I should stress at the beginning that I am neither a doctor nor an optician so if I use the wrong terms, consider the source.
I have however been fascinated by photography since getting my first SLR in my very early teens. That was followed by a few years of getting my hands covered in chemicals as I learned how it all worked. The move to digital was a no-brainer but offers so many possibilities.
They say “the camera never lies”.
There is a world of difference between the camera and your eye and I will use that to challenge the above statement (ignoring of course the wider truth that some “CGI” is now indistinguishable from reality – and if you still believe that CGI is not “real” take a look at this stunning piece of video – the first few seconds defy believe).
When a camera takes a picture, let’s say outside in the brilliant sunlight (clearly not in the Northeast of England) with some trees and dark shadows, it records faithfully what it can… and therein lies the rub – “what it can”.
The camera stores images in digital memory. It stores 3 colours – red, green and blue and it stores them with a limited dynamic range – that is, the range from the lowest brilliance to the highest brilliance and that is FAR from complete. Technically there are only so many digital “bits” and so only so many “levels” of any of the colours – the range is just not wide enough for reality – and it would not make any difference if it was – because your screens you view the images on are ALSO not capable of reproducing the brilliance of sunlight.
So I will firstly argue that the camera DOES lie in that it does not show you the complete range from the darkest shadow to the brilliant sunlight.
That is the first issue with “normal” photos and though there are ways to improve this (RAW images contain more bits-per-pixel than JPG – and HDR photos take multiple exposures to try to “cluge” a wide dynamic range picture) the result is often beautiful and WELL worth pursuing but far from perfect and the mechanism (as described above) for displaying the image is also far from perfect as it, too is unable to display the brilliance of sunlight down to the darkness of the deepest shadows (we’re ignoring the fact that the image is flat rather than 3D – that’s a WHOLE other discussion).
But this is only the beginning. When you use your EYES to look at a similar scene of high contrast, your eyes and brain cheat in many ways, NONE of which are replicated by the camera.
a) You see a combination of the truth and what you expect to see. That is why people sometimes see “ghosts” – if we are not sure what it is we’re looking at – the brain desperately tries to create sense out of disorder. There is a video out there that demonstrates this.
b) The individual sensors in your eyes can selectively desensitise to give you a non-linear image of wider dynamic range than a camera would manage. i.e. areas of strong light are suppressed over time – dark areas are magnified – one would guess the history of this is – if you spotted the animal in the shadows that was coming to get you – you survived.
When you look at an image on a screen, your eyes do not work the same way that they do when looking at real life – because the screen image does not have the dynamic range from dark to light to trigger the same responses in the cells.
Don’t believe me? Do you squint when you see a photo of bright sunlight? No. If you look at a photo of darkness will more detail emerge from that photo the longer you look at it? No.
So when someone comes along with a beautiful HDR photo and the photographic “experts” complain about HDR not being “pure” it reminds me of the people who say that valves are best (generalisation – the old ways are best) – I find myself smiling.
I take photos with the best equipment I care to carry around (more often that not a modern Android phone) and I often use photo tools to render those images to as near as what I THOUGHT I saw or I WANTED to remember and that, at the end of the day is what matters – unless of course you’re selling the images and even then – the image on the right is nothing like reality – but it would still look lovely on a wall. A “pure” photo can never reproduce reality exactly – so treat the camera as an artistic tool and enjoy.
A note for Android lovers… “Camera FV-5” app promises RAW format images. If you have something like a modern Samsung or similar phone with high grade camera – you’re in for a treat! RAW will allow a greater range of post-editing as there is more information to start with.