Close Examination of Fuji X-Series Lag Time

rlx wrote:

Hi Cass. I very much appreciate your contribution doing all those measurements and I am glad you discovered the effect of a focus adjustment on the lag. I have been more concerned with the lag I experience with manual lenses since I have used manual lenses very much since I got the XE1; something like a relearning of the basics with the marvelous EVF. But the 18-55 is a very good lens and now that I understand more the issues, and with your work, and with the new AV+MF mode I think the issue is going to find some resolution; i am optimistic.

I will try to reproduce the result with the 18-55.

I won't express any feelings with respect to the lag except for this one. I have suggested a couple of times in the past year that the lag has to do with the way the software was initially designed but I didn't elaborate much. I think that 'cug' explains it very well in this thread http://www.fujix-forum.com/index.php/topic/31478-delay-due-to-aperture-blades-stopping-down-performance-question/page-10#entry335389 and I suggest to anyone concerned by the lag issue to read cug's post .

Easycass wrote:

Hi there Rlx,

Wow, I did try the 18-55mm and couldn't induce it to show the longer lag time. Good that you have managed to show it. I am not sure what is going on with the lenses, but it is like the extra manual focus adjustment prior to shooting does something to the motors/servo in the lens, and either the firmware gets confused by the action, or there is some design feature whereby perhaps something electro-mechanical, perhaps like shared use of motors for both aperture movement and focus, causes a conflict whereby the lens needs to do something extra prior to shooting. It is weird...

Cass.

It will be interesting to see if Fujifilm responds to this.  Such a wide variation of shutter lag (which I have also seen when using the back-button focusing method) is really problematic for lenses that are intended to capture action or candid shots - lenses like the two new f/2.8 zooms, and the 56.

It would be interesting to do further analysis to determine if the lag variation happens while in AF mode.  Since I see it in the back-button focusing method I suspect it will also be present in AF usage.

I think this is also one of the reasons I so enjoy shooting with my Mitakon MF lens - there is a reassuring consistency with it's use, in terms of the shutter actuation, which I could never put my finger on.  But this analysis explains it.