AstroMuni

Its a nice picture. What camera have you used and what software did you use for stacking? Take a look at your darks. If there is amp glow then during processing its cancelled out leaving a dark area.

Thats a great shot. Good luck with longer exposures. Just watch out that you dont end up with elongated stars. For longer exposures the polar alignment becomes more critical. And any mount errors show up too. Having said all this 1min is very doable.

Thats a great first attempt. What software did you use to stack?

Correct. I have the ASI224mc and thats what I have done. I then screw in the 1.25" nosepiece so it can be attached to my scope.

I have noticed that and have tried to fix the wobble as best I could. Changing the focuser on this scope is beyond my skill capability

Did you notice a big difference when you swapped mirrors? I had toyed with this idea before the pandemic hit us but wanted to understand the full potential of my scope the way its built - spherical mirror and all. And technically your post can also be put in this one 😉

Great images 👍 So is your mirror from the SW 130PDS?

Here is my take on NGC6888 - The Crescent nebula taken as a set of 120 subs of 30sec each. Stacked and processed in SIRIL and finer detail worked in Gimp.

As long as the DSLR is mounted on an equatorial mount, it would still work. The pre-reqs are EQ mount, camera and control through a PC (to allow it to platesolve etc). I use ekos that can control the mount & camera and its Polar alignment tool is described quite well in this page https://www.stellarmate.com/support/ekos/align.html In a nutshell it asks you to point near the pole, takes an image and platesolves. It then asks you to rotate the mount and takes another image. It does this twice so captures 3 images. Using these it knows how far your mount axis is away from the true north. Then there is a helpful screen which guides you to align the mount. Sharpcap uses a similar process.

Thats a good suggestion. BTW, you dont need a guide scope. This can be done with the main scope itself.

Not sure if a right angled eyepiece adapter would help in this instance? Perhaps someone who has used one can comment.

Those are hard to see. You would need clear skies and high magnification to see that level of detail with your scope. You can make out the bands but not as crisply as the lovely images you see on the internet. Use stellarium or similar tool to get an idea of what to expect in terms of size. You can set the scope, eyepiece, barlow and the bortle rating in stellarium.

And hence my advice to the OP to check PA I like your detailed calculation and explanation though. As always its very comprehensive 👍

The polar alignment if accurately done should minimise tracking errors. As vlaiv has said, guiding will help for longer exposures. IMO you should be able to get atleast close to a minute without adding a guider. Are you controlling your mount via laptop? If so you can get it to platesolve and realign every few exposures. Thats what I do as I also dont have a guidescope.

Hi, In the Ekos documentation about Capture & Solve it states the following: Each time the solver is executed and returns successful results, Ekos can run on the following actions: Sync: Syncs the telescope coordinates to the solution coordinates. Slew to Target: Syncs the telescope coordinates to the solution coordinates and then slew to the target. Nothing: Just solve the image and display the solution coordinates. In general when you do a capture & solve the 'Slew to target' option is chosen. When Ekos attempts to Align the scope to a chosen target it captures an image, solves, if it notices a discrepancy it slews again. So at each of these iterations, does it sync the scope closer and closer to the target?

Beautiful

Yes, there is A Trous wavelet transform tool. @Girders If you havent already done so, you might wish to look at the Docs for SIRIL https://free-astro.org/download/siril-doc-0.9.11-en.pdf. There is a section on Planetary processing that should help.

Which of the rejection methods did you use? Also found this link that may help with running Firecapture on the Mac. https://solarchatforum.com/viewtopic.php?t=25027

Take care that you dont loosen the wrong screws. One set helps align the mirror. Also make a note of the orientation of the mirror. I put a piece of tape on both back of the cell and the OTA to tell me which way the mirror was originally oriented.

Siril is not that good with planetary stacking. You could try PIPP and AutoStakkert or Registax. EDIT: Just read again that you are using the Mac so maybe a challenge getting these to work. I use Linux and PIPP & AutoStakkert work under Wine.

Lovely. Did you use a phone adapter?

If you look at the payload capacity on skywatcher website you can see that 250P weighs 12kg. And the EQ5 mounts can carry only around 9-10 kg. So straightaway this rules it out 😞 You would probably need to go for HEQ6 to allow for extra weight you are likely to add to the train (eg. eyepieces etc.)

I am sure vlaiv can provide a detailed explanation but In a nutshell the faster the exposure the less chances of capturing any disturbances contributed by atmosphere etc. So each frame is as crisp as possible and anyway we stack several hundreds of frames to get final image so the detail is not lost.

Another alternative is Siril (a free software) that has the stacking ability and image manipulation tools. EDIT: There is StarTools as well which doesnt have stacking capabilities but good post processing. And Affinity from Serif which has both.

Welcome to the club The process of setting up and learning to get that first set of images is a steep curve but once done, its more or less a repeat of doing the same steps. But in the case of post processing there are many more variables and the learning curve is far steeper as there is a lot of jargon to be understood too.