CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
Hi... this is my first M42 shot
Telescope: XLT 150 (Newtonian) (f/5)
Camera: D5000, un-modded and without any special filter
Exposures: 20x15sec, stacked using DSS, processing - Photoshop
ISO 400
I guess I should have taken more frames for stacking. I saw pictures of M42 taken at 60 sec or even more. I tried a few 60 sec shots but (at ISO400) but they seemed to be way too overexposed. Is it that exposure time will be shorter if you are not using filter? I still need to learn how to go about systematically with photoshop processing. Obviously, I have a long way to go but I am thrilled at being able to capture some nebulosity. That's enough motivation to work harder!
Appreciate if you could share your thoughts on this. Thanks!
That's a great attempt! You can drop your ISO to the minimum if you are doing longer exposures. As long as the histogram is not clipped, you can normalise (shift) it back in post processing. I have done 5 minute subs of M42 at f/4 in Singapore before (at ISO 100), so it shouldn't be an issue going for a minute of exposure. However, you would still find that the core region would be blown out quite quickly. To solve this, you could take a set of shorter exposures for the core and use layer masking to add this to your longer exposure dataset which has the blown out core.
If the weather allows, try to maximise the number of sub frames that you take - in this case, more is always better! There is no single workflow for photoshop processing, however. It's mostly trial and error, although there are certain fundamentals like curve stretching and colour balancing that will always need to be performed. If you haven't already, you may want to try out using flats and darks to calibrate your image. Hope this helps!
