don4l

My old camera seems to have more hot pixels than normal ones, so I have several methods to deal with them. The first is dark frames. These really should be all you need with the 314L. That 285 CCD chip really is very good in this respect. My stacking software has a "remove hot pixels" option which sometimes cleans things up, but sometimes doesn't do much. For really bad cases I use Picture Window Pro V7. This has a very good "speck removal" tool hidden away under "Advanced Sharpen". This will work on a final colour tiff file. I cannot help with the autoguiding issue. I haven't even recalibrated since April or May.

Thank you for that. Your comment about different conditions on different nights makes sense to me. I use CCDStack to calibrate, align and stack. I tried PI some years ago and couldn't understand it at all. I'm using "STD sigma reject" for the data rejection. I presume this is CCDStack's name for sigma clip.

Hi vlaiv. You've written something similar recently, and I tried it out. I usually process and combine each night's data, and then combine the sub-totals. I did a comparison with a single process of several night's images, and there was a very noticeable improvement. The bit that I cannot understand is why a single batch of 21 subs of 600s should produce a better result than 3 "super-subs" of (7*600s).

Thank you! I had not spotted that all male thread. I've just realised that I don't really have a problem at F5, as I have some spacers already. My M56 to M54 adapter is 17mm. The TSM68i-M54a looks like it has an "optical length" of 7mm. If my calculations are correct, that puts me within 0.5 mm of what I need for the reducer. I don't think that will be a problem. So, thank you once again!

I'm looking at a new camera, but I am really struggling to find the adapters. If anyone has connected a G3 camera to an FSQ then I'd love to know what adapters you use. As far as I can see, the front of the Moravian 7 position filter wheel has a female M68 thread. My FSQ has M54 female at the rear for both F5 and F3.6 imaging. I cannot find anything to convert to M68 male. I'm struggling to believe that there isn't something out there. I would prefer not to have a special part machined, as I have a bad experience with this.

It is indeed. Most impressive. James Thank you both. I'm over the moon with it (so to speak) - and also my 3nm filter! The sky is looking better than last night, so it will be interesting to see the results. Last night I had to really dark adapt to see the stars in Cygnus. It isn't even dark yet, and I can already see the main stars. Camera is currently cooling.

Thank you, Geof. How did you get on with M16 last night? I tried it a couple of months ago, but it was only above the neighbour's hedge for 30 minutes each night.

What a fantastic night! Managed 210m of usable OIII on the squid. I tried this last year, but I didn't get anywhere. Here is a rough and ready (scaled down) last night's OIII on top of last years Ha,G,B.

Best night that I've had in a long time. I've managed 220 minutes of OIII on the squid in SH1129.

The sky looks black here, but the transparency must be poor. There is no hint at all of the milky way, and it took several minutes of dark adaptation to see the bottom two stars in Lyra. I can usually see them in a few seconds. Deneb was the only hint of Cygnus for a while. I've just restarted my attempt at the squid after a meridian flip. I can confirm that it doesn't show up in a 10min 2x2 sub taken through the green filter. Doh!

Wow, Brilliant.

What method are you using to get focus? I've recently acquired an EOS250, and although it makes an attempt to autofocus on Jupiter, or the moon, the results are unusable. The only way that works for me is to manually focus.

Excellent image! I've tried this through both 7 and 3 nm filters. I captured nothing at all through the 7nm, but the 3nm is very promising. I came to the conclusion that OIII is susceptible to light pollution and any moonlight (compared to Ha), and I would never have captured it with the 7nm filter.

Superb images!

Thank you! It should be fine at 805mm. Sometimes, if conditions are not great, I just do test shots with the Ha filter binned 2 x 2. Usually, a 60s or 120s exposure will give an idea of scale and brightness. It might be worth a try....

Thank you for your comments. Sorry about the delay in replying. I've been away on holiday! The Tal doesn't have much back focus, so I am using a Skywatcher ED80 with a ZWO 120mc mounted side by side with the Tal. This is far from ideal (weight and balance issues), and I hope to get a smaller guide scope at some point. I used to use the on-board guiding CCD chip on my SBIG camera. This gave trouble free guiding, but I was often very limited by the need to find a suitable guide star.

I like the first attempt at this year's data. It goes very deep. I tend to judge an image by the depth of information that it conveys, and your image has loads of detail. The reprocess looks prettier, but it isn't as impressive for me. I suppose that this is all very subjective!

This is the Crescent Nebula taken with my Tal200k. I don't normally image at 2000mm f/l because of problems with tracking, guiding and other issues. Some nights, I wouldn't even find my target at all!! When I did find the target, I would have to lose about 50% of the subs. I recently tried out my Tal and discovered that things have really improved over the last year. Platesolving, proper polar alignment, balancing the scope and a move to INDI have all made a huge difference. This image was taken between 15th and 21st June. Equipment: Tal200K F10, EQ6 Pro, STL6303 Software, CCDCiel, PHD2, CdC, CCDStack, Gimp Exposure: Ha 186m, OIII 154m (2x2), G 36, B 32m

I tried Kstars initially, but I didn't really get on with it. I had two main issues. The first is that it crashed a couple of times, and I couldn't understand what caused the crashes. The second is that it seems too tightly linked to INDI, which makes operation across multiple PC's a bit more difficult (for me?). Of course, this is purely a subjective opinion.

I've been using INDI since the beginning of May. I'm not going back to Windows/Ascom for the foreseeable future. Linux has come on in leaps and bounds since I last looked at it about 10 years ago. My system is INDI - CCDCiel, PHD2, Cartes du Ciel. TightVNC . Everything is working with remarkable stability and efficiency. As you say, it has become "mature". I'd also suggest that CCDCiel is a much more capable package than it looks. It certainly has some features that appear to be undocumented (Live stacking with auto alignment and dark subtraction, for example).

The top one for me too. Apart from the Ha, the dust lanes look better to me.

I fear that you might be right about the "addictive" part. I've already looked up Ceres. It's a bit low from here, but I might have a go with a DSLR in Spain in the not too distant future. If nothing else, it will be an interesting technical exercise.

I had a go at capturing an asteroid last week, and I was surprised at how easy it was. I didn't really understand that at Mag 9, it is fairly bright. It is moving very slowly (7" per hour), so imaged it over at least two nights to be sure that I had actually captured it - and then had a third go. The middle frame has fewer stars because it was cloudy. It clouded over as I was setting up, and I tried a shot just for the hell of it. Presumably the cloud was very thin, but I couldn't see any stars with the naked eye! This gif is composed of three frames. Each frame is 6 x 30s stacked subs, binned 2x2. Guiding was not needed. My gut feeling is that this would look quite good shot at a much shorter focal length. Camera: STL6303, Scope: Tal200k (f/l 2010mm) Mount: EQ6 Total exposure 9 minutes Dark calibrated in CCDStack and processed in the Gimp.

What are thoughts on the newish 250D? I almost ordered an 80D today when I saw the 250. It has Bluetooth, and weighs a lot less than the 80. It lacks the LCD info screen. If the noise is as low as the 80D, then it looks like a contender to me.

Lovely image. I especially like the detail in the Ha.