I shot a few star trails images last week back but just prior to my trip, I read somewhere that noise reduction (NR) on the camera should be turned off because this software can and often minimizes or removes your trails. As a result, my captured images are very, very noisy.
1) Was this a mistake to try this without NR on?
2) Is there an easy way in PS (CS2) to correct this?
3) If #2 is not possible, what other alternatives are they? Or am I SOL?
FWIW, I shot this RAW + JPG with a Nikon D2x ...
Thanks for the help as always.
Posted by Jack Graham on March 25, 2006 at 9:24 AM
I would probably suggest using film for star trails. As the technology get better, the noise factor will go away. Buy for not, in my opinion, film is the answer for star trails!
JG
Posted by Pablo Yanez on March 25, 2006 at 3:37 PM
Martin,
I think that while the above above post is in general true, you can actually get some decent digital star trail images. I have one posted on my PBase page here:
http://www.pbase.com/pyanez/image/52648997
and have taken several images at this or slightly longer time amounts (ie upto 1hour). On my Canon 20D I had to remove a few (dozen or so) obvious hot pixels, but it was pretty quick work. For really long exposures (hours) I would still go with film. Another approach that I have not tried, but you might want to research is stacking digital images (say 6 30 minute exposures), to create 1 much cleaner loooong exposure.
PS- it seems to me that in one small way digital is much better for this. It seems to behave much more linearly than film - ie an exposure 10X longer is 10X "brighter", from what I recall film does not behave at all in a linear fashion for very long exposures. The other nice thing (obvious) is that at the end of taking your shot you have the option (with knowledge) to adjust your exposure for a next shot if possible that same night rather than waiting for the film to come back. Traditional bracketing on film for exposures this long does not seem reasonable.
Good luck with your shots, let me know when you post some images.
Discussion
2 replies1) Was this a mistake to try this without NR on?
2) Is there an easy way in PS (CS2) to correct this?
3) If #2 is not possible, what other alternatives are they? Or am I SOL?
FWIW, I shot this RAW + JPG with a Nikon D2x ...
Thanks for the help as always.
JG
I think that while the above above post is in general true, you can actually get some decent digital star trail images. I have one posted on my PBase page here:
http://www.pbase.com/pyanez/image/52648997
and have taken several images at this or slightly longer time amounts (ie upto 1hour). On my Canon 20D I had to remove a few (dozen or so) obvious hot pixels, but it was pretty quick work. For really long exposures (hours) I would still go with film. Another approach that I have not tried, but you might want to research is stacking digital images (say 6 30 minute exposures), to create 1 much cleaner loooong exposure.
PS- it seems to me that in one small way digital is much better for this. It seems to behave much more linearly than film - ie an exposure 10X longer is 10X "brighter", from what I recall film does not behave at all in a linear fashion for very long exposures. The other nice thing (obvious) is that at the end of taking your shot you have the option (with knowledge) to adjust your exposure for a next shot if possible that same night rather than waiting for the film to come back. Traditional bracketing on film for exposures this long does not seem reasonable.
Good luck with your shots, let me know when you post some images.
P