Welcome to our community
Be a part of something great, join today!
ISO, ISO...
- Thread starter Jannard
- Start date
Rob Ruffo
Well-known member
No, but I did do a test on a 50" 1080p plasma, displaying a test grid at 1080 and 720p. Most people follow the diagram pretty closely, give or take 2 feet at most.
- Moderator
- #203
Jeff Kilgroe
Well-known member
I'm not sure how this thread degenerated to this discussion on viewing distances???
I'm going to disagree with most of you. I sit comfortably at 48" from my 30" displays and can still see pixels. I can see pixels on my 71" DLP at any distance less than 12 feet, actually I can see the gaps between them. My wife can see them at distances 10 feet and closer. I know I have good eyes, but most viewing distance formulas presented here (and pretty much anywhere else I've ever seen them) are usually a bunch of bunk that rarely applies in all situations and never seems to apply to me.
It's difficult to measure just at what point the eye begins to lose any benefit of further resolution. But most people, if made conscious of it, can make out details of 120-grit sandpaper at 12 feet or more and tell the difference between 120 and 200 grit papers at 15 to 30 feet, even if they're the same color. That's 120 and 200 granules per inch, respectively of relatively monochrome dots, which mostly differentiate themselves optically by their angle of reflectance. I can still tell the difference between orange peel spray and orange peel rolled drywall finishes at close to 70 feet and can tell between orange peel and knock-down at 100+ feet. And then someone here is trying to tell me that my viewing distance for a 71" 1080p DLP TV (about 32dpi) is fine at 10 feet or more because I can't resolve any more detail than that??? WTF are they smoking?
I'm going to disagree with most of you. I sit comfortably at 48" from my 30" displays and can still see pixels. I can see pixels on my 71" DLP at any distance less than 12 feet, actually I can see the gaps between them. My wife can see them at distances 10 feet and closer. I know I have good eyes, but most viewing distance formulas presented here (and pretty much anywhere else I've ever seen them) are usually a bunch of bunk that rarely applies in all situations and never seems to apply to me.
It's difficult to measure just at what point the eye begins to lose any benefit of further resolution. But most people, if made conscious of it, can make out details of 120-grit sandpaper at 12 feet or more and tell the difference between 120 and 200 grit papers at 15 to 30 feet, even if they're the same color. That's 120 and 200 granules per inch, respectively of relatively monochrome dots, which mostly differentiate themselves optically by their angle of reflectance. I can still tell the difference between orange peel spray and orange peel rolled drywall finishes at close to 70 feet and can tell between orange peel and knock-down at 100+ feet. And then someone here is trying to tell me that my viewing distance for a 71" 1080p DLP TV (about 32dpi) is fine at 10 feet or more because I can't resolve any more detail than that??? WTF are they smoking?
- Moderator
- #204
Jeff Kilgroe
Well-known member
You must not work in Hollywood. :biggrinjester:
Samuel Martin
Well-known member
- Joined
- Jan 8, 2010
- Messages
- 46
- Reaction score
- 0
- Points
- 0
- Location
- London, UK
- Website
- www.samamartin.com
This image is really cool. Impressive. I really like what I see....
Steven Caesare
Well-known member
- Joined
- Jun 6, 2007
- Messages
- 915
- Reaction score
- 0
- Points
- 16
That actually was my point earlier... many people may see the screen door... which is different form actually being able to see the difference between one resolution and the next higher...
-sc
Rob Ruffo
Well-known member
Actually I often do. You all know, it's hard to make a good movie, but we all try.
Craig Parkes
Well-known member
Ok, so I checked my math, and there is no way based on the presumed visual acuity of 0.3 provided by the clark vision website that at 5 feet the max noticeable is 1920 x 1080.
There may be other determining factors in how the screens are made that obscure the greater resolution (how plasma and LCD screens are built etc.) but my arguement is not so much in providing a resolution that most people will no longer be able to tell the difference, but a resolution at which it is visually impossible to tell the difference. I'll take the maths for visual acuity based on line pairings over you putting some friends in front of a plasma displaying different grids at this point for determining that.
- Moderator
- #209
Jeff Kilgroe
Well-known member
But it's not necessarily different. The gap or pitch between pixels (or screen door) typically shrinks as resolution increases. It is also, in most cases, a finer level of detail than the individual pixels, so to discount it as something different just doesn't seem like a good approach. It's true that it's different in that people may notice the screen door regardless of whether they're watching 1080p or 720p material on the same display and when viewing most people probably couldn't tell the difference between the two formats without knowing what to look for. And yet that really has no bearing on where to place a limit on resolution and the benefits of having more.
While I have not attempted specific studies of my own, I do know that 4K projection looks a hell of a lot more detailed than 2K projection. Even at screen sizes where many "experts" claim there should be no discernible advantage to having more than 2K resolution. Remember, 4K on a 20 foot wide projection screen is still only 17dpi. Projector optics these days do a fine job of blending pixels and masking pitch lines without sacrificing a terrible amount of sharpness. However, at about 6.8dpi, you can't tell me that 4K on 50ft wide theatre screen would not pale in comparison to 8K on the same screen, even when viewed from the back row, 80ft away. We can already see the advantages of increased resolution or detail in such a setting by comparing 70mm IMAX projection with conventional 35mm projection on the same width of screen at the same viewing distances. I have yet to see any situation where the increased detail does not win out.
- Moderator
- #210
Jeff Kilgroe
Well-known member
I'm completely agreeing with you here. Hey, so is the HDTV industry. Anyone notice just how many manufacturers are showing 1600p and quad-HD displays at CES this year? Oh, I guess that's why HDMI 1.4 supports 1600p and 4xHD. Hey, it even supports 4K 2:1. Cool.
Anyway, much of this argument was made the last time around when people were moving from 720p/768p to 1080 line displays. And before that by many people about HDTV being unnecessary at screen sizes smaller than 40" because "nobody can see the difference at normal viewing distances". And all the FUD about HD only being useful for big screen TVs over 42" and whatnot. I just had to shake my head then and I'm doing it now. I'll gladly take my 32" quad-hD TV, thank you very much.
Steven Caesare
Well-known member
- Joined
- Jun 6, 2007
- Messages
- 915
- Reaction score
- 0
- Points
- 16
I'm not suggesting there aren't certatinly benefits to be had from increased resolution for specific environments, nor am I suggesting that while there are people with above-average eyesight, many people probably have not really realistically tested what they are capable of resolving.
However, there are some physics involved here. There are only so many rods and cones in your eye, and therefore you can only differentiate so many pixels per degree of angular view, which as Adrian mentioned, is 1 per ~0.3 arc-minutes.
The distances you specifically mention sitting from your displays aren't too far from the beginnig of the range on that chart where resolutions > 1080p start to become noticable, so I don't think your experience suprising or out of the ordinary.
And certainly for 50 foot screens, there is a great likliehood that there are going to be seats less than 1.5X the screen width away, so no doubt the resolution will help.
But factors such as screen door do affect things. I've done quite a bit of comparing of projectors , and at the same viewing angle and resolution something like screen door from LCD or the pixel gap on some DLP's seem to make inidividual pixels stand out to a much grater degree.
I have both a business class LCD projector (with significant screen door) , and an SxRD projector, and at equvialent resolution/viewing distance ratio, there is a marked difference in how I feel pixels "stand out" despite my field of view being filled with the same number of pixels.
It's also of note that there seems to be a difference in what your eye can detect vresus what it can resolve. For example you might be able to detect a speck on a distant wall that's far smaller than 0.3 arc-min of your field of view. However, you will likely be unable to resolve if there are 2 or 3 specs within that same angle.
So... bring on the resolution fo the venues that need it: cinemas undoubtedly have seats that do. Chances are your 52" TV on the the wall 10' across the room doesn't.
-sc
I'm embarrassed to have posted the last thread with the images of different ISOs. I should have waited. Graeme and Deanan have been very busy in the last week so I thought I would give the new stuff a quick workout. David Mullen asked for tungsten... since I don't have a tungsten light here, I grabbed a candle. It white balances out to under 2000K, less than tungsten. I turned off all the lights in the garage and lit the candle. Best I can tell is this is ISO 4000.
The boys are going to yell at me again for posting this because they still aren't done. It won't be the last time...
Jim
Can you tell me, what is so special in this picture? (The colours look good in such dim light, I guess???)
I am not negative about your products. I'm just still learning all this optical stuff... Any good books to read?