[MKD]

There is a problem using stabilized lenses such as the 90mm 2.8 macro together with rear button for AF.

Namely, rear button AF doesn't activate the stabilization in the lens.

Using the shutter button for AF works fine, hitting it half way starts the lens stabilization.

This is a major oversight on Ricoh's end which needs to be addressed via a fw update.

[Kolor-Pikker]

Is it supposed to? My Canon camera worked exactly the same way (rear AF + IS on shutter half-press), so I'm not sure what your point of reference is.

[Royce Howland]

MKD, what firmware version is on your 645Z? I don't have a stabilized 645 lens to test with, but I do know some bugs were fixed along the way including a glitch with the back AF button and continuous AF mode.

[672]

the late firmware has a choice of IS activations in the custom settings menu. and what is the use of AF button + IS if you are not gonna hit the shutter button. why does the AF button have to start the IS?

[MKD]

The stabilization takes time to engage and for the actual elements to stabilize. This happens very fast, usually is done by the time the camera locks the AF so when using the shutter button for both AF and shutter release by the time you do a full press (to release) the picture has been stabilized.

When using the back button to engage AF (with the shutter button decoupled so it doesn't engage AF at half press, just for release), when you lock on a subject and press the shutter, the stabilization never engages. If the shutter button hasn't been decoupled, when using the back button to engage AF - you get a focus lock - but if you half press the shutter then the focus has been reset and the framing you've achieved by recomposing is ruined since half pressing the shutter will now refocus on the subject.

The back button AF should engage the stabilization in the lens.

Also, I use the latest 1.21 I believe fw.

the late firmware has a choice of IS activations in the custom settings menu. and what is the use of AF button + IS if you are not gonna hit the shutter button. why does the AF button have to start the IS?

[672]

MKD you did get me going on this topic. Here's what I found with my gear. 645Z firmware v1.20. 90mm (spring 2013). 28-45 (fall 2014).

The camera menu describes two SR options, ONE, is SR fires only at shutter release and TWO is SR fires whenever shutter is pressed halfway down. Option two on my camera with either lens will always fire the SR for about TEN seconds
using either the shutter button or the AF back button. Option one with the 90mm behaves exactly as option two,(SR activates whenever the shutter is pressed halfway or the AF back button is pressed), i suspect this is due to the lens being manufactured before the RICOH folks added the camera firmware for option one. I dont think the 90mm reads the firmware command to not activate when the shutter is pressed halfway.

Now on the subject of the 28-45 with option one, i found mine to be non repeatable. The SR generally fires for ten seconds when the shutter is pressed halfway. Occasionally the SR would not fire until the shutter was released, but this was uncommon. The AF back button always fires the SR using option one on the 28-45.

My camera is set to AF2 under button customization.

The results for me are to always leave SR options on two so as to get predictable results. And maybe see if I am behind a little bit on firmware.

In answer to your original question (statement actually)- my camera and lenses always fire SR using back button AF on either lens.