L Lenses for crop bodies

[paul13walnut5]

They have the potential to do a greater amount of work in a set period assuming all other things being equal.

Like it, but not quite getting there, in car metaphor terms. Lets suppose a photosite is a citroen SM, and that light is an autobahn? Does that help?

 

[Pi]

They have the potential to do a greater amount of work in a set period assuming all other things being equal.

In my analogy, what is equal is the total volume, which means approximately the same amount ow work.

 

[paul13walnut5]

So if a Citroen SM is on the autobahn....

 

[paul13walnut5]

In my analogy, what is equal is the total volume, which means approximately the same amount ow work.

No. In your analogy the toal volume was not equal. You said:

It is like saying that engines with higher volume are more powerful because they have larger cylinders.

Higher Volumes. Higher. Greater. More.

Not equal.

 

[Pi]

In my analogy, what is equal is the total volume, which means approximately the same amount ow work.

No. In your analogy the toal volume was not equal. You said:

It is like saying that engines with higher volume are more powerful because they have larger cylinders.

Higher Volumes. Higher. Greater. More.

Not equal.

My remark was in the context of yours "everything else being equal".

Engines with larger (total) volume are more powerful because ... they have larger (total) volume. Of course, there are a lot of footnotes here.

 

[dufflover]

And you don't think the above posts prove sometimes the simplification is has been over-simplified. IMO any explanation of FF vs Crop without mentioning pixel/photosite size and exposure is a bad one; which many are because they only talk about "1.6x crop factor".

I've seen posts where people think you can shoot at lower ISO in a FF camera because the sensor is larger and collects more light!

I like TDP but never been a fan of his samples shot on crop camera. Always softer than any practical image I've seen. And similar to this whole topic there's this constant debate on whether FF makes things sharper or is simply more lenient to a crap lens; and going off the whole principle of a lens image being constant, logically it's the latter. (at low ISOs obviously)

 

[Pi]

And you don't think the above posts prove sometimes the simplification is has been over-simplified. IMO any explanation of FF vs Crop without mentioning pixel/photosite size and exposure is a bad one; which many are because they only talk about "1.6x crop factor".

Any explanation which mentions this is a bad one. Pixel size is a secondary factor. You can replace the sensor by a film, or a piece of paper. The noise would still be there. The (dominant) noise is noise of the projected image, not noise created by the sensor. Google "photon noise". Any mentioning of pixels there?

I've seen posts where people think you can shoot at lower ISO in a FF camera because the sensor is larger and collects more light!

This does not make much sense without knowing the rest but the fact is that when you can shoot at the same ISO, it is like shooting at ISO 40 on crop.

I like TDP but never been a fan of his samples shot on crop camera. Always softer than any practical image I've seen. And similar to this whole topic there's this constant debate on whether FF makes things sharper or is simply more lenient to a crap lens; and going off the whole principle of a lens image being constant, logically it's the latter. (at low ISOs obviously)

You are making a fundamental mistake. The image on the sensor might be constant but it must be magnified more with the crop sensor.

I have done a few comparisons, follow the link in my signature. The difference is more than obvious.

 

[paul13walnut5]

You are making a fundamental mistake. The image on the sensor might be constant but it must be magnified more with the crop sensor.

I have done a few comparisons, follow the link in my signature. The difference is more than obvious.

Magnified? You talk some bollocks mate. An ef lens on an aps-c body throws exactly the same image circle as an ef lens on a 135 format or aps-h sensor.

There is no magnification involved. There is electronic cropping.

 

[paul13walnut5]

In my analogy, what is equal is the total volume, which means approximately the same amount ow work.

No. In your analogy the toal volume was not equal. You said:

It is like saying that engines with higher volume are more powerful because they have larger cylinders.

Higher Volumes. Higher. Greater. More.

Not equal.

My remark was in the context of yours "everything else being equal".

Engines with larger (total) volume are more powerful because ... they have larger (total) volume. Of course, there are a lot of footnotes here.

All other things being equal. Number of cylinders. Arrangement. Aspiration.

Whats heavier a tonne a feathers or a tonne of coal?

 

[Loswr]

You are making a fundamental mistake. The image on the sensor might be constant but it must be magnified more with the crop sensor.

Magnified? You talk some bollocks mate. An ef lens on an aps-c body throws exactly the same image circle as an ef lens on a 135 format or aps-h sensor.

There is no magnification involved. There is electronic cropping.

Sorry, the bollocks here is coming from you. When you look at the TDP ISO 12233 crops on your monitor, are they the teeny tiny size of the camera's sensor? If they're bigger, there is magnification occurring.

Is a crop sensor smaller than a FF sensor? When you compare the ISO 12233 crops from FF and APS-C with equal MP (example), do the 100% crops appear the same size on your monitor? If the crop sensor is physically smaller, how is it that the 100% crops appear the same size as those from the FF sensor? They're magnified more.

 

[Pi]

Whats heavier a tonne a feathers or a tonne of coal?

A tonne of coal because it has larger particles.

 

[Pi]

Magnified? You talk some bollocks mate. An ef lens on an aps-c body throws exactly the same image circle as an ef lens on a 135 format or aps-h sensor.

There is no magnification involved. There is electronic cropping.

A non-enlarged image is a large as this, more or less:

 

[candc]

I think we all understand that the slightly cropped image from an aps-c sensor compared to that of a ff one must be magnified slightly more to be viewed at the same size but we are not talking about orders of magnitude here. I think his point that the better iso performance is due to the larger size of the photosites and not the physical size of the sensor is right.

 

[paul13walnut5]

Sorry clever Dr. John.

I think you have joined a conversation in the wrong context.

I'm a nice guy so I'll give you the chance to read back a bit.

You may choose to reword your response once you have the context.

Please think carefully about what magnification actually means. Think about what image circle an EF lens throws. Think a bit about how that circle might stay constant on a focal plane set at a specific flange depth, no matter the body that is (hint hint clue coming up..) cropping affects that circle.

Sheeet. I'm teaching my very clever granny to suck eggs here. If you think optical magnification and sensor cropping or display scaling are the same thing then... cripes.

To remind you, the context of my bugbear was

Presumably this is because there was more light originally on the larger sensor.

I think a comparison would only be valid like for like, i.e. the subject light would be the same and the projected image circle would be the same at the focal plane regardless of the sensor area, otherwise a comparison would be meaningless. The larger sensor has larger individual photosites is the key.

Do you agree that the brightness of an image circle projected by a specific ef lens on a surface distance equal to the focal plane would be identical, in lab conditions, regardless of the sensor on the camera?

Have a terrific day.

 

[paul13walnut5]

Whats heavier a tonne a feathers or a tonne of coal?

A tonne of coal because it has larger particles.

I didn't ask about mass.

 

[Pi]

Whats heavier a tonne a feathers or a tonne of coal?

A tonne of coal because it has larger particles.

I didn't ask about mass.

And I did not say anything about mass.

I think we all understand that the slightly cropped image from an aps-c sensor compared to that of a ff one must be magnified slightly more to be viewed at the same size but we are not talking about orders of magnitude here.

The linear size is 1.6x larger, the area is 2.56x larger, and log_2 of that is about 1.36 (stops).

I think his point that the better iso performance is due to the larger size of the photosites and not the physical size of the sensor is right.

This explains why the D800 has the noise performance of a crop camera and much worse than that of the D600. Wait...

 

[Loswr]

I think you have joined a conversation in the wrong context.

...

Have a terrific day.

Yeah, my bad. Sorry for putting my oar in.

Isn't it 3am for you? Get some sleep, man...

 

[Pi]

You just proved your own point wrong, if the d800 has the same iso performance of a crop camera then its due to the size of the photosites which are the same size as those of a crop camera

And if it does not, did I prove you wrong?

 

[paul13walnut5]

Whats heavier a tonne a feathers or a tonne of coal?

A tonne of coal because it has larger particles.

I didn't ask about mass.

And I did not say anything about mass.

Ach, I misread you as being on about particle density. Silly me. But if you are talking about weight, as per the question, then you are wrong.


Can you then answer the conundrum about the projected image circle of any given EF lens being consistent no matter the camera attached to the lens. Will the image circle, regardless of what happens to it in the cameras electronics, setting for setting, be the same? The projected image circle only please. You have until the dartboard revolves....

 

[candc]

If an image viewed at 100% and the individual pixels have better iso performance then it is due to their individual size and characteristics not from whichever sensor they were plucked from