PhilB61

Interested in your decision, is this based on the quality of images, reduced noise etc from some back to back testing of various settings. I've generally left my AA26c in HCG and gain 100 more because I don't want to waste precious imaging time with experimentation, so am interested in your findings.

Image looks great, just needs lots more total exposure time to reduce the noise. My experience using clone and heal tools is that it's best to do so after stretching your image. If you do it on linear data, initially it may look better but when you later stretch the image, the clone/heal "repairs" stand out like a sore thumb. I have not found a way to do a temporary screen stretch in GIMP to assist in working on linear data, and would also be interested in hearing of any way of doing the this.

Works without errors for me on a Windows 11 pc, although gradient removal output seems noisier than previous version. Need to test on a few more images.

Lot's of good info above about which scope to take, Whatever you decide factor in at least a couple of evenings getting to grips with setting up, alignment etc, ideally before the trip otherwise you may have a very frustrating experience. Lot's of beginners post regarding issues with setting times, location and getting accurate alignment and Goto's. Some "testing" can be accomplished in the daytime.

I'm sure FLO will sort you with the correct adapter so long as you have told them exactly what your image train is. From my recollection the SW72 has an unusual focus tube thread pitch but FLO had some adapters specifically made. The only issue you may have is that without the rotator the camera may end up at an unusual angle when fully screwed on. This was not an issue with the slide in nose piece as you could obviously tighten up in any orientation.

If you get it to work I'd be interested to see the results. I've avoided drizzling mainly because of the massive increase in file size and resultant impact on processing speed etc. It is my understanding that it's mainly beneficial where you are undersampled in relation to your seeing conditions, and that in addition to dithering, you need a lot of subs to counter the increased noise that drizzle introduces. If you are only marginally undersampled and don't have many subs it may have a negative effect on your images, in addition to the obvious strains on your processing pc.

I would agree in general that the hassle may be greater than the benefits. However, it will depend to some extent on how accurately your mount currently tracks, what exposure times you use, and what focal length/image scale you are operating at. I suppose it comes don't to what issues do you have that you think guiding may resolve?If you are getting elongated stars, are you certain your polar alignment is accurate enough, could you reduce exposure length and just stack more? If you want to try guiding I would forget about PEC for now and just get basic guiding running, setup your system to guide directly to the mount from your pc or device, don't do it via the ST4 port, otherwise you will have to recalibrate on every new target. You will have to run a guide calibration at the start of each session if you break down your equipment. This will take about 2 -4 minutes, after that the time overhead will be about 30sec on each new target for the guider to acquire a guide star(s) and to settle. Be aware that touching the scope to alter focus, re-center etc may cause the guide star to be temporarily lost.

Don't underestimate the size of the telescope, all the ones you have listed are fairly large and will take up a fair bit of space both in storage and transport. Obviously I don't know your circumstances, so it might not be an issue, especially if you have a garage or shed for storage, but just something to consider. I think any of those scopes would give great views, and especially if you can get to a dark site.

I would also try a direct cable run to your PC ie not too through the iOptron USB hub, it won't be as neat but just for elimination purposes, it's worth testing.

So long as you get a good calibration near the location that PHD2 suggests, then no need to recalibrate either on different targets or after meridian flip. PHD2 knows where the mount is pointing and what side of pier and makes all the necessary adjustments. I'm a bit lazy and will often use the same calibration for many sessions so long as all my equipment is the same and assembled in the same orientation.

Do you know if that dither number is 7 pixels of the guide camera or of the imaging camera? I dither every 3rd or 4th sub on 120sec exposures. I think it's a good idea to experiment and see what works best for your setup. My comment regarding the guiding figures was in relation to your second image. If you look next to your rms figures you will see in brackets (0.00") that is your guiding figure in arcsec but for some reason yours is not being displayed. I would guess there is some missing info either in NINA or PHD2 relating to guide scope focal length or guide camera pixel size. Regarding your flats, If they are taken in the same session they should look very similar. If they are vastly different I would want to know why as yes that could mess up calibration. Having a uniform and consistent light source is necessary, I found taking sky flats didn't work for me and now use an Android tablet, display a pure white image and regulate brightness with sheets of white paper. Stars in your last image look good and round, at least on my phone.

No need to recalibrate guiding on every new target provided you are guiding directly through your pc and not using the ST4 port. As mentioned above you need set up a profile with guide camera and scope details directly in PHD2 using the new profile wizard if you have not already done. The guide rms figures are currently in px's so if your guide camera scale is say 4arcsec/px then you actual rms is 4 x 0.35= 1.4 arcsec which may account for the elongated stars you are seeing. This error will be more or less depending on your actual guide camera image scale.

I think they are both very good and that you are correct in that Sharpcap is more suited to planetary and NINA for DSO. In addition to image acquisition Sharpcap has tools for sensor analysis and polar alignment (with paid version) but it does not integrate with or control your mount or other peripherals. On the other hand NINA will integrate with every aspect of your system camera, mount, guider, focuser, plate solver, and much more and help you plan and implement a complete imaging session from start to finish. A typical session for me would be polar alignment with 3PPA plugin, focusing, target planning, schedule of image acquisition, dithering etc, slew to target, plate solve and sync, start guider, cool camera, start taking images, order into files and folders as specified, automated meridian flip etc and at end of session park telescope and warm camera, transfer photos to main pc. However it is easy enough to start simple and add in the more elements as you progress. If you have used earlier versions of Photoshop then Gimp will feel quite familiar, very similar tools, icons and layout. It's a powerful piece of software but obviously lacks some of the more recent tools of it's paid for competitors.

Regarding laptop/desktop pc acquisition software I think I have tried many/most of the current free/donation ware Windows packages available including NINA, APT, Backyard Nikon, Sharpcap ASICap, Firecapture, Altair Capture etc. Some are more aimed and suited to EEA or Planetary imaging and others more for long exposure DSO imaging. For me NINA is the stand out best, not just in terms of it's flexibility and overall functionality but also for it's user interface. Like all software there is a learning curve, but it's pretty short due to the intuitive layout of the menu's etc. For stacking I now exclusively use Siril, previously I used DSS but this now seems dated, Siril gives much more options at the pre processing and stacking stages, but at the expense of greater complexity to master. For planetary I have used Pipp, Registax and Autostakkert with success. For post processing of dso stacked images, again I primarily use Siril, together with Starnet and GraXpert, and for final tweaks I may use GIMP (similar to earlier Photoshop versions but free) You may notice that most of the above are open source, free or donation software but this does not imply that they are poor or inferior products, in fact many are cutting edge and in ongoing development. I do have one piece of paid for processing software which is Startools, I still occasionally use it but more often I prefer the results achieved using Siril, probably more a reflection on me than any deficiency in the software though. You could just download them all and have a play, see which ones you like most. In addition to the above there are also a number of paid for software packages, with a range of costs. At this stage I would say there is no need to go down that route but it maybe something to consider in the future when you have a better idea of what you want/need.

I understand that mounting left or right side is dependent on which firmware version. Left side is normal unless you have updated to a firmware version which allows EQ and Alt/Az modes, in which case you must mount on the right side. You can tell if you have the EQ firmware version as you are asked to select which mode to use at startup.