Damo127 Posted June 17, 2021 Share Posted June 17, 2021 Hi all, I wanted to share this, my first ever astro photograph! I bought myself a dslr literally last week so to say i'm new at this is an understatement. It's a pretty rubbish result by others standards but i'm still kind of proud of it and the experience has already taught me a lot. I would however appreciate any pointers on how i might squeeze more out of my existing set up (Yes i know if i had better xyz but having just spent £300 on a new camera i'm not shopping for any new kit just yet) My set up for the image: Sykmax 127 telescope on Alt Az mount (Goto) Canon 700d camera attached with T ring Intervalometer to auto control shutter. I took 150 subs @ ISO 800 on 20 second exposure, 50 bias, 25 flats and 25 darks. All were done at time of capture to ensure same temp (Although the bias could have been done whenever). To shoot the flats i put camera into aperture priority. Darks were shot at same 20 second exposure. Question: How do you know how many of these to take? Is there some kind of ratio or is it driven by other parameters? To process I used SiriL as i'm on a MacBook pro (an old one - see lessons learnt below). What i've learned: 1) I'm out of frame - i should have cranked up the ISO and taken another test shot. Question - once the synscan mount is tracking, is it possible to adjust it's position, to better frame up, and the scope continue's to track or will it simply move back to where it thinks the object is? I did a 2 star alignment and then asked it to find M81. When i double checked the precision of the alignment by driving back to the reference stars i could see one of them looked low in the frame the same as the final picture. 2) I started too early. I began shooting at about 11pm. M81 happened to be in the North East where there was still quite a bit of sunlight in the hemisphere compared to when i looked more West where the sky visually appeared darker. Maybe i should have gone after a different target - i only picked M81 since it's Magnitude was around 6.5ish where as other messier targets were around 8. Or i could have simply waited another hour and half but i was too excited! 3) Buy a better T ring adapter. I got a cheap job off eBay (Was about £7) however there's quite a bit of play when inserted into the scope causing it to sag under the weight of the camera. This might explain (partially) why the framing was bad but i noticed it more when i looked at one of the flats, you can see the edge of the telescope tube cutting off the left hand corners!!! 4) Using a 10 year old MacBook which i think has 4GB RAM was a BAD idea. Stacking alone took 28 HOURS!! and this was after it had rejected around 50 of my lights due to being unable to detect enough stars. Anything less than about 23 and it said no. Fortunately i looks like i can upgrade the RAM for around £20 so that needs sorting asap. It also took me days and numerous failed attempts to get the darn thing to actually run or to stop the happy auto logging out and closing the program. I finally cracked it last night (Wednesday) and have been trying to process the image since Monday morning. I think they're the main take aways from this first attempt. If anyone know's how i might be able to extract more from the image in post then i'd love to hear. So far i've basically been following a few youtube tutorials without really understanding what i'm doing. It would have been nice to see more of the galaxies arms in the image but perhaps i just don't have enough data 😞 So far i've cropped the image a bit, stretched it, used something called background neutralisation by selecting a sample of dark sky, and removed Green noise. I have to say though that while the result isn't brilliant I kind of half expected that and the fact that i've got anything at all feels like a win. Just having all the gear rigged up and siting back and realising that i'm doing something that i'd thought about for years was a really great feeling. Look forward to all the comments on top of the great advice i've already had - remember, i'm very new to this so be gentle 7 Quote Link to comment Share on other sites More sharing options...
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