Luminous Landscape Forum
The Art of Photography => The Coffee Corner => Topic started by: ErikKaffehr on March 07, 2015, 03:26:37 pm
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Hi,
I love pixels, and want to have enough of those to outresolve my lens: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/78-aliasing-and-supersampling-why-small-pixels-are-good
But, Zacuto has tested several single chip video cameras, including Arri Alexa, RED and an iPhone 4S and they found the iPhone S was actually good enough to be shown at a movie theatre. No question, the real cameras run circles around it, but with good lighting it was almost good enough.
Now, what my article shows is that small pixels are needed for good rendition. I shoot 24 MP on DSLR and 39 MP on MFD. Both are on the short side of what I would call proper rendition. But, I seldom print to make those images justice. One reasons is that those images are not good enough. Both 24MP and 39MP look great at A2 size, which is what I normally print. I would like to print larger, but wall space is limited. Very few images get printed larger than A2, and those images are often stitched panoramas.
A nice way to present images would be a 4K screen on the wall. Images can be switched, so I can show many images on limited wall space, nice! But 4k is just 8MP, OK 9.8 MP if we take form factors into account. So around 10 MP is what we actually can show, except in large prints intended to viewed close.
To make justice to modern day cameras it is more like 8K needed. Now, 8K may be around the corner but it may take long time to arrive.
My next investment may not be a new camera, but a new projector at 4K. It will not make my images justice, but it will be far better than the 2K projection I have right now.
For the cost of a 4K projector I would be able to make 80-120 70x100 cm prints. But wall price is even higher than 4K projection costs.
Best regards
Erik
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You ain't seen nothin yet. NASA has been using Giga-Pixel cameras for a little while by now and they want to go Tera-pixel in a few years.
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But, Zacuto has tested several single chip video cameras, including Arri Alexa, RED and an iPhone 4S and they found the iPhone S was actually good enough to be shown at a movie theatre.
We have been watching 600 to 800 lines of vertical resolution for half a century without complaints. That is the real resolution of 35mm movie projection in a good theatre.
http://www.motionfx.gr/files/35mm_resolution_english.pdf
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To make justice to modern day cameras it is more like 8K needed.
8k = ~ 7680 × 4320 = 33mp x 3 RGB light emitting elements, so w/o interpolation you might want a ~100mp (actually 120mp, 2 "greens" combined together in RG1BG2 bayer) sensel bayer camera... w/o interpolation... to do a real justice, no ?
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Quoting self from a few months ago:
Just personally: I no longer care much about printing. I still do it occasionally but it's not the focus of what I do. I am interested in making photos with 4K display in mind, though, and particularly in taking control of the R, G & B sub-pixels of each full-color display element. A nice thing about this interest is that it imposes some hard limits. A 4096x2160 image, if you provide non-interpolated RGB data for each display pixel, requires a Bayer sensor with 8192x4320 photosites (an R, G & B for each display pixel, with the two Bayer Gs averaged in some manner). That's 35.4mp.
I personally doubt that at a ~50–60" display size, viewed at typical TV-watching distances, going from 4 to 8K will make enough of a visible difference to be worth the bother. We may get 8K at some point anyway, of course, but let's see how 4K does first…
Anyway there's no harm in oversampling at the camera end, so bring on the mps. :)
-Dave-
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Hi,
No reason to watch either 4K or 8K at typical TV-watching distances. The company I am working with now is testing the use 4K as a common computer display. Before that we typically used 4x24" screens stacked. Optimal viewing distance for computer screens is probably around 80 cm.
What I have on mind is replacing say A2 size prints with high resolution screen. A quite often used criterium is that 180 PPI is needed for a really good print. Would you have say a 20x30" screen, the needed resolution would be 3600x5400 pixels which is 29 MP.
The reason I mention 8K is that it is in the pipeline. NHK is planning to broadcast the Tokyo Olympics 2020 in 8K.
On the other hand, my primary interest may be projection, where I find today's HD lacking, and 4K projector prices are a bit above my acceptance level.
A final point is that we are of course going to show todays images on tomorrows media.
Best regards
Erik
Quoting self from a few months ago:
I personally doubt that at a ~50–60" display size, viewed at typical TV-watching distances, going from 4 to 8K will make enough of a visible difference to be worth the bother. We may get 8K at some point anyway, of course, but let's see how 4K does first…
Anyway there's no harm in oversampling at the camera end, so bring on the mps. :)
-Dave-
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Hi,
Screen resolution tend to increase with a factor 2. We had HD, next is 4K and NHK will send the Tokyo Olympics in 8K.
Getting back to your reasoning, I don't agree. Clearly there are cases where a subject is single colour, like a red flower and such a colour will be resolved at 25% of the nominal resolution. The lack of colour resolution can create artefacts with high resolving lenses. Good reasons to go to small pixels.
On the other hand most colours are not pure, OLP filters help eliminate colour artefacts and demosaic algorithms are good at interpolating luminance.
Now, human vision is not very good at discriminate colour but is very sensitive to luminance. Try yourself. Convert an image to LAB, duplicate the layer, select "a and b" channels and apply say z a median filter of size of 3. Try to flip that layer on and off, are you able to a difference? Now do the same experiment on the L channel. Great loss of sharpness will result.
Best regards
Erik
8k = ~ 7680 × 4320 = 33mp x 3 RGB light emitting elements, so w/o interpolation you might want a ~100mp (actually 120mp, 2 "greens" combined together in RG1BG2 bayer) sensel bayer camera... w/o interpolation... to do a real justice, no ?
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Yep, we have known for years that the days of paper are counted.
Cheers,
Bernard
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No reason to watch either 4K or 8K at typical TV-watching distances. The company I am working with now is testing the use 4K as a common computer display. Before that we typically used 4x24" screens stacked. Optimal viewing distance for computer screens is probably around 80 cm.
Yeah, 80cm is about my viewing distance for my 22" monitors (I use two, typically splitting them between UI and image data). But for a 50–60" screen? A bit too close IMO. :) Having seen how good 4K video downsampled to 2K display can look I'm all for 8K capture whether or not we eventually get 8K display.
-Dave-
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36 mpx in my D800 can be overkill. If I'm doing the kind of thing I used to do with my old view cameras I love the D800, but if I'm shooting the dress rehearsal for a play, I don't need 36 mpx, and the 12 mpx D3 is my camera of choice. There are specialized situations where the sky's the limit on desired resolution, but not in everyday photography.
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Next step is 8K displays, but not sure when they will be moving to market at a price people will pay.
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Next step is 8K displays, but not sure when they will be moving to market at a price people will pay.
I am puzzled by the 8K video development, beyond the "because we can" rationale of some engineers and marketing people. What, if anything, is the evidence that viewers actually perceive a difference between 4K and 8K?
In the document https://pro.sony.com/bbsccms/static/files/mkt/digitalcinema/Why_4K_WP_Final.pdf Sony is arguing the advantages of higher resolution projectors (4K vs 2K in this case), including looking at the extreme requirement of matching what "better than 20/20" vision can make out when carefully, slowly viewing a high contrast still image (eye test chart), which is a more demanding requirement than with moving images (I know the reply: "some people watch movies of still text and examine it closely"!). And even from that commercially motivated advocacy of higher res. projectors, and then replacing its "2K vs 4K" by "4K vs 8K" it seems that only sharp-eyed people sitting in the first one or two rows of a cinema, or people siting as close to their big-screen TVs as the _height_ of its screen and less half the screen width would perceive any imperfections in 4K, and even th front rows look to be handled perfectly by 6K at most.
What is more, even if there is an argument that a few people can benefit from "a bit more than 4K", the useful threshold might be at some intermediate level like that 6K. It might be easiest technologically for cinema projection equipment to advance by doubling from 2K to 4K to 8K, but with content only ever needing to be recorded and processed at some intermediate level like 6K, and then up-ressed to match the display hardware. Note that my example of 6K video could be got as crop from a mere 24MP sensor in 3:2 format.
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I don't think I have 8k eyes ;D
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I have a 65" plasma HDTV which I often use to display my still images down-sampled to HD resolution, about 5.9MB.
As a result of my own testing, I find that in order to see all the detail displayed in these 2k images, I have to sit at a distance from the screen of no greater than 2.5 metres, wearing appropriate spectacles for the distance.
I'm interested in the new 4k UHD displays, because I love detail and resolution, but I can't see the sense in getting a UHD screen so small as 65" diagonal. Surely in order to appreciate the extra resolution that 4k provides, I would have to sit even closer than 2.5 metres from such a screen, say about 1.25 metres.
From a viewing distance of 2.5 metres, I would need a 130" UHD screen to enable the appreciation of all the detail in a 4k still image. If that 130" screen could display 8k, I would be back to a minimum viewing distance of 1.25 metres. Is this not the case?
The Samsung 110" UHDTV seems close enough to the right size for viewing 4k material, but it's a bit expensive at $150,000. ;D
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A few years back, a couple produced a movie about a husband and wife that were lost at sea while scuba diving on a dive trip when the dive boat miscounted and left the area, accidently leaving them there to die. I can't remember the name of the movie. It was shot on a Sony PD150 Standard Def NTSC DVCam camcorder. It had a pretty broad theater release and was fairly successful as I recall. Standard Def DVCam would be 720x480.
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...It was shot on a Sony PD150 Standard Def NTSC DVCam camcorder....
For moving images, the all HD/FULLHD/ULTRAHD/GAZZILLIONK fuzz is just that: fuzz.
The human retina has "high resolution" only in the central part of the field of view, so having high resolution on all the movie frame is physiologically useless.
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For moving images, the all HD/FULLHD/ULTRAHD/GAZZILLIONK fuzz is just that: fuzz.
The human retina has "high resolution" only in the central part of the field of view, so having high resolution on all the movie frame is physiologically useless.
That assumes that the viewer fixes his view on only the central portion of the screen. However, what if she directs her gaze at the edge of the screen?
Regards,
Bill
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That assumes that the viewer fixes his view on only the central portion of the screen. However, what if she directs her gaze at the edge of the screen?
Regards,
Bill
Still, having high resolution on the full frame would be physiologically useless: the viewer would see high resolution only on the edge.
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Still, having high resolution on the full frame would be physiologically useless: the viewer would see high resolution only on the edge.
Wikipedia: Saccade (http://en.wikipedia.org/wiki/Saccade)
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Wikipedia: Saccade (http://en.wikipedia.org/wiki/Saccade)
Indeed: as I understand it, our fine visual resolution depends in part on using saccade to detect edges, and that ability is at its peak for the detection of high contrast edges, leading to the peak angular resolution as measured with eye charts.
Moving images do not allow this, which is one reason that we have distinctly less resolution of moving images than of stills: note how bad the resolution looks on still frame grabs compared to the moving image they are grabbed from.
That is why I am betting that the difference between 4K and 8K video will only be noticed:
a) When reading the fine print at the tail end of movie credits.
b) In Warholesque movies with long still shots of eye charts and other finely detailed, high contrast subject matter.
c) When used to display still images and then viewing them from a distance of about half or less the width of the screen.
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I have a 65" plasma HDTV which I often use to display my still images down-sampled to HD resolution, about 5.9MB.
As a result of my own testing, I find that in order to see all the detail displayed in these 2k images, I have to sit at a distance from the screen of no greater than 2.5 metres, wearing appropriate spectacles for the distance.
I'm interested in the new 4k UHD displays, because I love detail and resolution, but I can't see the sense in getting a UHD screen so small as 65" diagonal. Surely in order to appreciate the extra resolution that 4k provides, I would have to sit even closer than 2.5 metres from such a screen, say about 1.25 metres.
From a viewing distance of 2.5 metres, I would need a 130" UHD screen to enable the appreciation of all the detail in a 4k still image. If that 130" screen could display 8k, I would be back to a minimum viewing distance of 1.25 metres. Is this not the case?
The Samsung 110" UHDTV seems close enough to the right size for viewing 4k material, but it's a bit expensive at $150,000. ;D
It's not been mentioned here how much of the 4K/8K content will have to be edited at the source production line and at output from the cable/Netflix-online pipelines in order cram that much redundant data to reach those high rez screens. Improved upsampling, compression, sharpening algorithms may not be able to do it justice. It seems unnecessary technology for mass consumption IMO.
Blu-Ray may be the only area of the entertainment industry that may show its benefit if they can keep up with re-scanning all that content such as 50 year old Technicolor movie restorations which I've been seeing broadcast through TWC's cable channel Turner Classic Movies (TCM). I can tell I'm seeing the Blu-Ray restoration from the improved image quality even through the that pixel squeezing black box. I just don't know at what point the sharpening is applied...during creation or by TWC. Blu-Ray screengrabs posted online in full 1080HD don't look as sharp on some of them as I see on my 32" 720p Samsung HDTV viewed 7ft away.
See the shots I took of the differences between a recently produced in HD commercial vs a TCM showing of 50 year old "Ride The High Country" Technicolor flick viewed at 60hz. My 6MP digital camera captures more than I can see so I have to dumb the sharpness and detail down in ACR to show how it looks to me viewed 7ft away.
Examining the big 4K screens at Best Buy shows sharpening halos even on 4K content. WTF!?
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A few years back, a couple produced a movie about a husband and wife that were lost at sea while scuba diving on a dive trip when the dive boat miscounted and left the area, accidently leaving them there to die. I can't remember the name of the movie. It was shot on a Sony PD150 Standard Def NTSC DVCam camcorder. It had a pretty broad theater release and was fairly successful as I recall. Standard Def DVCam would be 720x480.
Danny Boyle's 28 Days Later from 2002, a zombie genre classic, was shot in Standard Def PAL for a deliberately edgy lo-fi look. (Issue #1 of The Walking Dead comic came out in 2003. The opening scenes are notably similar to those of the film.)
-Dave-
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It's not been mentioned here how much of the 4K/8K content will have to be edited at the source production line and at output from the cable/Netflix-online pipelines in order cram that much redundant data to reach those high rez screens. Improved upsampling, compression, sharpening algorithms may not be able to do it justice. It seems unnecessary technology for mass consumption IMO.
That's often a problem, Tim, but really a separate issue. Even if there is a very slow transition to full 4k broadcasting because of bandwidth restrictions, I'd still like a large, 4k OLED screen for displaying my own stills, and perhaps experimenting with a new camera that boasts 4k video capability, such as the Samsung NX1.
The issue is fundamentally one of screen size and cost. This has always been the issue. I remember well the days before HD transmission was introduced. The argument was constantly raised that the average size of the (then) current TV sets was too small to result in any benefits from HD. Sizes ranged from 14" to an impressive 36" using the old CRT technology. At normal viewing distances, HD did not make much sense.
However, within a few years 55" and 65" screens became affordable, employing the new LCD and Plasma technology, and the issue then became, for those who were interested, a concern that most so-called HD transmissions were not full HD. Many were just standard definition interpolated. At best they were 720p or 1080i at source. Only certain Blu-ray recordings exploited the full benefits of HD resolution, using 1080p.
With the introduction of 4k video, we are now back to square one. The current screen sizes suitable for full HD viewing are too small for UHD or 4k. However, I expect that in a few years, the 110" screen will become fairly common and affordable for many of us. By then, the largest screens, that only the rich will be able to afford, will probably be 140- 200 inches diagonal, which will begin to make sense for 8k video and stills. ;)
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However, within a few years 55" and 65" screens became affordable, employing the new LCD and Plasma technology, and the issue then became, for those who were interested, a concern that most so-called HD transmissions were not full HD. Many were just standard definition interpolated. At best they were 720p or 1080i at source. Only certain Blu-ray recordings exploited the full benefits of HD resolution, using 1080p.
I can't tell whether the content piped through my cable system is 720p, 1080i or standard def interpolated but I do agree the current 50" screens displaying regular HD looks pretty bad viewed within 7ft. Viewing a 50" 4K TV required I step back even farther just to be able to see the entire screen without panning my head left to right and its resolution looked like a computer screen but not on the level of a Retina.
However, my main concern are the affects huge amounts of 4K/8K data streaming will have on net neutrality bandwidth policies down the road and whether I'll have to pay higher prices for internet and/or settle for severely slowed internet transfers when I don't stream movies.
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my main concern are the affects huge amounts of 4K/8K data streaming will have on net neutrality bandwidth policies down the road and whether I'll have to pay higher prices for internet and/or settle for severely slowed internet transfers when I don't stream movies.
Net neutrality is mainly a myth: those who can pay for CDNs near customers will get more speed regardless of carrier policies.
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For these things to be relevant to the mass market, it must mean that people have much larger TV viewing rooms than I've ever had. My limited experience with 50 inch (or so) screens has been at other people's houses, where the TVs were far too large for the room they were in, and annoyingly so. The concepts of source-material resolution are not even in the vocabulary of most folks; big is always better, it seems.
I have assumed (perhaps incorrectly) that the moves to 4k and now 8k were being driven by the requirements of the pro film industry that need to show films in large movie theatres, so I have not really understood why those are even being discussed in the consumer videocam arena. But it's probably an unstoppable migration.
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The concepts of source-material resolution are not even in the vocabulary of most folks; big is always better, it seems.
That's true for almost any technology, and let's thank those guys for paying for R&D ;D
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For these things to be relevant to the mass market, it must mean that people have much larger TV viewing rooms than I've ever had. My limited experience with 50 inch (or so) screens has been at other people's houses, where the TVs were far too large for the room they were in, and annoyingly so. The concepts of source-material resolution are not even in the vocabulary of most folks; big is always better, it seems.
I personally refuse to let my TV dominate my rec room. I have a 40" set now, which is large enough although the room can handle a 46" or even 50" without getting unbalanced. The most meaningful objects on display in that room are my friend Kirsten's paintings, a sculpture by another friend and my guitar amps. The modern tech must be kept in its place. :)
-Dave-
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... The current screen sizes suitable for full HD viewing are too small for UHD or 4k. However, I expect that in a few years, the 110" screen will become fairly common and affordable for many of us. By then, the largest screens, that only the rich will be able to afford, will probably be 140- 200 inches diagonal, which will begin to make sense for 8k video and stills.
The limits of useful resolution only increases in proportion to screen size if people keep viewing these ever bigger screens from the same distance, rather than using them to sit further back and so fit more drinking buddies into ever bigger man caves. My anecdotal evidence from cinemas is that most people do not want to be within "one picture height" of the screen; that close, too much of image towards the sides of the screen is at the periphery of your field of vision, unless you zoom your head from side to side a lot. If that "> 1PH" viewing distance is right, Sony's hi-def propaganda (https://pro.sony.com/bbsccms/static/files/mkt/digitalcinema/Why_4K_WP_Final.pdf) at most makes the case of needing up to 6K, and its more balanced version of definition requirements would be met by under 5K, which I mention only because some people already have this via a 27" iMac or Dell 5K monitor.
P. S. As with audio, we seem to face the irony that the great majority of people who can afford to buy into the extremes of fidelity (based on meeting the measured capabilities of a lucky minority youths with 20/10 vision or greater than 22KHz frequency response) are far older than those well-endowed youths, and so can no longer hear or see the differences.
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Hi,
My favourite way to look at images is projecting on a 73" inc screen. Viewing distance is about 1.8 m (6 ft). At that distance the resolution of 20/20 vision is about 0.5 mm. Long dimension on the screen is about 1600 mm, so pixel size is 1600/1920 = 0.83 mm, so fine detail is far from optimally sharp. Going to 4K resolution would give a pixel size of 0.41 mm, a good match for 20/20 vision.
Let's assume that we want to have a screen replacing a 13x24" print (which happens to be my standard print size). It is widely accepted that around 180 PPI is needed for an excellent print (corresponding to 50cm viewing distance with 20/20 vision). To match the quality of an excellent print 4160x2340 pixels would be needed, so 4K would fall short of a normal A2-size print.
So, what I can see, 4K is about minimum to implement my normal presentations with very good image quality. Add to this that 4K has a much wider colour gamut than sRGB or Adobe RGB. So I clearly see that 4K has clear benefits. But, mainstream media and games are driving this market and we will not get decent prices until 4K media is available.
Best regards
Erik
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The limits of useful resolution only increases in proportion to screen size if people keep viewing these ever bigger screens from the same distance, rather than using them to sit further back and so fit more drinking buddies into ever bigger man caves.
BJL,
It's not compulsory to sit close enough to be able to distinguish all the fine detail in an image, especially when the audience consists of a group of drinking buddies who probably would not be unable to discern any fine detail due to intoxication. ;)
My anecdotal evidence from cinemas is that most people do not want to be within "one picture height" of the screen; that close, too much of image towards the sides of the screen is at the periphery of your field of vision, unless you zoom your head from side to side a lot.
Have you not noticed that many of these large UHD screens are now curved. This is so one doesn't need to turn one's head so much when sitting close, and one gets a more 'immersive' experience.
When buying a camera, bulk, weight, resolution and cost are major considerations. Since one doesn't have to carry a TV set, weight is not an issue, so bulk, resolution and cost remain the major issues. These modern 4k OLED screens are so thin they hardly take up more space than a large picture on the wall, so the main consideration for me is cost. Even small rooms usually have a sufficiently large wall area to accommodate a picture which is a mere 110" diagonal, although one might have to move away some of the clutter. ;)
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Even small rooms usually have a sufficiently large wall area to accommodate a picture which is a mere 110" diagonal, although one might have to move away some of the clutter.
Having room for such a screen is not the issue; I am betting that video on a 110" screen (280cm: what happened to the metric system in Australia?!) will be viewed from a distance of at least five feet (150cm) at which range 4K UHD will likely have a visible advantage over current HD, at least to sober viewers, but 8K will have no further advantage.
I do not think that a bit of curving will change that much; that reduces the oblique viewing of the edges of the screen, but still makes the angle between center and sides too wide for comfort if you sit less than one picture height from the screen.
But I am happy for chasers of big spec numbers to drive down the cost of devices that could be geninely useful for displaying digital still images. The day will come when some galleries are truly digital, displaying photographs on such devices, with more DR than any printer can dream of.
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As with audio, we seem to face the irony that the great majority of people who can afford to buy into the extremes of fidelity … are far older than those well-endowed youths, and so can no longer hear or see the differences.
Indeed. I've been wearing glasses (near sighted) since age 12 and am now in my second decade of using the progressive variety. As for hearing…well, the attached pic hints at what my ears have been exposed to over the past 40+ years. (More appropriate names for the innocent-seeming Sustain knob on the pictured gizmo would be Sonic Mayhem or perhaps Audiologist Cha-ching.) :D
-Dave-
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The day will come when some galleries are truly digital, displaying photographs on such devices, with more DR than any printer can dream of.
Unluckly, that day the archivial problem will probably worsen.
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Unluckly, that day the archivial problem will probably worsen.
Why? Because prints will not be made in some cases, and image files on digital media are considered less archival than prints?
I have seen this discussion recently, and it makes little sense to me, because:
a) The cost of storage on hard disks is tiny compared to the costs of storing film or prints under archival conditions, so that multiple copies can be stored for a far lower price than the temperature/humidity controlled storage needed to archive prints.
b) Transferring collections of image files to new physical media from time to time is also easy and cheap, so the fear of no longer being able to read files on old, obsolete media is misplaced. In most cases I expect the file transfer will even be "automatic", as part of an online storage service, or routine hardware updates.
c) File formats like JPEG and TIFF might go out of fashion for recording new images, but the widespread archival needs of news organizations, libraries, governments, and such will ensure that the codecs needed to read them will not be lost. At a guess, a complete set of specifications and codecs for all current image file formats, including even the hundreds of variants of raw formats, would fit in a small fraction of a Terabyte, and will continue to occupy a tiny fraction of the space used to store image archives.
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Why? ...
There are many reason.
First of all, not requiring a print will devalue the printer competence, which will consequently lead to a loss of printing competence.
On the digital archives, the problem isn't the file format but the filesystem format and the physical medium of the archive.
Today is extremly difficult to read a 5.25 floppy disk.
What will happen, in ten years, to today's hard drives? We now have SATA drives, but before that there was IDE drives.
I'm now sure I could buy a IDE controller if I wanted to.
So, keeping accessible a digital archive could, in the long run, cost much more than archiving physical objects like prints.
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Net neutrality is mainly a myth: those who can pay for CDNs near customers will get more speed regardless of carrier policies.
Don't know where you're getting that information but I know for a fact it doesn't explain why dpreview's site and any other site whose point of source servers are not in the US downloads MUCH FASTER than any local site or any within my home state of Texas. And we're not even talking about video streaming which I don't even bother with except for a few YouTube and Vimeo selections a few times a month.
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Don't know where you're getting that information but I know for a fact it doesn't explain why dpreview's site and any other site whose point of source servers are not in the US downloads MUCH FASTER than any local site or any within my home state of Texas. And we're not even talking about video streaming which I don't even bother with except for a few YouTube and Vimeo selections a few times a month.
I'm getting my information from wikipedia (http://en.wikipedia.org/wiki/Content_delivery_network).
About "any local site", this is a clear demonstration of the "net neutrality myth": both dpreview and "any local site" may be on the same "cable" but dpreview has more server, more powerful and has more output bandwidth because it paid for that with his connection provider.
Net neutrality is a myth because it just take into account "the cable" but not all the other factors that determine the output speed of a site.
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First of all, not requiring a print will devalue the printer competence, which will consequently lead to a loss of printing competence.
I agree that if high-end printing were to be abandoned entirely, that would be a problem -- but all I expect is that on-screen display could become one of many presentation options used by galleries in the future. Far older image display formats, going back before silver halide to cyanotype and before that to oil painting are still is use, and still pursued seriously by many artists, so I very much doubt that printing will be abandoned entirely.
On the digital archives, the problem isn't the file format but the filesystem format and the physical medium of the archive.
Today is extremly difficult to read a 5.25 floppy disk.
Did you read all of my post? I agree that a particular physical medium for storing digital information cannot be trusted to be "archival", but the information in the files can be, through the ease and low cost of transferring to new media from time to time, and the fact that this transfer to new media is almost automatic these days, with complete file collections being copied to newer, larger capacity storage devices each time the mass storage is upgraded or a new computer is acquired.
P. S. Color prints do not have a great record of archival durability so far!
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I'm getting my information from wikipedia (http://en.wikipedia.org/wiki/Content_delivery_network).
About "any local site", this is a clear demonstration of the "net neutrality myth": both dpreview and "any local site" may be on the same "cable" but dpreview has more server, more powerful and has more output bandwidth because it paid for that with his connection provider.
Net neutrality is a myth because it just take into account "the cable" but not all the other factors that determine the output speed of a site.
But can you show or can anyone determine if the gargantuan data stream of packets from one with a "Power Bandwidth" provider such as dpreview is slowing other smaller sites?
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Having room for such a screen is not the issue; I am betting that video on a 110" screen (280cm: what happened to the metric system in Australia?!) will be viewed from a distance of at least five feet (150cm) at which range 4K UHD will likely have a visible advantage over current HD, at least to sober viewers, but 8K will have no further advantage.
I do not think that a bit of curving will change that much; that reduces the oblique viewing of the edges of the screen, but still makes the angle between center and sides too wide for comfort if you sit less than one picture height from the screen.
But I am happy for chasers of big spec numbers to drive down the cost of devices that could be geninely useful for displaying digital still images. The day will come when some galleries are truly digital, displaying photographs on such devices, with more DR than any printer can dream of.
I got the recent AVSforum newsletter that shows this setup...
http://www.avsforum.com/forum/139-display-calibration/1904321-colorimetry-research-cr-100-cr-250-experience-thread.html
I wonder how many can afford that setup and whether there's a sustainable market for such huge screens. Good grief they put more effort and money toward viewing content with such expensive calibration routines than we photographers who create content. Something's upside down here.
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I got the recent AVSforum newsletter that shows this setup...
http://www.avsforum.com/forum/139-display-calibration/1904321-colorimetry-research-cr-100-cr-250-experience-thread.html
I wonder how many can afford that setup and whether there's a sustainable market for such huge screens. ...
And yet the first thing I note is that the comfy chairs are far more than one screen _width_ from the screen, and so barely able to distinguish between HD and 4K, let alone between 4K and 8K! So it is probably a good thing that they are obsessing about color accuracy rather than definition*.
* At least video people know the difference between definition (number of lines or pixels or such) and resolution (lines per mm, pixels per mm, etc.); I wish still photographers would use that terminology more often.
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And yet the first thing I note is that the comfy chairs are far more than one screen _width_ from the screen, and so barely able to distinguish between HD and 4K, let alone between 4K and 8K! So it is probably a good thing that they are obsessing about color accuracy rather than definition*.
* At least video people know the difference between definition (number of lines or pixels or such) and resolution (lines per mm, pixels per mm, etc.); I wish still photographers would use that terminology more often.
I'm a definer, not a resoluter. ;D
In fact I had to use a third of my 6MP Pentax K100D DSLR resolution (by switching to 35mm focal length & cropping in ACR) to capture how the definition of my 32in/720p Samsung HDTV actually looks to my eyes viewing from 7ft. in order to carefully output sharpen (requiring several back & forth iterations) for downsampling to 700 pixels wide and still retain the definition as it appears in this thread.
My camera's AF kept micro-focusing on the teeny-tiny frickin' pixel grid of the HDTV I couldn't see with my eyes instead of the contrasted edges of the actual scene. Downsampling can work wonders for web viewing in this instance.
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But can you show or can anyone determine if the gargantuan data stream of packets from one with a "Power Bandwidth" provider such as dpreview is slowing other smaller sites?
I highly doubt that a single entity can perform such determination, since multiple systems are involved in the data transfert between you and dpreview/smaller-site.
But must be kept in mind that the "net neutrality myth" is not about "site speed" but "data packet speed", which means that to have a "net neutrality" all data packets are equals.
So if dpreview has the 1000x output bandwidth of the smaller site, dpreview will always go faster.
To be clear, "net neutrality" is very much like speed limits on a public road: all vehicle cannot go faster.
But a delivery business like FedEx will always use more road than me. no matter what.
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We have been watching 600 to 800 lines of vertical resolution for half a century without complaints. That is the real resolution of 35mm movie projection in a good theatre.
http://www.motionfx.gr/files/35mm_resolution_english.pdf
I would love to see this test repeated as it was done over 10 years ago and before there was a rather large upgrading of projection equipment to handle 3D, 4K, etc.
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I would love to see this test repeated as it was done over 10 years ago and before there was a rather large upgrading of projection equipment to handle 3D, 4K, etc.
I think we would have a result very much correlated with the relative vs absolute pitch, that is very few people would recognize the higher resolution frame when showed alone but many would see the difference between a high resolution and e low resolution frame.
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...that is very few people would recognize the higher resolution frame when showed alone but many would see the difference between a high resolution and e low resolution frame.
For the sake of "progressing science", side-by-sides are valuable.
For the sake of predicting what quality people will be able to appreciate? If one can appreciate 4k (over HD) only in a frozen side-by-side, then it seems safe to assume that one does not need 4k for regular viewing (in that particular setting)?
-h
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For the sake of "progressing science", side-by-sides are valuable.
For the sake of predicting what quality people will be able to appreciate? If one can appreciate 4k (over HD) only in a frozen side-by-side, then it seems safe to assume that one does not need 4k for regular viewing (in that particular setting)?
-h
I agree with you: as I early said, higher resolution in movies is physiologically useless.
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A few years back, a couple produced a movie about a husband and wife that were lost at sea while scuba diving on a dive trip when the dive boat miscounted and left the area, accidently leaving them there to die. I can't remember the name of the movie. It was shot on a Sony PD150 Standard Def NTSC DVCam camcorder. It had a pretty broad theater release and was fairly successful as I recall. Standard Def DVCam would be 720x480.
Open Water was the film. Cleverly done.
The reason they used the lo-fi camera was for aesthetic reasons. It looked rubbish on a big screen if talking technically, but it conveyed the story well - which was the point. The thing with film/video is that picture quality can be dire, but if the sound is spot on then it will 'look' great. However beautifully shot footage with duff sound will seem awful.
The Richard Linklater film, Tape was also shot on on a camcorder. As was the very influential Timecode, the cameras for which were bought by the director Mike Figgis from consumer electronic shops on Tottenham Court Road in London.
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Indeed: as I understand it, our fine visual resolution depends in part on using saccade to detect edges, and that ability is at its peak for the detection of high contrast edges, leading to the peak angular resolution as measured with eye charts.
Moving images do not allow this, which is one reason that we have distinctly less resolution of moving images than of stills: note how bad the resolution looks on still frame grabs compared to the moving image they are grabbed from.
That is why I am betting that the difference between 4K and 8K video will only be noticed:
a) When reading the fine print at the tail end of movie credits.
b) In Warholesque movies with long still shots of eye charts and other finely detailed, high contrast subject matter.
c) When used to display still images and then viewing them from a distance of about half or less the width of the screen.
Moving images look poor quality as screen grabs as they are deliberately shot at low shutter speeds to give a smooth image.
If you shoot at higher shutter speeds and at the same frame rate, then the sharper frame image makes for a staccato look of moving subjects. Famously used during the beach scenes in Saving Private Ryan or typically when Zombies are chasing someone. So it's not wise to bet on things based on false comparisons between stills and video. ;)
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Moving images look poor quality as screen grabs as they are deliberately shot at low shutter speeds to give a smooth image.
If you shoot at higher shutter speeds and at the same frame rate, then the sharper frame image makes for a staccato look of moving subjects. Famously used during the beach scenes in Saving Private Ryan or typically when Zombies are chasing someone. So it's not wise to bet on things based on false comparisons between stills and video. ;)
In all honesty regular video frames are bad compared to same resolution stills. Besides the usual long shutter speed movement blur, there are 2 more reasons: Even normal HD has only half or one fourth of the color resolution compared to luminance, thus color resolution for typical 4:2:0 HD video is only 960x510 pixels. Only top tier professional video cameras can shoot 4:4:4 with full amount of color pixels, but even that is not distributed at full color resolution, because of the saved bandwidth and because it does not mattar much with a moving image.* Second reason is the extremely efficient compression methods used with video, typically delivery formats are 5% of the original data stream, often even less.
*) eye is much more demanding what comes to luminance, thus we are actually watching TV and videos with advertised resolution B&W with an overlay of half resolution color layer. It is also worth remembering that 35mm movie projection in a good theatre has the resolution of only 600-800 horizontal lines, less than HD video.
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In all honesty regular video frames are bad compared to same resolution stills. Besides the usual long shutter speed movement blur, there are 2 more reasons: Even normal HD has only half or one fourth of the color resolution compared to luminance, thus color resolution for typical 4:2:0 HD video is only 960x510 pixels. Only top tier professional video cameras can shoot 4:4:4 with full amount of color pixels, but even that is not distributed at full color resolution, because of the saved bandwidth and because it does not mattar much with a moving image.*
So video throws out information that matters little perceptually (or never was there in the first place, or cannot be recreated using common display tech). Why is that a problem? The Bayer CFA does something similar for cameras, so does JPEG still-image compression (and to a degree, chroma noise reduction).
Second reason is the extremely efficient compression methods used with video, typically delivery formats are 5% of the original data stream, often even less.
Again, video does its best to provide perceptually good results at minimum bandwidth cost. Since two video frames are often very similar, it only makes sense to exploit this in compression (for many but not all applications).
I do agree that one should be careful about re-using perceptual results from video perception to still images.
While it has been mentioned that our spatial resolution is effectively "less" for moving images than still-images, there is this issue of aliasing. If your camera/scaler/... creates aliasing, it can create annoying moving artifacts in video that moves (often counter to real movement). In still images, the same amount of aliasing can be acceptable. Thus, I think that video processing equipment tends to sacrifice some sharpness in order to reduce visible artifacts, while still-image equipment might let through more ("fake detail") aliasing. If you are displaying your 80MP images on your 4k LCD tv using the built-in scaling, results may or may not be optimal...
-k
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Why is that a problem?
That's not a problem, but is a fact that a still image contains more information that a movie frame, no matter what the movie frame resolution is.
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That's not a problem, but is a fact that a still image contains more information that a movie frame, no matter what the movie frame resolution is.
Not sure if that is a "fact", but I'd be willing to accept that your typical video stream allocates less bits per frame than your typical still-image file.
"Information" is a relatively well-defined concept, but what we are interested in here is perceptual quality. Perceptual quality correlates poorly with information, especially when comparing two different concepts such as video streams and stills.
My point is that even though 4k video will have 2x2 downsampled chroma, what does it matter if we are unable to see the loss of quality for the wast majority of content (probably less for 4k than 1080p).
-h
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My point is that even though 4k video will have 2x2 downsampled chroma, what does it matter if we are unable to see the loss of quality for the wast majority of content (probably less for 4k than 1080p).
That's my point too.
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Open Water was the film. Cleverly done.
The reason they used the lo-fi camera was for aesthetic reasons. It looked rubbish on a big screen if talking technically, but it conveyed the story well - which was the point. The thing with film/video is that picture quality can be dire, but if the sound is spot on then it will 'look' great. However beautifully shot footage with duff sound will seem awful.
The Richard Linklater film, Tape was also shot on on a camcorder. As was the very influential Timecode, the cameras for which were bought by the director Mike Figgis from consumer electronic shops on Tottenham Court Road in London.
Yes, Open Water. I did not see it in a theater. I believe the reason they chose the Sony PD150 was that was what they could afford. The film was nearly all self-funded until near the end of production. They were working and living their regular jobs/lives and taking weekend trips to make the movie.
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Moving images look poor quality as screen grabs as they are deliberately shot at low shutter speeds to give a smooth image.
True, buy I was thinking about something different and simpler: you often see glaring pixelation in a frame grab, while pixelation is less noticeable or not at all noticeable when watching the video stream from which the frame was taken. It is harder for our eyes and brains to make out fine details of a moving subject or image, probably in part for the reason I mentioned, about saccades.
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It is also worth remembering that 35mm movie projection in a good theatre has the resolution of only 600-800 horizontal lines, less than HD video.
Yet somehow manages to look so much better than that and why numbers do not always tel the truth - that's if those figures are even true.
I have a HD projector for watching at home and it produces an awesome 190cm/75" image. However it isn't a patch of films at the cinema which still look great at much closer effective viewing distances. If I was to sit close enough to my project's image to get the same field of view as I get at cinema, the image falls apart as I can see the pixels and information that makes up the image.