Currently I own the Nikon N80 camera body and am considering about going digital via D70. The AF of the CAM900 on the N80 works reasonably well, even in low light(I even read that it works much better than the one of the Elan7e in low light... ). However this ability to focus reliable in low, or not optimum light, or low contrast is really restricted to the center af sensor which is the only cross type sensor out of five. Yea, you'll be okay if you only use the center af sensor all the time. However, since the N80 and so the CAM900 has been around for considerable time, (ca. 4-5 years) I had hoped that Nikon would finally incorporate something more similar to the CAM1300(3 or 5? cros af sensors) found in the F5 and F100 which is more reliable and needs no AF-assist illuminator - and not the (please forgive me)4-5 year, _OLD_ CAM900. - Hey, they even included the 1,005 pixel Color 3D Matrix metering in the D70, so why not a better AF Module?
I think it's just a matter of economics more than anything else.
Since the AF system in the D100 and D70 are the same, I'm sure Nikon saved a lot of development time and effort by reusing the technology they developed for the D100 (I don't know whether this is in the form of firmware, or an application-specific IC or whatever).
Ditto, I guess for the use of the 1005-pixel RGB matrix meter that was lifted probably whole from the D2h (and D2x, I suspect). Short of putting the D2h's AF module into the D70 (which would have p*ssed off a LOT of people and really messed up their product lineup) they had no reasonable economic choice but to continue using the CAM900, which they have in more than adequate supply (now that it's used in five current camera bodies F65, F75, F80, D100, D70).
Sure the single cross-type sensor is a limitation, but for the price I wouldn't expect all of Nikon's top technologies.
The D70 represents the next step in advancing pro features down to entry-level cameras - the 1005-element RGB meter is of great envy to anyone who owns a D100/S2/14n, not to mention the flash synch. While it was intriguing that Nikon could lower costs to provide such a feature on the D70, it would probably cost a bit more to also have given the camera the CAM1300 module. One of the key selling points of the D70 was to give it just enough features that elevated it from the rest of the field but still put it within close pricing of the Digital Rebel. Remember too that there must be product differentiation within a family - to have given it both the Color Matrix Meter and a CAM1300 would have certainly cannibalized sales of the D1H/X...it would have appealed to users who want pro features but don't care about such things as a field-hardy build or a vertical grip.
Yes, you are right in many points. There are a lot of new, great pro features on the D70. However the CAM 900 is a technology 4-5 YEARS OLD. As I heard, the AF on the digital Rebel is one of the fastest out there due to the incorporation of their NEWEST af technology. My personal opinion is that regarding the metering, the usual, highly reliable 10-segment 3d Matrix metering found in the F100 & F80 would have been more than sufficient for 99% of all D70 users...I would have preferred a faster, more reliable AF instead...
From what I've read in various forums over the last month regarding user experiences with pre-production models of the D70 they found the AF to be superior to that of the digital Rebel both in speed and sensitivity.
I am very happy with Cam 900 and lack of Vertical Grip and the Build AND the "PRICE". If Latest AF module and all the Bells are very important then I would have gone to D2H or D2X. I get what I pay for.
I am happy because I could afford a DSLR now with decent spec. I would have been very sad indeed if Nikon has introduced the latest and the Greatest and priced D70 at 2000 USD.
There's no effective difference between the D70 and the D-Rebel - both cameras feature an AF system that has only *ONE* cross-hair sensor - the rest are still slightly tilted vertical sensors. The fact that the D-Rebel has seven and the D70 has five is irrelevant in practical applications - one still has to use the center sensor for the majority of subjects in order to guarantee the best lock-on. Now if Canon had placed their 45-point AF system in the D-Rebel, things would be different. As it is, either camera's AF system will fit nicely for 90% of the intended user base.
This might be a little off topic but... Considering the usefullness of an 5 point AF sensor with one cross type sensor and four vertical & horizontal sensors around it I sometimes feel a horizontal alignment of 3 cross type sensors without above and below sensors similar to the one in the F90X would be sufficient enough and perhaps more effective. I really feel that the upper and lower sensor are really hardly used compared to the left and right one which I always use for portraits and people photography.
Upper and lower sensors are used heavily in action photography where off-set compositions are often a way of life. Action doesn't occur in a horizontal plane only. More importantly, in situations where dynamic AF is engaged to "capture the moment," consistent behaviour in cross-sensor capability is highly valuable - single-axis sensors tend to lose lock too easily in most situations - regardless of their placement in a focus array.
Don't forget that your horizontal sensors become vertical sensors and vice versa when you use the camera in portrait mode. When the F90x is used in portrait format, you no longer have any horizontal coverage aside from the strip down the middle of the viewfinder.