Larger sensor just a luxury?

[mjhoward]

For some reason, I think OP maybe thinking FX lens and DX lens has the same image circle.

I think he is expecting the DX image circle to start out the size of the FX circle, but then get shrinked down (and 'intensified') before it gets to the sensor.

Similar to the way you would focus the light through a magnifying glass to burn something. When it's diffused (large image circle), it can't burn anything. When it's focused (small image circle), it'll burn ants all day long. In both cases there is the same amount of light coming through the glass, only the area it is focused on is changing. I think he is expecting the same thing to be happening inside the camera.

Oh thanks, now you understand what I'm talking about. So am I right?

No.

 

[EchoingWhisper]

Let's just make it simple. Shooting a evenly lit white wall.


Total amount of light collected
FX > DX because of larger area.

Expousre:
Same.

Please keep in mind that expousre has nothing to do with the size of the overall area. At a partcular spot, they receive the same amount of light. i.e. The 1mm x 1mm center of the center of DX or FX receives the same amount of light when all other conditions are the same.

Gorrect. Because exposure is about the density of light, not the total amount of light. Per mm, they are receiving the same amount of light. But DX is actually receiving less light because on the entire sensor because it is smaller. But low light capabilities is actually not determined by sensor size, but lens itself. Realise why larger sensors at the same f stop is always better in low light? Because they always have larger lenses at the same f/stop.

 

[o hey tyler]

Echoing Whipser, if you're going to post a question asking for input... And 100% of the people are telling you wrong... Why are you so insistent that you are right, if YOU were the one posing the question in the first place?

 

[EchoingWhisper]

Echoing Whipser, if you're going to post a question asking for input... And 100% of the people are telling you wrong... Why are you so insistent that you are right, if YOU were the one posing the question in the first place?

I didn't ask the question about the depth of field and low light part. I was just asking if there was any other benefits other than resolution, given that depth of field, depth of field distribution, perspective and low light abilities are not factors (or at least to me).

 

[EchoingWhisper]

I think he is expecting the DX image circle to start out the size of the FX circle, but then get shrinked down (and 'intensified') before it gets to the sensor.

Similar to the way you would focus the light through a magnifying glass to burn something. When it's diffused (large image circle), it can't burn anything. When it's focused (small image circle), it'll burn ants all day long. In both cases there is the same amount of light coming through the glass, only the area it is focused on is changing. I think he is expecting the same thing to be happening inside the camera.

Oh thanks, now you understand what I'm talking about. So am I right?

No.

Kay. I'll not debate anymore. I guess I'm wrong, since you guys are saying that I'm wrong even after understanding what I'm trying to say. But I'm still not clear why am I wrong, cause' my logic don't seem to go with your explanation and no one had explain why my logic is wrong, they just tell me why they're right.

 

[Dao]

Let's just make it simple. Shooting a evenly lit white wall.


Total amount of light collected
FX > DX because of larger area.

Expousre:
Same.

Please keep in mind that expousre has nothing to do with the size of the overall area. At a partcular spot, they receive the same amount of light. i.e. The 1mm x 1mm center of the center of DX or FX receives the same amount of light when all other conditions are the same.

Gorrect. Because exposure is about the density of light, not the total amount of light. Per mm, they are receiving the same amount of light. But DX is actually receiving less light because on the entire sensor because it is smaller. But low light capabilities is actually not determined by sensor size, but lens itself. Realise why larger sensors at the same f stop is always better in low light? Because they always have larger lenses at the same f/stop.

Take a photo with Nikon D700 paired with a 50mm DX lens, then take another photo with the same D700 paired with a 50mm FX lens. Do you think there are difference in terms of exposure in the center between the 2 photos?

 

[analog.universe]

Let's just make it simple. Shooting a evenly lit white wall.


Total amount of light collected
FX > DX because of larger area.

Expousre:
Same.

Please keep in mind that expousre has nothing to do with the size of the overall area. At a partcular spot, they receive the same amount of light. i.e. The 1mm x 1mm center of the center of DX or FX receives the same amount of light when all other conditions are the same.

Gorrect. Because exposure is about the density of light, not the total amount of light. Per mm, they are receiving the same amount of light. But DX is actually receiving less light because on the entire sensor because it is smaller. But low light capabilities is actually not determined by sensor size, but lens itself. Realise why larger sensors at the same f stop is always better in low light? Because they always have larger lenses at the same f/stop.

Take a photo with Nikon D700 paired with a 50mm DX lens, then take another photo with the same D700 paired with a 50mm FX lens. Do you think there are difference in terms of exposure in the center between the 2 photos?

By the same token you could put either the 50mm FX or DX lens a on D7000, and compare the center crop with a center crop of the same lens on a D700, and get the same exposure.

 

[Josh66]

Oh thanks, now you understand what I'm talking about. So am I right?

No.

Kay. I'll not debate anymore. I guess I'm wrong, since you guys are saying that I'm wrong even after understanding what I'm trying to say. But I'm still not clear why am I wrong, cause' my logic don't seem to go with your explanation and no one had explain why my logic is wrong, they just tell me why they're right.

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

 

[jaomul]

High quality full frame sensors can produce better images than high quality crop sensors. If the physics doesn't make that clear just look at the photographs

 

[EchoingWhisper]

No.

Kay. I'll not debate anymore. I guess I'm wrong, since you guys are saying that I'm wrong even after understanding what I'm trying to say. But I'm still not clear why am I wrong, cause' my logic don't seem to go with your explanation and no one had explain why my logic is wrong, they just tell me why they're right.

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

Yep, DX lens just gets rid of all that wasted light, that's why it is smaller. So if the DX lens is made larger, at the size of an FX lens, doesn't it gain back all those wasted light?

 

[Josh66]

Kay. I'll not debate anymore. I guess I'm wrong, since you guys are saying that I'm wrong even after understanding what I'm trying to say. But I'm still not clear why am I wrong, cause' my logic don't seem to go with your explanation and no one had explain why my logic is wrong, they just tell me why they're right.

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

Yep, DX lens just gets rid of all that wasted light, that's why it is smaller. So if the DX lens is made larger, at the size of an FX lens, doesn't it gain back all those wasted light?

So, basically, if you took a DX lens and turned it into a FX lens, would it behave like a FX lens? Is that what you're asking?

I think your question has the answer in it...

 

[Dao]

Kay. I'll not debate anymore. I guess I'm wrong, since you guys are saying that I'm wrong even after understanding what I'm trying to say. But I'm still not clear why am I wrong, cause' my logic don't seem to go with your explanation and no one had explain why my logic is wrong, they just tell me why they're right.

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

Yep, DX lens just gets rid of all that wasted light, that's why it is smaller. So if the DX lens is made larger, at the size of an FX lens, doesn't it gain back all those wasted light?

Let me put it this way. Hope that will help you understand.

Using a DX macro lens , take a photo of an area that has thousands of dead ants (not moving). In your photo, you capture 40 ants and the size of one of the ant is 4mm life size image on DX sensor.

Now you happened to find a macro lens which the front element is a big as a basketball (make up lens) and you mount it on the same camera. In your photo, you still capture 40 ants and the size of the same ant is 4mm life size as well.

(Assuming same shutter speed, iso and aperture #)


I think you maybe believe that since the lens is much bigger, more light is entering the sensor at a given time. And all light endup in the sensor.

 

[EchoingWhisper]

Let's just make it simple. Shooting a evenly lit white wall.


Total amount of light collected
FX > DX because of larger area.

Expousre:
Same.

Please keep in mind that expousre has nothing to do with the size of the overall area. At a partcular spot, they receive the same amount of light. i.e. The 1mm x 1mm center of the center of DX or FX receives the same amount of light when all other conditions are the same.

Gorrect. Because exposure is about the density of light, not the total amount of light. Per mm, they are receiving the same amount of light. But DX is actually receiving less light because on the entire sensor because it is smaller. But low light capabilities is actually not determined by sensor size, but lens itself. Realise why larger sensors at the same f stop is always better in low light? Because they always have larger lenses at the same f/stop.

Take a photo with Nikon D700 paired with a 50mm DX lens, then take another photo with the same D700 paired with a 50mm FX lens. Do you think there are difference in terms of exposure in the center between the 2 photos?

No. But that is not the correct comparison, because DX mode in D700 decreases the pixel count. A better comparison would be the D3 with 50mm (at f/2.8) VS D300 with 35mm (at f/2.0)

Check the difference in noise levels, background control etc.

The comparison isn't perfect either, because the D3, as a professional camera, gets higher end sensor (more is paid and put into it to make the sensor better). But it would be a much better comparison.

 

[EchoingWhisper]

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

Yep, DX lens just gets rid of all that wasted light, that's why it is smaller. So if the DX lens is made larger, at the size of an FX lens, doesn't it gain back all those wasted light?

So, basically, if you took a DX lens and turned it into a FX lens, would it behave like a FX lens? Is that what you're asking?

I think your question has the answer in it...

No, the size of the DX lens will be the same as FX, only that it covers only the size of a DX sensor.

 

[EchoingWhisper]

I can see why would would think that, because it does kind of make sense - but it just doesn't work that way... I'm trying to think of a good way to explain it...

If you had a FX lens on a DX body, the image circle is much larger than the sensor. Yes, there is more light coming through it than the DX lens, but that light is just wasted - it isn't doing anything, since it isn't hitting the sensor. The DX lens just gets rid of all that wasted light.

Yep, DX lens just gets rid of all that wasted light, that's why it is smaller. So if the DX lens is made larger, at the size of an FX lens, doesn't it gain back all those wasted light?

Let me put it this way. Hope that will help you understand.

Using a DX macro lens , take a photo of an area that has thousands of dead ants (not moving). In your photo, you capture 40 ants and the size of one of the ant is 4mm life size image on DX sensor.

Now you happened to find a macro lens which the front element is a big as a basketball (make up lens) and you mount it on the same camera. In your photo, you still capture 40 ants and the size of the same ant is 4mm life size as well.

(Assuming same shutter speed, iso and aperture #)


I think you maybe believe that since the lens is much bigger, more light is entering the sensor at a given time. And all light endup in the sensor.

Hmmm, that's a good point.