A Sculptor Galaxy (NGC 253) from last night. Clouds and a tree derailed things a bit but ended up with 28x 5 minute subs (ISO800) using my modded Canon 40D win combination with my f9 ED100 (with .85x FF/FR) refractor. Captured in my red zone backyard using Sequence Generator Pro and processed in StarTools. Lots of wind initially which made for poor seeing and jumpy guiding (using an OAG) and the sky was particularly bright. In the end I was reasonably happy with the noisy result but always keen for advice. Colour is still an issue and will probably always be using the CLS-CCD filter, but the results I get not using it seem inferior in other ways. My only thought is do a greater number of shorter subs (3 minutes) or lower the ISO to 400 and stick to 5 minutes subs to help with noise. The 5 minute subs with the fiiter seem okay on this object though although perhaps I’m missing something?
Ben, considering the less than average conditions, you've managed to pull out some detail and structure so credit to you for giving it a go. I have the same filter but never use it on galaxies as I find, like you, the colour always looks a bit odd. I guess under highly light polluted skies, this filter seems the best option. I captured this galaxy a few weeks back using an unmodified canon DSLR and the colours look good. Try adding some more data using a UV/IR cut filter on your modded camera without the CLS ccd filter.
With a rather slow scope ( f9 ) and CLS ccd filter, you are forced to increase your sub length or risk more noise by upping the ISO, so it's a bit tough for you. I have also noticed the sky is brighter than normal despite the moon set and clear skies.
I hear you Peter! I’m still new to Sequence Generator Pro so really the night was also a lot about getting a work flow happening.
As for the CLS filter I think it helps counter balance the modded camera a little but really should have used my undmodded 600D on this! Just need a new dark library for it.... just when I think I’m on top of a few things! Many thanks for the suggestions :-) If I get a less windy night I’ll try some lower ISO light frames with the f5 8” Newt.
Just shows what can be achieved with even small aperture telescopes. Obviously aperture helps but it isn’t NEEDED. Of course, it all depends on the result that you’re happy with.
Here is my second crack at this using a 200mm Newtonian and an unmodded Canon 600D. Colour is much easier to manage although not necessarily right (i.e. my lack of understanding)! Taken Friday night (roughly half moon) from my red zone backyard with a camera sensor temperature around the 30C mark. Not ideal but had to try :-)
23x 5 minute guided subs, ISO400, Canon 600D, 200m f5 Newtonian on HEQ5 with Coma Corrector.
Captured using Sequence Generator Pro (still trying to work out a better start up process?), calibrated and stacked in Nebulosity and processed in StarTools.
From a light polluted location and half moon in the sky using a DSLR, you couldn't ask for any better than that! Great job on photographing and processing.
Interesting results there....
Is your modded camera fitted with a Baader replacement filter? (or similar)
Not sure Ken. I believe the 40D has just had the front filter removed? Picked it up from Diego here on iceinspace a while back. Certainly makes a difference on various Nebula and, with its battery eliminator, the sensor doesn’t run quite so hot. Still quite noisy though. 600D has a much finer noise pattern (assume it’s just the newer sensor).
Ben,
Thanks. Only checking as the normal replacement filter used in the standard Mod is also a UV-IR cut, so an additional UV-IR filter shouldn't be required......
I thought I’d try combining all my subs on this image and to my surprise it worked in Nebulosity (translation + rotation + scale). So now it’s 51x 5 minute subs. Think this is possibly the best of the three and stars are nicer too I think? First image past 4 hours :-)
On Astrobin: www.astrobin.com/314860/
As someone getting into astrophotography, it seems great. Compared to yours, mine looks "ugly" (My second astrophoto - Sculptor Galaxy).
I used ISO800. Will try ISO400 next time.
As someone getting into astrophotography, it seems great. Compared to yours, mine looks "ugly" (My second astrophoto - Sculptor Galaxy).
I used ISO800. Will try ISO400 next time.
Regards, Fernando
My first pics I don’t think I’ve ever shown anybody! Looks like you have something there in your image, just need to pull back a bit in stretching it perhaps although I’m new to this as well. Lots and lots of trial and (mostly) error! I have lots of versions of my image. I’m doing my best not to overdo anything: cop some of the noise and not always a black background so that the object seems more ‘natural’ and related to the camera and scope that took the image. Well that’s what I tell myself anyway
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