[gazonk]

Hm, so you down sample your photos to a quarter of their original pixel count?

No, please pay attention to what I wrote: A 4000x3000 monitor has 12 million real pixels each consisting of RGB sub pixels. But a 12mp camera has only 12 million pixels which each are red, green (usually 2x as many green) or blue. So in order to get 12 million "multicolor pixels", you'll need a 48mp camera. In fact, you may benefit from even more, because of noise.

I haven't tried, but I would guess that there's a quite visible difference on a typical "HD" screen (1920x1080) between viewing an image taken with a 2mp camera and one taken with a 8mp camera.

[Gimbal]

So my point is, If a 14MP camera can reproduce a sharp 60" image that is clean. What benefit is higher MP? In my book zero.

14Mp and 60" means 78dpi, maybe that is the perfect and ultimate resolution, I don't know.
21MP and 60" means 93dpi, yes I see it now, we definitely must avoid that.

[Gimbal]

No, please pay attention to what I wrote: A 4000x3000 monitor has 12 million real pixels each consisting of RGB sub pixels. But a 12mp camera has only 12 million pixels which each are red, green (usually 2x as many green) or blue. So in order to get 12 million "multicolor pixels", you'll need a 48mp camera.

Yes, but you do know that a 12Mp sensor does produce (after interpolation) a 12 Mpixel picture, thus you need a 12Mp monitor unless you downsample the picture again.

[lithos]

F***********UCK!

Figure of speech, you gormless nerds.

Figure of speech. It was the first res I could pull out of my.

[Eigengrau]

IMHO, no one needs to prove that they are a great photographer to post here.

I'm sure that Pentax (nor any other manufacturer) doesn't require their customers to deliver breathtaking pictures either.

While I think maybe the original post wasn't carefully worded, it is also true that we've got far too many armchair pros that will complain about the lack of FF all day long without really getting out and shooting often. I'm more inclined to listen to someone's opinion about photographic equipment if they have some work to show that they are serious about the art.

[gazonk]

Yes, but you do know that a 12Mp sensor does produce (after interpolation) a 12 Mpixel picture, thus you need a 12Mp monitor unless you downsample the picture again.

That's not the point. The point is that a 48mp picture will look better than a 12mp picture on that 12mp monitor, since the 12mp interpolation from 3+3+6mpixels from the Bayer sensor cannot contain as much information as a downsample of a 48mp image.

[Urkeldaedalus]

A few thoughts:

1. These arguments are sort of pointless. Until we know that the camera exists, its actual megapixel count and what format (APS-C or FF) it will use, there will be no way to resolve any of these debates.

I'd like to think that Pentax sort of has an idea of what they're doing, though, so you'd think whatever decision they make for this camera will make some sort of logical sense. If they've made a 21 mp APS-C camera, maybe they have a good justification for doing so.

Wait a second, this is Pentax we're talking about. This doesn't have to make any logical sense at all.

2. Superior image quality or not, the Canon 7D has sold very well since it was released. If Pentax releases a comparable body and improves High ISO and AF performance compared to the K-7, you'd have to think it will be a successful camera as well.

3. There's nothing stopping Pentax from releasing two models, one a high MP model and the other with say 12 mp and great high ISO performance -- the so called k-x Super that people have been wanting since the k-x was first announced. This would be a strong two camera strategy -- offer something very different at two different price points.

[Pentaxor]

No, no one would ever call a brand new FF camera as a replacement of an APS-C model (and a discontinued model, no less).

And no, I don't believe a FF model at Photokina. It just does not make economic sense for Hoya.

and the 645D does make economic sense for Hoya? :ugh:

[Gimbal]

That's not the point. The point is that a 48mp picture will look better than a 12mp picture on that 12mp monitor, since the 12mp interpolation from 3+3+6mpixels from the Bayer sensor cannot contain as much information as a downsample of a 48mp image.

So the point is that 48 is more then 12. Well, I think you are right.

[gazonk]

So the point is that 48 is more then 12. Well, I think you are right.

Please, don't be such a troll.

[Christopher M.W.T]

A few thoughts:

1. These arguments are sort of pointless. Until we know that the camera exists, its actual megapixel count and what format (APS-C or FF) it will use, there will be no way to resolve any of these debates.

I'd like to think that Pentax sort of has an idea of what they're doing, though, so you'd think whatever decision they make for this camera will make some sort of logical sense. If they've made a 21 mp APS-C camera, maybe they have a good justification for doing so.

Wait a second, this is Pentax we're talking about. This doesn't have to make any logical sense at all.

2. Superior image quality or not, the Canon 7D has sold very well since it was released. If Pentax releases a comparable body and improves High ISO and AF performance compared to the K-7, you'd have to think it will be a successful camera as well.

3. There's nothing stopping Pentax from releasing two models, one a high MP model and the other with say 12 mp and great high ISO performance -- the so called k-x Super that people have been wanting since the k-x was first announced. This would be a strong two camera strategy -- offer something very different at two different price points.

Thankyou, couldn't have said it better.

The other point to add, is anyone here actually an engineer/designer/fabricator/etc for any of the major camera or sensor manufacturers? Most likely no.

[jsherman999]

Bring on the Megapixels!

As regards resolution – more MPs are better. Current sensor pixel density is still limiting resolution if you're using good glass and are not stopped down too far into diffraction territority.

As regards noise, with the current high fill-factors (micro-lenses; backside illumination), with the same sensor technology, noise is mostly dependent on the total amount of light falling on the total sensor area which should be the same for similar APS-C format sensors. Take a 10MP & a 40MP APS-C format sensor. The 40MP version would have sensels (the photosensitive part of a pixel) that are ¼ the area of the 10MP version (assuming a fill-factor approaching 100%). However the same amount of total light would fall on the two APS-C sensors, and if the resultant picture is printed out the same size, both images would appear to have the same noise level at mid-ISO levels, but the 40MP version should be sharper, unless either on-sensor NR (if CMOS) or PP NR was strong enough to wipe out the resolution advantage.

There is a noise difference between the two sensors which see-saws at low & high ISOs as mentioned in the summary below.

See http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/index.html,
particularly http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#pixelsize

His summary:
Among the important measures of image quality are signal-to-noise ratio of the capture process, and resolution. It was shown that for fixed sensor format, the light collection efficiency per unit area is essentially independent of pixel size, over a huge range of pixel sizes from 2 microns to over 8 microns, and is therefore independent of the number of megapixels. Noise performance per unit area was seen to be only weakly dependent on pixel size. The S/N ratio per unit area is much the same over a wide range of pixel sizes. There is an advantage to big pixels in low light (high ISO) applications, where read noise is an important detractor from image quality, and big pixels currently have lower read noise than aggregations of small pixels of equal area. For low ISO applications, the situation is reversed in current implementations — if anything, smaller pixels perform somewhat better in terms of S/N ratio (while offering more resolution)
...
Rather than having strong dependence on the pixel size, the noise performance instead depends quite strongly on sensor size — bigger sensors [i.e. larger than APS-C] yield higher quality images, by capturing more signal (photons).


This recent, interesting paper looks at the optical challenges of going below 2μm pixels. Sony has already introduced one of the recommendations: Back-Side Illumination. While increasing sensitivity, BSI also reduces the dielectric stack height, paving the way for more pixels per mm2. The paper can't be hyper-linked to directly. You can get it by googling for

""Microlens performance limits in sub-2μm pixel CMOS image sensors".

It's at the Optic InfoBase site and there's a link in the Abstract section to a full text pdf.





Dan.

.

Very interesting stuff, Dan. Thanks for posting this link and summary.


.

[tigrebleu]

Right. Because my only complaint with the K20d was that it needed 6 more megapixels. I hope this isn't true, aps-c or FF. If Nikon is still putting out 12mp FF's, that smoke the competition in hish ISO IQ, then why doesn't everyone feel the need to keep pushing the bar?

Well, the D700 does smokes competition vs. APS-C, but when measured against the 21 Mpix 5DII, the difference is slim up to ISO 3200. Beyond, the D700 is getting better and better than the 5DII as ISO goes up, though. (Both these cameras are better than Sony's A900/A850, thanks to much better noise reduction algorithms. Sony still has a lot to learn to stand up against Canon and Nikon.)

Anyways, 21 Mpix on a FF is like about 9 Mpix on an APS-C, still below the actual APS-C average of 12-14 Mpix. So a new Pentax 21 Mpix FF sensor would have less noise than the K-x using Pentax's actual noise reduction and a similar sensor design.

But you got a point: who needs more Mpix? Not a lot of people indeed. Most would trade the added Mpix for better high ISO performance anytime, and that's why there are cameras like the D700 out there.

But some need that extra resolution, and that's where the 5D Mk II comes in. This camera is actually chewing a bit at the digital medium format market because of its high resolution. I bet the next 1Ds Mk IV will have between 25 and 30 Mpix. As long as there will be people in search of more IQ at a lower cost, the manufacturers will keep pushing the bar, for better or worse.

After many years doing event photography, I'm getting more and more advertisement assignements, and in this kind of business, resolution often matters. These days, I need more Mpix than a higher ISO. (I did rent the 5DII a couple of times to get access to such resolution, in fact.)

If Pentax launches a FF DSLR, I want it to be at least 18 Mpix, no less.

Using the same sensor materials and design, a FF camera with 2.25 times the surface area of an APS-C camera equals roughly 2.25 times more pixels with similar noise performance. I'd go with a 22-27 Mpix FF camera at any time, since it would have the noise performance of a 10-12 Mpix APS-C camera.

I think the trend is that MPix race will keep going on, at least for FF cameras.

In APS-C however, the Mpix race is reaching its limits, as we can see with the 7D. If Pentax launches a 21 Mpix APS-C camera, I'll pass on this one unless it gets awesome reviews for its high ISO quality.

Because what I need is, of course, 6 more Mpix on my K-7 sensor to get more noise at ISO 800 and above.


Joke aside, I really wish it will be full frame and I really, really wish it will have full HD video with FULL manual control. So I can use the excellent Pentax glass when shooting videos instead of having to buy a 5DII and some Canon glass.

[philippe]

While I think maybe the original post wasn't carefully worded, it is also true that we've got far too many armchair pros that will complain about the lack of FF all day long without really getting out and shooting often. I'm more inclined to listen to someone's opinion about photographic equipment if they have some work to show that they are serious about the art.

This is what I did with a K20d and three Limiteds (15, 21, 35mm), although not the plain reproductions, which were done by the Vatican, but the about 280 photo's of the reportage... VdH|books, the Art Publishing Company

[falconeye]

A 4000x3000 monitor has 12 million real pixels each consisting of RGB sub pixels. But a 12mp camera has only 12 million pixels which each are red, green (usually 2x as many green) or blue. So in order to get 12 million "multicolor pixels", you'll need a 48mp camera. In fact, you may benefit from even more, because of noise.

This is OT but I hear this often.

Both possible simple statements ("needing 48MP camera" or "needing 12MP camera for 12MP RGB output") are false statements.

As a matter of fact, you have to compute or measure a Bayer sensor's modular transfer function (MTF) (which includes the demosaicing algorithm) and compare it to a full color sensor (which is mathematically well described).

As it turns out, the Bayer sensor's MTF is very close to a full color sensor's MTF for black & white line pair patterns but significantly less for colored line pairs. To tell the truth, Bayer sensor demosaicing algorithms are architected to maximize MTF for a slanted grey-level edge.

I have measured MTF curves myself and with a good lens, a Bayer sensor can indeed deliver the full resolution of a full color sensor (1.25px blur widths) which can be surprising and confusing indeed.

Therefore, a Bayer sensor's RGB output normally looks very close to a full color sensor's one. Because the human eye primarily judges sharpness in the luminosity channel. The human eye actually plays similiar tricks to a Bayer sensor

As a rule of thumb it has now become a tradition to treat a Bayer sensor with N pixels and a full color sensor of 1.5N pixels to be of equivalent resolution. So, you would need a 18MP camera to exploit the full potential of a 12MP display.