Noise reduction by INCREASING ISO

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Archive 2004 · Noise reduction by INCREASING ISO

coolmib
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p.2 #1 · Noise reduction by INCREASING ISO

I'm wondering if this phoenomenon applies to D60. Any one tried?

Also, for the grey card, the histogram is in the dead center, a +1 over exposure won't push the curve off chart. But in real life, a +1 over could wash out the high light ...

Mar 01, 2004 at 08:24 AM

Kyle Yates
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p.2 #2 · Noise reduction by INCREASING ISO

This sort of technique has been used in the "Traditional Wet Darkroom" for years and was known as "Pushing / Pulling".

You would either deliberately over / under expose the original film shot on the camera and then in the development process you would then increase / decrease the developement time. You could do this either when the film itself was being developed -- not usually good unless the whole roll was under / over exposed, or at printing time which gave you the maximum flexibility. Of course you didn't have Photoshop Layers then.

The principles ares similar for digital -- but if you want good analysis read some of the older photographic texts on "Pushing / Pulling". It's still valid for digital as "Noise" is equivalent to Grain.

Yes it DOES work in a D60 or any other camera where you can either manually set the exposure / aperture or dial in exposure compensation.

Mar 01, 2004 at 09:48 AM

gfiksel
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p.2 #3 · Noise reduction by INCREASING ISO

Even in a real life pushing +1 still leaves enough padding on the right due to a large dynamic range of the sensor.
As far as other cameras, I guess, it depends on the noise vs. ISO curve. But, it's digital, costs nothing to try

Mar 01, 2004 at 12:58 PM

gfiksel
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p.2 #4 · Noise reduction by INCREASING ISO

Thanks, Kyle. Very interesting notion.

Mar 01, 2004 at 12:58 PM

David Savkovic
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p.2 #5 · Noise reduction by INCREASING ISO

I like this info. I am going to try it with my D100 and 1D.

Mar 02, 2004 at 10:19 PM

Peter
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p.2 #6 · Noise reduction by INCREASING ISO

Hi Guys- I think I can lay claim to first describing this technique. I discovered it using the kodak 720X which has a very large DR with up to 2 stops recoverable "blown" highlights. I also noticed that ISO noise did not increase as fast as Iso steps, and for very high Iso shooting with this incredibly clean sensor, like 2400 and up, I demonstrated that you get cleaner files "pushing" the exposure by up to 1 stop, and "pulling" the exposure back in the Raw converter, than by fully exposing without overexposing at the 1 stop lower ISO. I coined "push-pull" for this and you'll see it in Golbraith's Kodak forum going back well before even Reichman wrote about it. It also works with the 14N, and should with any DSLR as long as the DR is there to recover the details. I liken this to Dolby tape hiss reduction where in order to increase the S/N ration, you add noise and saturate the dynamic range then remove the Dolby noise in the playback. Anyway, it's worth trying, and nobody is getting rich on it, so what the heck. Best....Peter

Mar 02, 2004 at 11:00 PM


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