I never mentioned anything about lenses, I was on about film. 35 mm film in particular

A lens will easily out resolve a 24 megapixel sensor in the correct conditions. All lenses have limitations of one sort or another though.

My post was in response to a post basically stating that

The lenses are not good enough to cope even with 24Mp, and 24Mp in a camera is pointless when clearly it's not.

You took a tiny bit of my response and took it entirely out of context.

Yeah, sooner I suspect... I'm certain we'll be seeing 4k on all sized displays soon regardless of whether anyone can see the difference, as ZX50 has said, we're already seeing 2048x1536 in tiny devices and that trend sets to continue as phone/tablet makers try to out do each other. We'll soon see 4k Ipads I'm sure. The natural progression is that high end TVs will adopt this in the next 18 -24 months followed by mid range in 3 years or so.

I look forward to 2017 when I can come back to this post and see how accurate I was

I think you are a little out....People are already importing 39" 4K TV's that are selling for just over £300 (+ shipping + Tax), on Amazon. This is what happened with decent large ips monitors, as soon as the imports began and started to take off, the main manufacturers jumped in to compete. I'm guessing that during 2014 we will see prices drop to very affordable levels as production ramps up.
The predicted prices are already tumbling ready for CES later next week. Polaroid have already announced a sub $1,000 50" TV.
Japan display have developed a 12.1" tablet screen that will be unleashed on the market during 2014, opening up the tech to many TP manufacturers...
So, I doubt you will have to wait until 2017...

Yes I think 4k TV's and for that matter computer monitors will become the norm in a relatively short time scale when production ramps up and it will be as cheap to produce a 4k ready TV as a normal HD one.

The question is really about when the content will be ready to take advantage.

Off topic but your main argument for lenses being able to resolve 24Mb in a camera seemed to be because film Doesn't have pixels which didn't make any sense to me, when film does have a limited resolution because of grain.

To be fair to D@ave you would need a decent pro or semi pro lens to resolve that amount of detail, or a prime lens set to the optimum aperture so diffraction effects and so on don't come in to play.

It's a mute point since there are already pro video cameras that will quite happily shoot at 4k resolution.

There is already a very expensive pro canon DSLR than can shoot at 4k and it is rumoured that the panasonic GH4 will be able to shoot at 4k as well so it's only going to be a matter of time before 4k is available on prosumer and maybe even consumer cameras

What percentage of people print photographs.
And what percentage of people use a monitor/watch TV ?

Seems to me that the digital camera needs 4K TV, and for that matter 4K tablets.
In fact a camera probably needs a 4K monitor far more than a monitor needs a 4K+ camera.

Yep. I think a ton of people will view their photos on either their full HD TV screen, or their computer monitor. I think the reason people turned towards digital cameras was because they didn't have to go to the camera shop to get the images put on paper so they could look at them. Since digital cameras started becoming popular, all people had to do to view the images they'd taken is to transfer the files to their computer and then open them up. This could be what sells the 4K TV the most. I'd absolutely love to view a very high resolution image that I'd taken with a digital camera on a 4K TV.

I'm not a photographer but I thought that a lot of people manipulate the image after they take it. If so then the extra resolution would be very useful especially if zooming, it's much easier to downscale rather than upscale.

Precisely the point I made.

Starting with 24Mp picture you can crop away 50% of the picture leaving a 12Mp image. Effectively this doubles the optical zoom capability of a specific lens compared to using it on 12Mp camera.

A relatively inexpensive 300mm lens becomes effectively a much more expensive 600mm one

Image stabilasation makes it a lot easier to use long lenses on a DSLR if you haven't a tripod handy.

Unless they want to manipulate it for a specific reason, I think it's a shame to alter it.

I think you're getting your maths a bit wrong here 12 megapixels is 4,000 X 3,000 if you multiply them together you get 12 million

24 megapixels is something like 5,656 x 4,242, multiply them and you get roughly 24 million.

a 24MP photo isn’t twice as wide as a 12MP photo. It’ll have twice as many pixels, but that means it’ll only be 41% wider and 41% taller.

A 600 mm lens produces a 2X zoomed image compared with the 300mm.

So to crop the equivalent of 600mm from a 300mm image would mean you need to crop 1/2 of the width and 1/2 of the height.

So it would be 2828 X 2121 which is roughly a 6 megapixel image

I didn't say 50% of the pixels in each direction, I said 50% of the area which is 12Mp. But as you say it doesn't double the image size. I will produce an example.

No, it doesn't.

I said (not meaning to start a semi-off-topic debate ) that: "some argue that even 16 MP hits the limit of affordable lens resolution and practical use". Of course, in reality, there is no sudden cut-off point beyond which further improvements won't be seen but the law of diminishing returns is definitely starting to kick in once you get above say 16MP. You need better and better lenses to take full advantage of the extra megapixels and with zoom lenses being by far the most popular these days, that is becoming harder and harder to achieve at affordable prices. It's a lot easier to design more sensor megapixels than more intrinsic lens resolution, sensors are advancing faster than the lenses. Outstripping them really, in the mass market. An extreme example would be a 16 or 24MP sensor in an iPad - I'm sure they will happen within a few years, but the lens will be by far the limiting factor and you'd need a lab test to see the improvement (with the same lens).

How much sharper would the pictures produced with a decent lens be, if used in a 24MP camera compared to a 16MP camera of equivalent quality and price? maybe 5% or 10% tops, I'd say, perhaps less. Definitely not 50% or more as you suggest (all assuming the same format). For most people, especially the majority who in my experience don't do much cropping or viewing of say 16MP+ photos at 100%, it's just not worth bothering with more megapixels as they already get all the quality they want out of what they've got. For some semi-pro enthusiasts it's different, because for them, every 1% of improvement matters,

Always remember the law of diminishing returns and the difficulty of making better lenses, especially the long consumer zooms that most people seem to use these days.

I agree and I also wonder why the BBC seemingly worry about investing in 4K.

All the negative dialogue I've heard from people who acknowledge that its a better picture and huge jump forward, but still say it's pointless, surrounds the fact that 8K is only a couple of years behind and so this will obsolete 4K????

However, why would you obsolete 4K for 8K?

Surely the logical thing to do would be to retain 4K and 8K and instead obsolete HD when 8K arrives, and then downscale 4K / 8K to HD / SD resolutions via the set top boxes for those with older tv's rather than transmit those in native resolutions.

To me the suggestion that you'd keep HD and drop 4K for 8K to leave HD and 8K makes no sense whatsoever. When 4K is such a step forward the logical way to progress with TV is to drop the lowest standard format each time. With downscaling existing from set top boxes and downscales being of such excellent quality, why would you retain an older standard? It's a crazy suggestion!

I just upscaled a photo I took in 1997 (with a 640 x 480 digitial camera) to 4k!
Cool eh?

If The displays actually implemented BT 2020 there would be a great improvements in what you see..
But as the video I have referred to earlier states -
http://www.youtube.com/watch?v=QPrNh...re=c4-overview

there is I need for Higher Frame rate ( at the moment only perhaps60 Hz -it need to be at least 100++) Higher dynamic Range this may be 12 bit (rather than current 8 bit which runs out all too easily), and a Colour Gamut which is wide ( NOT BT 709 which HD uses) .....let alone how many pixels!

SO UHD has the possibility - But the current TV display (or HDMI) do not have this.....and there is not the production equipment and workflows there to routinely support it (YET)....

No but you were claiming that it made a 300mm lens equivalent to 600mm which is factually incorrect.

There is no problem in having a lens that will resolve 24 megapixel of detail, agreed it needs to be a pro or semi pro type. You only need to double the resolution of a lens to quadruple the megapixel rating of it remember.

There is certainly no issue in having a lens that will get all the detail needed for an excellent 4k video image.

Back on Topic...
The problem is the cost of equipment. 8K is so close behind 4K that it would mean updating all the equipment in too short a time frame. Broadcasters will be wary of the 4K upgrade and obsoleting the equipment before end of life. If that decision is made then there will be a longer delay in broadcast UHD.

Stuck the camera out of the window with a 300mm telephoto

Lower picture is field of view of original image (6000 x 4000 pixels)

Next is same shot cropped to (4000 x 3000 pixels)

Upper shot is cropped to pixels for a A4 300 ppi print.

I think it clearly shows the advantage of starting with 24Mp.

http://www.imagesup.net/dt-11138876421211.png

Ha! Ha! I'm surprised anyone would be able to see what was in the picture.

If you look at the IMDb website you will see that most films are still being made in 2k format, including some shown in IMAX Digital, due to the very high cost of 4/8k post production. There will be no market for anything better than HD unless content, that people want to watch, becomes commonly and inexpensively available.
As for shop demos, my local JL showed an up-scaled Sony HD promo disc on a 4k TV until the genuine 4k material arrived, it looked surprisingly good much better than normal HD but I bet the data rate was the maximum possible. The same is true of 4k demos that will have been mastered on a TV identical to the one you are watching to ensure any problems are covered up.

Link to images doesn't seem to be working for me so here's the link below that's been copied.

http://www.imagesup.net/pt-11138876421211.png

I don't think 4K discs will be sold in great quantities until, as you say, the price of the hardware comes right down to under £900. Only the very well off people might get them as soon as they're released to the public.