Canon ef-s 17-55mm 2.8 is usm GONE

[rs]

I don't have a full frame camera yet, but haven't I read that since the sensor is larger the light gathering ability is better compared to a crop sensor? If so, just another reason to go full frame.

Yep. It's like comparing two solar panels. If they're of the same sensitivity and one is 2.56x bigger, it'll gather 2.56x as much light.

 

[meywd]

I don't have a full frame camera yet, but haven't I read that since the sensor is larger the light gathering ability is better compared to a crop sensor? If so, just another reason to go full frame.

Yep. It's like comparing two solar panels. If they're of the same sensitivity and one is 2.56x bigger, it'll gather 2.56x as much light.

Its not the sensor size, its the pixel size, if two sensors has the same pixel density while one is full frame and the other is crop then both will have the same light gathering ability, however since most full frame sensors has larger pixels you see better high ISO performance, and even though this is the case now, the real cause is not just the pixel size, its the SNR, because if you have theoretically a pixel with zero noise, then no matter the pixel size the total image will be the same.

Imagine you have a bucket of water covering an area, and also have 9 smaller ones that cover the same area, if the rain volume was the same for both areas then the total amount of water collected should be the same in both cases, the difference in the sensors and pixels case is that when the analog signal is converted to digital there will be some noise in the data, and if that noise is greater than the light signal data then the data will be lost, which what happens in low light when using a crop.

 

[Loswr]

Its not the sensor size, its the pixel size, if two sensors has the same pixel density while one is full frame and the other is crop then both will have the same light gathering ability

Imagine you have a bucket of water covering an area, and also have 9 smaller ones that cover the same area...

Ummmmm....no.

The area is not the same, a FF sensor is 2.56-times larger than an APS-C sensor.

 

[meywd]

Its not the sensor size, its the pixel size, if two sensors has the same pixel density while one is full frame and the other is crop then both will have the same light gathering ability

Imagine you have a bucket of water covering an area, and also have 9 smaller ones that cover the same area...

Ummmmm....no.

The area is not the same, a FF sensor is 2.56-times larger than an APS-C sensor.

Sorry for not stating it more clearly, but I am taking about pixels and not sensors.

 

[Loswr]

Sorry for not stating it more clearly, but I am taking about pixels and not sensors.

The pixel discussion is tangential to the point under discussion. The question (which you quoted) was, "Does a FF sensor gather more light than a crop sensor?" The answer is, "Yes, because the FF sensor has a 2.56x greater area."

Your statement that, "It's not the sensor size, it's the pixel size," is flat out incorrect in that context. Compare the 5DII and the 30D, or the 7DII and 5Ds: similar technology, approximately equivalent pixel pitch. Which one of each pair gathers more light? Which one of each pair has lower noise?

 

[rs]

Its not the sensor size, its the pixel size, if two sensors has the same pixel density while one is full frame and the other is crop then both will have the same light gathering ability

Imagine you have a bucket of water covering an area, and also have 9 smaller ones that cover the same area...

Ummmmm....no.

The area is not the same, a FF sensor is 2.56-times larger than an APS-C sensor.

Sorry for not stating it more clearly, but I am taking about pixels and not sensors.

Sorry for not stating it more clearly, but what have the individual pixels got to do with this? We're talking about whole sensors, or whole images. We should view both at the same size - ie print or on screen. If you want to reproduce one bigger than the other, then equivalence is thrown out of the window and comparisons can stop there. It's sensor size, not pixel size which counts.

 

[meywd]

Sorry for not stating it more clearly, but I am taking about pixels and not sensors.

The pixel discussion is tangential to the point under discussion. The question (which you quoted) was, "Does a FF sensor gather more light than a crop sensor?" The answer is, "Yes, because the FF sensor has a 2.56x greater area."

Your statement that, "It's not the sensor size, it's the pixel size," is flat out incorrect in that context. Compare the 5DII and the 30D, or the 7DII and 5Ds: similar technology, approximately equivalent pixel pitch. Which one of each pair gathers more light? Which one of each pair has lower noise?

Its not the sensor size, its the pixel size, if two sensors has the same pixel density while one is full frame and the other is crop then both will have the same light gathering ability

Imagine you have a bucket of water covering an area, and also have 9 smaller ones that cover the same area...

Ummmmm....no.

The area is not the same, a FF sensor is 2.56-times larger than an APS-C sensor.

Sorry for not stating it more clearly, but I am taking about pixels and not sensors.

Sorry for not stating it more clearly, but what have the individual pixels got to do with this? We're talking about whole sensors, or whole images. We should view both at the same size - ie print or on screen. If you want to reproduce one bigger than the other, then equivalence is thrown out of the window and comparisons can stop there. It's sensor size, not pixel size which counts.

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

 

[Loswr]

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

Adding more area makes it better. Refer to my questions above. The 5Ds and 7DII are same-generation and have nearly identical pixel size. By your logic, the 5Ds should not deliver a better image than the 7DII, because it merely has more pixels. Feel free to demonstrate the truth of that logic. The weight of evidence is not in your favor.

 

[meywd]

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

Adding more area makes it better. Refer to my questions above. The 5Ds and 7DII are same-generation and have nearly identical pixel size. By your logic, the 5Ds should not deliver a better image than the 7DII, because it merely has more pixels. Feel free to demonstrate the truth of that logic.

Although both of the 5Ds and the 7DII are current that doesn't mean that the same technology was used in both, and you can never know for sure unless you have insider knowledge, if you compare the 5Ds/7D II/5D III/6D at dpreview on ISO 3200 for example you will see that the 5Ds image looks different than the other three cameras, which I think - no I don't know for sure either - is caused by a reduction in read noise or a calculation that reduce it when saving the raws, so you can't draw any certain conclusions from that comparison.

 

[Loswr]

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

Adding more area makes it better. Refer to my questions above. The 5Ds and 7DII are same-generation and have nearly identical pixel size. By your logic, the 5Ds should not deliver a better image than the 7DII, because it merely has more pixels. Feel free to demonstrate the truth of that logic.

Although both of the 5Ds and the 7DII are current that doesn't mean that the same technology was used in both, and you can never know for sure unless you have insider knowledge, if you compare the 5Ds/7D II/5D III/6D at dpreview on ISO 3200 for example you will see that the 5Ds image looks different than the other three cameras, which I think - no I don't know for sure either - is caused by a reduction in read noise or a calculation that reduce it when saving the raws, so you can't draw any certain conclusions from that comparison.

Sorry, but you're just really missing the point here. Put two buckets in the same rainfall, one with a 1 m2 opening, the other with a 2.56 m2 opening. Which collects more water?

A larger sensor collects more light than a smaller sensor. Image noise is inversely proportional to total light collected. Bigger sensor = more light = less image noise.

 

[Ozarker]

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

Adding more area makes it better. Refer to my questions above. The 5Ds and 7DII are same-generation and have nearly identical pixel size. By your logic, the 5Ds should not deliver a better image than the 7DII, because it merely has more pixels. Feel free to demonstrate the truth of that logic.

Although both of the 5Ds and the 7DII are current that doesn't mean that the same technology was used in both, and you can never know for sure unless you have insider knowledge, if you compare the 5Ds/7D II/5D III/6D at dpreview on ISO 3200 for example you will see that the 5Ds image looks different than the other three cameras, which I think - no I don't know for sure either - is caused by a reduction in read noise or a calculation that reduce it when saving the raws, so you can't draw any certain conclusions from that comparison.

Sorry, but you're just really missing the point here. Put two buckets in the same rainfall, one with a 1 m2 opening, the other with a 2.56 m2 opening. Which collects more water?

A larger sensor collects more light than a smaller sensor. Image noise is inversely proportional to total light collected. Bigger sensor = more light = less image noise.

Thank you.

 

[StudentOfLight]

If by "more light" you mean there is more data in the image file, then you are correct, but that is not the point, because more Data doesn't mean a better image, more Data on the pixel on the other hand will make an image better, a sensor is not a single piece of light collecting surface, its an array of pixels, adding more pixels doesn't make your image better, it makes it larger.

Adding more area makes it better. Refer to my questions above. The 5Ds and 7DII are same-generation and have nearly identical pixel size. By your logic, the 5Ds should not deliver a better image than the 7DII, because it merely has more pixels. Feel free to demonstrate the truth of that logic.

Although both of the 5Ds and the 7DII are current that doesn't mean that the same technology was used in both, and you can never know for sure unless you have insider knowledge, if you compare the 5Ds/7D II/5D III/6D at dpreview on ISO 3200 for example you will see that the 5Ds image looks different than the other three cameras, which I think - no I don't know for sure either - is caused by a reduction in read noise or a calculation that reduce it when saving the raws, so you can't draw any certain conclusions from that comparison.

Sorry, but you're just really missing the point here. Put two buckets in the same rainfall, one with a 1 m2 opening, the other with a 2.56 m2 opening. Which collects more water?

A larger sensor collects more light than a smaller sensor. Image noise is inversely proportional to total light collected. Bigger sensor = more light = less image noise.

The iris is like an inverted funnel that limits the collection of rainfall from more oblique angles

 

[Ozarker]

Just trying to learn a little: Since my crop sensor does not gather as much light as a full frame sensor would... then would that mean an f/2.8 lens on a full frame camera would behave like a slower lens on a crop sensor camera?

Example: On a full frame camera with lens X set at f/2.8, ISO 100, 1/250th of a second I get a correct exposure of my subject. If I then take the same lens, settings and subject but use a crop sensor camera... would I have to decrease my shutter speed to get the same exposure?

If true... then my f/2.8 lenses will seem lightening fast on a FF body compared to crop. Which means the performance (speed) of my EF 400mm f/5.6L would greatly improve on a full frame body.

Am I correct? If so, I can hardly wait to go full frame.

 

[Loswr]

Just trying to learn a little: Since my crop sensor does not gather as much light as a full frame sensor would... then would that mean an f/2.8 lens on a full frame camera would behave like a slower lens on a crop sensor camera? Example: On a full frame camera with lens X set at f/2.8, ISO 100, 1/250th of a second I get a correct exposure of my subject. If I then take the same lens, settings and subject but use a crop sensor camera... would I have to increase my shutter speed to get the same exposure? If true... then my f/2.8 lenses will seem lightening fast on a FF body compared to crop. Which means the performance of my EF 400mm f/5.6L would greatly improve on a full frame body. Am I correct?

No, you'd get the same exposure on FF as on crop. But the FF image will have lower noise. Accordingly, on FF you could choose to stop down to f/4 for more DoF, or boost the shutter speed to 1/500 s to stop motion, and still have slightly less image noise after raising the ISO to compensate. Now...the noise difference at low ISO isn't much, so in bright light the FF benefits are less. But at ISO 3200, you'll certainly notice the difference.

 

[Ozarker]

Just trying to learn a little: Since my crop sensor does not gather as much light as a full frame sensor would... then would that mean an f/2.8 lens on a full frame camera would behave like a slower lens on a crop sensor camera? Example: On a full frame camera with lens X set at f/2.8, ISO 100, 1/250th of a second I get a correct exposure of my subject. If I then take the same lens, settings and subject but use a crop sensor camera... would I have to increase my shutter speed to get the same exposure? If true... then my f/2.8 lenses will seem lightening fast on a FF body compared to crop. Which means the performance of my EF 400mm f/5.6L would greatly improve on a full frame body. Am I correct?

No, you'd get the same exposure on FF as on crop. But the FF image will have lower noise. Accordingly, on FF you could choose to stop down to f/4 for more DoF, or boost the shutter speed to 1/500 s to stop motion, and still have slightly less image noise after raising the ISO to compensate. Now...the noise difference at low ISO isn't much, so in bright light the FF benefits are less. But at ISO 3200, you'll certainly notice the difference.

Thanks again!