Originally posted by nosnoop No, I fully understand all the flash systems, and my logic is sound. All the advanced flash features such a high speed sync and multiple wireless flash require a TTL metering system - and pre-flash (P-TTL) metering is the most efficient way to doing this. Without this efficient way of having TTL metering with the advanced flash feature, you won't see them implemented in all the bodies including entry ones.
Exactly - just think a minute and why have they adopted this approach? Why did Oly abandon their OTF TTL metering? Why has all the manufacturers decide on the same type of system? As I said, that's because it is the most efficient way of implementing flash TTL metering for all the advanced flash feature. There may be alternatives, but if they require complex circuitry or high cost to work with traditional TTL (e.g. radio trigger as other suggested), you simply won't see them implemented other than the top end body.
Aperture ring is not exactly the same. Though the main similarity to my logic is the redundancy as aperture can be controlled electronically; just like traditional TTL is a redundant system in a camera with P-TTL. Other than the extra expense of the mechanical aperture ring, it is also one of the main support issue when people forgot after they moved it off the "A" position.
I still can't see your logic nor it is considered to be "sound". There is always counter examples in the Pentax land, that is, the *ist D and *ist DS, which support traditional TTL auto flash without significant problems and issues, unlike the P-TTL which is renowned for underexposure and inconsistent results.
Still, you've forgot that the *ist D and DS Do support all advanced flash features (except that DS won't wireless flashed) you have insisted that old type TTL cannot co-exist with. But this is simply not the case. And, the *ist DS had never been an expensive camera you supposed to, neither.
Just think how much "expensive" that TTL mechanism would be. My bottom line of the film MZ-30 SLR has that. My MZ-30 costed me only $170 did have that and it works flawlessly, again.
The same case is for the aperture ring. It simply won't cost much as a $130 K-1000 could have it and still I can even use a digital Pentax lens on the K-1000 without any problem.
All in all, just don't try to speak too much for the manufacturers for what they have done to destroy compatibilities, i.e., simply defending for them from time to time. That's we, users and customers (actually you me are both brand supporters anyway), paid them and will pay them. But many of the times, owing the conflicts of interests, they would try to suck quality as well as compatibilities from we old users, and these acts are NOT PURELY because of technical reasons as you suppose, but MERELY because of financial and marketing reasons which are the true ones.
Afterall, we need to voice out our wills to keep our brand to drop as less compatibility features as they would do.
Also, for all we read here, we should know Pentax is not Canon and Nikon, they should keep the compatiblity better so as to maintain an edge over the big 2, but not follow they wrong ways to cheat money from their old customers.