D500 ISO question

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I have been shooting my D500 in manual mode with auto ISO with the max ISO at 3200. I have noticed that on many shots the Noise at ISO 3200 is less than noise at intermediate ISO steps like 2000 or 2250. Has anyone else noticed this?
 
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I have been shooting my D500 in manual mode with auto ISO with the max ISO at 3200. I have noticed that on many shots the Noise at ISO 3200 is less than noise at intermediate ISO steps like 2000 or 2250. Has anyone else noticed this?
I have my D500 set to the same settings as you do. I have also noticed more noise at lesser ISO’s, but am not sure why that is.
 
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I often do the same as you, Dan. But I have only noticed more noise at lower ISO settings on the D500 when pushing too much in post. Can you post some examples of what you're seeing?
 
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I often do the same as you, Dan. But I have only noticed more noise at lower ISO settings on the D500 when pushing too much in post. Can you post some examples of what you're seeing?
I’ll have to look at my photos and see if I kept any. I likely have deleted them all, as I don’t like photos with that much noise in them. Now photos at 3200 with minimal noise are easy for me to share as I know of several I have kept, like the blue jay ones like this.
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I have been shooting my D500 in manual mode with auto ISO with the max ISO at 3200. I have noticed that on many shots the Noise at ISO 3200 is less than noise at intermediate ISO steps like 2000 or 2250. Has anyone else noticed this?
This has to be an artifact of the particular scene and exposure as there is no technical basis for it.
 
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Perhaps, but I have seen it documented in camera reviews of other cameras.
The dynamic range of the D500, like all other digital cameras, decreases exponentially with increasing iso.

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My guess is that it could have something to do with the noise reduction algorithm.

It might amp up more around the ISO 3200 mark . I've no first hand knowledge, just making a SWAG.
 
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This is something that is amenable to an objective test. All one needs to do is photograph the same scene, which should include some light and dark areas, at progressively higher iso values and look at the raw files as well as the out-of-camera jpegs.

Since the D500 and D7200, which I have, have almost identical dynamic range performance, I'll try to do this myself in the next few days. I would encourage DynaSport to also do this with his D500.
 
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This is something that is amenable to an objective test. All one needs to do is photograph the same scene, which should include some light and dark areas, at progressively higher iso values and look at the raw files as well as the out-of-camera jpegs.

Since the D500 and D7200, which I have, have almost identical dynamic range performance, I'll try to do this myself in the next few days. I would encourage DynaSport to also do this with his D500.
That would make way too much sense. Honestly, I have limited time to shoot and don’t normally like spending it doing tests. I prefer to see how the camera and/or lens does in my shooting. But I do like seeing the results of other people’s tests. But, I will give it a shot. But I don’t know that I can replicate what has happened, because when it does it I have been in auto ISO letting the camera use spot metering to determine proper exposure and usually adding in +2/3 a stop exposure compensation. Doing that, I have noticed at times ISO 3200 files have less noise that ISOs between 1600 and 3200. I saw a review of a camera a while back (I can’t remember which camera it was now) where the reviewer experienced the same thing. But as conditions are constantly changing and angles and other variables, I’m sure when I post examples folks will criticize the shots and say they aren’t the same in one way or another and they’ll be right. The point of my original post was to see if anyone else had noticed this, not debate if it is real or not.
 
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Steve Perry's new e-book on exposure and metering has a great chapter on ISO (and noise). Too complex to summarize here, but all raising ISO over the base does for you is amplify the signal (noise and all). Weaker signal (underexposed/dark) more noise.

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He also addresses the dual gain amp:

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See that bend at 3-400 in the graph Jim posted? That's the amp kicking in.

My 2 cents, and I'm sticking with it :)
 
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The fundamentals are well covered in Marc Levoy's video series which I have been trumpeting here for several weeks. There ain't no free lunch.

Or, the laws of physics are not subject to repeal.
 
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Thom Hogan had to say this in his review here: Nikon D500 Camera Review | DSLRBodies | Thom Hogan

"Dynamic range: I’m still trying to figure some of this out. The D500 has almost twice the full well capacity of the D7200, yet it clearly isn’t a stop better than the D7200. Indeed, the D7200 is slightly better in usable dynamic range up to about ISO 400, the D500 slightly better than the D7200 above that. Some of that is due to the dual gain nature of the D500’s sensor (it changes gain strategy at ISO 400)."
--Ken
 
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Thom Hogan had to say this in his review here: Nikon D500 Camera Review | DSLRBodies | Thom Hogan

"Dynamic range: I’m still trying to figure some of this out. The D500 has almost twice the full well capacity of the D7200, yet it clearly isn’t a stop better than the D7200. Indeed, the D7200 is slightly better in usable dynamic range up to about ISO 400, the D500 slightly better than the D7200 above that. Some of that is due to the dual gain nature of the D500’s sensor (it changes gain strategy at ISO 400)."
--Ken

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