have been hoping for more data, but the weather...
So, best I can do for now is 126x60second lum + 59x60second colour for a total of about 3 hours. Tried to get as close as I could to the Hubble APOD as a colour reference, so it looks pretty red. The camera is low noise, so no calibration. Vignetting is an issue with the 1.25 filters, so I have cropped the image, awaiting a decent set of sky flats. Stars need work, but will do that when/if there is more data to work with. http://www.astrobin.com/full/251726/0/?real=&mod=
Not a geat image, but probably enough to confirm that there is no major issue with the camera. Thanks for looking. Ray
So a read noise of about 1.8-1.9 ? From my calcs based on this thread that would give a required sub time for your 250f4 of ~ 62-69secs, so an actual 60s sub sounds about right (on paper). Do you think you'll continue with these acquisition settings for future LRGB images ?
Very Smooth Ray! I like it. I need to order some LRGB filters.
thanks very much Glen - fun eh?
Quote:
Originally Posted by rmuhlack
So a read noise of about 1.8-1.9 ? From my calcs based on this thread that would give a required sub time for your 250f4 of ~ 62-69secs, so an actual 60s sub sounds about right (on paper). Do you think you'll continue with these acquisition settings for future LRGB images ?
thanks Richard. While I try to work out the best way to treat the data, will continue with these settings, but the real interesting stuff will come with gain of 200 and above where 20 second subs will be optimal. Hope to gradually work up to that, but the sky will need to clear. Also want to try some NB some day.
Very impressive Ray. You must have copied some of Eric's data! Sorry, not funny.
Very sharp and detailed and I love the colour. I can see some star "fuzz" that I associate rightly or wrongly with small well cameras. So close to the formula here. Perhaps back off the gain a tad more to protect the stars more or you will have to use star masking almost from the start of your processing.
The core is nice and intact though. You probably also have some tilt as the centre stars are nice (except the brighter ones with some edge fluff) but they are off the further out you go.
60s exposures huh...? and not that many either, Wowee and a fine image to boot ..Gee back in the day, we would admire someone who eyeball guided a 2hr exposure ...I only did it once and after developing it, the negative showed it was out of focus and needless to say the guiding was rather dodgy ...never again
Nice work Ray. Detail is very nice and I like your star colour. Not 100% a fan of the galaxy colour, but it still looks good. Back ground has a quite a lot of noise left in it. It looks like colour noise but could also be noise in the luminance, so while it might be a lower noise camera I think with short subs and stretching some noise amelioration is going to be needed. That aside though, the sensitivity of the sensor is clearly obvious with 60 second subs compared to those that I do with the STXL of 20 minutes. My f ratio is quite slow but not that slow.
Resolution is very similar to mine. Watch out you'll be accused of pilfering an image too. It seems a 10" scope can trump a 20" too.
great first light Ray. camera is looking the goods.
looking forward to seeing what happens when you crank the gain and shorten the subs (and apply some flats).
are you going to hold onto the 694 chip?
What gain setting did you use?
and a fine image to boot 
...I only did it once 
and after developing it, the negative showed it was out of focus 
and needless to say the guiding was rather dodgy 
