kirkster501

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!

Of course @susan-parker Even the Hubble uses filters with a mono sensor(s). I've got two as well. I don't think mono is going anywhere but OSC are a lot more popular now with their large sensors, high efficiency and bit depth. They make an attractive device to get something in the can quickly. Is mono dead? No. But are things heading towards OSC? Possibly for many people.

A perenial favourite. The Double Cluster is a great distance from us too, about 7000 light years, out in the Perseus Arm of the galaxy. Were they at the distance of the Pleiades they would fill the night sky. Great image and nice star colour.

Imagine the surface area of the sphere of Vega's light!!! And 25 years later an almost impossibly small fraction enters your 7mm wide pupil at night. Astonishing to think. So you can calculate the photon rate per second into your eye from Vega. It's still in the millions. Repeat for some of the galaxies.... How minute we are.

So frustrating to get to Bortle 1/2 even 3 skies and it’s clouded out. Happened to me earlier this year in North Cornwall, Bortle 2, and saw the stars once in ten days. I sometimes think we emotionally associate the lower Bortles with clear skies. I know I do. But there’s no connection between the two whatsoever of course.

Yeah weather has been rubbish for astro lately. I bet the gang at FLO have invested in massive cloud machines that make us sit in front of the computer and buy things from them😂

If at some point I can produce pictures with a OSC like Peter did here - I do not have his natural ability but you get my point - I will be a very happy person indeed.

I ordered (and was delivered) a few bits last week. Thank you. I noted that the stock level was a precise number and that when you picked it for my order the stock level went down by one Glad you invest in proper stock keeping software, unlike many others.

I use Linux a lot at work. Linux runs the 21st century world. However, YMMV but I just find it just too much of a faff for my astro work. Get yourself a license for windows 10 pro from softwaregeeks or any other legal place that sell licenses for the sake of £20 or so. That would be my advice, FWIW.

You will find you won't get much detail in the spiral arms if the moon is out.

The OP point is a very valid one and i hear this said all the time. Not helped by pictures on telescope boxes etc setting the wrong expectations. To the OP, the planets are very, VERY far away. Rather like looking at a building from 20 miles away, it is still going to be small in the telescope and more magnification is not necessarily going to make it any better. You have to learn to observe.

HEQ5. Fabulous mount. Was my first GEM mount and loved it. Loads come up used on here and on ABS.

I think the current generation of OSC are so good now that they can rival in UK skies anything that a mono could. That said, i plan to get a mono QHy268 for luminance and maybe some narrowband. I'll grab the colour with OSC and abandon separate RGB channels in the future.

I'm lovin' it.

Plenty of clouds where they came from. I think the Mars opposition is going to be a wash out this year. Had my new QHY268C camera for three weeks and not had chance to properly use it yet.

I had an owl fly into me at the telescope in the middle of nowhere at 2 in the morning, I nearly cacked myself.

My limited abilities don't touch the sides of what my stuff could do in the hands of an expert allied with good skies. EDIT - hit send before I'd done accidentally... Some APODS have been done on the venerable ED80 Skywatcher. A fine telescope indeed.

A quick ten mins In the HOO Palette, here is mine and yours. Mine is using 3nm Astrodon filters. Not sure about yours Dave? That N channel is doing something weird to the colour so I removed it - I am not familiar with the HNO workflow at all. I do not have RGB in as wide a field as yours Dave so I can;t combine my stars with yours.

I think your main channels are superb. Not too sure about this palette personally though, different strokes for different folks...... I have my own LRGB version of this so will see if I can blend your M27 core object with my stars from my RGB version of M27.