5D mkII Image noise in long exposure

[sethlowephoto]

Hey all, was shooting some stars last night with my 5dII, and was getting some HORRIBLE image noise. Was at ISO 160, f/9 and about 30 minute exposure. Here is a screen shot at 100% from lightroom, SOOC. I do shoot raw. Just wondering if anyone one else has these issues, and how they resolve them.  Thanks!

[SwissBear]

It is known that long exposures do not work well in the digital age. For startrails, there is an easy solution: shoot many pictures (p.ex. 30/15sec exposure each, normal post in LR), and then do an overlay. I used GIOTTO if i'm right.
This works quite nice, only fills your memory card. Another advantage: if clouds roll in, you still can make a nice movie

[sethlowephoto]

@SwissBear thanks for the info. I had never really done one longer than 3-4 minutes before, so I was really surprised when I saw the image.  Will have to try the method you mentioned. 

[wsheldon]

Hey all, was shooting some stars last night with my 5dII, and was getting some HORRIBLE image noise. Was at ISO 160, f/9 and about 30 minute exposure. Here is a screen shot at 100% from lightroom, SOOC. I do shoot raw. Just wondering if anyone one else has these issues, and how they resolve them.  Thanks!

Really long exposures like that are hard for any digital sensor, and your results look pretty typical to me. That is one area where the 5D mark III and particularly the 6D show major advantages over the mark II, though (see http://petapixel.com/2012/12/13/canon-6d-and-5dmk3-noise-comparison-for-high-iso-long-exposures/).

Did you use long-exposure noise reduction? As I understand it that will record a second dark-field image and try to remove the hot pixels, and I believe it works for RAW as well as JPEG.

[Mr Bean]

It is known that long exposures do not work well in the digital age. For startrails, there is an easy solution: shoot many pictures (p.ex. 30/15sec exposure each, normal post in LR), and then do an overlay. I used GIOTTO if i'm right.
This works quite nice, only fills your memory card. Another advantage: if clouds roll in, you still can make a nice movie

^^^^^^
This works well. I found the same issue when first attempting star trails. There's a program around called STARTRAILS.exe (I think) that allows for merging of multiple images. 1-2min exposures on my 5D3 worked well, then merged into one.

[Harry Muff]

In Photoshop, you can use Image Stacking and use the Median method.