lens light-gathering abilities

pschlute · 08-23-2019, 02:39 AM - **2 Likes**

Originally posted by beholder3

The Apsc sensor is 2;25 times smaller than a FF sensor. And you print to what size?

There is a huge magnification going on with every digital photo. Or do you watch your apsc photos on a screen sized 16x24 mm?

If we take a K5/K1 in crop mode sensor as an example 16.3MP 4928x3264 pixels. My monitor is 2560x1440. In full screen view I am seeing the image at around half its actual size, not enlarged at all, let alone a huge one.

When you print an image your print size is determined by the image file pixel dimensions and the ppi. At say 300 ppi You could print that image at 16"x10.88". No enlargement required. No magnification

The point is that pixels in an image file do not have a physical size.

Last edited by pschlute; 08-23-2019 at 03:12 AM.

beholder3 · 08-23-2019, 02:45 AM - **1 Like**

Originally posted by GUB

It would be quite cool to have a monitor at 7372:4924 resolution. But I don't think we are there yet even with large screen tvs are we?

Pixel count or size have no relevancy in this discussion at all unless someone declares it is only about different photo end results sizes. So far the thread opener has not made this statement.
So for the time being I can only advise any reader to flat out ignore every single post mentioning pixel size or pixel count here in this thread about light gathering of lenses.

---------- Post added 23rd Aug 2019 at 11:51 ----------

Originally posted by pschlute

If we take a K5/K1 in crop mode sensor as an example 16.3MP 4928x3264 pixels. My monitor is 2560x1440. In full screen view I am seeing the image at around half its actual size, not enlarged at all, let alone a huge one.

When you print an image your print size is determined by the image file pixel size and the ppi. At say 300 ppi You could print that image at 16"x10.88". No enlargement required. No magnification

The point is that pixels in an image file do not have a physical size.

I was talking about size in millimeters.

I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera.

pschlute · 08-23-2019, 02:53 AM - **2 Likes**

Originally posted by beholder3

Pixel count or size have no relevancy in this discussion at all unless someone declares it is only about different photo end results sizes. So far the thread opener has not made this statement.
So for the time being I can only advise any reader to flat out ignore every single post mentioning pixel size or pixel count here in this thread about light gathering of lenses.

Ahem...point of order Sir...

It was you that brought pixel size into the discussion by claiming that every digital image required "huge magnification".

**GUB** · 08-23-2019, 03:06 AM - **1 Like**

Originally posted by beholder3

I was talking about size in millimeters.

That was a bit silly considering you were responding to a statement about resolution.

pschlute · 08-23-2019, 03:11 AM - **1 Like**

Originally posted by beholder3

I was talking about size in millimeters.

I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera.

I hope you understand that a pixel has no physical size.

Dartmoor Dave · 08-23-2019, 03:21 AM - **1 Like**

Originally posted by beholder3

I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera.

Please think very carefully about the important point that pschlute has stated far better and far more succinctly than I've done: Pixels in an image file do not have a physical size.

Now this next bit is going to blow your mind: a 16"x10.88" print from a 16 megapixel file is effectively a contact print. It's a print at 1:1 resolution, in which one pixel on the sensor equals one dot of ink on the print (told you it would blow your mind).

It can seem counterintuitive, which is why so many people prefer the comforting myths of equivalence, but when we're talking about digital photography the physical size of sensors and screens usually has very little to do with things. After all, your computer doesn't need to know the physical size of your monitor to display photos properly, does it? All it needs to know is the pixel resolution

beholder3 · 08-23-2019, 03:22 AM - **1 Like**

Originally posted by pschlute

Ahem...point of order Sir...

It was you that brought pixel size into the discussion by claiming that every digital image required "huge magnification".

Is this a joke? Magnification is the difference between input / sensor and output size. Pixels are nowhere part of the equation.

---------- Post added 23rd Aug 2019 at 12:24 ----------

Originally posted by pschlute

I hope you understand that a pixel has no physical size.

Again: Pixels are not relevant. And: pixels on the sensor do have a size.

**GUB** · 08-23-2019, 03:28 AM - **2 Likes**

Originally posted by beholder3

Is this a joke? Magnification is the difference between input / sensor and output size. Pixels are nowhere part of the equation.

---------- Post added 23rd Aug 2019 at 12:24 ----------

Again: Pixels are not relevant. And: pixels on the sensor do have a size.

When I set my editor image to 100% it matches the image pixel to the screen pixel so you are simply wrong

Dartmoor Dave · 08-23-2019, 03:29 AM - **2 Likes**

Originally posted by beholder3

Pixels are nowhere part of the equation.

Oookaaaayyyy. . . .

Um. . . .

So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly?

**GUB** · 08-23-2019, 03:31 AM - **1 Like**

Originally posted by Dartmoor Dave

Oookaaaayyyy. . . .

Um. . . .

So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly?

OK, you are back on the Dartmoor mushrooms aren't you!

Dartmoor Dave · 08-23-2019, 03:34 AM - **3 Likes**

Originally posted by GUB

OK, you are back on the Dartmoor mushrooms aren't you!

This thread is making me feel that way. And the problem is, from now on I'm only ever going to be able to talk about resolution in terms of micro-elves.

slartibartfast01 · 08-23-2019, 04:12 AM

Originally posted by Dartmoor Dave

Oookaaaayyyy. . . .

Um. . . .

So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly?

As in Discworld?

Gimbal · 08-23-2019, 04:14 AM - **1 Like**

It has now been stated by everyone, pixels are not used to measure size. Right, keep that in mind for the rest of this post. Pixels are not ….

So take for example an image projected on a 35mm frame/sensor and then viewed on a 24” screen.
Has the image size been reduced? (Remember, pixels are NOT a measurement of size, millimeter are.)

It has been enlarged.

If we now take an image from a APS-C sensor and display it on the same 24” screen, it has to be enlarged even more then the FF image to fill the screen. ENLARGED, even though it was down sampled. Pixels are NOT used to measure size.

swanlefitte · 08-23-2019, 04:53 AM

Originally posted by GUB

When I set my editor image to 100% it matches the image pixel to the screen pixel so you are simply wrong

That is a real equivalence.
A monitor with one pixel will display one pixel or down sample or up sample. But it is 1 pixel. How can you say that huge pixel vs a camera pixel is magnification of the sensor?
One pixel is equivalent to one pixel. I guess you can say the pixel is magnified but that has no real meaning.

**GUB** · 08-23-2019, 04:55 AM - **1 Like**

Originally posted by Gimbal

It has now been stated by everyone, pixels are not used to measure size. Right, keep that in mind for the rest of this post. Pixels are not ….

So take for example an image projected on a 35mm frame/sensor and then viewed on a 24” screen.
Has the image size been reduced? (Remember, pixels are NOT a measurement of size, millimeter are.)

It has been enlarged.

If we now take an image from a APS-C sensor and display it on the same 24” screen, it has to be enlarged even more then the FF image to fill the screen. ENLARGED, even though it was down sampled. Pixels are NOT used to measure size.

So when my image viewer magnification is set to 100% it should show the image at the size of the sensor according to that.

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08-23-2019, 02:39 AM - 2 Likes	#181
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Originally posted by beholder3 The Apsc sensor is 2;25 times smaller than a FF sensor. And you print to what size? There is a huge magnification going on with every digital photo. Or do you watch your apsc photos on a screen sized 16x24 mm? If we take a K5/K1 in crop mode sensor as an example 16.3MP 4928x3264 pixels. My monitor is 2560x1440. In full screen view I am seeing the image at around half its actual size, not enlarged at all, let alone a huge one. When you print an image your print size is determined by the image file pixel dimensions and the ppi. At say 300 ppi You could print that image at 16"x10.88". No enlargement required. No magnification The point is that pixels in an image file do not have a physical size. Last edited by pschlute; 08-23-2019 at 03:12 AM.

08-23-2019, 02:45 AM - 1 Like	#182
beholder3 Pentaxian Join Date: Dec 2011 Posts: 3,112	Originally posted by GUB It would be quite cool to have a monitor at 7372:4924 resolution. But I don't think we are there yet even with large screen tvs are we? Pixel count or size have no relevancy in this discussion at all unless someone declares it is only about different photo end results sizes. So far the thread opener has not made this statement. So for the time being I can only advise any reader to flat out ignore every single post mentioning pixel size or pixel count here in this thread about light gathering of lenses. ---------- Post added 23rd Aug 2019 at 11:51 ---------- Originally posted by pschlute If we take a K5/K1 in crop mode sensor as an example 16.3MP 4928x3264 pixels. My monitor is 2560x1440. In full screen view I am seeing the image at around half its actual size, not enlarged at all, let alone a huge one. When you print an image your print size is determined by the image file pixel size and the ppi. At say 300 ppi You could print that image at 16"x10.88". No enlargement required. No magnification The point is that pixels in an image file do not have a physical size. I was talking about size in millimeters. I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera.

08-23-2019, 02:53 AM - 2 Likes	#183
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Originally posted by beholder3 Pixel count or size have no relevancy in this discussion at all unless someone declares it is only about different photo end results sizes. So far the thread opener has not made this statement. So for the time being I can only advise any reader to flat out ignore every single post mentioning pixel size or pixel count here in this thread about light gathering of lenses. Ahem...point of order Sir... It was you that brought pixel size into the discussion by claiming that every digital image required "huge magnification".

08-23-2019, 03:06 AM - 1 Like	#184
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by beholder3 I was talking about size in millimeters. That was a bit silly considering you were responding to a statement about resolution.

08-23-2019, 03:11 AM - 1 Like	#185
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Originally posted by beholder3 I was talking about size in millimeters. I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera. I hope you understand that a pixel has no physical size.

08-23-2019, 03:21 AM - 1 Like	#186
Dartmoor Dave Pentaxian Join Date: Aug 2012 Location: Dartmoor, UK Photos: Gallery Posts: 3,882	Originally posted by beholder3 I do hope you do understand that taking the image of a 16x24mm apsc sensor and printing it to your 16x10 inches involves a LOT of magnification. And less so if the image had been from a large format film camera. Please think very carefully about the important point that pschlute has stated far better and far more succinctly than I've done: Pixels in an image file do not have a physical size. Now this next bit is going to blow your mind: a 16"x10.88" print from a 16 megapixel file is effectively a contact print. It's a print at 1:1 resolution, in which one pixel on the sensor equals one dot of ink on the print (told you it would blow your mind). It can seem counterintuitive, which is why so many people prefer the comforting myths of equivalence, but when we're talking about digital photography the physical size of sensors and screens usually has very little to do with things. After all, your computer doesn't need to know the physical size of your monitor to display photos properly, does it? All it needs to know is the pixel resolution

08-23-2019, 03:22 AM - 1 Like	#187
beholder3 Pentaxian Join Date: Dec 2011 Posts: 3,112	Originally posted by pschlute Ahem...point of order Sir... It was you that brought pixel size into the discussion by claiming that every digital image required "huge magnification". Is this a joke? Magnification is the difference between input / sensor and output size. Pixels are nowhere part of the equation. ---------- Post added 23rd Aug 2019 at 12:24 ---------- Originally posted by pschlute I hope you understand that a pixel has no physical size. Again: Pixels are not relevant. And: pixels on the sensor do have a size.

08-23-2019, 03:28 AM - 2 Likes	#188
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by beholder3 Is this a joke? Magnification is the difference between input / sensor and output size. Pixels are nowhere part of the equation. ---------- Post added 23rd Aug 2019 at 12:24 ---------- Again: Pixels are not relevant. And: pixels on the sensor do have a size. When I set my editor image to 100% it matches the image pixel to the screen pixel so you are simply wrong

08-23-2019, 03:29 AM - 2 Likes	#189
Dartmoor Dave Pentaxian Join Date: Aug 2012 Location: Dartmoor, UK Photos: Gallery Posts: 3,882	Originally posted by beholder3 Pixels are nowhere part of the equation. Oookaaaayyyy. . . . Um. . . . So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly?

08-23-2019, 03:31 AM - 1 Like	#190
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by Dartmoor Dave Oookaaaayyyy. . . . Um. . . . So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly? OK, you are back on the Dartmoor mushrooms aren't you!

08-23-2019, 03:34 AM - 3 Likes	#191
Dartmoor Dave Pentaxian Join Date: Aug 2012 Location: Dartmoor, UK Photos: Gallery Posts: 3,882	Originally posted by GUB OK, you are back on the Dartmoor mushrooms aren't you! This thread is making me feel that way. And the problem is, from now on I'm only ever going to be able to talk about resolution in terms of micro-elves.

08-23-2019, 04:12 AM	#192
slartibartfast01 Pentaxian Join Date: May 2015 Photos: Gallery Posts: 1,931	Originally posted by Dartmoor Dave Oookaaaayyyy. . . . Um. . . . So maybe a digital sensor is full of microscopic elves painting oil paintings very quickly? As in Discworld?

08-23-2019, 04:14 AM - 1 Like	#193
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	It has now been stated by everyone, pixels are not used to measure size. Right, keep that in mind for the rest of this post. Pixels are not …. So take for example an image projected on a 35mm frame/sensor and then viewed on a 24” screen. Has the image size been reduced? (Remember, pixels are NOT a measurement of size, millimeter are.) It has been enlarged. If we now take an image from a APS-C sensor and display it on the same 24” screen, it has to be enlarged even more then the FF image to fill the screen. ENLARGED, even though it was down sampled. Pixels are NOT used to measure size.

08-23-2019, 04:53 AM	#194
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	Originally posted by GUB When I set my editor image to 100% it matches the image pixel to the screen pixel so you are simply wrong That is a real equivalence. A monitor with one pixel will display one pixel or down sample or up sample. But it is 1 pixel. How can you say that huge pixel vs a camera pixel is magnification of the sensor? One pixel is equivalent to one pixel. I guess you can say the pixel is magnified but that has no real meaning.

08-23-2019, 04:55 AM - 1 Like	#195
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by Gimbal It has now been stated by everyone, pixels are not used to measure size. Right, keep that in mind for the rest of this post. Pixels are not …. So take for example an image projected on a 35mm frame/sensor and then viewed on a 24” screen. Has the image size been reduced? (Remember, pixels are NOT a measurement of size, millimeter are.) It has been enlarged. If we now take an image from a APS-C sensor and display it on the same 24” screen, it has to be enlarged even more then the FF image to fill the screen. ENLARGED, even though it was down sampled. Pixels are NOT used to measure size. So when my image viewer magnification is set to 100% it should show the image at the size of the sensor according to that.