TiffsAndAstro

Hadn't even considered edge of field issues of which I'm likely to have at least some. I'll definitely concentrate on non mosaics if my new camera turns up, but I'll try and take some test data to practice with whole I wait just 9 to 15 days M31 won't be high enough to image for me for at least a couple of months. I could always swap back to my dslr for m31 if needed, I hope.

Manually? In gimp maybe? I was thinking that but not sure (yet) how I'd deal with only showing one panels overlap, if that makes sense? I was thinking just aligning by eye in gimp, but I think of a lot of things that are trickier than I initially think my plan is to align then gradient removal or gradient remove from each panel then align. I Was also thinking of taking one sub of one panel, then one on next panel etc. sort of to even out gradients and possibly not dither?

Not even installed it yet but it's the only free option I've found so far I'll keeping looking around but I doubt there's a free tool that includes plate solving. appreciate the warning though. If I get half a clear sky I can try out and see with little time wasted with this weather.

Ty but I will need to learn 2 or 3 panel mosaics via free tools just for m31. An old unsupported panarama stitching tool from Microsoft called ice might do the trick, apparently it can stick linear data together. Gradients might be an issue then, but I can experiment with removing them first. If there is a gap in clouds tonight I might try a test and see. I say three so I can have one for center of m31 and then one either side, so no chance of a seam through the middle.

Will have a look ty

that would be nice. but, orthogonal to what? currently with my stuff screwed in finger tight my dslr is where it is, if that makes sense. i don't think i could make it orthogonal to anything. im hoping i won't need to do anything from this random link i found: http://www.company7.com/library/techin/orthogonality.html i haven't had to, so far.

yes manual. i did order one origionally from flo way back, but there seemed no way to actually attach it to my optical train. i'll ask them again once i get camera set up and working as i have a feeling ill need at least some other adapters/spacers. it was only about £20. sent it back with my first scope (the one with the welded on dew shield). i think i'd like a nicer rotator at least with markings on it for orientation. looks more pro too. i think i can use it and the filter drawer to contribute to back spacing without using it all up. but who knows, lol? for £16 i wanted this https://www.svbony.com/sv210-caa-camera-angle-adjuster-for-sv550-80f6/#W9162A but it seemed a struggle to work out how/if it would fit my gear. amd i assume M48 but all those Ms really confuse me as a beginner. don't even ask about the M4 screws i bought on ebay. god knows what they really are.

yup, got confirmation email. ill do an unboxing, first light and review video lol in 9 to 15 days including custom clearance....

well, its done. tec cooled imx533, plus filter drawer plus uv/ir cut filter delivered and customs/taxes all covered (i guess we'll see) for £514. which seems a good deal. they have another 'flash sale' on reduced the price by about another £60.

Great use of a caravan. Needing a forklift makes it a tad impractical for most people

I've never seen the milky way and that makes me sad but there's still stuff I can do, even in bortle6 which it seems is not that bad. huh max, min, mean are for ADU? i thought they were something else, but not sure what that something else was, lol. higher is better? at least i have a term i can google for now ty lol. Seems lower is better and it's relative for each set up but, I can keep an eye on it in future. Better than waiting for phd2's bonging of cloud audio. I did find a tool called Fits Liberator which looks handy. Gives adu for previous taken images.

Cheers it's obviously possible as people make great images on higher bottles than me, but maybe only via narrow band. Still seems to be impossible magic to me right now

my tldr from that video. please point out anything i misunderstood 1 longer exposures gain more benefits as bortle number gets lower. 2 rather than using unity gain as a default, use it to (ideally) just fill the well depth and so preserve as much dynamic range as possible. 3 balance the above with you gear's ability to do longer exposures and things like wind and aircraft. and guiding blips. 4 somehow magically track snr as you image so as to see when diminishing gains start to occur and can at least make a slightly informed descision on when to stop. 5 don't bother cooling camera to minus one billion degrees. cool it enough so that it is a stable temperature, above freezing to avoid frosting and low enough that dark noise (i think it is) is trivial compared to light pollution noise. 6 use same gain for flats as lights cos why not 'just in case it does matter' 7 close your eyes in a very dark room and those flashes you occasionally see are actually cosmic rays hitting your retinas (ok i just added this to see if anyone read this far) ty again for linking that most excellent video.

the lower your bortle, the better it is to do longer exposures it seems. or at least lower bortle gets the most out of longer exposures?

****after watching this excellent video*** this is such a good video in so many ways (but also horrible in its implications) i can see why you linked it. no pressure or expectations on answering any/all the stuff i ask below. it would be asking a lot of anyone apart from maybe the guy in the video what temperature do you cool your 533 sensor to? because for me with bortle6 and f5.8 scope i should be able to set the imx533 to just say +2 (or even higher) centergrade and avoid ar glass window frosting if the svbony doesn't have a ar glass window heater (which is doubt it does) and swamp the read noise with just the light pollution? then i can have a single library of darks as its unlikely to be more than 32 centegrade at night in the nw uk there is talk of future sensors being able to read whatever pixels you want whenever you want. there needs to be software that can recognise (for example) the pixels of a galactic core and read them out more often then those pixels in the wisps around the edge and can get best shot noise per pixel no matter if imaging a bright or much less bright area of a target? also the sensor's outer pixels could be used for guiding? is there an equivalent or another name for "PSF signal weight" when stacking in siril because its options don't inlcude that phrase. maybe "wighted fwhm" or "noise"? also thinking about dual narrowband and osc, i think (im definately not sure as i doubt i've compared enough good images to really get a good understanding of what i personally like) i prefer broadband 'colour' over what appears to me to be a narrow range of reds for Ha and even smaller range of greenyblues for O and nit much else?. i don't mean stars i mean in nebulosity. its why i've asked here in the past if the colour in my one and a half 'decent' images is really just stretched noise resulting in colour. if its not, and its 'real' colour from the target, why don't other people seem to like it as i do? how is he measuring his diminishing returns in snr/number of subs as he continues to gather more data? is there a way in Nina? not sure how this can be used for the broadband ill be doing, even if/when i get dnb filter. not sure if lrgb directly equals osc. but then im not even sure i can combine osc with Ha + Oiii into one final result. how many exposures are required for ground based images to rival the snr of hubble and reveal feinter detail? its interesting that both lucamatico and cuiv both seemed to conclude that sub times don't really matter, but because their tests are in bortle 6/7 and bortle9 their tests wouldn't show much difference, but there would be in lower bortle areas. this is such a good video. apologies in advance, but as you have a 533 colour sensor, soon after mine arrives (if i do get it) i'll be asking you what gain (101?) what offset (+70?) and stuff like that. sorry so to sum up what is my ideal exposure length? (lol sorry couldn't resist) seems longer exposures won't hurt snr, but have disadvantages for planes, wind, blips in guiding. im not sure if there can ever be a correct answer for this question as only so many of the factors that influence it can be knowns. if i live near an airport, the likely hood of planes is higher which would suggest shorter exposures. but not too short did the video guy turn this into an online tool to so others can more calculate all this? its really weird that i thought i got better results with my dslr at iso 200 (accidentally) than the recommended 800 but set it back to 800 because that had the best noise response. i was doing 180 sec subs. a while back. i think i'd have to do as guy says lower than unity gain balanced against the amount of bright/darker of the areas of my target and balance that with my gears ability to do longer exposures and aircraft frequency? i like how the two 'presenters' towards the end clearly didn't understand the point the main guy was making lol

still watching video it will take a while. i did see a cuiv video using sharp cap info via nina to determine optimum exposure lengths and they came out at like 7 seconds or something silly. something about the only thing that really matters is swamping read noise. but im hoping your video explains this and related stuff really works and it looks like it will. many bullet points during intro main thing i can't get my head around though is if wanted signal is directly proportional to exposure time, how would a longer exposure help as long as its long enough to make the wanted signal greater than signal that is not directly proportional to exposure time. i doubt im explaining that too well, sorry. back in at least 1hr 30mins i lied. a better way to explain my question might be. even in bortal 9, the photons per sec from light pollution cannot be greater than the photons per second from a target source, else the target source could never be imaged. this i guess isn't true for the specific wavelengths used in narrow band (as light pollution is not strong in those wavelengths), but might be in broadband?

Can I ask say why one 5 mins sub is better than five 1 min subs? This seems to be quite a topic on YouTube. I would imagine longer means feinter details captured, but if stacking multiple images this might not be the case? Maybe if stacking was additive, but that would just result in blown out stacking results?

This setup should let you image process for ten years touch wood. Plenty storage is definitely useful.

For some context in case it helps, I'm using an 8 year old gaming pc to do my processing and a 9 year old MacBook pro to control my imaging sessions. Both work fine for their new uses and a newer desktop will make processing faster but for stacking etc I can go do something while I wait. Certainly fast enough for me for maybe 2 images a month cos clouds.

Nah I'm going for the tec cooled one. Seems a relative bargain if there is such a thing. Will probably have to sort a rotator separately but like you said with a square sensor its less of an immediate issue. Getting the filter drawer and UV/ir cut filter with it. https://www.svbony.com/sv605cc-camera/#F9198K-F9127A-W9184A

i think i'll skip svbony's solitary rotator offer as i think its for a specific telescope. m68 is pretty rare. does anyone know if i get a astro essentials one from flo it should still work with my gear and allow me to get back focus? seems a decent range of spacers included with the svbony? ill email them and ask i guess. also a rotator doesn't seem as vital for a square sensor. https://www.svbony.com/sv605cc-camera/#F9198K-F9127A-W9184A is there anything obvious i might have missed to check on? other adapters or anything? another slight update, svbony been replying to a few questions to me this morning and im now very impressed with their answers and speed of response. they also told me not to buy today and wait until tomorrow when the price will drop further im going to have to bite the bullet and see what happens, i think

So good you bought it twice? (Sort of). So far I haven't seen any bad comments and yours have just confirmed for me I should go for it over a 585 even with the added cost. I had a really clear and great reply from Nina at svbony clearing almost everything up. I just hope the svbony version compares reasonably well to the competitions version. Only one way to find out. I'll let forum know how I get on

not keen on eletrickery i guess ill see how i current one gets on powering both items if i can find a suitable t junction etc. and some cardboard i might even stretch it to premium cardboard.