Larger sensor just a luxury?

[2WheelPhoto]

(One of our cats has just got sick - the poor little thing threw up all over the bed and woke me up. Funny how it's always me that gets woken up by the cats...)

I thought you meant entrance pupil. I think that learning a few of these optical concepts would not only help you get your thoughts across, but also help with your general understanding.

Anyway, yes, if the entrance pupil is fixed, then the luminous flux is fixed: it's a very simple relationship to conceptualise. The light from an object point spreads out and part of it goes through a hole and then gets focused onto the image. That hole is the entrance pupil, and the area of it determines the rate at which light energy passes through it and on to the image, if it stays in the same location. For a fixed entrance pupil size and location, the luminous flux from an object point will be the same, regardless of the focal length of the lens. (That's why entrance pupil size can be more important than f-number in astrophotography.)

Oops, she's thrown up again. Time to clean up...

(Oh, and if you keep the same entrance pupil diameter - 'lens size' as you were calling it - and field of view, the DoF is indeed the same between formats.)

Coverage is a red herring, and it is also a relephant.

Hope your cats are alright!

Yes, the DoF should be the same between format.
It is the photographer who alter the DoF when he/she try to frame the subject in the same way when using different format. So a head shot photo in larger format should have a shallower DoF than a smaller format (same head shot framing) because the subject to camera distance decrease when shooting with larger format medium.

But that is offset by the larger fstop of smaller formats with the same entrance pupil size.

No its not. if you had pin head size pupil size / entrance compared to big..... nevermind. LoL good luck "getting it"

 

[chuasam]

It's one of those cases where if you have to ask, then it shouldn't matter to you.

Hey! I was going to say that.

A different perspective is debatable

the same way that the law of gravity is debatable.

Sure you get get great pictures with a camera of any size. Is a larger sensor a luxury? Well it really depends on what you are doing with your camera.

 

[EchoingWhisper]

Hope your cats are alright!

Yes, the DoF should be the same between format.
It is the photographer who alter the DoF when he/she try to frame the subject in the same way when using different format. So a head shot photo in larger format should have a shallower DoF than a smaller format (same head shot framing) because the subject to camera distance decrease when shooting with larger format medium.

But that is offset by the larger fstop of smaller formats with the same entrance pupil size.

No its not. if you had pin head size pupil size / entrance compared to big..... nevermind. LoL good luck "getting it"

I don't know what to say, you guys got the information through but I don't agree with it because you guys are just saying that you're right without supporting it. For me, I couldn't get my information/opinion/idea through anyone except Helen B.

 

[zcar21]

Most of us can't explain it but the benefits are obvious, just look at the pictures.

The Full-Frame Advantage

Regardless of what people say about ken rockwell the pictures speak by themself.

 

[Helen B]

I think that most of the controversy in this thread has been because of communication problems, not because there was anything fundamentally incorrect about what EW was trying to say. Once the vagueness was cleared up, and a few irrelevant points removed, what EW was talking about was neither new nor controversial. It was as if he had read it somewhere and partly understood it - but I could be wrong about that, of course.

Best,
Helen

 

[Kolia]

EW, you have been provided with multiple diagrams and links to various sources.

I wouldn't say that proof hasn't been provided. Don't alienate the people trying to help you.

 

[EchoingWhisper]

I think that most of the controversy in this thread has been because of communication problems, not because there was anything fundamentally incorrect about what EW was trying to say. Once the vagueness was cleared up, and a few irrelevant points removed, what EW was talking about was neither new nor controversial. It was as if he had read it somewhere and partly understood it - but I could be wrong about that, of course.

Best,
Helen

I didn't read it. I just went by my common sense that if the entrance pupil was the same size then luminous flux shall be constant. But instead they say its not the same, so I tried to explain, but they just didn't understand what I say.

 

[EchoingWhisper]

EW, you have been provided with multiple diagrams and links to various sources.

I wouldn't say that proof hasn't been provided. Don't alienate the people trying to help you.

But those source don't directly go against my points. Those source are right but what I was saying is that if the lens size is the same (entrance pupil - I didn't know the term before Helen B came) then total amount of light (luminous flux) would be the same, and those source didn't actually said that I'm wrong in any way.

 

[zcar21]

I think you guys missed my point at my fourth sentence. Given that the lens is the same size (not including VR and AF), you get the same amount of light no matter how large of a sensor it hits as long as they have the same amount of pixels. A f/2.8 APS-C lens is smaller than a f/2.8 full frame lens. A f/2.0 APS-C lens will provide about the amount of light as a f/2.8 full frame lens. (APS-C is about 1 time smaller than a full frame sensor, so it gets 1 time less light at the same f stop). So the SNR of *should* be the same. I said should cause' I don't know if a larger sensor will have better SNR even if they get the same amount of light.
Please correct me if you find me wrong.

This is the reason you can't believe what we're saying, The statements are wrong. f/2 is f/2 on either ff or aps-c, same amount of light. You know about the square law of light? Well, the inverse happens here. You can change aperture to balance dof but you'll be changing the amount of light. A bigger sensor-less magnification is what makes the difference and all the benefits we're been talking about.

 

[Dao]

I think that most of the controversy in this thread has been because of communication problems, not because there was anything fundamentally incorrect about what EW was trying to say. Once the vagueness was cleared up, and a few irrelevant points removed, what EW was talking about was neither new nor controversial. It was as if he had read it somewhere and partly understood it - but I could be wrong about that, of course.

Best,
Helen

I didn't read it. I just went by my common sense that if the entrance pupil was the same size then luminous flux shall be constant. But instead they say its not the same, so I tried to explain, but they just didn't understand what I say.

In the opening paragraph, you said

"Depth of field and low light ability is almost the same, given that the lens is the same size and sensor design is the same (same megapixels)"

Later one, you said what you mean by lens size is the entrance pupil.

So now you are saying

"Depth of field and low light ability is almost the same, given that the lens has the same entrance pupil size and sensor design is the same (same megapixels)"


Is that what you meant? I am trying to understand your statement. If not, can you tell us what you really meant?

 

[Helen B]

I think that most of the controversy in this thread has been because of communication problems, not because there was anything fundamentally incorrect about what EW was trying to say. Once the vagueness was cleared up, and a few irrelevant points removed, what EW was talking about was neither new nor controversial. It was as if he had read it somewhere and partly understood it - but I could be wrong about that, of course.

Best,
Helen

I didn't read it. I just went by my common sense that if the entrance pupil was the same size then luminous flux shall be constant. But instead they say its not the same, so I tried to explain, but they just didn't understand what I say.

Trouble is, that's not what you said until the words were given to you. You introduced a few red herrings (irrelevant issues) that suggested that you didn't really understand what is going on.

Don't forget that the discussion has been largely theoretical, and that there are practical issues that should also be taken into account. There's an interesting discussion going on right now about wide apertures and sensel density, for example.

I think you guys missed my point at my fourth sentence. Given that the lens is the same size (not including VR and AF), you get the same amount of light no matter how large of a sensor it hits as long as they have the same amount of pixels. A f/2.8 APS-C lens is smaller than a f/2.8 full frame lens. A f/2.0 APS-C lens will provide about the amount of light as a f/2.8 full frame lens. (APS-C is about 1 time smaller than a full frame sensor, so it gets 1 time less light at the same f stop). So the SNR of *should* be the same. I said should cause' I don't know if a larger sensor will have better SNR even if they get the same amount of light.
Please correct me if you find me wrong.

This is the reason you can't believe what we're saying, The statements are wrong. f/2 is f/2 on either ff or aps-c, same amount of light. You know about the square law of light? Well, the inverse happens here. You can change aperture to balance dof but you'll be changing the amount of light. A bigger sensor-less magnification is what makes the difference and all the benefits we're been talking about.

Once you realise that when he says 'the same size' he means the same entrance pupil diameter, and he is referring to the same field of view, he is actually correct, I'm afraid.

Best,
Helen

 

[Balmiesgirl]

ABSOLUTELY !

A larger sensor is nothing more than a luxury.

I spent all kind of crazy money on my Hassies because I had no idea what else to do with that extra cash...

Lol! Ya I totally agree

 

[zcar21]

Once you realise that when he says 'the same size' he means the same entrance pupil diameter, and he is referring to the same field of view, he is actually correct, I'm afraid.

Best,
Helen

It doesn't matter, we all know you can change aperture and focal length to get equivalent dof, or perspective. The fact of the matter doesn't change, bigger sensor=less magnification=better quality.

There's not point discussing, if somebody say the difference in low light ability between ff and aps-c is almost the same all the rest of benefits we happen to mention don't matter.
A couple of months ago I started a thread saying that the different between older and newer entry level dslr are mininum and not worst the extra money. But saying that ff and aps-c is almost the same in that respect is ridiculous.

 

[Nikon_Josh]

But that is offset by the larger fstop of smaller formats with the same entrance pupil size.

No its not. if you had pin head size pupil size / entrance compared to big..... nevermind. LoL good luck "getting it"

I don't know what to say, you guys got the information through but I don't agree with it because you guys are just saying that you're right without supporting it. For me, I couldn't get my information/opinion/idea through anyone except Helen B.

Sorry to say this EW, but alot of your views are rather strange and not very well researched at all. You seem to come on more often than not and just come out with stuff that is fiction rather than fact.

You were even shown the other day to have deliberately started a thread to cause a war between Nikon and Canon users which in my opinion is a shameful act on your part and shows the way you conduct your business on this forum.

 

[Kolia]

I think that most of the controversy in this thread has been because of communication problems, not because there was anything fundamentally incorrect about what EW was trying to say. Once the vagueness was cleared up, and a few irrelevant points removed, what EW was talking about was neither new nor controversial. It was as if he had read it somewhere and partly understood it - but I could be wrong about that, of course.

Best,
Helen

I didn't read it. I just went by my common sense that if the entrance pupil was the same size then luminous flux shall be constant. But instead they say its not the same, so I tried to explain, but they just didn't understand what I say.

Trouble is, that's not what you said until the words were given to you. You introduced a few red herrings (irrelevant issues) that suggested that you didn't really understand what is going on.

Don't forget that the discussion has been largely theoretical, and that there are practical issues that should also be taken into account. There's an interesting discussion going on right now about wide apertures and sensel density, for example.

I think you guys missed my point at my fourth sentence. Given that the lens is the same size (not including VR and AF), you get the same amount of light no matter how large of a sensor it hits as long as they have the same amount of pixels. A f/2.8 APS-C lens is smaller than a f/2.8 full frame lens. A f/2.0 APS-C lens will provide about the amount of light as a f/2.8 full frame lens. (APS-C is about 1 time smaller than a full frame sensor, so it gets 1 time less light at the same f stop). So the SNR of *should* be the same. I said should cause' I don't know if a larger sensor will have better SNR even if they get the same amount of light.
Please correct me if you find me wrong.

This is the reason you can't believe what we're saying, The statements are wrong. f/2 is f/2 on either ff or aps-c, same amount of light. You know about the square law of light? Well, the inverse happens here. You can change aperture to balance dof but you'll be changing the amount of light. A bigger sensor-less magnification is what makes the difference and all the benefits we're been talking about.

Once you realise that when he says 'the same size' he means the same entrance pupil diameter, and he is referring to the same field of view, he is actually correct, I'm afraid.

Best,
Helen

I think the whole misconception comes from EW's belief that all the light entering a lens is being focused on the sensor by some extra glass in a cropped sensor camera.

The ants picture example was a good one but didn't get traction.