What would the FFF have to do in order to be competative?

DMillier wrote:

Scottelly wrote:

abera wrote:

dellaaa wrote:

Reading a recent post that included a 60M pixel Bayer sensor shot, the the discussion turned into a debate as to whether the FFF would ever arrive.

Looking at the Bayer photo what do you believe the FFF sensor would have to do better than the current generation of Bayer sensors? What are the design criteria the FFF design team have?

I don't know but given the physics of the design and the past Foveons, low light performance would most likely not be on par with the Bayer, agreed?

Foveon has three photodiodes per pixel, none with correlated double sampling. This means very high read noise which means high noise floor which mean poor performance in areas with little light. This means poor low light performance and relatively low dynamic range.

If that's the case, then why did early Foveon sensors have so much more dynamic range than the Bayer pattern CFA sensors of their time?

Source? Or are you talking way back when Foveon was competing with aging and noisier CCD designs?

The issue with read noise can not really be solved

Why not?

CDS plus the way the colour has to be calculated introduces more noise.

- there will naturally be more photodiodes, but also CDS is quite impossible to achieve with this kind of design.

What is CDS?

Correlated double sampling.

https://en.wikipedia.org/wiki/Correlated_double_sampling

Some fancy non-destructive multiple sampling might be possible but it would not only slow things down even more, but also not be as effective.

From QE point of view the advantage of Foveon is not having colour filter array blocking light, but on the other hand there is plenty of dead space between the photodiodes. I'd guess one might be able to achieve slightly larger QE with Foveon which would help somewhat in low light situations, but not with the noise floor itself.

Historically, Sigmas have required extensive image processing both while taking the shot and afterwords (SPP). Will the FFF shoot at the frame rates of the current Bayers? Again, given the history, this seems doubtful.

Foveon's problem is the very poor color separation.

Huh? I thought it was supposed to be noise that was Foveon's "problem."

The poor colour separation fix adds yet more noise

In principle this could be helped by placing narrow band color filters on top of the sensor, but then some wavelengths would be totally lost and could cause some interesting artifacts.

To get decent color out of Foveon the processing indeed will be rather strong - this increases noise for color photography.

Where do you get this idea?

So with low light and speed out of the equation, whats left, detail and color rendition.

The main advantage is reduction in false color artifacts (e.g. moiré). This advantage goes away once diffraction (and lens deficiencies) does anti-aliasing, but it's still a long way from today.

Detail situtation has many variables, but regardless of them lots and lots of pixels would be needed in this hypotetical FFF to compete.

Color accuracy is vastly better on conventional sensors. That's why the CFA is there for.

Wrong. The Quattro generation was one of the most color accurate sensors of its time. Technology has moved on, but for the money you probably couldn't get a camera with a more color accurate sensor than a Quattro.

Is this actually true? Evidence...

If the exposure is good, colour accuracy depends on the input profile for raw data conversion rather than the sensor. If the exposure is off, for instance at one end of a range of bracketed shots, then Quattro colour can be crazy bad.

Don