[Ian Stuart Forsyth]

The great thing about it being just numbers is that we can do all sorts of amazing things with the data on our computers, which we call post-processing. And speaking of computers, I notice that none of the equivalentists have explained yet how my computer enlarges the physical size of my sensor to the physical size of my screen, when it doesn't know what those sizes are.

How does my slide projector know how much enlargement is needed to project it onto my wall? does this not knowing invalidate the fact that my slide has a physical size and needs to be enlarged so that it can be displayed on my wall ?

[pschlute]

How does my slide projector know how much enlargement is needed to project it onto my wall? does this not knowing invalidate the fact that my slide has a physical size and needs to be enlarged so that it can be displayed on my wall ?

But with a computer screen there is no need for someone else to say "back a bit, up a bit, hold it just there"

[slartibartfast01]

How does my slide projector know how much enlargement is needed to project it onto my wall? does this not knowing invalidate the fact that my slide has a physical size and needs to be enlarged so that it can be displayed on my wall ?

Your slide projector doesn't even know the wall is there.

[Fogel70]

But with a computer screen there is no need for someone else to say "back a bit, up a bit, hold it just there"

But someone might say: "can you zoom in so the inage fill the whole screen". Or "can you maximize the window please".

[slartibartfast01]

But someone might say: "can you zoom in so the inage fill the whole screen". Or "can you maximize the window please".

But that can be done with a single click not by trial and error by manually moving the projector.

[GUB]

But someone might say: "can you zoom in so the inage fill the whole screen"

Yes I ask my computer to do this all the time. It checks out the exif , finds the pixel count , works out how many image pixels have to sit on every screen pixel and downsizes accordingly.
All you silly sods have to do is find a sensor size entered in the exif and you then at least have a basis to start your argument on.

[Dartmoor Dave]

How does my slide projector know how much enlargement is needed to project it onto my wall? does this not knowing invalidate the fact that my slide has a physical size and needs to be enlarged so that it can be displayed on my wall ?

So now you just have to explain in what way a digital photo, when you look at it on a computer screen, is an optical projection of an image captured by the camera's sensor. Rather than just digital values displayed at whatever your screen's pixel resolution is.

I'm getting a horrible feeling that you think that all those little squares in your photo of the K7 sensor are each getting optically enlarged up to bigger squares on your computer screen.

It isn't an optical enlargement. The physical size of the pixels on your camera's sensor loses all meaning at the point where the electrical charge is measured and stored as a digital value. And the concept of physical size only regains any meaning at the point where it is displayed at whatever pixel resolution your monitor happens to be.

It has no relationship, in any way at all, to what a slide projector does or to what an enlarger does in a darkroom.

[Gimbal]

Luckily you don't have to understand it, and you don't have to know the original size of the sensor to print at whatever size you choose.
And no, the computer does not need to know the original size either, but that does not mean that there isn't ratio of enlargement involved and that this ratio effects the outcome.

However, everyone does know by experience that an APS-C sensor prints bigger then a phone sensor. And most people know that a FF prints better then a crop sensor, and FF is beaten by a MF. But that is all a coincidence of course.

[dbs]

Just a couple of times Steve, I decided to move onto beer & pretzel's 😉

---------- Post added 08-23-19 at 11:12 PM ----------



Just made a big order from Amazon for pretzel's you need me to send some over Dave?



What have I learned today??
#01: Gub thinks the truck is more useful

#02: Dartmore Dave Really can blow my mind (great printer / megapixel factoid)

#03: Dartmore Dave might be on mushrooms, he's seeing fast moving elves painting.

#04: Gub might of got into Dartmore's Daves stash, he's seeing elves with tap measures.

#05: Make sure you stock up on snacks & beverages before you ask a question 😉

Yes thanks
Cheers

[pschlute]

Luckily you don't have to understand it, and you don't have to know the original size of the sensor to print at whatever size you choose.
And no, the computer does not need to know the original size either, but that does not mean that there isn't ratio of enlargement involved and that this ratio effects the outcome.

However, everyone does know by experience that an APS-C sensor prints bigger then a phone sensor. And most people know that a FF prints better then a crop sensor, and FF is beaten by a MF. But that is all a coincidence of course.

Not understanding it and yet still insisting that there is an "optical" enlargement taking place is not very scientific.

Perhaps you can explain this to me...... Manufacturers have improved their specs by creating larger MP cameras. Todays K3 is 24MP, my original DS was 6MP. If according to you the pixels are somehow "enlarged", it would make more sense for the trend to be going the other way....ie back towards 6MP cameras with todays tech. They would require much less "enlargement" Why is that not happening ?

[GUB]

That is what I like about this thread - it makes me think about these things more so I can verbalise them.
Have I got this worked out right? I just hit the calculator and worked out there is about 2 million pixels on my monitor (1920 x 1080)
So for my 36 million pixels of my K-1 image to fill the screen I would have to blend about 18 image pixels onto every monitor pixel.
If that isn't downsizing (EDIT downsampling) then what is?

[Gimbal]

Not understanding it and yet still insisting that there is an "optical" enlargement taking place is not very scientific.

Perhaps you can explain this to me...... Manufacturers have improved their specs by creating larger MP cameras. Todays K3 is 24MP, my original DS was 6MP. If according to you the pixels are somehow "enlarged", it would make more sense for the trend to be going the other way....ie back towards 6MP cameras with todays tech. They would require much less "enlargement" Why is that not happening ?

I have not mentioned "optical" enlargement or talked about pixel sizes at all. That is all you. I'm in the total sensor area camp. The bigger the better, the number of pixels are not that important but usually the more the merrier.

---------- Post added 08-24-2019 at 01:35 PM ----------

That is what I like about this thread - it makes me think about these things more so I can verbalise them.
Have I got this worked out right? I just hit the calculator and worked out there is about 2 million pixels on my monitor (1920 x 1080)
So for my 36 million pixels of my K-1 image to fill the screen I would have to blend about 18 image pixels onto every monitor pixel.
If that isn't downsizing then what is?

No, that is down sampling. You reduce the number of pixels to fit the output device, it has nothing to do with size.
Maybe it will fit perfectly on a 24" screen, or a 5" phone, or a bill board, who knows? Size is not involved.

[Fogel70]

Not understanding it and yet still insisting that there is an "optical" enlargement taking place is not very scientific.

Perhaps you can explain this to me...... Manufacturers have improved their specs by creating larger MP cameras. Todays K3 is 24MP, my original DS was 6MP. If according to you the pixels are somehow "enlarged", it would make more sense for the trend to be going the other way....ie back towards 6MP cameras with todays tech. They would require much less "enlargement" Why is that not happening ?

Eh what, there is no difference in magnification pixels on APS-C 6MP or 24MP printed the same size. Both are APS-C sized.
The only difference is that 24MP may offer higher resolution on the prints.

[GUB]

No, that is down sampling. You reduce the number of pixels to fit the output device, it has nothing to do with size.
Maybe it will fit perfectly on a 24" screen, or a 5" phone, or a bill board, who knows? Size is not involved.

Yes you are right - down sampling it is - too late at night.
And after all how can you downsize something that doesn't have a size

[pschlute]

That is what I like about this thread

The other thing about this thread that I like is the good natured way it is being conducted by those on both sides of the argument. I commend you all.