Quote Originally Posted by ameerat42 View Post
I wonder Y??? - The AF-P programming shouldn't clash with the AF-S type.
....

^^Presumably the Σiggy is AF-S-equivalent.
The wonders of proprietary gobbeldygookiness .. I guess!
That was the first thing I thought too .. why would additional instructions on focusing with AF-P break the already coded instructions on how to focus with AF-S.

Siggy is HSM = AF-S equivalent.

I do know that there are size limits on how firmware code has to be written .. as an example; if the fw size allocation is say 4Mb, and the current firmware is already at 4Mb, then some code has to be re written to account for both types of instructions.
This is different to simply adding new code to operate the new feature.
Not sure on the specifics of the D800's, but I remember it was an issue on the D300.

Oh! I forgot to say too. I had a quick peek online to see if others had similar issues, and I found some info on some cameras and lens combos(but not the D800 and my model 12-24.
I read that a power cycle may re sort it out .. but not in my case.
Will try to see if Sigma has any more info on the situation .. old 12-24 isn't Sigma dock compatible either, so would have to go back to Sigma to update it.
But long term isn't going to be an issue(for me), I do have plans to get me the Siggy 12-24/4 as an update to my older model. f/4 version is dock compatible.

strange side story: I'd been stuffing around with a filter holder for my model 12-24 some time back and got a system working, but not happy with the limited filter range I could get for it.
So I decided to bit some bullets, and get a properly made filter holder for my 12-24.
Hit the buy button, and then it came and wouldn't fit. No way to get the holder to sit on my 12-24. Was going to raise a racket with the company I bought from, only to realise closely at what I DID buy and I bought the holder for the f/4 model!(idiot! )

So, I have to buy the 12-24/4 model now .. I have a filter holder and filters for it that have sat unused for a couple of years or so now!