SilverAstro

DSS can not compensate for those parts of the sky that have rotated out of the camera frame during the 2nd and 3rd hours Ah ! what we need are circular sensors !! doh

Hehee ! Nice one , yep just a little ! Shame about the clouds

Thanks for those, I'll have a think about them, (the middle one is well rotated by 90deg but I guess that it a software/posting glitch !? ) cos I was imagining a streak due to the 'frame rotation' due to the nature of an alt-az mount that it would appear to be like a bull's-eye display, the object in the middle with a set of arc stars round it getting bigger the further out. ( Like a star trails picture round Polaris in fact ! )

and it is real difficult thinking it / typing it without being able to wave one's arms about well, I can, but you lot cant see !!! I think I need a beer , , ,

The reason for the question was this business of the proportion of streak*, it being a degree of rotation, which in the meanwhile of my domestic you are all talking about Cos I was trying to get my head round -> if they are similar scales or maybe even if they are not, the proportion of any streak due (*edit as Ian has just said !) should be the same and thus not the reason for DSS accepting the one lot compared to the other lot. and on top of all that they are both taken on the same alt-az mount so it cant be drive jitter sooooo I'm not sure where to go next with it ! * I like streak, easier to type than "field rot "

Indeed ! that is the thought that I was having that caused me to put in the > Edit : hold !! that if one did not re-align the camera with the scope (and/or celestial sphere) then it would still be limited to the 'common circle view' that was causing the Nigel crop, so I went away to have a think, , and then domestic got in the way So if two of us thunk it it must be right Any moment now we'll be back to de-rotating mechanisms !

I am sooooo pleased to hear that ! It was giving me nightmares thinking of all those luvverly subs going awol, now I can get on with the rest of my life LOL !

I cant see it ! You are right, I cant see frame rotation, interesting ! Perhaps you could post a streaky one because I dont think I have seen a picture of this frame rotation wot everyone is on about (people dont generally post their duds, but they can often be as informative, like what not to do ! as the good ones ) As you say, high in the south is supposed to be the poor direction, very interesting. Nice dumbell, nice image.

Or divide one nights set into two or three batches, stack each, rotate each by hand in software of choice, and then stack the resulting two or three combo frames ? ? ( been there, Tshirts etc, also helps with jogged tripods ) Edit : put the above on "hold" I'll have to re-think that, it may not have been my problem, perhaps it was just lens distortion in my camera lens , , , or jogged tripods ! my head hurts

Hi Steve very interesting very nice images, amazing in fact The two of Andromeda - are they full frames or cropped ? Reason I ask is, are the scales of the images as presented comparable ?

Hmmm, but what about 460EX 3 x ASI1600 and then , , oh you got there before me hmmm, how does one quote two posts when the second one you want is on a different page , , ,

Yes I remember, that will make for an interesting comparison. Good job you are not (yet) into solar ! , , lots of sun data out there today as well

I'm quite tired out just reading you ! At this rate you are going to have to take on an assistant (or three!) ( (s)he could be using the other Ha filter on one of your other rigs ) How did you get on with / finish up on that Cygnus Loop marathon ? It is a beautiful object, not so 'in yer face' as the NAN ? ! @>"running at -25°C." All the impressive sensitivity etc aside - I'm am still amazed that these things can run at that sort of temp without turning into a block of ice !! Watching with enormous interest , , ,

A fine clear night and I have taken another liberty with your pics Stars from the Ha +Ha,neb +the single O,neb (didnt notice the SII in time !) I wondered why I had lost a lot of red then realised it had turned into most of the yellow, I suppose that should happen ?

Ooops, sorry, re-read and I see you have already found the Hb ! There is also an interesting hydrogen at 21cm - but a little outside these types of sensor lol !

Thanks for that explain ( and no I dont like sulfur neiver ) ! I had been thinking that the only wanted light was that of the nebula, but now you explain I suppose the 'unwanted' is light pollution and/or the moon. Yes I am seeing now I think. Ancient physics reminds me of the Hydrogen Balmer(sp?) series producing beta gamma &etc, I have seen discussion somewhere about a Hbeta filter, but there was doubt if it was needed as it produced only the same hydrogen region image, something like that. As for DSS yep, I know, a little mysterious at times , but I have only used it for simple stacks of camera&tripod pics. of lots of short exposures. It is throwing away 1/2 your life ! so you must beat it into submission ! Good luck with the usb.

Very nice ! ( and only 2min to download on my slow 3G, followed by 1.5min whilst my lappy untangled its VirtualMemory and returned control to me ) Shame about DSS not liking 50% of your subs, wonder why that is ? Have you done any exposures in white/mono light and/or RG&B ? with it for comparison. Presumably the 5nm filter cuts out a lot / needs a lot longer exposure ( me never having done anything like this should probably ask that in the beginners section ! ) ie. in what way does the 5nm image differ from, for example, a broad band red as given by a moded dslr (apart from needed exposure duration and noise !? )

Sorry ! my bad, my age showing, they used to be swapfiles and pagefiles and things in days of yore ! So that isnt the problem then, I mean not mis-set silly big or silly small by some misfortune

Agreed, not the prob then, as long as your Swapfile is on C ? Might it be on D ? but why has the m/c become slow, 4GB RAM wouldnt explain it unless it used to be somewhat bigger and evaporated ! and is your swapfile still the same size as you thought it was, oh and did it get defragged as well, to make sure you have a contiguous big one for max speed you need to , , , ask an expert cos it is a long time since I did this on mine !! something like make it small, then defrag, then make it large again ? or the other way round ? Just a few random thoughts for your consideration, prob a load of old . . . !

Defragment recently ? Is it possible that the auto defragger has been turned off ? I dunno Win7, but Vista has a built-in defragger that is normally enabled and runs in the background but it can be turned off ( like mine is, hmm that reminds me, I must do a defrag ! )

I think the first one was the real one, just that it was photographed from the other side and you are in fact an alien. Now you are trying to pretend

That is a bit shocking ! A cheap low class supply may produce 21v off-load and drop to reg 13v on load. But I would not have expected that of a Maplin one ( or would I ? ! ) Did you measure that while it was supplying your mount, or open-ended ? Have you something unimportant to hang on it to see ?

Gosh yours is a big one, mine's only little Actually, my equipment used to be a 6" Newt and a camera on a tripod. But the Newt is retired ( nackered mirror coating after 50y, needs redoing but not worth the cost ?) and daughter has made off with the tripod, but give me a wee while and I may figure out how to get my camera to selfie hand-held in the dark !! edit, ooops forgot to mention my binos.

Great pic ! I like the composition, "I've got my eye on you" or ( taking cue from your other posts ) " I've not got all the gear I want yet but I'm on my way" How did you avoid star trail in 25sec ? and that is an interesting part of UM, you split Mizar-Alcor pair !

An interesting read but I am bothered about his second NA pic., the 'mouse over' one. How can you get more red light by interposing a filter ! More contrast yes, but not more light which is what he seems to be implying?, and makes it look like, in that example. However, he has committed a basic sin of comparative experiments (!), he has changed two variables at once, a ) inserted a filter and b ) changed the method of exposure. I would like to see that replicated by someone else.