Camera sensor and dark images

[boblui]

It's not "fake" - it's amplification of the signal from the sensor - the more the amplification, the more noise you get.

Are you sure about that ?

the video does convince me that "amplification" is nothing more than multiplying the numbers coming out from the sensor with a larger number in the raw converter software. You can do it with the image processor in the drone or with ACR in your computuer, there seems to be NO difference. If this is indeed the case, the ISO number is totally meaningless hence "fake" is a fair description.

 

[RobotBee]

Are you sure about that ?

the video does convince me that "amplification" is nothing more than multiplying the numbers coming out from the sensor with a larger number in the raw converter software. You can do it with the image processor in the drone or with ACR in your computuer, there seems to be NO difference. If this is indeed the case, the ISO number is totally meaningless hence "fake" is a fair description.

Pretty sure. It's upstream of the raw file creation and storage, and part of the analogue processing carried out by the hardware.



It's well proven that shooting at a higher ISO produces less noise than shooting at a lower ISO then boosting to the equivalent exposure in post processing.

Try it.

 

[boblui]

Pretty sure. It's upstream of the raw file creation and storage.

View attachment 103480

It's well proven that shooting at a higher ISO produces less noise than shooting at a lower ISO then boosting to the equivalent exposure in post processing.

Try it.

Just tried with my old Olympus EM5. 50 F1.4 lens f8 1/30 sec. Took two RAW pictures :

1) ISO3200, no post-processing
2) ISO200, pushed by 4 stops in ACR .

Results :





Can you tell which is which ? Now I am totally convinced that ISO is fake for digital cameras.

 

[LivinLarge]

That's interesting. I was not sure where the amplification took place in the pipeline.
One would think that the ISO would be set by the sensor manufacturer and that for a given shutter speed and aperture, you could expect a certain brightness value as a result.
I do expect that there is some fudging of numbers by camera/drone manufacturers however you would hope that within one brand and model series, you could expect some consistency, certainly not to be off by this much.

 

[RobotBee]

That's interesting. I was not sure where the amplification took place in the pipeline.
One would think that the ISO would be set by the sensor manufacturer and that for a given shutter speed and aperture, you could expect a certain brightness value as a result.
I do expect that there is some fudging of numbers by camera/drone manufacturers however you would hope that within one brand and model series, you could expect some consistency, certainly not to be off by this much.

I'm sure some of the numbers are marketing BS - for example they may add higher "ISO" values by effectively boosting the exposure digitally - presumably that's what "expanded" and "extended" and "boosted" etc ISOs are, but to say that the fundamental concept of ISO amplification is no different to changing a slider in a raw processor is absurd. The effect of the ISO amplification is baked into the raw data that's captured in the raw file.

 

[SkyeHigh]

Are you sure about that ?

the video does convince me that "amplification" is nothing more than multiplying the numbers coming out from the sensor with a larger number in the raw converter software. You can do it with the image processor in the drone or with ACR in your computuer, there seems to be NO difference. If this is indeed the case, the ISO number is totally meaningless hence "fake" is a fair description.

CCD sensors used in virtually all cameras are analogue devices. The ISO equivalent settings to traditional film sensitivity are created by amplifying the CCD image stream before digital encoding takes place.

Amplifying the CCD stream will increase the apparent sensitivity to light reaching the sensor but it also equally amplifies the noise.

ISO 100 was the most common rating for film and the development of CCD sensors was guided to create a device with equal sensitivity. The base ISO is the device sensitivity that gives the best image quality and least noise.

CCD’s were first developed for TV cameras that had relatively low resolution and contrast but development spurred mostly by Canon increased the resolution and pixel density for the stills market.

It’s quite ironic that the first working ‘digital’ camera was developed by Kodak. No doubt someone in senior management said ‘Not interested, we make film, not cameras’.

 

[boblui]

.... the fundamental concept of ISO amplification is no different to changing a slider in a raw processor is absurd.

The evidence cannot be clearer. The signal amplification performed by the sensor hardware is obviously fixed and the RAW image you get out from the sensor is the same no matter what ISO setting is used. The ISO number is just there to make people feel at home. It affects only the presentation of the picture.The lower the ISO, the darker the ( JPG ) picture. Violating such expectation can be devastating for some.

 

[RobotBee]

The evidence cannot be clearer. The signal amplification performed by the sensor hardware is obviously fixed and the RAW image you get out from the sensor is the same no matter what ISO setting is used. The ISO number is just there to make people feel at home. It affects only the presentation of the picture.The lower the ISO, the darker the ( JPG ) picture. Violating such expectation can be devastating for some.

Haha got to love a good electronics hardware conspiracy theory.

Good one mate

 

[SkyeHigh]

Haha got to love a good electronics hardware conspiracy theory.

Good one mate

Sadly there will always be those who believe the junk posted on YouTube. Any idiot can put a video together these days demonstrating their ignorance - unfortunately too many do!