[audiobomber]

Sony's A7S is a "wake-up" call to the industry and photographers, that there's value in large photosites and low light cameras. Its far from an ideal camera, but i have a friend with it and he loves it for non-video work.

The difference is, the A7S sensor has a higher SNR than other FF sensors, which is its purpose. The Sony 24mp APS-C sensor has the same SNR as 16mp, and significantly higher resolution, therefore it is a better sensor.

[GeneV]

You've been sucked in Gene. Fuji lies about ISO and uses heavy NR on raw files. It's a shame that DXO can't test Fuji. The results would make the games obvious to everyone. From the DPR review of the XT-1:

"By our tests, the X-T1's measured sensitivities are around 1/2 - 2/3EV lower than marked, which is unusual for a modern camera. This means that for any given light level, the X-T1 has to use a significantly slower shutter speed, brighter aperture or higher ISO to get an image of the same brightness as an accurately-rated camera.

It's unusual to see this sort of discrepancy and we're disappointed that Fujifilm persists with a system that, while technically compliant with the ISO standard, ends up appearing rather disingenuous."

"Even a cursory glance at this comparison tells you that Adobe Camera Raw's processing of the X-T1's files looks radically different compared to its output from conventional Bayer cameras. Chroma noise is strikingly low, and detail retention is impressively high - very much like the camera's JPEGs, in fact. Because of this, direct comparisons have to be treated with a degree of caution - it's best to assume that the demosaicing process of the X-Trans CMOS sensor behaves as though it's doing substantial chroma noise reduction relative to ACR's standard treatment of Bayer sensors. Again we also have to factor in the X-T1's over-rating of its ISOs.

Even bearing this in mind, the X-T1 performs very well when its Raw images are converted with ACR. There's essentially no chroma noise, and luminance noise is suppressed until around ISO 3200, at which point you start to notice some hints of noise reduction artefacts - something not normally seen in Raw files. But again, it's very important to understand that the X-T1 looks artificially good in comparison to the other cameras here."
Fujifilm X-T1 Review: Digital Photography Review

Aside from all that, many people believe the X-Trans is a Sony sensor behind a Fuji colour array. The K-3's 24mp Sony sensor is easily superior, IMO. 16mp is yesterday's news.

Interesting. The samples in DPReview make it look strikingly superior. However, if the ISO is really that much slower, then why do the DPR samples not appear darker? Does DPR equalize the brightness in PP?

[audiobomber]

Interesting. The samples in DPReview make it look strikingly superior. However, if the ISO is really that much slower, then why do the DPR samples not appear darker? Does DPR equalize the brightness in PP?

They just go with the manufacturer's ISO setting. Shutter speed varies. They know they're being unfair, I had one of the principals tell me so. He also said they were intending to make changes to level the playing field.

[philbaum]

The difference is, the A7S sensor has a higher SNR than other FF sensors, which is its purpose. The Sony 24mp APS-C sensor has the same SNR as 16mp, and significantly higher resolution, therefore it is a better sensor.

You missed my point. While many mfr like Canon and Nikon and Pentax are adding mp in an iterative fashion, Sony, by themselves, went in the opposite direction and reduced mp by 50% over any other FF. The last 12mp FF was the D700 which was very popular in its day. The really odd thing was that some of the A7S reviewers said that the pictures from the camera had this odd pleasant quality to them, much like MF cameras. Examples of those reviewers are Steve Huff, Ten reasons why the Sony A7s is the best A7 body yet.. | STEVE HUFF PHOTOS , and Reichmann from Luminous Landscape, as well as many others.

You said that the K3 has the better sensor than a 16mp camera, yet DXO actually rates the K5 sensor higher, 82, than the K3, 80. Primarily i suppose because of the K3's lower dynamic range in several areas: Pentax K-3 versus Pentax K5 - Side by side camera comparison - DxOMark.

I'm delighted when any company comes along and thinks up a new approach. And the A7S was a breath of fresh air, at last to the astrophotographers among others.

[audiobomber]

You missed my point. While many mfr like Canon and Nikon and Pentax are adding mp in an iterative fashion, Sony, by themselves, went in the opposite direction and reduced mp by 50% over any other FF. The last 12mp FF was the D700 which was very popular in its day. The really odd thing was that some of the A7S reviewers said that the pictures from the camera had this odd pleasant quality to them, much like MF cameras.

I'm delighted when any company comes along and thinks up a new approach. And the A7S was a breath of fresh air, at last to the astrophotographers among others.

I understand what you're saying, Variety is great. because people use their cameras differently. But there was nothing special about the D700 sensor. It is inferior in every measurable way compared to a D810 sensor. The reason the D700 remained popular is because it is a fully featured body like the D800 and unlike the D600/610, not because it had 12mp.

I don't doubt that A7S images look fantastic, but it's easy to find reviewers raving about how special A7R images are too. Both are great for their intended purpose. The A7S for video and high ISO, the A7R for high resolution and cropping. For all the fuss made about the A7S SNR, it's only 1/3 of stop better than the A7R. I'm more impressed by resolution, which is not included in DXOMark sensor scores. The comparison linked below shows the difference that resolution makes. Same lens, Sigma 35mm f1.4.

Sigma 35mm F1.4 DG HSM A Nikon on Nikon D700 versus Sigma 35mm F1.4 DG HSM A Nikon on Nikon D810 versus Sigma 35mm F1.4 DG HSM A Nikon on Nikon Df - Side by side lens comparison - DxOMark

DXO hasn't tested any lenses on an A7S, but note that a perfect 12mp sensor and perfect lens cannot achieve more than 12mp resolution. The A7R and FA 55mm resolves 29mp. IMO, the real raison d'être of the A7S is 4K video, not stills. The slight bump in SNR is just a bonus feature.

You said that the K3 has the better sensor than a 16mp camera, yet DXO actually rates the K5 sensor higher, 82, than the K3, 80. Primarily i suppose because of the K3's lower dynamic range in several areas: Pentax K-3 versus Pentax K5 - Side by side camera comparison - DxOMark.

A difference of 5 points in Overall Score equals 1/3 of a stop. A difference of 2 points is irrelevant except for internet bragging rights. The reason the Sony 24mp sensor is superior to the 16 is because it holds its own on sensor performance and pulls ahead in resolution, regardless of lens used.

Sharpness comparison between Pentax K-5 IIs and Pentax K-3 - DxOMark

[jimr-pdx]

A difference of 5 points in Overall Score equals 1/3 of a stop. A difference of 2 points is irrelevant except for internet bragging rights.

if only we had iso 80 or 64 on the K-3, we could brag even more
And two points is the difference between nx300 and K-s1 in fact. I do hope they get to the nx1's sensor soon, since it's now in the nx500 for us smaller-cam fans.