a FSQ85 without reducer so does have a wide, flst field.... ?

Hi all, Been doing some captures with my OSC CMOS QHY268C. This is my first CMOS deep sky and I am impressed with it. All going well apart from one problem. My flats look bonkers.... You can see the ADU is clearly 27000. So why is the screen completely white and not a "flat" ??? The ADU is 27000 on all the individual flat files. Why is SGP showing the capture at only 27000 totally whited out? The resultant master flat is not calibrating out the vignetting properly on the lights. Look at the master flat above. It is incorrect representation of the true amount of vignetting The only way round this is to De CFA the master flat, linear fit all components and remerge the four channels again. When I do that I get this, which looks much more like a flat and it works much better. However having to do this rules out the use of the batch pre-processing script. Any thoughts as to what is going on please folks? Regards, Steve

Holy thread revival. How did you get on? You should not have "optimise dark frames" ticked in WBPP with a CMOS sensor - OSC or mono. Darks should match lights exactly in exposure. Flat-darks should match exactly flats. Dark current is not linear in CMOS sensors so you cannot optimise darks. You debayer after image calibration. You should cosmetically correct immediatly before image registration.

Nicely done and great galaxy with good colour. You've got a slight gradient running up to the top. Super work.

It's very nice. Well done, a big investment in telescope time and it has paid off. I am always in two minds on SHO and HOO images I do. Whether to remove the NB stars and put RGB ones in their place by doing 40 mins each in RGB. On the one hand is meant to be a narrowband image and as a consequence contain narrowband stars. On the other hand RGB stars look more natural. Steve

Yeah, trying to collimate at the end of a long day to get a spot of observing in and being impatient to get to the EP is never the best time! As I found last night! That's why I do all my DSO imaging with refractors nowadays. SCT is visual and for planetary AP.

I am convinced I have sussed it out with the laser holographic method - a very fast way ( two minutes) to get it 99.9% there in the day time. I just tried it during a snatched fifteen minutes between work Zoom calls. I will see tonight hopefully and will report back.

Wanted to do some Mars observing last night. Collimation was not bad on my C925 anyway, but ever being the perfectionist, thought I'd give it a tweak. Hmmm, and another, and another, you know how it is, and messed it all up and it's now miles out. Thing is, when I tweak the screws (Bobs Knobs) it moves the star out of the camera FoV so I have to keep bringing it back into the FoV and that gets to be a real PITA very quickly. So next clear night got to sort it out - and will do so visually 🙈. So I wasted a great (rare with skies of late) opportunity to do some Mars observing and imaging!🙈 I may try my holographic laser method and try to do this during daylight hours. I'm not worried and familiar enough with collimation and done it ten billion times and maybe I was just tired last night and should have just enjoyed and left it alone! So the moral of the story is..... if it's not too bad then don't mess with it!