General > General Technical Chat

Just because technology can do something, doent meant its always right

<< < (21/43) > >>

tooki:

--- Quote from: tggzzz on June 20, 2022, 06:34:35 pm ---
Of course it doesn't care; the photo-chemistry is the same.

My suspicion is based on looking at the single frame of 70mm film in my possession.

--- End quote ---
So not even a representative sampling, or even a non-representative selection, but one single frame? That’s completely useless for the purposes of drawing conclusions, especially as broad (and goofy) ones as you’re making.


--- Quote from: tggzzz on June 20, 2022, 06:34:35 pm ---
--- Quote ---Anyhow, at least today, the only remaining manufacturer of motion picture film, Eastman Kodak, makes 65mm camera film* in the same ISOs as 35mm: 50, 200, 250, and 500. (Observe that none of these come even distantly close to the high ISOs modern digital cameras can capture cleanly.) The data sheets (one per film speed) — and thus the specs — are identical for all film sizes it comes in, from 8mm through 65mm.

As an aside, no wonder 70mm movies are so rare, and 60fps 70mm even rarer: at 24fps, a 1000 foot reel’s runtime is just under 9 minutes and costs around $1500, according to the price list I’m looking at. So at 60fps, that’s just three and a half minutes! (35mm is less than half the cost.) The intermediate film is even more expensive, but print film is massively cheaper.

*camera and intermediate films are 65mm, print film is 70mm.

--- End quote ---

Thanks for the hard numbers. It appears that my suspicion was pretty accurate, despite your snide comment.

For my 35mm stereoscopic slides I had to use 64ASA film, in order to minimise[1] the visible grain. Only one speed you mention is slightly slower (~1.3 times) than that, the others being ~3, ~4, ~8 times faster.

One day perhaps I'll digitise them to try to see the relative grain size.

--- End quote ---
Nothing —nothing — there supports your claim, which, to preempt any goalpost shifting, was that 70mm film uses a coarser grain than 35mm. That’s ridiculous. First of all, you don’t have a representative sample of different film types. Second, visible film grain depends not only on the film stock, but how it was shot and processed. (If you push process it to use it as higher ISO than it is, you get more grain.) Third, did you not notice the part about the SAME films being available in 35mm (as well as 8 and 16mm)? The fact that you have a sharp low-ISO piece of (still) photographic film doesn’t tell us anything. There is also high-ISO photo film that sacrifices resolution for sensitivity. Additionally, you’re comparing slide film to motion picture film, which is negative. (So your movie film is, by definition, at least one generation older than a slide, though typically far more generations removed.)

Nothing about your comparison results in anything remotely approaching a valid conclusion.

Simon:

--- Quote from: bd139 on June 20, 2022, 06:28:32 am ---Interested to see where monitor tech goes. I have a 27” 4k and a 27” 5k next to each other and the 4k one looks horrible now. More pixels really does help with text sharpness and eye strain.

--- End quote ---

well you will have to find out what the human eye can actually resolve to convince me. I can't remember the equivalent PPI but we are practically at that of printed matter. OK 4k/5k maybe but 8k? nah.

Simon:

--- Quote from: tggzzz on June 20, 2022, 08:27:06 am ---
--- Quote from: Simon on June 20, 2022, 05:26:53 am ---Yes and as soon as you move further away your screen gets bigger. I have a 42" monitor and 27" monitors. Both 4k, both look the same because I sit as close as 0.5m from the 27" ones but will be about 1.5m from the 43" one. The eye has an angle of view, The pixels actually take up an angle of our vision so it is about angular resolution. if we can see 150 degrees across and want a 4k monitor that is 150/4k gives you the angular resolution. That is fixed because we will always change our distance from the monitor based on it's size unless you are like my ex colleague with eye sight problems that had a 32" and put his eyes up to it with enlarged text.

--- End quote ---

My point was about TV, not computer monitors, and in conditions where they cannot change the distance.

Hence your statements, while correct, do not refute the two differing reasons for interest in HDTV when it was being developed.

--- End quote ---

Yes because whatever the size, increasing resolution works the same. The screen will be sized to the distance you sit from it, or you will view at a distance to suit the screen. I am of course omitting the case in the UK where we express our net worth in the size of screen we put in our living rooms only to watch anything like it is a tennis match :).

A low resolution will always look bad. At a certain increased resolution you will stop seeing the difference once it exceeds the resolving capability of your eyes.

bd139:

--- Quote from: Simon on June 20, 2022, 08:40:23 pm ---
--- Quote from: bd139 on June 20, 2022, 06:28:32 am ---Interested to see where monitor tech goes. I have a 27” 4k and a 27” 5k next to each other and the 4k one looks horrible now. More pixels really does help with text sharpness and eye strain.

--- End quote ---

well you will have to find out what the human eye can actually resolve to convince me. I can't remember the equivalent PPI but we are practically at that of printed matter. OK 4k/5k maybe but 8k? nah.

--- End quote ---

Well the thing is the human visual system is a little more complex than throwing a PPI at it. That's just a projection onto a 2d plane. Firstly the resolution in your eyes is much larger in a smaller area and lower in peripheral vision. On top of that the brain fills in a chunk of information as it sees fit so the perception model needs to be considered too.

The human eye needs to be able to focus on any part of the screen and you need to consider the best case vision so the worst case has to be used. Add to that the worst case distance and focal plane and you're talking about 576 megapixels worth of resolution (quoting the Roger M Clark figure).

8k is ~ 33MP so there's a long way to go to 576MP. And you need to consider the size, focal plane etc within that.

At the edges, there's absolutely bugger all resolution in your eyes and the brain fills all the shit in which is why the RGB back lit TVs work so well with a few pixels.

Add the whole film grain discussion to this, thinking how the grain is perceived, and there's a shit load of resolution required worst case and a whole load of personal perception and terribly eyesight warping it into generalisations.

But this is mostly used to display art which is a corrupting and highly subjective influence as well!

Simon:
Don't know what you mean by focal plane, yes we see with the centre of our eyes the most, I think from memory it is something like a 1.5 degree angle that has most of the ability with the rest being peripheral vision or pieced together and yes all of the screen needs to be of a resolution that the centre of the eye cannot see the pixels but what is that resolution? (angular resolution will do as it will be agnostic to the screen size/distance)

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod