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02-11-2014, 08:09 AM   #1
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Is this the Foveon that finally out-performs Bayer

I've been waiting for years for the Foveon sensor to live up to it's promise... with the release of the Dp2, I have a 14 Mp foveon sensor that outperforms my k5 and in many ways, and would seem to be at least equivalent to the 24 Mp K-3.

I'm trying to decode the Foveon hype and as far as I can tell the Sensor in Bayer numbers is about a 22 MP sensor, in that the number of pixels across is 5700, 300 less than a K-3.. but based on comparisons between , my 2700 pixel DP2 and 6000 pixel k-5 I'd guess the actual resolving power will come in somewhere about 34-36 Mp, in a package that fits in your pocket. Foveon sensor have a proven ability to punch above their weight class, the only question at this point is how much? This camera has the potential to leave the D800 sensor in the dust, in terms of the clarity of the image, and possibly lw/ph.





Awaiting the test reports....

02-11-2014, 08:14 AM - 1 Like   #2
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Don't you think the merrills already outperformed bayer sensors? Especially considering the size and price of the cameras?

Of course using the cameras is an exercise in patience.
02-11-2014, 11:43 AM   #3
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QuoteOriginally posted by Mr Bassie Quote
Don't you think the merrills already outperformed bayer sensors? Especially considering the size and price of the cameras?

Of course using the cameras is an exercise in patience.
They outperform Bayers pixel for pixel, what I'm interest in will be if an approx. 22 mp Foveon will outperform 36 Mp bayer. Test shots posted on the forum suggest 14 Mp foveon is darn close to 24 Mp bayer, depending on which camera and lenses are used either one can be better. Increasing the Mp count, will the difference be more or less?
02-11-2014, 12:09 PM   #4
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I appreciate the images I see from these foveon sensors. They are really nice. I haven't looked at the tech behind it to understand why the camera has to have fixed lenses and such a narrow photographic scope.

I mean, I want my digital to have fast focusing to shoot action as well as good performance in low light when at social events. I can shoot ISO 100 and 400 on my medium format BW film if I want it slow and methodical and get real BW. But I understand not everyone wants to roll their own in that regard.

02-11-2014, 12:16 PM   #5
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QuoteOriginally posted by normhead Quote
They outperform Bayers pixel for pixel, what I'm interest in will be if an approx. 22 mp Foveon will outperform 36 Mp bayer. Test shots posted on the forum suggest 14 Mp foveon is darn close to 24 Mp bayer, depending on which camera and lenses are used either one can be better. Increasing the Mp count, will the difference be more or less?
It is kind of apples and oranges to me and, considering the price of these cameras, their image quality is unparalleled for the price. It seems silly to compare them to a D800 or a 645D, though I have seen those comparisons and the sigmas are certainly in the running as far as image quality. Definitely not the slam dunk for the big boys that it ought to be IMHO.

---------- Post added 02-11-14 at 02:18 PM ----------

QuoteOriginally posted by tuco Quote
I appreciate the images I see from these foveon sensors. They are really nice. I haven't looked at the tech behind it to understand why the camera has to have fixed lenses and such a narrow photographic scope.

I mean, I want my digital to have fast focusing to shoot action as well as good performance in low light when at social events. I can shoot ISO 100 and 400 on my medium format BW film if I want it slow and methodical and get real BW. But I understand not everyone wants to roll their own in that regard.
There are interchangeable lens foveon cameras. I have never seen one.

I have used my DP2M under difficult circumstances with varying degrees of success. Shoot it like one of your film cameras and you will do fine. Their B&W images are really nice to my eyes.
02-11-2014, 12:47 PM   #6
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QuoteOriginally posted by Mr Bassie Quote
It is kind of apples and oranges to me and, considering the price of these cameras, their image quality is unparalleled for the price. It seems silly to compare them to a D800 or a 645D, though I have seen those comparisons and the sigmas are certainly in the running as far as image quality. Definitely not the slam dunk for the big boys that it ought to be IMHO.[COLOR="Silver"]
For me it's worth carrying a DP2 in my bag for when conditions warrant using it. It takes hardly any space.

QuoteOriginally posted by Mr Bassie Quote
There are interchangeable lens foveon cameras. I have never seen one.I have used my DP2M under difficult circumstances with varying degrees of success. Shoot it like one of your film cameras and you will do fine. Their B&W images are really nice to my eyes.
Photoguy has one.. I've posted images showing my DP2 produced better images than my k-3, he showed images showing his SD1 was not quite as good as his K-3. My interpretation is right now the Sigmas need that recessed built in lens to do all of what they do. Our images of course are extremely preliminary, in that the conditions weren't completely controlled and there was some suggestion that my DA 35 2.4 wasn't quite as sharp as it should be. You can only go so far with info from a couple of ad hoc trials.
02-11-2014, 02:38 PM   #7
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How ugly !
02-11-2014, 03:03 PM - 1 Like   #8
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QuoteOriginally posted by fs999 Quote
How ugly !
For some reason I kinda like the look.

It reminds me of:



And it's weird that I like the look of the Sigma because I don't really like the look of that Kodak. Maybe it's because the Sigma's look took me by surprise. It doesn't look like a slippery little P&S or MILC and doesn't look like a retro-DSLR.

.

02-11-2014, 03:09 PM   #9
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QuoteOriginally posted by normhead Quote
My interpretation is right now the Sigmas need that recessed built in lens to do all of what they do.
I think having a single lens built and mounted specifically for each unit makes it easier to get pixel-perfect images. Every camera and lens is a little different. When the two are fixed together, Sigma can ship them out knowing that the two work perfectly together.

Still, as long as the focus is just right, I can still get pixel-perfect images with the SD1M and the 18-35mm. That combo is way bigger than a DP, though.



I want to know how the new structure of the next Foveon sensor holds up against the current one at low ISO. I'm betting the low-light performance will now be on par with a Bayer one, but what about the resolution?



The new chip doesn't have all the colors individually at every pixel anymore, which I though was the whole point of a Foveon sensor. I'm really eager to see how that actually affects the image.
02-11-2014, 04:06 PM   #10
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QuoteOriginally posted by scratchpaddy Quote
I think having a single lens built and mounted specifically for each unit makes it easier to get pixel-perfect images. Every camera and lens is a little different. When the two are fixed together, Sigma can ship them out knowing that the two work perfectly together.
Yes I think the single lens is an important part of the great performance of the DPxM.

I'm just hoping for a camera that takes away the poor performance and keeps the great image quality. Worst case scenario I will buy a current generation DP3M for a great price!
02-11-2014, 06:37 PM   #11
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I don't care much about the new sensor as the current X3 sensor meets my very specific need of it as a high detail landscape camera.
I'd rather they create a new DP0m with a 20mm equivalent lens, and this together with a DP1m will already cover all that I need for wide view landscapes.

Combing these with a faster camera with a 'normal' lens (Eg. K30; X100S; MILC; etc ) will suffice for lots of stuff.
02-11-2014, 11:24 PM   #12
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We are back to film days.

Yet we refuse to draw any analogy to it, and therefore talk in absolutes.
We have a new film in town. Great grain, lovely colour. Kodak Portra it is (say, a new Foveon). Is it better than the other film, namely, the Fuji Velvia (current Bayer average CMOS from Sony)?

It is impossible to say, because they deliver a picture in a different quality, that suits different tastes.
02-12-2014, 02:25 AM   #13
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QuoteOriginally posted by scratchpaddy Quote
I think having a single lens built and mounted specifically for each unit makes it easier to get pixel-perfect images. Every camera and lens is a little different. When the two are fixed together, Sigma can ship them out knowing that the two work perfectly together.
I'm sure Ricoh GR owners would agree with you, Scratchpaddy. And with no AA filter, some nice sharpness in a small body at a lower cost.
02-12-2014, 07:36 PM   #14
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Dick Lyon, one of the co-founders of Foveon had a very interesting post at DPReview:

Original Post here

Kendall, long time...

You're right that there won't be much aliasing. A lot of people seem to have the idea that aliasing has something to do with different sampling positions or density, as in Bayer. But that's not the key issue. The problem with Bayer is that the red plane (for example) can never have more than 25% effective fill factor, because the sampling aperture is only half the size, in each direction, of the sample spacing. If you take the Fourier transform of that half-size aperture, you'll find it doesn't do much smoothing, so the response is still quite too high way past the Nyquist frequency. That's why it needs an anti-aliasing filter to do extra blurring. But if the AA filter is strong enough to remove all the aliasing in red, it also throws away the extra resolution that having twice as many green samples is supposed to give. It's a tough tradeoff.

In the Foveon sensor, the reason no AA filter is needed is not because of where the samples are, or what the different spatial sampling densities are. It's because each sample is through an aperture of nearly 100% fill factor, that is, as wide each way as the sample pitch. The Fourier transform of this aperture has a null at the spatial frequencies that would alias to low frequencies; this combined with a tiny bit more blur from the lens psf is plenty to keep aliasing to a usually invisible level, while keeping the image sharp and high-res.

In the 1:1:4 arrangement, each sample layer has this property, but at different rates -- very unlike the Bayer's red and blue planes. The large area of the lower-level pixels is the ideal anti-aliasing filter for those layers; the top layer is not compromised by the extra spatial blurring in the lower layers, so it provides the extra high frequencies needed to make a full-res image.

Another good way to think of the lower levels is that they get the same four samples as the top level, and then "aggregate" or "pool" four samples into one. This is easy to simulate by processing a full-res RGB image in Photoshop or whatever.

The pooling of 4 into 1 is done most efficiently in the domain of collected photo-electrons, before converting to a voltage in the readout transistor. The result is the same read noise, but four times as much signal, so about a 4X better signal-to-noise ratio. Plus with fewer plugs, transistors, wires, etc. to service the lower levels, the pixel fill factor is closer to 100% with easier microlenses, and the readout rate doesn't have to be as high. Wins all around -- except for the chroma resolution.

The main claim of Bryce Bayer, and the fact that most TV formats and image and video compression algorithms rely on, is that the visual system doesn't care nearly as much about chroma resolution as about luma resolution. Unfortunately, trying to exploit that factor with a one-layer mosaic sensor has these awkward aliasing problems. Doing it with the Foveon 1:1:4 arrangement works better, requiring no AA filter, no filtering compromises. So, yes, the chroma resolution is less than the luma resolution, but you'd be hard pressed to see that in images.

If you throw out the extra luma resolution and just make 5 MP images from this new camera, you'll still have super-sharp super-clean versions of what the old DP2 or SD15 could do. Now imagine adding 2X resolution in each dimension, but with extra luma detail only, like in a typical JPEG encoding that encodes chroma at half the sample rate of luma. Whose eyes are going to be good enough to even tell that the chroma is less sharp than the luma? It's not impossible, but hard.

Speaking of stories from the old days, Foveon's first version of Sigma Photo Pro had a minor bug in the JPEG output, as you probably recall: our calls to the jpeg-6b library defaulted to encoding with half-res chroma. It took a while, but a user did eventually find an image where he could tell something was not perfect, by comparing to TIFF output, and another user told us how to fix it, so we did. It we could have gotten that original level of JPEG quality from the SD9 with 5 million instead of 10 million pixel sensors and data values, and could have gotten cleaner color as a result, would that have been a problem? I don't think so; except for marketing, and they had enough problems already. Same way with Sigma's new one, I expect; if 30 M values gives an image that will be virtually indistinguishable from what could be done with 60 M, but with cleaner color, will someone complain?

Probably so.

So, it's complicated. Yes, reduced chroma resolution is a compromise; but a very good one, well matched to human perception -- not at all like the aliasing-versus-resolution compromise that the mosaic-with-AA-filter approach has to face.

Dick

disclaimer: I've been away from this technology too long to have any inside knowledge. And give my apologies to Laurence for my too many words.
02-12-2014, 08:17 PM   #15
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Hope they addressed the battery life issue.
The Merrills were fantastic film-like (aka, you only get a few rolls of "film" per battery) landscape cameras :-)
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