# R5 has a dual gain sensor



## Mark3794 (Aug 1, 2020)

Well i didn't notice that there is another thread about this, how do i delete a thread?  

Bill Claff at Photons to photos published the first measurements regarding the R5 sensor. It looks like it has a second gain stage starting at iso 400, like the sensors made by Sony.
Looks like there is some noise reduction going on in raw, but it doesn't seem to affect image quality if you compare the R5 with the Z7 or A7RIII on Dpreview compare tool.







Photographic Dynamic Range versus ISO Setting


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## analoggrotto (Aug 1, 2020)

I wish there was a way for the camera to skip or avoid that initial dip.

This is not terribly surprising as I think some of the Canon Cinema lenses have dual gain systems


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## Deleted member 378221 (Aug 1, 2020)

analoggrotto said:


> I wish there was a way for the camera to skip or avoid that initial dip.


Hmm, I think the dip isn't much of a problem. If you check the source ISO 200 and 400 are pretty much identical, and the dip is only ISO250 and 320. It should be easy to avoid those two settings when you know that they aren't optimal.


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## analoggrotto (Aug 1, 2020)

Loibisch said:


> Hmm, I think the dip isn't much of a problem. If you check the source ISO 200 and 400 are pretty much identical, and the dip is only ISO250 and 320. It should be easy to avoid those two settings when you know that they aren't optimal.


Yeah, I think there is a "dip" at 125 on my 5d4. It would be nifty if the camera would simply bump these ISOs up and increase shutter speed compensate for the given exposure. Minor stuff really. I'll be shooting base ISO a lot if my pre-order is ever filled, United States Congress does not ban the R5 due to overheating, and if Covid19 allows some travel.


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## Deleted member 378221 (Aug 1, 2020)

analoggrotto said:


> Yeah, I think there is a "dip" at 125 on my 5d4. It would be nifty if the camera would simply bump these ISOs up and increase shutter speed compensate for the given exposure.


That would be catastrophic for video, or any other time you need creative control over the shutter speed (water flow long exposures or in the other direction: freezing action). I'm glad it works the way it does.


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## shadow (Nov 21, 2022)

Read Noise in DNs versus ISO Setting



Nice site. A lot of work went into this. Somewhat complete listings of various gain stages. Curious as it seems like a logarithmic amplifier instead of dual or triple stages might be a design niche, I wonder if any mfg has thought of using that. In another business in high freq imaging and data acquisition I was in, years ago we had a signal to noise dynamic range problem similar to what is illustrated in cameras. So the solution was a Log amp that modified our micro volt signal so it didn't follow these typical linear charts, but compressed it. This might be a solution to lower light imaging, to a point as dark noise always exists if no light at all. Basically say a flattened response say 100-6400 iso. I noticed one camera on a video that had 3 bumps..

I saw this S/N ratio ISO video who showed the various performance curves.


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