slow autofocusing slow autofocusing with the Fuji 50mm f2 near the MFD

[stevem44]

Hi,

I am considering buying the Fuji 50mm f2, which generally has had excellent reviews: very sharp, good microcontrast, close focusing ability, fast autofocus, light weight, relatively inexpensive, etc.

However, some users have reported that the autofocus was very slow close to the minimum focusing distance. Have others also experienced this problem? I have read about a similar problem (focus hunting) on the Fuji x-forum, which was attributed to Fuji's 3.0 firmware update, in which the problem was resolved when camera was returned and the 2.1 firmware was installed. Regarding the focus hunting problem, it was mentioned that Fuji knows about this problem, which will be resolved in a future firmware update. Should I wait until this problem is resolved or do most people think that this is a permanent problem.

Thanks

[Doug Pardee]

I have no definitive information to impart. But my impression has been that the complaints of hunting with the new firmware are specific to using AF-C with apertures of f/9, f/10, and f/11. With the older firmware, phase-detect AF is still used at those apertures with AF-C. With the new firmware, contrast-detect (hunting) AF is used at those apertures in AF-C. This is (again, my impression) unrelated to focusing distance -- just to selected aperture. As to whether this will be fixed in a firmware update, that probably depends a lot on whether the newer f/11 PDAF limit was abandoned in favor of the older f/8 limit for a reason, or if that was just a mistake.

Be aware that even phase-detect has its limitations. When you're shooting at MFD at f/8 or wider, your depth of field is typically going to be thin. When the camera tries to AF, it's possible that the target is initially so out-of-focus that the camera can't make it out. In that case, Fuji does a three-step PDAF: it focuses to distance (near infinity), then close-up (near MFD), then to the focus distance it's determined. WIth some lenses, this can look like hunting (with LM lenses it usually just looks like a shimmer when focus locks on). And there's the standard caveat for all OSPDAF systems to date: if the camera can't get a good image to PDAF from, it always reserves the right to switch to contrast-detect (hunting) AF.

Edited November 30, 2019 by Doug Pardee

[stevem44]

Doug,

Thank you for your detailed response.

Regards,

Steve