[Fastback67]

When I first heard mention of the K3 and read 24 Mega-pixels, I assumed that Pentax had finally put together a Full Frame camera. Then I read that it was still using an APS-C sensor??? So how did we pull that one off ???
It has always been my understanding that one could only fit so pixels on any given size sensor without adversely effecting the image. I thought this was the reasoning behind full frame cameras? 24 Mega-pixels from an APS-C sensor smells like a gimmick to me, but maybe there is more to this story... as I said, "School Me" please.

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Last edited by Fastback67; 10-28-2013 at 01:42 PM.

[Adam]

When I first heard mention of the K3 and read 27 Mega-pixels, I assumed that Pentax had finally put together a Full Frame camera. Then I read that it was still using an APS-C sensor??? So how did we pull that one off ???
It has always been my understanding that one could only fit so pixels on any given size sensor without adversely effecting the image. I thought this was the reasoning behind full frame cameras? 27 Mega-pixels from an APS-C sensor smells like a gimmick to me, but maybe there is more to this story... as I said, "School Me" please.

24-megapixel APS-C cameras have been around for a while now (both Sony and Nikon have em). You're not going to get the same low-noise image as from a 24-megapixel FF sensor, but it should still be an improvement over the K-5 thanks to newer tech.

[jatrax]

Well, it's actually only 24mp

And Nikon has 24mp on APS-C for some time now. Canon has 20mp as well. So it can be done. How good will be the results? I will be happy to tell you in about 2 weeks.

27 Mega-pixels from an APS-C sensor smells like a gimmick to me,

Not sure how you think it is a 'gimmick' MPs are MPs, no trickery like they do with boosting the ISO sometimes. How good the image is, well that remains to be seen but early testers say things like: "you will be blown away". So we will see.

[ElJamoquio]

When I first heard mention of the K3 and read 27 Mega-pixels, I assumed that Pentax had finally put together a Full Frame camera. Then I read that it was still using an APS-C sensor??? So how did we pull that one off ???
It has always been my understanding that one could only fit so pixels on any given size sensor without adversely effecting the image. I thought this was the reasoning behind full frame cameras? 27 Mega-pixels from an APS-C sensor smells like a gimmick to me, but maybe there is more to this story... as I said, "School Me" please.

The 'bad' portions of the higher MP camera were really making assumptions that aren't really true - that a small pixel having a bit of error is as bad as a large pixel having a bit of error.

That isn't true for anyone, but particularly untrue for those who post-process their pics... and if you're worried about noise you should be post-processing your pics.

So the objection - too many megapixels - isn't really relevant to DSLR's that are made today.

[RobA_Oz]

For a start, it's 24 MP, not 27, but that's just a detail, and the K-3 isn't the only 24MP APS-C camera available. As for the superior noise performance of the larger format sensor with the same pixel count, it seems that notion is not necessarily even theoretically correct. Recent comparative testing between the K-3 and the Nikon D610 seems to bear that out, even if the testing wasn't entirely scientific.

[Winder]

When I first heard mention of the K3 and read 27 Mega-pixels, I assumed that Pentax had finally put together a Full Frame camera. Then I read that it was still using an APS-C sensor??? So how did we pull that one off ???
It has always been my understanding that one could only fit so pixels on any given size sensor without adversely effecting the image. I thought this was the reasoning behind full frame cameras? 27 Mega-pixels from an APS-C sensor smells like a gimmick to me, but maybe there is more to this story... as I said, "School Me" please.

More pixels offset noise! - DxOMark

[TER-OR]

Presumably, more pixels and same size sensor mean smaller pixels - which should mean more resolution. That added to newer technology should mean better performance.
Generally, with phones and pocket cameras more mps is essentially worthless...though the image could be larger the sensor is still tiny. That density may not translate to super-high resolution on a larger one, but I'm no expert.

[Dr_who]

When I first heard mention of the K3 and read 24 Mega-pixels, I assumed that Pentax had finally put together a Full Frame camera. Then I read that it was still using an APS-C sensor??? So how did we pull that one off ???
It has always been my understanding that one could only fit so pixels on any given size sensor without adversely effecting the image. I thought this was the reasoning behind full frame cameras? 27 Mega-pixels from an APS-C sensor smells like a gimmick to me, but maybe there is more to this story... as I said, "School Me" please.

Technology is always evolving.

[Clavius]

So why doesn't anybody talk about diffraction anymore nowadays?

[Fastback67]

Ooops... sorry about the typo!

I know other folks are producing 20+ MP cameras with APS sensors, but those same companies are producing FF sensors that are still 20+ MP. You can buy a cell phone with a crappy 40 MP camera sensor these days, but...

[elliott]

The Lumia's 40MP camera is not crappy, it is very good for what it is. They use the extra pixels to average the image to cancel out noise, so you're not actually getting a 40MP image out of it.

[lister6520]

A 24MP sensor is more noisy than a 16MP one of the same size and technology at 100% crop. A 24MP image scaled down to 16MP is no more and no less noisy than the native image from a 16MP sensor (of the same size).

The noise is inverseley proportional to the effective pixel area. Taking an extreme case, for simplicity's case, imagine a 10MP and a 40 MP sensor of the same size. Four pixels of the 40MP sensor have more or less the same capture area as one pixel of the 10MP sensor. This means that the averaged output of the four pixels of the 40MP sensor will have just as much noise as the output of the simple pixel on the 10MP sensor. Averaging of pixels is what is being done in principle when scaling down.

The end result is that for a given final picture size and sensor size the noise will be the same regardless of the pixel count. This of course unless you go too far and the 'empty' space between pixels starts to become significant in relation to the sensitive area of the pixel. However this typically only happens at very high pixel densities found in tiny high megapixel sensors such as found in cell phones. So there is no reason whatsoever why a picture shot with the K-3 would have any more visible noise than a K-5.

[rawr]

I thought this was the reasoning behind full frame cameras?

There are several types of reasoning behind full-frame, just as there are about other sensor sizes - and about film sizes or engine sizes too for that matter. Some are of course technical, others relate to marketing and selling the stuff. Sometimes it's hard to separate the two.

Pentax aren't doing anything new or risky by running with 24MP. Nowadays 24MP is no big deal even for cheap consumer APS-C DSLR's. Nikon's base model lineup (D3200, D5300) is all 24MP now, as is Sony's. And due to tech evolution, all those 24P boxes perform better than earlier models did, even if the older cameras had half the resolution of current models.

[Fastback67]

Thanks folks... It seems that I have my answer.

[carrrlangas]

I´ve seen credible calculations for monochrome sensors stating a limit of 200Mpx for APS-C, so teh limit should be arround 60Mpx for a beyer APS-C sensor?