[Fogel70]

I will show you DxOmark's *equation* if you like.

They only measure the screen data. That's the real value from examining the RAW file, it's what they do for a living, make a RAW converter.

Here's some news for you: the print data on the other hand is fictional. Made up. Derived from that formula, which doesn't even mention sensor format.

All those years, still no understanding, Fogel?

What you still fail to see is that the screen score is like looking at pixel on a screen at 100%. And as long as pixel size is the same size a smartphone sensor would score the same a medium format sensor if based on same sensor tech. If pixel size differs between compared cameras, the higher resolution camera will be compared at higher magnification than the lower resolution camera, as they are compared pixel by pixel.

---

Last edited by Fogel70; 08-20-2019 at 10:25 PM.

[Photobill]

As there are people on this forum that are "WAY" smarter than and yes my original question has been fully answered and I thank you!!!
I have kept up on the thread and I have been amazed that this one item has not been brought up.

My heading was: Lens Light - Gathering Abilities

Does not a lens have a maximum opening? This opening would only allow in a maximum amount of light. Yes deferent sizes of sensor's can absorbs deferent amounts of light from the same lens but the exact same amount of light passes through the aperture???

The one item that I have not seen brought up is:
Is it a lens designed for a aps-c or is it a lens designed for a FF?
The FF lens would allow in "MORE" light than a lens designed for a aps-c sensor so wouldn't it technically have better light gathering capability. 😈😈😈😈😈😈😈😈😈😈😈😈😈😈
NO NEED TO ANSWER! I WAS JUST AMAZED IT NEVER GOT BROUGHT UP

[dbs]

I better get some more popcorn

[GUB]

As there are people on this forum that are "WAY" smarter than and yes my original question has been fully answered and I thank you!!!
I have kept up on the thread and I have been amazed that this one item has not been brought up.

My heading was: Lens Light - Gathering Abilities

Does not a lens have a maximum opening? This opening would only allow in a maximum amount of light. Yes deferent sizes of sensor's can absorbs deferent amounts of light from the same lens but the exact same amount of light passes through the aperture???

The one item that I have not seen brought up is:
Is it a lens designed for a aps-c or is it a lens designed for a FF?
The FF lens would allow in "MORE" light than a lens designed for a aps-c sensor so wouldn't it technically have better light gathering capability. 😈😈😈😈😈😈😈😈😈😈😈😈😈😈
NO NEED TO ANSWER! I WAS JUST AMAZED IT NEVER GOT BROUGHT UP

The answer is really simple - back to my first post where I mentioned visualising the image circle cast by the lens. Well the apsc lens would only throw an effective circle of a size that the apsc sensor alone can sit in. But the light intensity at any point within that circle would be identical to the light intensity at that point with a ff lens. So same fstop for both.

[Dartmoor Dave]

Does not a lens have a maximum opening? This opening would only allow in a maximum amount of light. Yes deferent sizes of sensor's can absorbs deferent amounts of light from the same lens but the exact same amount of light passes through the aperture???

Camera manufacturers know that photographers expect ISO 100 and ISO 200 and so-on to be the same from one camera model to another, irrespective of sensor size, so they design the hardware to make sure that that's the case. And they know that photographers will expect f/8 and f/11 and so-on to be the same from one lens to another too, so they design their lenses to make sure that that's the case. Cameras and lenses are built so that photographers can rely on exposure settings being the same from one format to another.

It's amazing really. It's almost as if the people who design cameras have been to university to learn about it, rather than just endlessly regurgitating half-digested pap from the internet.

Now lenses of the same focal length have different fields of view on different formats, and some of the side-effects of this have led to an obsession among some people with a thing that they call "equivalence". It's a cult that has grown from a faulty understanding of how cameras work that was posted by just one blogger to begin with, but has spread. And this causes a problem. If we leave the incorrect assumptions posted by equivalentists unchallenged then unwary newcomers to photography might fall for it and the cult will keep growing. But when we do challenge the equivalentists, this reinforces their delusion that they are taking part in a two-way debate that they have something meaningful to contribute to -- rather than being merely factually wrong. So unfortunately, threads like this tend to go on and on.

All I can ask you to do is just accept the simple answer that you were given right at the start: you use the same exposure settings on APS-C and full frame, and on medium format and on large format view cameras too. A lens with an f/2 maximum aperture is a lens with an f/2 maximum aperture no matter which format you put it on, and the exposure settings will be the same. The lens really does not magically gather different amounts of light depending on the format you use it on.

Just trust that the people who designed and made your cameras and lenses knew more about what they were doing than random guys on the internet do.

[GUB]

Camera manufacturers know that photographers expect ISO 100 and ISO 200 and so-on to be the same from one camera model to another, irrespective of sensor size, so they design the hardware to make sure that that's the case. And they know that photographers will expect f/8 and f/11 and so-on to be the same from one lens to another too, so they design their lenses to make sure that that's the case. Cameras and lenses are built so that photographers can rely on exposure settings being the same from one format to another.

It's amazing really. It's almost as if the people who design cameras have been to university to learn about it, rather than just endlessly regurgitating half-digested pap from the internet.

Now lenses of the same focal length have different fields of view on different formats, and some of the side-effects of this have led to an obsession among some people with a thing that they call "equivalence". It's a cult that has grown from a faulty understanding of how cameras work that was posted by just one blogger to begin with, but has spread. And this causes a problem. If we leave the incorrect assumptions posted by equivalentists unchallenged then unwary newcomers to photography might fall for it and the cult will keep growing. But when we do challenge the equivalentists, this reinforces their delusion that they are taking part in a two-way debate that they have something meaningful to contribute to -- rather than being merely factually wrong. So unfortunately, threads like this tend to go on and on.

All I can ask you to do is just accept the simple answer that you were given right at the start: you use the same exposure settings on APS-C and full frame, and on medium format and on large format view cameras too. A lens with an f/2 maximum aperture is a lens with an f/2 maximum aperture no matter which format you put it on, and the exposure settings will be the same. The lens really does not magically gather different amounts of light depending on the format you use it on.

Just trust that the people who designed and made your cameras and lenses knew more about what they were doing than random guys on the internet do.

Nice one Dave

[Gimbal]

A lens with an f/2 maximum aperture is a lens with an f/2 maximum aperture no matter which format you put it on, and the exposure settings will be the same.

Right, everyone agrees on that.

The lens really does not magically gather different amounts of light depending on the format you use it on.

Sort of, it’s the size of the lens that does it. And a larger sensor needs a larger lens.
A phone lens with an aperture of 1.8 does not collect as much light as a FF lens with the same aperture. That is why the FF sensor will beat the phone in dark situations. The same goes for binoculars, a large front lens will give you a brighter image. And yes, it’s not magic. The more photons you collect, the better the image.

[Fogel70]

As there are people on this forum that are "WAY" smarter than and yes my original question has been fully answered and I thank you!!!
I have kept up on the thread and I have been amazed that this one item has not been brought up.

My heading was: Lens Light - Gathering Abilities

Does not a lens have a maximum opening? This opening would only allow in a maximum amount of light. Yes deferent sizes of sensor's can absorbs deferent amounts of light from the same lens but the exact same amount of light passes through the aperture???

The one item that I have not seen brought up is:
Is it a lens designed for a aps-c or is it a lens designed for a FF?
The FF lens would allow in "MORE" light than a lens designed for a aps-c sensor so wouldn't it technically have better light gathering capability. 😈😈😈😈😈😈😈😈😈😈😈😈😈😈
NO NEED TO ANSWER! I WAS JUST AMAZED IT NEVER GOT BROUGHT UP

Yes, you are right. A FF lens let in more light than an APS-C lens at the same aperture, and there are adapters that can use this fact, and can turn an FF lens into a faster APS-C lens.
They are called focal reducers, speed bosters or lens turbo, and they compress the FF image circle into an APS-C image circle. and the FOV is kept the same as when used on FF camera.
So an FF 50/1.4 lens with a speed booster adapter for APS-C becomes something like 35mm f/1.0.

If you want deeper understanding of this Metabones have a detailed document describing the princple behind it.
https://www.metabones.com/assets/a/stories/Speed%20Booster%20White%20Paper.pdf

[GUB]

Yes, you are right. A FF lens let in more light than an APS-C lens at the same aperture, and there are adapters that can use this fact, and can turn an FF lens into a faster APS-C lens.
They are called focal reducers, speed bosters or lens turbo, and they compress the FF image circle into an APS-C image circle. and the FOV is kept the same as when used on FF camera.
So an FF 50/1.4 lens with a speed booster adapter for APS-C becomes something like 35mm f/1.0.

If you want deeper understanding of this Metabones have a detailed document describing the princple behind it.
https://www.metabones.com/assets/a/stories/Speed%20Booster%20White%20Paper.pdf

Yes you can add an extra lens to a 50mm and make it a 35 mm -- your point?

[Fogel70]

By compressing the FF image circle to APS-C the intensity of light will be doubled for the APS-C camera.
So on APS-C you get one stop faster shutter speed or one stop lower ISO at same aperture on the lens.

[pschlute]

Yes, you are right. A FF lens let in more light than an APS-C lens at the same aperture

A FF lens has a larger image circle and so can illuminate a larger sensor like a FF one. The amount of light that hits and is recorded by each individual pixel is not more compared to a aps-c lens, it is not brighter. This is the confusion.

Example: I stand in front of a window that is large enough to completely illuminate my face and take an incident meter reading at my face. I then move to the next room which faces the same direction. It has floor to ceiling glass windows. The room appears a lot brighter. But the incident meter reading at my face is the same.

[GUB]

By compressing the FF image circle to APS-C the intensity of light will be doubled for the APS-C camera.
So on APS-C you get one stop faster shutter speed or one stop lower ISO at same aperture on the lens.

And you have achieved all this by converting your 50mm to a 35mm. So you have moved your iris at whatever diameter it is at from a point theoretically 50mm from the sensor to a point 35mm from the sensor. As such you have changed your f-stop - hence the brighter image. No cracks in the space - time continuum here.

"[I]same aperture on the lens[I] better worded as "same iris diameter".

[Fogel70]

A FF lens has a larger image circle and so can illuminate a larger sensor like a FF one. The amount of light that hits and is recorded by each individual pixel is not more compared to a aps-c lens, it is not brighter. This is the confusion.

Example: I stand in front of a window that is large enough to completely illuminate my face and take an incident meter reading at my face. I then move to the next room which faces the same direction. It has floor to ceiling glass windows. The room appears a lot brighter. But the incident meter reading at my face is the same.

If you had read my whole post it was about compressing FF image circle into an APS-C image circle.
This will make the image on APS-C sensor brighter as the same amount of light is focussed on a smaller area.

[GUB]

If you had read my whole post it was about compressing FF image circle into an APS-C image circle.
This will make the image on APS-C sensor brighter as the same amount of light is focussed on a smaller area.

I am still trying to work out the relevancy of this.

[Fogel70]

I am still trying to work out the relevancy of this.

If adapting FF lenses for APS-C, you can choose to capture same amount of light as on FF, or half of it.