Johnnyaardvark Posted April 16, 2015 Share Posted April 16, 2015 Think I quite like guiding... in fact super impressed with it! The skies were better than the previous night so tried some 10 minute and 5 miinute subs. Various edits/crops below. Nikon D5000, SW ED80 and FF/FR on HEQ5 Pro 4x 600s @ 640ISO and 10x 300s @ 800ISO A few darks, loads of flats no bias frames as I don't have any for 640ISO yet! Still a little noisy and lacking a little colour maybe. More processing? I feel I have had to stretch the image quite a bit anyway possible due to proximity of street lights as much as anything. Never the less quite happy with the improvement over the other night and loads of faint fuzzies in there as well Comments/feedback welcome please. Steve M51 Whirlpool Galaxy - Widefield by sja88, on Flickr M51 Whirlpool Galaxy - with IC4263, NGC5169, NGC5173 and NGC5198 by sja88, on Flickr M51 Whirlpool Galaxy - Crop by sja88, on Flickr StuartJPP and Werisit 2 Link to comment Share on other sites More sharing options...
Smithysteve Posted April 16, 2015 Share Posted April 16, 2015 Nice! Great pics of M51, and there are several other galaxies in the FOV too! It sure is Galaxy season! Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
red dwalf Posted April 16, 2015 Share Posted April 16, 2015 that has come out very nicely Steve. Link to comment Share on other sites More sharing options...
Antares_Paul Posted April 16, 2015 Share Posted April 16, 2015 Nice job Steve. I'm a widefield man myself and the first image is my pick. Thanks for sharing. Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
red dwalf Posted April 16, 2015 Share Posted April 16, 2015 have you tried dithering ? i tried it while guiding and moves the mount a tiny bit to help with noise, only works with phd 2 and nebulosity and APT, might work with other software but i only use these two. Link to comment Share on other sites More sharing options...
xanthic Posted April 16, 2015 Share Posted April 16, 2015 Nice. More subs will reduce the noise. Can I ask why you are mixing up different ISOs? Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
Stephen Posted April 16, 2015 Share Posted April 16, 2015 Nice images Steve Stephen Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted April 16, 2015 Author Share Posted April 16, 2015 (edited) Thanks all for the feedback... Nice! Great pics of M51, and there are several other galaxies in the FOV too!It sure is Galaxy season! Yes, loads of faint fuzzies in there. I like the widefield and longer exposure time for that. Shows loads of stuff that I didn't know was there. Astrometry.net plate solving found:IC 4277IC 4278IC 4257IC 4282IC 4284IC 4285NGC 5195NGC 5194NGC 5229NGC 5198NGC 5169NGC 5173IC 4263 Quite a few elliptical galaxies and some fairly bright ones! have you tried dithering ? i tried it while guiding and moves the mount a tiny bit to help with noise, only works with phd 2 and nebulosity and APT, might work with other software but i only use these two. Hi Rob, I want to give this a go but currently don't have software that will stagger my imaging to allow PHD/XXX (software) to dither between subs. I know Graham is having a go at this (I think he is using BYEOS). I have BYNikon as a trial (or did) but with out spending quite a bit on a USB to serial cable the Nikon D5000 (and most Nikons?!) are restricted to 30s subs in bulb mode. I get round this using an intervelometer (£10 of ebay) and can set a sequence of longer subs in bulb mode without problems but don't think I can easily sync this with PC software to automate the dithering. I may try it manually as with longer subs it wouldn't be impossible. I would have to take a sub, turn off PHD, dither, start PHD take a sub... repeat process. I am looking at Astro-modified DSLR's and will either go down the Canon route (but will be disappointed that I can't easily use my Nikon lenses) but will probably need a new cam for daily/holiday use at some point soon as well as my D5000 is getting old. I could also consider having my D5000 serviced and the filter removed and buy a new camera for holiday use. Would then probably get the $60 serial cable as well and buy in to BYNikon fully. Questions about this sort of stuff I will post eventually in another thread! Anyhow, certainly like the idea of dithering... Step at a time though and really happy to have got guiding up and running. Still some tweaks to do in terms of mounting the finder guider and taming cables. Nice. More subs will reduce the noise. Can I ask why you are mixing up different ISOs? Thanks Leigh. Actually the different ISO was not entirely intentional. I dropped the ISO to 640 for the longer subs as I thought it may bring noise down a little. Since my subs looked a little red (probably sky quality) I though I would try some shorter 5min subs. Was initially going to do them at 640 but then decided to up the ISO to increase the sensitivity. By the time I took my darks I thought I had stayed at 640ISO so did a few 10 minute darks and some 5 minute ones on 640ISO. So actually didn't have/use any 800ISO darks when stacking in DSS. Have to say taking darks takes a lot of time when you are using 10 minute subs so only got about 3 dark frames. Is it a no-no to use different ISO's? RE: Stacking it was just a first go with this data and decided to stack all my lights (640's and 800' ISO) only discarding 5% in the quality setting. It would be interesting to see if the following would make much difference: - adding some darks at 800ISO helps (I would have to make some 5 minute ones and they would not be at exactly the same temperature) - adding some 640ISO Bias frames. - restacking the data with only the 640ISO 10 min subs and then again with only the 800ISO 5 minute subs but probably not a great deal! Thoughts/comments welcome... Steve Edited April 16, 2015 by Johnnyaardvark Link to comment Share on other sites More sharing options...
xanthic Posted April 17, 2015 Share Posted April 17, 2015 DSLR cameras have a sweet spot where the noise is balanced with the sensitivity. I've only used Canons in the past and most of those run best at ISO800, though there are a couple of models with exceptions. It might be worth doing some test shots at 400, 800 and 1600 to see what gives the best results but bear in mind that the evening temperatures are rising and this will contribute to noise in the image. Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
wolfman_55 Posted April 17, 2015 Share Posted April 17, 2015 Great images........ Dave Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
Antares_Paul Posted April 19, 2015 Share Posted April 19, 2015 Steve - I know you know what's in the image but I was bored this morning so created an annotated image in Pixinsight. The forum didn't like the file extension so I added a link rather than the image itself. Supersize so you can have a good look around Link to comment Share on other sites More sharing options...
Antares_Paul Posted April 19, 2015 Share Posted April 19, 2015 (edited) Couldn't edit the original post above Steve - I know you know what's in the image but I was bored this morning so created an annotated image in Pixinsight. The forum didn't like the file extension so I added a link for downloading the image rather than then viewing it here. Supersize so you can have a good look around Edited April 19, 2015 by Antares_Paul Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted April 19, 2015 Author Share Posted April 19, 2015 DSLR cameras have a sweet spot where the noise is balanced with the sensitivity. I've only used Canons in the past and most of those run best at ISO800, though there are a couple of models with exceptions. It might be worth doing some test shots at 400, 800 and 1600 to see what gives the best results but bear in mind that the evening temperatures are rising and this will contribute to noise in the image. Thanks Leigh, Food for thought and will probably give that a go sometime. Mostly I think 800ISO is ok on the Nikon but 400/640 would be better if the skies are dark enough and still enough to allow longer exposures. Any thoughts on mixing ISO's? Is it worth me trying to take some 5 minute darks at 800ISO even if the temperature is a little different? and, how much difference to BIAS frames make? Did you dither when you used a DSLR? Thanks Steve Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted April 19, 2015 Author Share Posted April 19, 2015 Couldn't edit the original post above Steve - I know you know what's in the image but I was bored this morning so created an annotated image in Pixinsight. The forum didn't like the file extension so I added a link for downloading the image rather than then viewing it here. Supersize so you can have a good look around Thanks Paul. You should have been able to edit the post... are you using taptalk? It is doing some funny things for me at the moment. Did you process the image at all or just add the overlay? There were quite a few galaxies (I assumed) that astrometry did not pick up and I was not sure if they were artefacts or actual astr objects... looks like from your image they are actually things out there!! Very cool. The PGC and TYC naming conventions are new to me... what software did you use to add the names? Thanks Steve Link to comment Share on other sites More sharing options...
Antares_Paul Posted April 19, 2015 Share Posted April 19, 2015 I didn't touch your image at all. I merely image solved then annotated in Pixinsight. If I'm quick enough the edit button is still there but after a certain amount of time it disappears. Link to comment Share on other sites More sharing options...
Antares_Paul Posted April 19, 2015 Share Posted April 19, 2015 OK, to confirm. The edit box function ceases after 5 minutes. Link to comment Share on other sites More sharing options...
xanthic Posted April 20, 2015 Share Posted April 20, 2015 Thanks Leigh, Food for thought and will probably give that a go sometime. Mostly I think 800ISO is ok on the Nikon but 400/640 would be better if the skies are dark enough and still enough to allow longer exposures. Any thoughts on mixing ISO's? Is it worth me trying to take some 5 minute darks at 800ISO even if the temperature is a little different? and, how much difference to BIAS frames make? Did you dither when you used a DSLR? Thanks Steve I think the main issue would be having to do darks and flats for each ISO. Time wasted when you could be getting more data if you ask me. I never did any dithering, though I didn't do a huge amount of DSLR imaging before I moved to CCD. Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted April 20, 2015 Author Share Posted April 20, 2015 Fair comment Leigh re: Darks. Actually never thought of that... I'll mostly stick to fixed length Subs in future as well unless I am look at something with lots of contrast. Paul (and anyone who is interested) here is the annotated image with names of distant fuzzies... maybe useful since its a popular target at the moment. M51 Widefield Annotated by sja88, on Flickr Best wishes Steve Link to comment Share on other sites More sharing options...
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