Jezphil

Thanks Olly. I’m using Deep Sky Stacker for this. Will try the ‘groups’ function and allocate darks/flats to each group and of course maximise my lights. I don’t know where that leaves me with the algorithm.

Just checked this out in Deep Sky Stacker. Makes complete sense now. Hadn’t used that ‘groups’ function before.

Thanks. Don’t the darks get rid of hot pixels though? Might these not be in different places on subsequent nights?

Cooled CDD Astro cam.

Okay, got it. Thanks

Thanks. This is really useful. I use DSS so will try this. Need to look at the software to figure out that last bit though. So do you put respective dark frames in with each group and you need an unticked frame for it to know that there the different dark frames apply to different groups?

I've got two sets of Ha subs of the same DSO from different nights. Ignoring how closely they are matched in framing terms for the purposes of this question, which of the following would be correct? 1 The best result would come from stacking the first and second days's subs separately and then combining them. 2. Best result is to stack all the subs from both nights in one go. 3 Doesn't make any difference. My (beginner) feeling is that it is best to treat them as two sets and stack separately so that each can benefit from its own dark flats to eradicate hot pixels which might vary from one night to the next. If so, another question arises...if you did this, would you then combine the unstretched masters and stretch them as one, or stretch them individually? I'm thinking most likely the latter. Can't believe how quickly astrophotography has turned me into someone who loves nerdy questions like this 🤪 but I'm very interested to hear what you clever folk here think. Thanks in advance.

Thank you!

Just checking here as a I think I discovered the answer to this the hard way on Friday night. I took some subs and with my software marked three key stars and saved those markers and coordinates. In the middle of the session I did a meridian flip. I loaded in the x-marks-the-spot markers to align the post-flip stars with the pre-flip ones but none of the stars seems to match. I realise now this must have been because my camera would have been turned upside down by 180 degrees during the flip. Would that make sense?

Yes, Streatham Hill.

I tried out the software over two nights with my first attempt at a CDD narrowband target - Melotte 15. The marker crosses were a huge help - I could get an SII shot nicely aligned with an Ha one from a previous night and there are lots of other good features, as described in your tutorials, Carole. Thanks for your assistance. Still a beginner's final result, but happy with what I got and I am properly hooked. This image is from my Bortle 8 south London garden.

Just viewed these and they are super useful - thanks so much for posting. Plenty of tips I didn't know about - in particular, how the negative function can be so useful for nebulas, and until watching this I hadn't understood the two sequencing order options - can now see how the 1,2...1,2...1,2 choice works, which looks like a great one to use.

Ah - yes, of course. Got it. Nice solution. - sounds obvious now but I hadn't twigged. I did actually ask Atik about this and they simply told me Artemis 'has its limitations', so thanks for your answer as their response was, ahem, less than helpful. Definitely sticking with Artemis now, especially with its star markers. Re Dusk: they said they'd kept it simple 'for new users'. But yes, surely too simple, even for me.

I managed to do a real world comparison of Artemis and Dusk last night, dodging between a few clouds. Among other aspects, I think one of the great features of Artemis is the star marker function where you can store locations of stars from a previous session and match them exactly for another night's data gathering (as mentioned above by Carole). A brilliant feature, but this function was for some reason dropped for Dusk. Looking at the sequencer function of Artemis, does it only allow you load in the same number of images for each sequence? So if you are leaving it set up to go through sequences for three narrowband filters, automatically changing the filter for the second and third sets, are you stuck with a set number of exposures for each sequence? i.e. the number you have entered into the 'repeat count' window in the sequencer window? In other words, what if you wanted to vary repeat counts and do, say, 20 for Ha, 25 for OIII and 30 for SII? It doesn't seem to allow a different number for each sequence. Or is this me being dumb? (it has been known!)

Artemis on a PC 👍

All solved now and it is up and running well. Thanks for all your help and advice!

Ah!!! There it is! Lurking in the depths. No need to apologise - your help has been amazing. Thanks so much.

Thanks Ian. This link leads to a page titled 'Capture' and has a button 'download capture for Windows'. All very promising, until you download it. You get a file that offers a menu of options: Dawn, Dusk, Infinity, but unfortunately nothing named 'Artemis' or 'Capture' which is bizarre. If you have a zip file, that would be brilliant!

Hi Carole. Okay, I tried out Dusk last night and yes, it is really lacking, as you and others have helpfully pointed out above. I've always been a die hard Mac user, but picked up a PC this morning as so much astrophotography software is geared towards Windows PCs and I've finally relented (plus, my Mac was getting VERY dew-covered outdoors last night which was concerning). I've downloaded Atik Infinity for Windows, but it is the latest version which looks quite basic, like Dusk, with the same awful histogram. Please can I take up your offer of getting hold of the previous version of the software? Jez

I can't find this unfortunately. However, I just found that dragging two fingers (laptop set up, no mouse) seems to give a zoom. The crosshairs also zoom off and away across the screen, so that's far from ideal. The only RHS of the display button/option is a square with for arrows in that re-centres the crosshairs. Thanks for your response - will try this out tomorrow night.

Hi Carole Thank you for this really helpful reply and kind offer - much appreciated. Understood re the looping and that clears up a big question for me. I'd seen some of the forum discussion on how Artemis had much better functions and it looks good in Atik's online tutorial. I don't know if Artemis is useable on a Mac which I'm using, and will check that out. There's a great cloudless night our way tomorrow (fingers crossed), so I'll see how I manage with Dusk for the time being.

I’m using a CCD camera and Atik Dusk (with Atik 460EX) for the first time so forgive them basic nature of these two questions… 1. I’m viewing what the camera sees by looking at the looped exposures and can alter the speed of the looping with exposure length and binning. So it’s not a ‘live view’ and there are delays between frames. Is this the only way of seeing what the camera sees? Does it not offer a live view? 2. The looped image window takes up less than a quarter of the display screen. It is tiny. When I have cross hairs displayed on the screen, the looped image window gets placed in the tope left quarter. Why is it so small? Should the rest of the frame be taken up with a live view? Why aren't the cross hairs over the centre of the looped image window? Thanks in advance.

When it got into the StellarMate section I was lost. I am connecting directly, so thanks for the tip.

Thanks. Okay. I've used ASTAP previously, but as a stacking software alternative to Starry Sky Stacker. Looking at the KStars and Ekos... KStars is pretty straight forward, similar to SkySafari which I have been using. Ekos and INDI are a bit baffling even after watching online videos. Where can you get tuition for setting up and understanding these things? Would pay £40 per hour of Zoom time for help to get my head around this. Any takers?

Thanks. Have downloaded ASTAP and EKOS. Looks baffling but will try to find my way through 😬