BrendanC

Thanks! It's a nice cluster isn't it? Although I was confused when I realised there are two Beehive Clusters, M44 and M48! I thought I'd find stars and clusters a bit dull compared to planets, galaxies and nebulae, but they're strangely satisfying with those colours. The colour was brought out when I post-processed in StarTools and Photoshop.

25 minutes of M44, 60 frames, 50 bias, 50 darks, no flats.

Just checked and I had that option switched on, both for camera and PC, so now I've switched it off and let's see if it works. Thanks!

So if it's just a tag, does that mean that my camera could still take something in portrait, even if I want it in landscape, but it would then just be displayed landscape? I can't get my head around all this. I'll just try it and see. If I really do have to rotate the OTA so the camera reliably takes shots in landscape, I guess I'll just have to do that.

@happy-kat I'm sure I've tried that but I'll take another look tonight, thanks. @Ouroboros Doesn't that just affect how the image is displayed, not the actual landscape/portrait orientation of the image itself? No matter, I'll try that too! Again, thanks for the suggestion.

I've recently realised why my DSLR sometimes does portrait and sometimes landscape. It's nothing to do with how I attach it to the scope. It's to do with whether the scope is pointing more upright or more horizontal. It switches automatically because of, from what I've read, sensors that tell it when to do portrait or landscape, depending on which way it's facing. Or something. It's really irritating. I've just noticed it's even switched from one to the other midway through a shooting session. This will probably affect my framing and stacking, and cause all my bright stars to have weirdly spaced, multiple diffraction spikes. One fix is to rotate the whole OTA so that the DSLR is always pointing up. I'd rather not do this because I'd like to keep the option of using the eyepiece, which would be rotated to a weird angle. Also it will be harder to access the camera for battery changes etc. A much better fix would be simply to tell the darned thing always to shoot in landscape, or always to shoot in portrait. But I cannot seem to find any way to do this. There are 'landscape' and 'portrait' modes, but they also enhance the image in strange ways that I don't want them enhancing. Or do I need to create a custom mode? Does anyone have a fix for this? It's a Canon EOS1000D but I expect this issue (and, hopefully, fix) applies to similar models.

If you're interested in a modded DSLR, this is where I got mine from and whereas it might cost a little more, I've been very pleased with the results from my lowly EOS1000D and the service is good too: https://www.cheapastrophotography.com/

This is probably heresy, but what do people think of using the Google Photos filters on their astro photos? I tend to find that, after spending ages on a photo, and then uploading it to Google Photos, if I apply a filter it almost invariably looks better! This annoys me. I don't want my photos to look better after being put through a poxy filter, I want them to look worse. I want them to be fine after I've diligently spend hours on them. Humans good, algorithms bad. Or, if I just think it looks better, is that ok? Should I stop worrying and learn to love Google Photos?

There are things wrong with this image - overexposed and non-round stars for example - but I thought I'd post it all the same.

No problem, and thanks for the response.

Oooh, that's a good one. Ta! Praise be for Ben the Ignorant. :)

Thanks everyone for the helpful suggestions! As luck would have it, I did actually find an entire leg for sale on Astroboot, for 16 quid, so that's not too bad (even if delivery costs £13!) Totally get what you're saying about the clamp being riveted, so it looks like maybe replacing the whole leg is in fact the best (and perhaps only) solution to this. I just wanted to have it as pristine as possible, and I won't be overtightening them any time in future...

Thanks for the suggestion but I'd rather have something that looks 'right'. The clamp still works but it looks a bit rough. The mid term plan is to sell and upgrade and I'd be happier selling something in as mint condition as possible. I'm surprised they're not more readily available as spares online.

Good call, but no joy I'm afraid. I'll just keep checking. Thanks for the recommendation!

So, I overtightened one of the all-too-flimsy height adjustment clamps on the tripod legs and fractured it (see photo). I've tried gluing it but it didn't take. The photo makes it look a lot worse than it is - in reality you can barely notice it and it doesn't really affect the operation because it still holds the leg in place - but I'd rather either fix it or replace it. For fixing it, does anyone have a recommendation for glue that will definitely work? I guess I could just strap it with duck tape. For replacing it (my preferred option, in case I ever want to sell this), I've looked around and can't seem to find this as something that can be bought separately. Any recommendations on that score?

I know, I know, lots of this one taken before and I've already submitted mine, but after seeing what StarTools can do I gave it another go, properly this time, by actually following an actual tutorial. I have to say, I'm very impressed and have bought a license. So much detail revealed that I didn't know existed. This is with my setup as per my signature, bringing together frames from two separate shoots which total around 250, plus 50 darks and biases, no flats. I had to crop out more than I wanted because of stacking artefacts but managed to keep the Running Man nebula in (one lot of frames was portrait, the other landscape, hence the double diffraction spikes on some stars) and I added a luminosity layer in Photoshop just to finish it off (which might have pushed it over the edge, not decided yet), but I'm pleased with this one. I wanted to get M42 as good as possible as it's really my first proper stab at a DSO, and now I feel a bit more confident moving ahead to others. Total inspiration from this forum I have to say. Post-edit: And now, having watched the StarTools demo by Ivo Jager who developed it, I can already see that I've overdone the deconvolution because I have those dark rings around my stars... https://www.youtube.com/watch?v=hqm4mB2TKN0&t=6s Oh well, I'll try again and do it better! (but don't worry, I won't repost here)

Thanks all. I was just wondering whether dithering - as in, changing the optical train, as you say - was something I should be doing given I'm not guiding and if so, whether that would be a hardware (camera/scope/mount) or software setting. I'm going to leave dithering for another time. This was really about calibration and I'm happier with that now.

Brilliant, thanks all. It's very much clearer now. I actually tried using darks in DSS and it really didn't work out. I think this could be why - it's just not suitable for my situation. I might try again sometime, but I'll also experiment with just flats. Nice to know that I can do the flats after the shoot too rather than sticking around in the cold and dark, Gollum-like. I'll also think about whether or not to use AV focus. I just did it because I read somewhere that you should, but I can see it introduces something random into the process that should be under control. Finally, @Pompey Monkey I'm not guiding, but when you say I should be dithering, do you mean I should be whether or not I'm guiding? In which case, is this something I should be looking at my camera to control (Canon EOS1000D), or software? I thought DSS could handle this sort of thing? I realise this isn't strictly related to calibration but I'd like to tie this final one off, now I'm a bit clearer on the other stuff.

Thanks for this, really appreciate the feedback - and here we go again... When you say "Otoh, darks don't always work with non-cooled dslrs, and you replace them with bias frames." Does this mean that, given I'm using a non-cooled DSLR, I should forget about darks and use bias frames instead? "You can also replace flat darks with bias frames." Does this mean I can, or I should? And if I replace dark flats with bias too, then does this mean I don't need to bother with darks at all? In which case 'the recipe' becomes: ANY TIME Bias - 50 frames, optics covered, exposure time=shortest DURING SHOOT Flats - 25 with the cap off, diffuse white frames eg t-shirt with light behind it or morning sun, exposure=AV mode Yes? No? Somewhere in between?

There are lots of links out there, all of which claim to be 'the definitive guide' but every time I read one, I notice that they've said something that makes no sense, or they're unclear about a certain specific part of it, or there's a huge debate that ensues around very obscure technicalities. I just want to know whether this extraordinarily basic 'recipe' I've come up with, for my specific situation of having a DSLR, could work, as very, very, very, very basic starting point, as a general rule. without going into any specifics whatsoever.

I know, I know, this has been discussed endlessly here and elsewhere, but I've read lots and watched lots and some of it I understood and some of it I didn't. A lot of it I didn't, actually, mainly because every time I think I get it, someone else contradicts what I think I've 'got'. I've reduced it all to this, regardless of the number of lights I take, assuming I'm using a DSLR, with all the below steps at the same ISO value as the shoot: ANY TIME Bias - 50 frames with the cap on, exposure time=shortest DURING SHOOT Darks - 50 with the cap on, exposure=as per shoot Dark Flats - 25 with the cap on, exposure=AV mode Flats - 25 with the cap off, diffuse white frames eg t-shirt with light behind it or morning sun, exposure=AV mode I know everyone has their own take on this (which is kind of my problem understanding it) but, reducing this to the very, very, very basics, as a starting point for a total noob with calibration... would this work?

I tried Star Tools but couldn't really get to grips with it. Perhaps I'll give it another go, see what I can get out of my original M42 files having seen these great examples.

Hot dang, I hate it when people take better photos than mine! That's really nice, great colours.

Nice one, thanks. I'm also going to try and get my head around this: https://www.reddit.com/r/astrophotography/comments/426yef/a_brief_guide_to_calibration_frames_darks_flats/

So in theory I could just take some now, assuming I'm using the same settings such as exposure time and ISO?