Delboy_Hog

Thanks Adam, that would be helpful. I've been considering doing the ED80 focuser, I've seen a couple of guides on that, and it feels like there's fewer parts to mess up / displace, but the mechanics of the mounts might be more than I dare, even if all they need is pulling apart and cleaning!

Thanks Adam, good point. Nothing super-serious on the whole - I can use it all still and you probably wouldn't know there were any issues from the images - it's just that I'd rather get it checked out and fixed up now before anything gets more of an issue, and with the nights getting shorter, it's as good a time as any! For the Star Adventurer, it's 'sticking' (best way I can describe it) at various points of rotation around its axis - and on one side more than the other. The HEQ5 has a very slight 'play' (wiggle room?) in RA and (I think) some Dec backlash thing going on. And the focuser on the ED80 isn't gripping too well any more, I'm having to tighten the little focuser screw pretty tight to keep it in place, and even then I'm a bit nervous about imaging objects high in the sky! Derek

Thanks Steve, I've asked FLO, but unfortunately their workshop is all full up at the moment. I'd clocked Rother Valley did it - delivery / postage might be brutal but I've bought from them before and they always seem reliable. Thanks for shout, I might drop them an e-mail and see what they can do.

Hi All, Does anyone have any recommendations for getting a reliable service on astronomy equipment? I'm not the handiest of people and despite the various websites and tutorials on how to do it, I worry about causing costly damage if I get it wrong. I've got a couple of bits of astro kit that I'm looking to get checked - my HEQ5 and Star Adventurer, and ideally I could use someone to look at the focuser on my ED80. Any recommendations would be much appreciated! Derek

Absolutely, I've had so much fun trying to image with the Skywatcher Mak 127 (which I see in your signature too!) on its alt-az mount. Granted I'll never win any awards for the resulting images, and at 1,500mm focal length you have to be prepared to ditch 95% of your 30s frames, but it's still fun - and very rewarding too! That said, I've hugely enjoyed having an HEQ5 and small refractor for those occasions where I need a slightly higher success rate!! And yes, on the dither, any direction at random is good. Although be aware that your mount might take more time to settle down when you nudge it in certain directions. It might not of course, but where mine will settle almost immediately in two directions (apologies, I can't remember which), it will continue to move slowly in the others for 10 - 20 seconds after I've stopped pushing the button! The dithering and settling process eats into your total imaging time, so I mean to experiment with how many frames I can get away with taking between dithers. There's a skill in getting the size of dither right. Small is fine, I gather it only needs to be a couple of pixels. I went too large to start off with and the stacking software rejected a few batches of images, though using the long focal length Mak there weren't many stars in the field of view to align - with the ED72 I think you'll be fine....good luck!

Hey LeeHore7, that's a nice looking image you've got there! Yes, as Michael says, I think it's walking noise - on an equatorial mount that doesn't have the field rotation, it appears in straight lines (I encountered this a while back, see: I scratched my Soul (nebula) - but don't know how? - Imaging - Image Processing, Help and Techniques - Stargazers Lounge Dithering has indeed helped, and having also tried this on my Alt-Az mount where I don't guide or dither, I have tried moving the mount a tiny bit between frames. Time consuming (can take a few seconds for the mount to settle afterwards), but definitely worth it. Doesn't need to be a big movement, and you can get away with doing it once every few frames if you're taking lots of them (e.g. one dither every 3-5 frames). Be prepared for having to do a fair crop of corners / edges afterwards, to account for field rotation and moving the mount to dither, especially if you're taking lots of exposures over a long period of time, but otherwise it should work fine! On a separate note (I also have a 600d), you might not need the dark frames for 30s exposures if you're dithering, especially if you're stacking 100+ frames as you did here. While the 600d is a bit of a noisy beast if you start pushing it to 2+ minutes (especially on warmer nights!), I haven't noticed much of a difference with or without darks on shorter exposures - though I should stress I am no expert, so others may disagree! Maybe have a look at the master-dark file and see how yours looks?

Thanks Eddie, I'll have to have a look at that!

I didn't figure it out I'm afraid @JemC, I found the "save files simultaneously to DSLR" option on the ASIair, so have gone back to using RAW files from the camera's memory card, rather than the FIT files from the ASIair, though would still like to know what's going on here! Because I have to break up and pack away my kit after every night, the approach I have now means I can stick the intervalomter in the camera and start taking darks while I strip down the rest of the kit, rather than having to keep the ASIair plugged and powered. Though having learned the hard way that you can't stack a combination of FIT lights and RAW calibration frames in DSS, I decided to go back to all RAW stacking. Like you @Eddie Jones, I wondered if you could just crop and process the quarter that had data in. That might still be the answer, I'm not sure, but since it didn't seem right, I was worried that some of the data might be missing / have been compressed in some way etc etc.

I've had a similar issue on a couple of different occasions (albeit with the older version of the ASIair. How far (if at all) did the mount move within the 60 steps? Yours sounds weird if things had all worked previously, although I've found some settings reset following an update to the app etc, so worth double-checking the settings are still the same as you remember. And just in case helpful, some things I got wrong at various points were: - Tried to calibrate guiding on Polaris - Plugged the ST4 cable into the ASIair rather than the camera - Hadn't given a big enough figure for the calibration steps in the guiding menu - Not provided enough power (either to the ASIair or to the mount I was trying to guide) Hopefully something helpful there. Good luck!

The other thing I'm learning is how different images look on different screens - it's very strange! I've just looked through the images on this thread again, and they look so different from my phone to the laptop, and different again on my work laptop...how on earth do you know what your image really looks like if it's different to everyone depending on their screen!?

Holy Moly, that's a lovely version - lots of faint stuff, detail in the dust lanes, and I love the colour you've got in the stars - that's something else I need to work on - it's white blobs only for me at the moment! I really must check out this Startools! What's the secondary point spread thingy?! Thanks for that - it's comforting to know that there's good stuff in the data. Like many of us, I've got a lot of projects in mind, but I've taken a number of images where I did something wrong and something doesn't work for some reason, it can get disheartening. I'm finally getting to the point where I can take a reasonable set of images....I've just got to learn what to do with them!

Many thanks for that, that's hugely helpful to hear the similarities / differences with Pixinsight. The masking is probably next on my list to learn, I think. It's a helpful one for night-landscape shots too. And yes, I definitely agree that there's a fine line on how far to push it - and it seems very easy to go that one stretch too far! I think what I've learned most from this thread is that there are other tools that I'm not yet using that can get my data a bit further in the right direction before it starts to come apart - I just need to get some experience of using those tools. The big problem I have (like everyone) is the weather. I learn new skills, but then not get the astro kit out for 2 months and have forgotten it all next time around! (Shakes fist at clouds!) Thanks again for your thoughts on the processing!

Lovely! So many good processes - I really like these - the faint stuff around the edge of the galaxy is there (that I didn't manage to bring out), but in a way that makes it distinct from the background sky. That seems to be quite an art (or science?!) - my version (albeit riddled with gradients) just seems to merge indistinctly with the background sky. That's definitely on my list of things to correct. And some people seem to be managing to bring out the dust lanes more clearly, and get some detail of a swirl in the core too - that's barely visible in my go at this - presumably that's controlling the brightness and boosting contrast, some how? I guess more data would help with that too. Thanks for taking the time to play with the data. I'm still trying to master consistently some of the steps that Vlaiv and others have kindly set out, but if anyone has any techniques they've used for galaxy processing on their own data, I'd be fascinated to hear them!

Thanks all, I'm intrigued by the different approaches, software, brightness, contrasts etc. Makes me realise just how much I've got to learn! Will definitely try again / add more data on this (preferably moonless!), and as discussed in other threads recently, I definitely still need to master flat frames! The 6d is a great camera, but certainly comes with some challenges! Hoping to get to some darker skies once we're out of lockdown too!

Thanks David, yes I suspected it wasn't the darks - and as you say, I rarely use darks with the 6d unless my exposures are 10+mins - a good dither between frames more or less does the trick there, especially in this cold weather! I would agree with you that the flip shouldn't affect the flats - it hasn't for me in the past. But this time there are artefacts that seem to be generated through the flat frames (i.e. they're not there when I just stack the lights) that are being repeated across the frame (e.g. see the light and dark smudges in the top right and bottom left of the full frame). I'm not sure if there's a light frame that the flats are correlating to that isn't stacking in the same orientation, or what's going on... The only things I can think of that would make the flats not correlate to the lights is that the white t-shirt flats technique either added some dust to the front of the scope lens (which must have blown away when I took the t-shirt off, as the lights I took after that point don't work with the flats either!) or possibly that there was some crinkle or mark on the t-shirt, or an issue with the even lighting of the screen I was using. Looking back over the frames, I also wonder if I didn't help myself by not re-framing precisely enough after I'd moved away to a brighter star to check focus. There's also some shift in the orientation (field rotation?) in the stacked frames, which you can see in the full field image above, which may not have helped my cause, though again, neither of those have been a problem for DSS before...