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08-22-2019, 02:22 AM   #151
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Or People who thinks that noise performance per pixel is all that matters are like people who think that the number of horsepower is all that matters when it comes to go fast.

“Look,” they say, “this truck has 600 horse powers, it’s much faster than the small BMW with only 340 horse powers”.

But they are wrong.

08-22-2019, 02:30 AM - 1 Like   #152
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I need a sugar fix....Tim Tam thats the ticket
08-22-2019, 03:01 AM - 1 Like   #153
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The truck would accelerate faster off a cliff edge. Wait a minute. . . didn't that other thread end up this way a few days back?
08-22-2019, 03:07 AM   #154
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QuoteOriginally posted by Dartmoor Dave Quote
The truck would accelerate faster off a cliff edge. Wait a minute. . . didn't that other thread end up this way a few days back?
I don't know about that but i know the truck is more useful.

08-22-2019, 03:19 AM - 1 Like   #155
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QuoteOriginally posted by Dartmoor Dave Quote
Wait a minute. . . didn't that other thread end up this way a few days back?
Don't almost every thread go this way?
08-22-2019, 03:26 AM   #156
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Naaa I am not going to go down the signal noise and all that stuff road. Never studied it since I made my camera choice(K-1). What you have is what you have. All I need to know is keeping noise down is part of best practise. But lenses - that is another story!.
08-22-2019, 10:49 AM   #157
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QuoteOriginally posted by Dartmoor Dave Quote
People who say that a bigger sensor has lower noise because the lens collects more light, ignoring the fact that it's actually because of the noise performance per pixel, are like people saying that a car with a high performance engine goes faster because it has a bigger fuel tank, rather than more horsepower.
The lens and the sensor together define the light gathering, not only one part.
A sensor smaller than the image circle of the lens kind of throws away light the lens managed to capture.
And adding a wide angle converter to a lens can equalize the limitations of such a smaller sensor.

Anyhow the noise performance per pixel is *only* relevant in a scenario where the person making the comparison is happy with comparing potentially vastly different magnifications = output format sizes = viewing distances.
Such an approach is as valid as any other personal decision for personal comparisons. But other people might disagree with it. There are many ways to compare things and none of them is THE ONLY TRUTH.

Generally I suggest everyone tries out everything they care about. Only then you really know if something is relevant.
08-22-2019, 05:40 PM - 1 Like   #158
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QuoteOriginally posted by beholder3 Quote
Because everything we talk about is essentially about human perception. This human perception in physical terms does „downsampling“ and „averaging“ and is limited by what our eyes can resolve.

That is where my previously posted bit about „magnification“ comes into play. Magnification changes everything.
We're actually not talking about any of that, Beholder, we're just talking about the RAW files, not output devices.

That's a whole other topic, because these days enlarging does not work like it did on film at all, and images are forever being downsampled not upscaled.

I have a friend who's worked internationally as a graphic designer, and because of the viewing distance issues you've pointed out, was always happy with a 2Mb photo because that was the standard for a giant advertising billboard. Very detailed if you're sitting in a car!

08-22-2019, 06:50 PM - 2 Likes   #159
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QuoteOriginally posted by beholder3 Quote
A sensor smaller than the image circle of the lens kind of throws away light the lens managed to capture.
I'm not sure I understand your point.



(Copied from Understanding Crop Factor | B&H Explora)

Each individual pixel in the sensor, is capturing exactly the same amount of light that it was going to capture. Now, you can bend the light by introducing another lens in order to get a (modified) lens where the sensor is no longer smaller than the image circle of the lens. But, in doing so, you've altered the parameters you're dealing with.

I don't think you can think of it as the sensor throwing away light, when you're not utilizing the entire image circle that lens is capable of.

To steal another image from the B&H article:



Sensors are not capturing the whole scene, because we don't use round sensors in our cameras and we don't generally view round images. And each pixel, when using the same lens, whether on APS-C or FF is receiving the same amount of light, that light having passed through the same aperture and the same lens. So, by your argument, every sensor is throwing away light. But that does not alter the amount of light on any given part of the sensor that is exposed to light.
08-22-2019, 08:28 PM   #160
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QuoteOriginally posted by MarkJerling Quote
Sensors are not capturing the whole scene, because we don't use round sensors in our cameras and we don't generally view round images. And each pixel, when using the same lens, whether on APS-C or FF is receiving the same amount of light, that light having passed through the same aperture and the same lens. So, by your argument, every sensor is throwing away light. But that does not alter the amount of light on any given part of the sensor that is exposed to light.
This is only the lens part of the equation.
When you capture the images you also add shutter speed and sensor area to the mix.
Longer shutter speed captures more light, a larger sensor capture a larger area of the same illuminance.
The amount of light that images are made of is: illuminance x sensor area x shutter speed.

So with same illuminance and shutter speed FF capture 2.25x the light of APS-C in the images.

Last edited by Fogel70; 08-22-2019 at 08:40 PM.
08-22-2019, 08:39 PM - 2 Likes   #161
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QuoteOriginally posted by Fogel70 Quote
This is only the lens part of the equation.
When you capture the images you also add shutter speed and sensor area to the mix.
Longer shutter speed captures more light, a larger sensor capture a larger area of the same illumination.
The amount of light that images are made of is: illumination x sensor area x shutter speed.

So with same illumiation and shutter speed FF capture 2.25x the light of APS-C in the images.
QuoteOriginally posted by Fogel70 Quote
So with same illumiation and shutter speed FF capture 2.25x the light of APS-C in the images.
And yet the exposure remains the same which is an unfortunate dose of reality for equivalence fools.
08-22-2019, 08:50 PM   #162
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QuoteOriginally posted by GUB Quote
And yet the exposure remains the same which is an unfortunate dose of reality for equivalence fools.
Of couse it is, as exposure is illuminance x shutter speed, doh.
08-22-2019, 08:56 PM   #163
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QuoteOriginally posted by Fogel70 Quote
Of couse it is, as exposure is illuminance x shutter speed, doh.
Of course what is?
08-22-2019, 09:03 PM   #164
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I have to go and do evening chores so on the presumption that "it is " refers to exposure staying the same , then please explain the point of :
[I]
'This is only the lens part of the equation.
When you capture the images you also add shutter speed and sensor area to the mix.
Longer shutter speed captures more light, a larger sensor capture a larger area of the same illuminance.
The amount of light that images are made of is: illuminance x sensor area x shutter speed.

So with same illuminance and shutter speed FF capture 2.25x the light of APS-C in the images.
08-22-2019, 09:19 PM   #165
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QuoteOriginally posted by GUB Quote
I have to go and do evening chores so on the presumption that "it is " refers to exposure staying the same , then please explain the point of :
[I]
'This is only the lens part of the equation.
When you capture the images you also add shutter speed and sensor area to the mix.
Longer shutter speed captures more light, a larger sensor capture a larger area of the same illuminance.
The amount of light that images are made of is: illuminance x sensor area x shutter speed.

So with same illuminance and shutter speed FF capture 2.25x the light of APS-C in the images.
An FF sensor captures 2.25x of the exposure, as the FF sensor has 2.25x the area of APS-C.
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