10-07-2018, 09:41 AM
(10-05-2018, 09:46 AM)JJ_SO Wrote: Ihere are tons of occassios, when each available f-stop counts for a good result. Also, there's a zone in which noise becomes questionable. Wether the picture suffers of it or not. And the more f-stops are in between, the better. You were asking for examples of 14 stop ranges, well knowing there's not method to measure them in a RAW. It's not getting a better excuse the more you repeat the comfort of Canon shooters who have to live with blown highlights and noisy shadows. I guess one can arrange himself with a less big bandwidth of tones. But as there are enough alternatives, why limiting myself?You say there are tons of occasions where each available f-stop <sic> counts "for a good result".
Of course the human eye can adapt to much more contrast and more light difference, just by scanning a scene, as seeing is a constant adaptation. But if we take the human eye as model for a lens or a camera, there's no reason to deliver corner sharpness at all. Also no reason to freeze action with 1/4000 of a second. In fact, most of all very good photographs we know today would not have been possible or look much different than they are. Next predictable blurb is "no printer can print 14 stops" and the answer is as predictable as well "no, but a tonemapped picture" - and if you also think tone mapping is devil's work, I suggest you close your eyes next time you visit a gallery with fine art prints. Ah, you don't do these kind of things? Well, then...
What is the issue then of showing one or a few of those tons of occasions?
What there are tons of is camera gear collectors/users, not photographers, that write on the interweb about how 14+ stops at base ISO is a need, a requirement.
People who think blown highlights is something evil, who are afraid of shadows, and people who have no understanding about human vision and quote the silliest of things about human vision they could find on the interweb that suits their belief (yeah, the earth is flat too according to the interweb, and the moon landings a hoax). (Oh btw, JoJu, I don't mean you with the above people, just the general "below 14 stops of DR is bad" interweb dwellers). Oddly enough, the people who have no understanding of human vision have used human vision most of their lives too, but are too... dim? to make connections between what they actually see and what that means.
They do not think about why we use sunglasses, they do not think of a lot of things. Like, paper has a quite low DR, 6 stops or something like that is what we can print. Yet, when we print black, we perceive it as black. When we print nothing (white), we perceive it as white. If our vision would have "14 stops of DR", we would see black waaaay past that "paper black", and we would see white waaaay past that "paper white". We would see the paper-black as a darkish mid tone and the paper-white as a lighter mid tone-ish tone.
We actually see about 6.5 stops of DR at any one time. Our eye sight can adjust to light levels in two ways: chemical changes in the retina (slow adjustment) and change in pupil size (fast adjustment).
That is similar to changing the sensitivity ("ISO setting") and aperture change.
We all know from experience that when we go from a dark environment into daylight, our eyes "hurt/strain" for a while. This is because we need to chemically adjust still, and the pupil is trying to close more than is comfortable. Our eyes adjust all the time.
So, some people claim that they see the world in 14 EV of DR or even 20 EV of DR. They never try to see what they actually see. They never really (try to) notice that when they look at a darker part of the view that they kinda lose what is in the lighter part, and vice versa.
With the adjustment of our eyes, we can see what is in the shadows, when we focus on the shadows. And we can see what is in lighter parts, when we look at lighter parts. That is true, by adjustment we can see different parts of a big DR range. But that is by adjusting the white and black point, not by expanding the DR range we can "see".
If we actually stretch the DR range of an image to 14 stops, and view it however we like (tonal map the "new black" to "paper black" and the "new white" to paper white", or tonal map those to the brightest white and darkest black screen we can find), we will see an oddly contrastless, lifeless, "grey" unnatural scene, totally different from how we are used to see. When we look at images with a tonal curve of 6 to 8 stops of DR, we see a "natural" scene that does not look alien or unnatural to us, just varying somewhat in contrast.
We can adjust a lot, but adjusting to the extremes can take upto 30 minutes. We can temporarily blind someone with a flash of light, but we can also see in the same brightness of light as that flash after appropriate adjustment time.
Yes, I am sure that in some galleries you can find images where different DR ranges have been pushed together in a tonal map HDR fad craze, for impact and alien look. Tastes differ and what to some is art, to others is kitsch and in bad taste.
Yes, we can shoot in harsh, unattractive light, and claim that we need 14 stops of DR to not have any "blown highlights" and can "pull all that detail from the shadows". Really beautiful works of art, those will become. So for those who have a shadow pulling hobby, they can continue claiming the need for "better DR".
Real photographers won't mind upping the ISO (say 800, or 3200) when the situation calls for it, and not dismiss the results as "too little DR". Real photographers also don't mind contrast. They don't even mind working to get good light for their landscape images. Imagine that.
Sure, you can think of really odd or unfortunate situations where one camera is a better tool to use than other. But all the nonsense that gets written about DR is staggering.
On sharpness of the human eye... If you print something and only want to stare at the center, then yes, you don't need sharp corners. If you want to use that as counter argument against high DR regarding our vision, it is not really a fair one. If you look at a dark part of a print, you don't start to see it as a mid tone grey just by looking at it, nor does the white of the print become a mid tone.
The (central) sharpness perception of our vision also plays a role in what FOV in images we see as "natural". A horizontal frame shot with a 50mm lens looks pretty "natural" to us, depth perception and width wise. our eyes are actually fish eye ultra wide lenses, with a 2 eyes combined FOV or about 200 degrees. No one with a Samyang 10mm FF prime and a FOV of 122 degrees will seriously claim that images taken with such a lens look "natural" to us.