Datalord

So, I set up the scope this afternoon with the promise of a full night and pointed it at NGC2146, a 10.6 mag galaxy and started a 12 hour plan with 300s bin1 lum and 180s bin2 colour. Obviously the weather here gave the forecast a middle finger and I managed to get only 56 minutes. In desperation I processed what I had. I can only dream of what I could get out of this with 12 hours of data. Since these are broader spectrum filters, I guess I end up in the same conundrum with the stars, but I think I can tame them somewhat with masked stretching. Or maybe I should just go even lower on colour filters and starfields.

Wait, too high? You mean, the resolution is too high, thus i should do 2*2? Or the number is too high? Where I am now, I have [removed word] seeing all the time, so I really should only do bin2, but in the remote I hope to have better seeing.

0.52"/pixel. From what I can gather, that is ok if I have good seeing, but not good enough for anything below that. Although even with good seeing, that doesn't take into account the saturation of the well and the exposure time reduction. On the other hand, I do like the resolution of bin1. Bloody hobby...

During the few nights I've had to test out my new scope, I let it spend some time on M1. I did it before I had it properly collimated, which shows as a bit of fuss on the stars. I also need to tune the focus quite a bit, which I find to be a right pita. 15*1200 bin1 Ha and 13*1200s bin1 O3. CFF 12" RC, G3-16200 with astrodon 3nm Ha and Baader 7nm O3. Stacked in DSS (PI gave me nonsense about not being able to find star pairs), processed in PI with flats, darks, bias. One of the things I'm considering in the future is whether I should reduce the exposure time and get more frames instead. Stars become saturated and bloated quite fast and it seems like it picks up plenty of detail. 600s? 300s? Another option is to do bin2 and drizzle the data after, combine that with going down to 300s. Any advice? Finally, should I open the pocket liner and invest in 3nm O3 filters to match the Ha? will that make a notable difference in the ease of processing?

So, today I decided to just do the narrowband flats. I turned telescope up during the day, took one second shots through 3nm filters and it got me 20000 ADU flats. Easy, peasy. More fiddling needed with luminance, though...

Yeah, I have used perspex previously for flats. I'll give it a go.

Good point. I'll try the dither routine as well.

hmm, good idea. I'll try out the one I have, although it was way too bright for the RASA.

It's for the secondary mirror. Adjusting the exact spacing between primary and secondary.

I'm getting there with my new setup, but one thing is giving me concern. I can't figure out how I can get a consistent, repeatable setup for taking flats, especially considering I want to set my gear up remotely. I've heard of flip covers, but... That thingy will be in the way of any kind of screen I move in front, which means there will be space between the plate and gear giving me concerns for reflections and bad flats. Another option is shooting at the dawn sky, but my experience from the RASA tells me I will pick up stars even at fairly bright skies. Anyone with opinions or experiences on things I can try out? I'd prefer not to invest in the flipper before I am 100% certain it can work on this.

Went back and checked the individual frames. This pattern above is only present on the RGB shots, not on the luminance. So I guess it's a filter problem, but why? And how do I get RGB to work with this setup?

So, I asked the seller of the scope to have a look and he sent it on to CFF. Meanwhile, today, while I was adding some stars to my pointing model, I used Vega. Placing vega in the top left, made a clear projection in the bottom right where I essentially saw the inside of the scope, with vanes and everything. So that was definitely a reflection. Right now it is trying to tick away on some Ha and O3 on M27. I'll post a quick and dirty stack from there tomorrow.

Well, my assumption was that imaging on something extreme would reveal things I have to sort before trying fainter objects. Thanks for the comforting words.

In other words, nothing to worry about?

Hey, I have had first light with my CFF 12" RC, with a G3-16200, which is the usual nightmare of tinkering with all the stuff that needs to click. I got some reasonable focus on a took an hours worth of data on Sadr. Below is a stack of 4*180s blue WITHOUT flats, with and AutomaticBackgroundExtraction done in PI. Dustbunnies, ok, flats will deal with that. The "copycat" diffraction spike is only present in the blue. Is that a filter problem? I use Baader LRGB. The huge odd pattern, what is that?! I don't presume flats will cure that.