I have no doubt that Canon closely monitors the market, sales, debate forums like this, and quite possibly the internal development within Nikon.
Did they throw away all existing plans at the release of the D800 to make a worthy competitor? My guess is no, the development time for a given camera is probably measured in several years, and the development of new sensor technology may be on the order of 5 years (wild guesswork). It is possible that Canon have the resources to develop a large number of radically different camera/sensors in parallell, and pick only those needed at introduction date, but I doubt that it makes business sense.
What tends to happen, as I understand, is that a budget is allocated for certain research projects and various prototypes are produced on a regular basis. Any particular project can be brought forward, and research & development budgets re-allocated, if market circumstances or management priorities change.
I recall reading a news item a number of years ago, 4 or 5 years ago I think, that Canon had succeeded in producing a 30mp sensor. I can't remember what size of sensor that was.
I think that if improved DR at base ISO was simple, everyone would offer it. The fact that Sony sensors are doing better than most others in this department, and have so for some time, suggests to me that Sony are doing something clever that the others cannot (either due to patents, expensive existing production lines, priority of video or something else.)
Maybe, but not necessarily. I've often wondered why P&S cameras do not have fast frame rates like some DSLRs, such as 6 frames per second or faster. What's the problem? I doubt that the reason is it's too difficult technologically. It's more likely an issue of cost, weight, size, and perceived market demand. The processors would have to be bigger, heavier and/or more expensive in such a camera.
More likely, the people in the marketing department have made a decision that the sales advantages of a P&S camera that has a fast frame rate are outweighed by the disadvantages of higher cost, weight and bulk.
Likewise with Canon DSLRs. It seems that all recent Canon DSLR models employ componentry which
can't handle high analog signal levels. This seems to me to be largely a matter of size, weight, and cost. The same process that results in low noise at high ISO, could result in low noise at low ISO, with componentry that can handle higher signal levels.
The main principle in reducing noise, as you probably already know, is to boost the analog signal from the sensor prior to A/D conversion and all other signal processing,
not so that over all noise is reduced in absolute terms, (in fact it must be increased to some degree at the time of analog amplification), but so that the noise is
less as a proportion of the signal. That is, SNR is improved.
It seems to me, broadly speaking, that Nikon, in conjunction with Sony, are boosting the analog signal, straight off the sensor, by the same degree whatever the ISO setting, whereas Canon boosts only the signals above base ISO. By boosting only high-ISO signals, they can keep their D/A converters and other transistors, smaller and cheaper.
In other words, if Canon were to boost the low-ISO signals by the same degree they boost the high-ISO signals, they would need more robust and more expensive D/A converters.
This might be turning into a long post, but I'd like to mention my experiences with the Canon 50D, because I think they are relevant to the current discussion. This camera has a base ISO of 100. I bought it, and was using it on a European and Russian holiday/river-cruise, before the DXOMark results were published.
When I looked at the DXO graphs for the 50D much later, I was shocked. This camera, according to DXO, has a base ISO of 200. ISO 100 is noted on the ISO-sensitivity graphs as having the same sensitivity as ISO 200. On all other graphs, performance at ISO 100 doesn't get a mention, implying that ISO 200 is the true base ISO of this camera.
However, there's no mention in the Canon manual, or on the camera's menu, that ISO 100 is an expanded ISO. What the f***s going on! Can any smart, technologically gifted person reading this post, tell me?
The reason I'm so pissed off, is that I'd taken hundreds of photos in poorly lit conditions where the use of flash and/or tripod were not allowed, such as various museums and that amazing place, the Hermitage in St Petersberg. I'd used ISO 100 to get the cleanest images possible when I could have got equally clean images at ISO 200 at double the shutter speed, or at least use a sharper aperture such as F4 as opposed to F2.8.
Of course, when confronted with such information, I'm the sort of person who will carry out real-world tests to confirm or disprove the DXO results.
My tests confirmed the DXO results, at least in respect of DR. There appeared to be no advantage whatsoever in using ISO 100 instead of ISO 200 with the 50D. But clearly there is the advantage of the faster shutter speed that ISO 200 affords.
But what about shot noise, I asked myself. Surely double the exposure should result in lower shot noise. So I began scrutinising my test images at greater magnification, magnifying the smooth midtone areas by 400% and even 600%.
At such great magnification on screen, I could discern some slight difference in midtone texture, but it would be totally irrelevant on any print that were not absolutely huge. If anyone who owns a 50D wonders what shot noise looks like, and just how insignificant it can be, then try my experiment comparing ISO 100 with ISO 200.
On the 50D, ISO 100 is not an expanded ISO which results in cleaner shadows but more easily blown highlights. It's an ISO with a slightly better-processed analog boost.
