Budgie1

If you're using DSS then at the bottom of lower window, where the image list appears, you can add groups. So, the first night you can add the Lights, Darks, Flats & Flat Darks into the Main Group window. Then put in the Lights, Flats & Dark Flats from the second night into Group 1.....etc and stack them all together. If you use the same exposure settings & sensor temp for both nights then you only need to one set of Darks, likewise, if you left the kit setup and didn't move the camera or focus then you may get away with only using the one set of Flats & Dark Flats as well.

You've got a lot more good data in there, Chris. Try to stretch it a bit more and make sure you don't cut off the black by trying to make the background too dark during the stretch. You can tone this down afterwards. You don't say what software you're using but I put your stack through my normal work flow in PixInsight and came up with the image below. I didn't want to remove the purple on the right of the image in case it was a star, so I left it in there. You can see the extra amount of detail in the Crescent and the extra background nebulosity there is in there.

In basic form, it automates the process. You set the amount of noise reduction you want and press GO. The good thing about this script/process is that it removes noise from the background but leaves the detail in the main target. The default noise reduction is 0.9 on the slider, but I found this is a bit too much in most cases. Somewhere between 0.6 & 0.8 will eliminate most of the noise without making the image look too flat & false. It's worth trying the free trial, even if just to see what it does.

Yep, NoiseXTerminator is at the top of the Software list. Here's the main NoiseXterminator page with the download link: https://www.rc-astro.com/resources/NoiseXTerminator/

If DBE & ABE aren't working then process it normally to a starless background, then you can use SCNR to remove the green cast (30% should do it). For the purple try Scripts > Utilities > CorrectMagentaStars and run it with default settings. Just running these two, quickly on your attached file does the job:

The two pictures I ordered from My Picture arrived in the post this morning. The printing is good but I have to say that the one of the Elephant Trunk came out better than the Rosette. This is strange because the Rosette image I uploaded was 2124 x 1443, where as the Elephant Trunk was from my website at only 1200 x 800. The brightness on both is fine and so is the detail. Taking a photo of them this evening with a mobile doesn't really do them justice, but here you go:

The files should be in the PixInsight program folder, here's where mine are and what they're called: The original StarNet has now been replaced with StarNet2, which I linked too on the first page of this thread. This is a much improved version on the original, so I would download that one. I think Steve - @teoria_del_big_bang also put a link to a tutorial for how to install StarNet2 in PI.

Even later to the party but I didn't get time to have a go until this evening. Anyway, here's what I managed to do with the data using h46 & o65 and put through PI. The stars are not very good, the colour is okay but they're a bit eggy. I used StarXTerminator to separate the stars so I could work on the nebula and spent more time on that than the stars, so maybe should have done more with those.

You say "you try to slew to object and it just gets stuck. ", do either of the axis actually move with the hand controller or just don't respond at all? It may sound obvious but are the cables to both axis pushed fully home?

Hi Ed, Some don't have an issue using NB duel band filter with the ASI294MC Pro, others do. After swapping to gain 200 and offset 30 when using NB filters, the flats work just fine for me. Have a read through this thread, which explains it better than I can:

If you have a camera with setpoint (TEC) cooling, you can make the temperature the same. I normally set my ASI294MC Pro to -10°C for everything. If you have one of the fan cooled Altair cameras then I'd say it would be best to do the darks at the same time as the lights, to make sure the sensor temps are the same.

Yes, I've created a Darks Library for each gain & offset I use, and each has the full range of exposure settings I'm likely to need. A nice job for a rainy day, which we get a lot of up here!

I use APT for imaging. I take 30 darks for each exposure length, off scope with the cover over the camera sensor, and they cancel out the amp-glow with no issues. The reason I use a gain of 200 with NB filters is because I, a many others, have had issues with the flats not working correctly on the ASI294MC Pro with the gain at 120. Others have found that with a gain setting of 200, the flats work fine. You may also find that long exposure flats work better with this sensor as well, anything upto 3-4 seconds. In the Lights menu under Settings, I use Kappa Sigma Clipping. Under RGB Channels Background Calibration > "RGB Channels Background Calibration" is ticked. On the Background Calibrations - Options window > Calibration Method is "Rational" and "RGB Channels Background Calibration Method" is "Minimum". This removed the green cast on the stacked image. The thing to remember is that these two cameras share the same sensor but the internals and firmware will be different, so you may have to play with the settings above to get what's right for the Altair.

I don't know about the PS version of StarXTerminator, but the PI version has a tick box marked "Generate Star Image" and in StarNet2 for PI it's called "Create starmask". When used it creates a second image with only the stars and leaves the starless version in the original image. When adding the stars back in, I just use PixelMath to add them together.

I have the ZWO camera with the same sensor and it also has the amp-glow you describe. In my case the amp-glow is removed by the darks and I've used DSS & PI for stacking. One thing I did find is that there's a residual of the amp-glow remaining if I used Bias frames in the stack. So now I only use darks, flats & flat darks. I'm not sure I can help with the gain & offset settings, as I think they're different in the Altair, but on the ZWO I use gain of 120 with a UV/IR cut filter and 200 if I'm using the L-eXtreme or Askar Duo-Band filters. Offset for both I use 30, which is the default with the ASCOM driver. Not much help, I know, but it may give you something to go on.

I'm not sure what software you use for processing but StarNet2 and StarXTerminator are both very good. Although they both allow you to remove the stars from the image, the stars are not lost, both of these also create an image with just the stars, which allows you to work on the stars and the background image separately. When you've finished processing both of them, you can put them back together again. Working on background (nebula or galaxy) and the stars separately means you have more control over the adjustments you make. It also makes is easier if you want to use SHO or HOO for the main target and add RGB stars.

I don't know if you can get replacements, but they are glued to the lower leg tube. I know this because one of mine has come loose and I have to make sure I don't leave it stuck in the law when I pack up for the night.

....not forgetting the cushion & mug versions! Isn't there an "unsubscribe" link at the bottom of their promo emails? I think I must have used it because I don't get any from them.

I've also used My Picture for canvas prints, I'm currently waiting on two arriving. The first one I had done was of the Orion Nebula and I made the image the same size as the canvas I requested and uploaded it in either TIFF or PNG, I can't remember. I found the print was a little on dark side, compared to the image I uploaded, so this time I brightened the images a little to compensate and we'll see what they turn out like.

What file format were they before you converted them to TIF and how did you do the conversion?

One other thing to try; I notice you have the Observation Date filled in, did you click on the "Acquire from image" button? If so, close the PCC window and then open it again, do the object search and then manually add the focal length & pixel size. Then run it again to see if it plate solves. This may not have any bearing on it, but I normally just type the details in and leave the ob data at the default.

So the focal length is 480mm then, not that 2mm should matter on this. Try the Canadian or UK database server from the drop-down at the top of the PCC window. If that doesn't work, could you post the image and I'll try it?

If you used your Evostar 80ED with the 0.85 reducer/flattener, then change the focal length to 510mm, instead of 478mm on the PCC data input. If it still doesn't plate solve then try a different database server.

I've been using NoiseXT in PI on a couple of re-processed images and it seems quite good. Soooo much faster than EZ Denoise, which is what I was using. Like Steve above, I found using a Denoise setting of 0.6 to 0.7 and leaving the Detail setting at 0.15 reduces the background noise nicely, without making it look too smooth and false. On non-linear images, it also works well to reduce the noise created by some processing, especially on the background. I found an initial setting of 0.4 or 0.5 worked well for this and meant I didn't need to use Topaz Denoise on the final image, which actually don't do the job as well as NoiseXT. Overall, I'm happy to keep using NoiseXT in place of EZ-Denoise & Topaz Denoise.

As above, do the flats work okay? Longer exposure flats do tend to work better then short ones with this camera. I used to use sky flats, normally the morning after, but recently I've started using my Samsung Tab A6 with an app called LightBox and that seems to work well with the t-shirt. I create the flats at the end of the session and then I can put everything away. The app is dimable and has worked successfully with both UV/IR cut & NB filters. Obviously, I'm using my Evostar 100ED DS Pro or 80ED DS Pro, so the tablet screen covers the end of the scope and you may not be able to use this if your scope opening is larger.