Hi There Sven
Sorry Jono, for every post that agrees with you, there are others who do not.
Indeed - how could it be otherwise when discussion a subjective judgement on a theoretical comparison
.
But actually, my position is that I don't know the answer to the question - and more to the point, nobody else does either (see below)!
I'm challenging what is an almost universally held belief on the internet (i.e. that CCD is inherently different from CMOS), because some technical people who I consider to be very knowledgeable and who are involved in sensor design, say that it is not the case. My argument here is not based on any personal technical knowledge, but on an understanding of logic and scientific methodology - which tells me that saying .Period. don't make it so!
CCD look cannot be replicated by CMOS no matter what the hardware and software chain is. Period.
see above Saying. Period. doesn't make it so - it just means you believe it to be so.
Moreover saying Leica of all manufacturers did a better job (compared to giants like sony, canon or nikon) is stretching things a bit. The difference between M and other CMOS cameras like the D800/e is due to Leica lenses than anything else. Once again CCD look cannot be repliçated by CMOS with current technology.
I will give you reasons. CCD can convert light to voltage, one CCD pixel produces one signal nothing else. Whereas in CMOS, at each pixel there is light conversion, amplification and noise reduction at sensor level. This leads to extremely high signal uniformity in CCD which cannot be matched by CMOS. But since there is massive parallel processing in CMOS high speeds are easy. This is the fundamental design so dont argue that one can change it. No amount of post processing chain can change this.
Another fundamental difference is near infrared sensitivity. CCD sensors can made with thick subrate (75-200 microns) increasing their sensitivity and spatial resolution as well as high/extended near infrared sensitivity. CMoS can have only 25-50 micron substrate thickness, so they never match the CCD's near infrared sensitivity and fine spatial resolution in this region.
Okay - we agree that CCD works differently from CMOS and produces a different output.
The point of discussion is not this, but whether it is the processing of this data which produces the distinction between the current crop of CCD sensors from the current crop of CMOS sensors (which we can also agree have a different look) - or whether there is an inherent and visible difference.
The person I was talking to at Leica is quite certain that it's the way that the data from the sensor is treated in the production of the RAW file which characterises the image, and NOT the distinction between sensor technologies.
Of course, until someone changes their approach to using the data from a CMOS sensor consciously with the same values which are applied to data from a CCD sensor then it's really not possible to come to any categorical decision about this - because there are no two such sensors to compare the output from.
On a slight side track, it's interesting to look at the output from the D3X and the Sony A900. It's radically different, with the Sony showing characteristics which make it (at low ISO) look rather more like the current crop of CCD sensors. With a poor high ISO response - the D3x is rather the opposite. This is only interesting because they are the same sensor.
Let's put it this way:
a) some people say that there isn't necessarily a definitive and observable difference between a CMOS and CCD sensor (whatever the current crop of sensors might imply). (FWIW I've been told this by technical people at Leica amongst others)
b) some people say there is a definitive difference between the look of a CMOS and a CCD sensor - whatever the processing between sensor and RAW file (I've been told this by you and Guy (and most of the rest of the internet).
Describing the way the sensors work really doesn't have any bearing on these positions. It all hinges around the intent of the processing of the information and whether this is more important than the data from the sensor.
What is clear is that Canon and Nikon process the data to produce the best possible high ISO response - because that's the visible and definable IQ factor which sells cameras. (and this is what the internet defines as the CMOS look)
What is also clear is that Phase and Hasselblad process the information to provide the best colour response - because that's what their clients want, and because it's an identifiable advantage over what Canon and Nikon do. (and this is what the internet defines as the CCD look)
What is also clear is that Leica have tried to process the information from the M240 to produce a sensible compromise - whether they have achieved this or not will become more obvious when the final firmware is released - but it's worth bearing in mind that both Sean Reid and Ming Thein have been surprised at how the files from the new M look like something in between the M9 and D800 files.
all the best