BrendanC

Thanks all. I have to admit, the age of the camera had, frankly, passed me by! Now I look again I can see that reviews etc are ten years old, some even older. This is very long in the tooth and I'm not sure I'd even really be prepared to pay £500 for tech that old. I'm not totally discounting it, especially after what @Realtimedoctor says, but it's not top of my list any more. So, I guess I'll look into the alternatives mentioned. I liked the 'search on Astrobin' idea so I'm going to see which decent OSC model tends most to be used with a 130PDS and take it from there. Unless, of course, anyone has a strong opinion having used a cooled OSC model with a 130PDS, for the £500-£1,000 price range and can say, for definite, it works really well...?

Great advice, thank you! The FOV is a big thing, especially when moving from a DSLR. Still, as others say, perhaps there are better deals to be had with newer models. Thanks everyone for the advice and hopefully I'll make the right choice for me. Cheers, Brendan

I did not realise that. Thanks! Looks like I'll be checking out the other alternatives then.

Interesting, I've heard of RisingCam before. I would probably be looking at a second-hand QHY though, I've seen them for around the £500 mark, and I doubt there are many second-hand RisingCams around. Also the support would worry me, paying something that price.. The reason I like the QHY cam is that I keep hearing good things about it, it has a wopping great sensor, and huge pixels.

Interesting, never thought about going through Astrobin. Nice idea. I can get good guiding with my NEQ6 and 130PDS, but I'm talking about the ratio of the resolution in arc seconds per pixel between my guiding setup - a QHY QHY5L-II with AngelEyes 50mm scope - and my imaging setup. The theory is you need to have a ratio below 5:1 maximum, otherwise you're pushing it, as encapsulated here: https://astronomy.tools/calculators/guidescope_suitability I'm thinking of how the camera will fit in with the entire imaging and guiding train. So, I've done some calculations and it seems the 533 would actually be OK but as I say, I'm kind of put off by that strange square sensor. The 294 is promising, but the QHY has a much larger sensor, which I also find attractive. I'll trawl through Astrobin and take a look.

Let's assume my budget reaches to the QHY device! What advantages would you say those cameras have over it, besides being cheaper? I'm not that keen on the 533's square sensor, and both of those cameras push my guiding setup to the limits. The QHY unit has lovely big pixels that would work very nicely with it. I just wondered whether anyone actually had this combination of devices. I know there are lots of choices out there.

Such as...? I'm all ears!

Hi all, I'm thinking of taking the step from DSLR to 'proper', cooled astro cam. I mainly shoot DSOs of all types, not solar system. I'm shooting in a Bortle 4 sky currently, but may be moving to London (argh) in a year or so. I'm not ready for the expense and faff of mono, so I want to go OSC with dual-band filter, probably the L-Extreme. I keep hearing good things about the QHY8L, which would also match my guiding setup if paired with my Sky-Watcher 130PDS on an NEQ6 mount. So, does anyone think this would be a ridiculous idea, or does anyone think it's a brilliant idea, or does anyone have any comments in between? Thanks, Brendan

The Horsehead and Flame Nebula. * 6:40 hours of H-Alpha from 80x300s subs * 4:54 hours of RGB at ISO800 from 38x300s + 4x240s + 16x180s + 20x120s subs (shorter subs while object going over light polluted area, progressively longer as it moves up/across the sky) * Bortle 4, Moon average 5% phase, 15° height * 25 flats, 25 dark flats, 50 darks * Sky-Watcher 130PDS with primary baffle, NEQ6 with Rowan belt, EOS1000D minus IR filter, 7nm H-Alpha filter, 0.9x coma corrector, APT, PHD2, APP, StarTools, Photoshop, Topaz DeNoise AI

I thought that would be the answer! As with everything in this maddening, wonderful hobby, 'it depends'! Right, time to experiment...

Just bumping this one gently to see if anyone can confirm that yes, I should really ideally be exposing Ha subs until the histogram reaches further across to the right, between 1/3 and 1/2 way across. I can see that it's going to be a balance between light capture and thermal noise, but all I need to know is, should I be doing this? I think the answer is yes. If someone could just say 'yes', I'd feel much better.

Yep, I know I'm losing resolution. It's just a way of being able actually to do something during those periods when the skies are clear and the Moon is inevitably big and bright! Thanks for this, and I think I've seen that Robin Glover presentation on YouTube. I went through a load of his stuff to arrive at 240s or 300s being optimal for my use case for RGB subs, but I'm just not sure how this affects Ha subs.

Interesting idea, I'll try that, thanks! I have tested without darks before and noticed a difference, which is why I use them now. But they're a real pain and I'd very much like not to have to use them. Looks like I'll have to do some testing.

Hi all, I've started doing some Ha imaging with my trusty little modded EOS1000D to create HaRGB images and getting some decent results (to my eye anyway). However, I've been thinking about exposure times and histograms. I have a darks library that goes up to 300s sub lengths, and so I've been doing Ha subs at 300s. But, I've noticed that the histogram is very much packed to the left, obviously because of the less light let through by the filter. So, I know a lot of this game is 'try it and see' but does anyone have a view on whether I could/should consider longer sub lengths when shooting Ha, to bring the histogram further to the right and improve SNR? And presumably if I do that, I'll also need to create a darks library for them (which would be painful, creating a darks library for each temperature at, say, 600s+)? Also, is there any 'mathematical' way of estimating by how much the sub length should increase? I did once come across a page that said a 7nm filter lets through X amount less light so you need to increase your sub lengths by X to compensate, but have never been able to find it since. Thanks, Brendan

Thanks! I'm pretty accurate with my polar alignment, at least according to Sharpcap. This is by no means a showstopper. I'm getting results I'm pleased with. It's just one of those niggles that you'd rather not have and after a while you decide to try and do something about it, if you know what I mean. I think I'm going to look into cone error, using the ConeSharp utility.

Thank you @vlaiv!

Any takers?

Perfect. Thank you again, this is awesome!

Works like a charm! I'm going to test it a lot more before I let it loose on my files, but I've run a few already, made sure it can distinguish 1C from 10C etc, and it's really fast and does exactly what I want. The only request is, could the folders just be called eg 12C rather than Temp_12C? It would just fit into my system better. Very small thing really, but while I've got the chance, it would be great to get this bit sorted. Thank you again! Really, really appreciate it.

Wow!!!!! Thank you so much! I shall test this asap and get back to you. Cheers!

Hi all, When I stack images from a session that involved a meridian flip, there's always a slight rotation in the pre- and post-flip images. I don't mean the 180 degree rotation. I mean there's a misalignment, so that before and after are a few degrees out from each other. It should ideally be pretty much exactly a 180 degree rotation, but it never is. This isn't a huge problem but it bugs me, especially when I want to make as much of the image as possible for large nebula etc, which I lose because I have to crop out the artefacts around the edges. I've looked around and found this thread which, after much discussion and diagrams, didn't really end up with a definitive answer or recommendations on how to fix it: https://stargazerslounge.com/topic/280998-rotation-after-meridian-flip-why/ Is this because my scope isn't completely straight on the mount ('orthogonal' is the word, I believe)? If so, what's the best way to fix it? Would ConeSharp help, for example? (see https://www.sharpcap.co.uk/conesharp) Thanks, Brendan

I'm not exactly 'happy' with them! I've just dabbled in the past. I'm not really invested in this, was just wondering if anyone had a quick, simple solution.

Thank you Alan, that's very kind of you! I daresay other people might find such a script useful too. No need to go ahead just yet (unless of course you want to), let's see if anyone has something 'pre-baked' as it were. I might also have another stab at doing it myself. I'll let you know how I get on. Thanks again.

Possibly! I just want a quick, easy utility that would do this. I know batch files can, and shell scripts. No idea about Python.

Hi all, I find it very much easier when processing my images, to have all my files sorted into files by temperature. However, I've decided I find it tedious! And it's such a mechanistic process, I'm sure it could be automated using a .BAT file. It would do this: 1. Start in the current folder 2. Set a counter to 1 3. Look for files with '1C 'in the name 4. If there's at least one file, make a folder called 1C and move them all to it, if not then do nothing 4. Increment the counter and repeat, to look for 2C, 3C etc until, say, 30C (yes, I do have some files at that temperature believe it or not - non-cooled DSLR during height of summer) So instead of having to do this all myself, I could just run, say, sort.bat and it would do it all for me. I think it's probably fairly simple if you know what you're doing. I've dabbled in code in the past and have looked around for examples, but can't really find anything I could adapt without spending frustrating hours/days/weeks/months/years/decades/centuries/millennia/epochs/aeons getting it wrong. So, does anyone have anything like this already, or any DOS gurus willing to have a go? Thanks, Brendan