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

Scottelly wrote:

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 probabky coukdn't get a camera with a more color accurate sensor than a Quattro.

Is this actually true? Evidence...

Here . . . I cherry picked this reference for you:

"The automatic white balance system caused a slight shift of neutral tones into the bluish/greenish/turquoise area of the color space, but the average color error level is very low."

https://www.shutterbug.com/content/sigma-sd-quattro-h-mirrorless-camera-review

This has little to do with the image sensor performance. It does show that in this particular situation the system (i.e. sensor + this particaular lens + this particular image processing) can give this specific performance. Change the lighting situation a bit (the spectrum and/or light levels, or even the lens) and things change to some direction. It's hard to imagine a single conventional Bayer CFA sensor camera which could not only match, but also surpass this performance. This does not meant the cameras at their default settings (or even other in-camera JPG settings) would necessarily have accurate colors - most brands tend to go for some kind of pleasant colors, not accurate ones, with their JPG engines.

Fact of the matter is that Foveon has very weak color separation and this does cause problems for accurate color reproduction and noise levels. It is also fact that neither is necessarily a problem in a specific situation, quite the contrary, most of the time things work just fine. Sigma's engineers have done a splendid job getting the results from the data the image sensor provides.

Foveon type multi layer system might work better in the future with different materials, maybe organic materials or perovskites. Plenty of perovskite developement is being done due to their potential for solar cells and at least one multilayer demonstration does exists (with hideous image quality). Maybe 15 years from now?

As for detail, how would the specs of the proposed FFF stack up against the 60M plus Bayer sensors? Would the advantage in detail make up for the shortcoming?

No. You need likely something like 70% of the pixel count to match conventional sensors, maybe more nowdays as AI-based demosaicing is on its way. This also diminishes the false color advantage.

Anyhow, as even 10MP is enough for very large prints...

The remaining design criteria, is color. Would Sigma's color rendition be enough for people to buy it?

Some like it's different colors and I'm sure many fans would buy because of them, but as the colors can be very problematic and lack in accuracy and because the conventional cameras are not exactly lacking in color accuracy, it's hard to see how the general public would get interested in this.

I don't know and would like rational, opinions as just what will the FFF bring to the table, and why any non L mount people in 2023 would buy it when 100M pixel Bayers are on the horizon that take great low light picture at high frame rates.

At this point, fanboys aside, the fact that we are still discussing this seems a bit absurd to me, so why did I start this thread lol?.

Foveon is very interesting concept and I'm happy it was brought to life. But it feels more like a hobby project, a niche project for those who desire something different. There aren't really any advantages over conventional sensors

Huh? You already gave one in your own reply here above . . . "The main advantage is reduction in false color artifacts (e.g. moiré)."

Also the absence of demosaic errors which can add artefacts. You may remember I was always keen on marketing Foveon as a low artefact sensor with an AA filter to reduce luminance aliasing. No one here at the time was keen on this idea (to say the least), apparently preferring false detail/acutance to accuracy

while the drawbacks may cause issues.

I hope a FF Foveon does see the light of day, but not only I'm not holding my breath, I'd expect the product to be a very low volume very high price item.

Of course the first FFF will be low volume and high priced, but for all we know Sigma will make a future generation in ten times the volume, allowibg them to price it very low, so it sells quite well. I'm not suggesting Sigma will fix all the problems with their in-house sensors, but thise sensors have improved in the past, and I have no doubt they will improve in the future too.

I think there will always be a market for good quality, unique products, which offer something different. Leica keeps making monochrome cameras. That is a niche product, but obviously a successful one, or they wouldn't keep doing it. I believe Sigma will continue to improve on the Foveon sensor, making more "niche" products with them in the future, and differentiating themselves from the competition by doing so.

I guess Sigma could try selling cameras at Leica prices but it didn't work with the SD1.

They don't need to sell at Leica prices, as the Quattros proved.

How much did Sigma make profit from them? I don't know. I'd imagine that very little if any. It would not surprise if the cameras were a loss making proposisition. IMHO the cameras for Sigma are just a hobby, a lovechild. Nothing wrong with that - actually likely a better thing for Foveon as no pressure to make profit. I could of course be wrong but without financical facts it's quite hard to say. But since they can't sell in the volumes of the bigger boys, nor have Leica pricing, it's hard to cover the R&D, marketing, manufacturing, service and support and other costs and make profit on top of that.