[RobA_Oz]

I'm sorry I misunderstood you. I didn't mean to be annoying, I was just confused.

I see that, and I see that I should have been more precise in my original post.

[Rondec]

I'm beginning to think that shake reduction is perhaps less valuable than better low light performance. I know this sounds contrarian, but think about it for a second. The best SR system advertise 5 stops benefit. Well for starters, 5 stops from what kind of shaking? Obviously is based on some lab designated shake standard. How does that standard compare to realistic in the field conditions? And do I really get 5 stops SR or actually only 3 or at best 4 based on my reality. Maybe it's because I may shake more than what I used to.

On the other hand, if the camera development is done with better low light performance ie. cleaner pictures at higher iso, well then I can crank up my shutter speed say 3 or 4 f-stops and then I know I have a realistic reduction in shake effect on the picture. Not some promised lab based standard 5 stop SR.

So if I have two options, get the 5 stop SR, or get 3 or 4 stops better iso performance, I'll take the iso option.

Just my 2 cents...

I don't think it has to be either/or does it? That is to say, if you took the SR system out the K-1 it would have the same low light capability. I find it most useful to take long-ish exposures of pretty still landscape scenes, but obviously nothing like what you can do from a tripod.

[TDvN57]

I don't think it has to be either/or does it? That is to say, if you took the SR system out the K-1 it would have the same low light capability. I find it most useful to take long-ish exposures of pretty still landscape scenes, but obviously nothing like what you can do from a tripod.

There is the big question of the lens mount diameter and image circle size. I'm sure for the cropped 645 it should not be a problem, but for full frame 645 it still needs to be confirmed that the mount diameter and image circle is large enough for a moving sensor.

[Rondec]

There is the big question of the lens mount diameter and image circle size. I'm sure for the cropped 645 it should not be a problem, but for full frame 645 it still needs to be confirmed that the mount diameter and image circle is large enough for a moving sensor.

My guess is that if Pentax updates the 645 digital system, they will decide between going with a full frame sensor or adding SR. It becomes increasingly difficult to stabilize as the sensor gets bigger. But a "full frame" 645 sensor would be a lot more expensive than current crop models.

[RobA_Oz]

There is the big question of the lens mount diameter and image circle size. I'm sure for the cropped 645 it should not be a problem, but for full frame 645 it still needs to be confirmed that the mount diameter and image circle is large enough for a moving sensor.

And, of course, the compatibility of the existing lenses with a full frame sensor and SR needs to be confirmed.

We had long and impassioned debates here, before the K-1 was released, with some arguing strongly that the K-mount throat wouldn’t allow an effective SR system to be employed. Let’s hope that the same outcome pertains with a full frame 645 sensor.

[RobA_Oz]

My guess is that if Pentax updates the 645 digital system, they will decide between going with a full frame sensor or adding SR. It becomes increasingly difficult to stabilize as the sensor gets bigger. But a "full frame" 645 sensor would be a lot more expensive than current crop models.

I’d suggest that adding SR to the current crop sensor would be the first thing they’d do, given that it looks like it would be the easiest and least expensive upgrade to the system. Adding SR to a full frame 645 sensor, by itself, would be more challenging from an engineering viewpoint due to the higher mass of the sensor sub-assembly.

If the mass of even the crop 645 sensor proves too difficult to add SR for low light stabilisation, the same system could usefully be limited to pixel or sub-pixel shift for DR and resolution increases, and for in-body perspective adjustment, all of which would be advantages for tripod-based architectural, studio or field work, for which the 645 system is well-suited.

[Rondec]

I’d suggest that adding SR to the current crop sensor would be the first thing they’d do, given that it looks like it would be the easiest and least expensive upgrade to the system. Adding SR to a full frame 645 sensor, by itself, would be more challenging from an engineering viewpoint due to the higher mass of the sensor sub-assembly.

If the mass of even the crop 645 sensor proves too difficult to add SR for low light stabilisation, the same system could usefully be limited to pixel or sub-pixel shift for DR and resolution increases, and for in-body perspective adjustment, all of which would be advantages for tripod-based architectural, studio or field work, for which the 645 system is well-suited.

Maybe so. Fuji has already added SR to their top end medium format camera. I'm saying they would choose between going to a full frame sensor (without SR) or adding SR to their current crop medium format sensor. If they went with a full frame sensor, it would be mainly because Fuji can't follow that path easily because their lens mount and lenses aren't full frame compatible.

[hjoseph7]

I was watching videos about this camera today : Hasselblad 907X 50C Medium Format Mirrorless H-CP.HB.00000612.01

[TDvN57]

Had anther look at the Sony sensor info and it seems as if they standardize on 3,76 pixel size for the MF and the 26mpx APS formats. What I did find surprising is that the pixel count goes from 24 to 26 for APS sensors then jumps to 100mpx for MF. For 35mm they show only one sensor at 24mpx. Does that imply Pentax will have to source future upgrades of the K1 from another supplier?

The MF sensors do look interesting and even on 151mpx it can produce 6.3fps, subject to downstream electronics of course. I'm not sure if I read it correct that the bit depth will drop to 12bit in burst mode. Even if it does, it is still worth it for some situations.

Products?Image Sensor?Consumer Camera?products?Sony Semiconductor Solutions Group

If you scroll down the pdf spec sheets can be downloaded as well.

Would be good if Pentax use some of the empty space in the 645z body for some upgraded electronics to handle the data faster.

[Serkevan]

Had anther look at the Sony sensor info and it seems as if they standardize on 3,76 pixel size for the MF and the 26mpx APS formats. What I did find surprising is that the pixel count goes from 24 to 26 for APS sensors then jumps to 100mpx for MF. For 35mm they show only one sensor at 24mpx. Does that imply Pentax will have to source future upgrades of the K1 from another supplier?

They probably aren't selling the 61MP sensor (on the A7R4) off the shelf yet. IIRC Nikon hasn't had problems sourcing the Z7's sensor so I guess Pentax will also be set.


That, or they use the Sharp 8K's sensor (33MP M4/3) upscaled to FF, which leaves us with *whips out calculator* 130 MP . Throw in pixel binning à la smartphone for improved detail and colour, and we end up with a 32MP quad-bayer array.

[TDvN57]

Apologies for being somewhat off topic.... I stumbled upon a video yesterday which explains in simple layman's style how gain and noise works from the sensor side and how a higher gain (iso) setting affects the end result. Helped me to better understand some comments from some tech guys on the forum who have spent their lives designing and building some of the stuff we take for granted.

Here is the link: CMOS Gain Settings Explained - Atik Cameras

[kaseki]

Apologies for being somewhat off topic.... I stumbled upon a video yesterday which explains in simple layman's style how gain and noise works from the sensor side and how a higher gain (iso) setting affects the end result. Helped me to better understand some comments from some tech guys on the forum who have spent their lives designing and building some of the stuff we take for granted.

Here is the link: CMOS Gain Settings Explained - Atik Cameras

What the video seemed to miss, which is essential to understanding the actual signal to noise in the pixel, is that the Gaussian noise in a collection of randomly generated electrons (from photons) is the electron count from the square root of the number of photons (2000ph => 45ph, rms => 22e, rms). So the signal to noise without counting the readout noise is also square root of the number of photons (2000ph/45ph = 45). For the 1000 generated electrons, 22e rms is 7 times the readout noise at low gain, and almost 22X the readout noise at high gain (if I recall the video reported details correctly).

Total noise is root-sum-square (rss) of the two noise sources; and hence, for photoelectron counts higher than, say, 100e, the noise in the signal dominates the noise in the readout, as one wants. So the readout is great, but nature is not so great. At 100e, the total noise is rss{7e, 3e} = 7.6e, rms, and the SNR (voltage) is 13. This would be a tad grainy, but once past the 2500 photon count region, the details should be pretty good, even pixel peeping, assuming the eye can detect contrast down to 2%. (That is, the apparent contrast between two pixels with nominally 2500 average photon counts each should look identical. This may not be true of actual video with the same parameters because the eye can sense small changes and the noise will have random values such that the contrast will intermittently be greater than 2%.)

Note: the quantum mechanical process of photons generating electrons (50% on the average) is itself probabilistic, and the above is likely optimistic.