Quote:
Originally Posted by lazjen
I normally use ISO 400, 800 and 1600 and have a number of darks for these at various times. For the matches at 10 and 30 seconds, my images look very similar to yours. Most of the image temps range from 22 to 27 degrees.
I just did a test at ISO 6400 at 30 sec... (temp here is about 27) and it was like yours - no noise (as in I can not see ANY noise on the black image). It's much clearer than any other dark I've done at the lower ISO. I do not have long exposure noise reduction on, but looking the properties of the image it does have the high ISO noise reduction on standard. Haven't tried the extra test as you did - I was just surprised by that result.
...time passes as I test things...
I did some more darks for 30 sec - 3200, 1600, 800 - all have noise like my other darks. I did one for 25600 and it has far less noise than the lower ISO images.
I'll have to try an ISO6400 night shot sometime to see how it looks.
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Thanks for the reply! Well if you're seeing similar results, maybe I have nothing to worry about. I haven't tried out taking any darks and using them to process any images yet, so that might explain why the images you've posted in the astrophotography forums here don't show any noise.
I was comparing my images to the ones Mike Salway took
here to test the long exposure noise for the 6D. If you look at the full res jpeg image there's a bunch of hot pixels, but none that are really bright like the test images I took. That's why I was concerned.
I was surprised by the lower noise at ISO 6400 too, especially considering every mention of hot pixels/noise I could find in the internet referred to high ISO settings.
I got a bit of amp glow from ISO 25600, and a fair bit of noise for a 30s exposure, but that was the last test image I took so the sensor was probably a bit warm.
I tried out some shots last night to compare ISO 3200 and ISO 6400 with different shutter speeds to gather the same amount of light. The ISO 6400 looked about as clean as the ISO 3200, but just didn't have the bright red, green, and blue pixels.
Interesting...