Long Expoisure Noise reduction - 20D

Canon EF 17-40mm f/4.0L USM

05/04/2006 09:02:49 AM · #1

Does anyone have any experience of the Long Exposure noise reduction, custom function setting on the Canon 20D.

I have only ever shot to a max of 30 secs, and have had little problem with grain. But one is always looking to improve.

Does this setting improve things, and is it worth waiting for it to re interpolate the shot. Or should I use the time to shoot my next image.
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Judi

Canon EOS-5D Mark III

05/04/2006 09:05:34 AM · #2

I don't know about the 20D but with the 350D and the 5D you will find the function in the menu under Custom Functions. Check your manual. I have done long exposures with and without the Noise Reduction...and boy...what a difference. Also, with long shutters (ie Bulb type) make sure you remove the eyecup and use the little rubber cover....also really helps. Y

Canon RF 24-70mm f/2.8 L IS

05/04/2006 09:14:48 AM · #3

Thanks

I know how it works and how to set it up ( special funtion 2)
It was more a question of does it deliver better pictures?

kirbic

Canon EOS R5

05/04/2006 09:15:11 AM · #4

Using the long exposure noise reduction will certainly help with fixed-pattern noise. Random noise will be unaffected. For random noise reduction, stacking multiple exposures is effective. Random noise is reduced by the square root of the number of exposures used, so if you stack 4 exposures, random noise is rudeced by a factor of 2 (by 50%).

05/04/2006 09:18:16 AM · #5

Originally posted by kirbic:

If stacking 4 images, what transparancy settings do you use for each layer?

Message edited by author 2006-05-04 09:48:11.

Canon PowerShot Pro 90 IS

05/04/2006 09:20:13 AM · #6

And before anyone say, I know stacking is not legal for DPC

coolhar

05/04/2006 10:32:03 AM · #7

I experimented with the noise reduction custom function for a while, doing with and without shots fo the same subject. My comparisons have lead me to leave it turned on all the time.

Canon RF 24-70mm f/2.8 L IS

05/04/2006 12:39:54 PM · #8

Originally posted by coolhar:

I experimented with the noise reduction custom function for a while, doing with and without shots fo the same subject. My comparisons have lead me to leave it turned on all the time.

for shortish exposures this seems a good strategy, but the 2 min plus ones begs the question both technically and impatiently, do I want to wait the same time again.

I am goind out this evening to give things a try...

Mr_Pants

SiPix Blink

05/04/2006 12:42:12 PM · #9

Originally posted by Artan:

Originally posted by kirbic:
Using the long exposure noise reduction will certainly help with fixed-pattern noise. Random noise will be unaffected. For random noise reduction, stacking multiple exposures is effective. Random noise is reduced by the square root of the number of exposures used, so if you stack 4 exposures, random noise is rudeced by a factor of 2 (by 50%).

If stacking 4 images, what transparancy settings do you use for each layer?

I would guess 100% for background, then 75, 50 and 25.

kirbic

Canon EOS R5

05/04/2006 12:44:37 PM · #10

Originally posted by Artan:

If stacking 4 images, what transparancy settings do you use for each layer?

Starting with the bottom layer in the stack, the opacity should be:

Layer 1: 1/1 = 100%
Layer 2: 1/2 = 50%
Layer 3: 1/3 = 33%
Layer 4: 1/4 = 25%

For more exposures, continue the progression. Blending mode should be set to "normal."