Budgie1

Thanks Mike, That sorted it, all downloaded & installed. It's blowing 40 mph and chucking it down with rain up here today, so a nice day to experiment with the script.

Hi Mike, I'm having an issue with the install on a Windows 10 PC. I downloaded GHS V1 but it seemed to disappear during one of the PixInsight updates and I never tried to install it again. I can't find any files relating GHS in the PixInsight program folder or in the settings. When I try to update PI to install GHS V2 I get this: I didn't get on with V1 as I work best with the live preview, now you've added this functionality and seeing some of the results others have had, I wanted to give it another go. So any suggestions would be appreciated.

I've been using a 240s exposures since trying this but I also used 300s last night. I'm not sure there's an idea exposure time, it's more about getting the gain above the threshold so the Flats work.

What gain & offset settings are yo using? Some using the ASI294MC Pro (me included) have had issues with the flat calibration frames causing the red & green gradients in the combined image in your second post, this only seems to happen when a duel band filter, like the L-eXtreme, is used. To make the flats calibrate correctly with this filter, the answer seems to be setting the gain at 200 and the offset at 30, see the thread below: I've now used these gain & offset settings over four sessions and haven't had any issues and the flats have calibrated correctly, including the Flaming Star, which I did this weekend.

Great mind and all that, guess what I've been focusing on during these two (very rare) clear nights? https://stargazerslounge.com/topic/391814-cone-flaming-star-over-2-nights/ There's a lot more colour in yours, David, one of the hazards of using a duel-band filter on a OSC camera.

With my FOV from the garden, I'm starting to run out of nebula targets now, but I managed a couple of clear nights on the Cone & Flaming Star. I imaged the Cone until it went into the trees and then switched to the Flaming Star for rest of the night, over both nights. The Cone is 4h 52m of 240s subs and the Flaming Star is 5h 12m at the same exposure. The kit: SW Evostar 80ED DS Pro with 0.85 FR/FF ZWO ASI294MC Pro, Gain 200, Offset 30, cooled to -10°C Askar Duo-Band filter Rowan belt converted HEQ5 Captured using APT & PHD2 Stacked & processed in PI with enhancement using Topaz AI C & C's welcomed.

As it's a flex tube, is the tube fully extended? Make sure there's nothing preventing it reaching the correct stops or allowing it to go too far.

If you're using the 11mm adaptor on the front of the ASI533, you should have or can buy a 1.25" filter holder to go inside the adaptor ring. This will take the 1.25" L-eNhanse or L-eXtreme filter and enable you to use the SW field flattener.

I managed to image over two nights in a row, yesterday & Monday! Getting one clear night is a rare thing this winter, let a lone two! Anyway, I went for California & Rosette. Both imaged over two nights due to trees to my South. Fortunately I can image California and then switch back to Rosette when it clears the trees. I managed 3h52m on California and and 3h4m on Rosette. Kit: HEQ5 Evostar 80ED DS Pro with 0.85 FR/FF ASI294MC Pro cooled to -10°C Askar Duo-Band filter Images were 240s at gain 200 and offset 30, calibrated with Darks, Flats, Flat-Darks. Stacked and processed in PI with starless enhancement in Topaz DeNoise. C&C's welcomed, as always. Note for ASI294MC Pro users: On the recommendation of @PadrePeace I changed the gain & offsets settings to try & solve the issue with the flats when using a duo-band filter, in my case Askar but also L-eXtreme. I'm happy to report that using a gain of 200 & offset of 30 meant the flats calibrated with no problems at all. I was also surprised at how little noise there was in the stacked image, both of these were much cleaner than normal.

The OVL FF pushes into the 2" eyepiece mounting on the focuser, it doesn't screw on like the SW FR/FF does. The camera & spacers do screw onto the FF though.

Good job you don't live up here then, with twilight all night in the Summer, you'd never get any sleep! 🤣

You can use the 100ED DS Pro without a flattener but the edges may have odd shaped stars. I got an OVL field flattener for my 100ED DS Pro for when I wanted the full 900mm focal length with a camera.

As I understand it (and this may be corrected by others with more knowledge ) the offset setting is there to make sure that no clipping occurs to the black part of your image. When offset is at 0 the peak will be hard up against the left hand edge of the histogram, this may lead to some of the black point being lost or not recorded. Increasing the offset will move the peak to the right on the histogram and you're looking for a gap between the left hand end of the histogram and left hand side of the base of the peak. I found this article which explains it in more detail: https://daleghent.com/2020/08/understanding-camera-offset

I've saved the icons of the processes I use most in workflow order down the right hand side of the screen. Then I can load the saved icons at start up and my basic workflow is there in front of me.

If you got the mount locally and it's easy to take back then that's what I would do. You can make the adjustments yourself, as long as you're happy to do it, and there are a few tutorials which take you through it. You have to remove the black cover around the RA axis to expose the drive motor and then remove the drive motor itself. (Be careful that you don't tighten the screws too much when putting the cover back on because its quite easy to break the cover. ) The adjustment process for the worm drive gear starts at 22 minutes into this video, I think the strip-down process is in the Part 1 video:

If the clutch is fully tightened, is that all the movement or can you continue to rotate the axis if you kept pushing in one direction? If that's all the movement then I would say it's backlash in the RA worm drive gear or the motor gear needs adjusting to mesh better.

I think the benefits of using the 200 gain, as I understand it, was to bring it above a threshold were the flats would work correctly when the likes of the L-eXtreme or Duo-Band (in my case) filters were used. I've now created two Darks libraries, one with gain 120 for use with the only the UV/IR cut filter and a second with gain 200 for use with the Duo-Band filter. Did the flats work okay with this image, although I know you sorted the issue you were having with the flats with the offset setting?

I put your image through PixInsight and you've managed to clip quite a lot of the outer dust from the M51 and the two smaller galaxies have nearly faded into the background. Watch the black end of the histogram when stretching the image and don't get too close to the bottom left of the peak. Likewise, you may need to be a bit more aggressive with the middle pointer on the histogram to bring out more detail. This will lighten the background but you can mask the galaxy and make the background darker. There was still quite a lot of gradient in the top left & bottom right of the image before it was stretched, but I managed to remove most of that. You also have a faint satellite trail up the right hand side, which can be removed during stacking. If you're using DSS then set the Lights stacking perimeters to Kappa-Sigma clipping and see if that removes it. I'm sure others will be able get more out of it but here's what I managed to get:

I did this before the discussion about the gain & offset settings with ASI294MC and I still haven't had chance to try the gain 200 setting yet. The camera was set to -10°C, gain 120, offset 8 and I used 240s exposures. I don't think I used flats with this one, due to them creating gradients, so only Darks for calibration. I'm not seeing anything in your image that can't be sorted in post-processing with a reduction of green using SCNR at, say, 50% and some playing with curves.

I like this area because you get 3-4 targets in the same frame. I managed 5.5 hours back in December using the EvoStar ED80 DS Pro, ASI294MC Pro and the Askar Duo-Band filter. It'll be nice to see your finished image. 👍

Guiding is worth the effort and, once you get it setup & get used to PHD2, it's not that difficult. For Polar alignment, I use the Pro version of SharpCap which has a PA tool and is only £10 a year. Post-processing software is more of an individual thing. You'll get lot of views about which one does the best job or is easiest to use, but I'd advise using what you're comfortable with and what gives the results you're happy with. If you've started with Siril then I would stick with that and see what it can do. I'm sure there's plenty of tutorials and help out there for it. Every day's a learning day with this hobby.

I still haven't had a clear night to try the settings, I was looking last night and I've had 5 days in 2022 when it hasn't rained up here! I think you've done alright with the Rosette, there's a little movement in the stars but the nebula is good. I took the liberty of putting your image through Topaz AI DeNoise & Sharpen, nothing major with the setting, see what you think.

How are you doing the Polar Alignment and is the mount level? On my own HEQ5 the built-in spirit level has been put in on the skew, so I've fitted my own and use that.

Did you try adding the 25mm long extender on the nose of the camera to give it a bit more travel outwards?

In my link it describes four causes; mechanical, optical, natural & pixel vignetting. Yours is more likely to be one of the first two. Starting with mechanical, what size of filter are you using and are they/it in a filter wheel, filter draw or screwed into the image train somewhere? It would also be handy to know the camera make/model or sensor size and whether a field flattener or focal reducer is being used (or is this the corrector you mention)? When you did the filter-less star test, how did you do this? Did you just remove the filter or was anything else removed from the image train and, if so, was the back spacing maintained?