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Old Mar 4, 2004, 7:42 AM   #1
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Default Reduce noise by increasing ISO?

Interesting noise observation for the 10D (works just like Dolby!):

http://www.fredmiranda.com/forum/topic/76284

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Old Mar 4, 2004, 8:41 AM   #2
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That is really wacky. I think I agee with the nay sayers that this is probably of less practical use than you might thing... but there are certainly times when it will be a win (like the "can't use a larger aperture" example.)

Hum, now that I think about it, I often shoot at the max aperture and 800ISO for sunset bird shots. I wonder if I could use it to have less noise. Maybe not so useless at all.

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Old Mar 14, 2004, 10:15 PM   #3
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Guys, the secret I found lately is this. I guess its valid for both 10D and 300D.

Brief story, I used to shoot at ISO400, but being in higher latitude, the sun angle can be quite low. So more than often I'll shoot in shades. What happened is, at a point I had to reduce the shutter speed up to a point where small birds with their rapid movement would induce bluriness. So what to do at this point ? Underexpose a little and adjust EC in C1 to compensate ? It works, but as soon as you raise the EC in either C1 or even PS, then noise starts to show, and its quite bad.

So lately, I decided to shoot with ISO800, but I now "shoot to the right", refering to the histogram, I try to always get it just before highlights are blown out. Then if I want to darken the background with C1, then doing this with layers in PS, my background would be very smooth.

So the choice are here, ISO400, on the edge or underexposed, or ISO800 and shoot to the right. I tend now to use more and more ISO800 because of it.

One thing you don't want to do is underexposed at ISO 800, that would be the worst case scenario.

Give it a try
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Old Mar 15, 2004, 10:48 AM   #4
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AAAahhhh. I hate it when this happens. I can'd find... success! A bit of searching turned up the link I wanted.
http://www.luminous-landscape.com/tu...se-right.shtml

It basically says that the sensors are capable of capturing more data in the lighter than the darker range. They had reasons for this that I didn't completely buy into, but their logic was interesting.

So it concludes that you should try to get your subject exposed more to the right of the histogram. That saying you'll "under expose and recover" is really not a good way to do it. I'm a bit surprised that the noise that 800ISO offers isn't bad enough to negate the benefits, but I've never done the testing necessary to really know.

Personally, I have underexposed and recovered with jpgs (not RAW) and it has worked. But I've also done it and recovery has failed.

Food for thought... I'd be interested in what both of you two have to say about the article.

Eric
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Old Mar 15, 2004, 10:54 AM   #5
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wat does "S/N" mean?

i'll probably feel really stupid once you tell me.....but i can't seem to figure it out..or find it in the article?
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Old Mar 15, 2004, 11:13 AM   #6
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Quote:
Originally Posted by photosbyvito
what does "S/N" mean?
Signal to Noise ratio...

Noise is always present... On weak signal, like in the dark or nightshots, the tiny signal just get mixed in with the noise. What resulted is when a camera tries to amplify the signal it also amplify the noise with it as well resulting in noisy pictures.
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Old Mar 15, 2004, 11:16 AM   #7
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oh ok

thanks
now that article will make much more sense
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Old Mar 15, 2004, 2:01 PM   #8
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Eric, thats exactly why I shoot with ISO 800 and expose to the right now. I read that article, at first I said, it can't be right... eventually I gave it a try and since then this is my newest method of shooting.

Give it a serious try, but make sure the meter of your 10D is 1/3 to the right of center, confirm this with the histogram.

Cheers
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Old Mar 15, 2004, 5:11 PM   #9
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will this work on a nikon?
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Old Mar 15, 2004, 5:45 PM   #10
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I don't see why not... it's pretty much algorithmic and should be camera independent
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