Manual focus

photosonic — Fri, 04 Apr 2014 15:34:56 GMT

I experience big difference in focusing ratio with different lenses.

Short with the FE 24-70mm ZA OSS and long with the 35mm f/2.0 on the RX1 and the FE 35mm f/2.8

purchased along with the a7.

Does anybody know if it is possible to fix with via a firmware update , since the lenses works in a "fly by wire"

way and not mechanicallly.

Is there anybody but me that experience focusing towards infinity by turning the focusing ring counter clockwise

as unlogical. And the same goes for the lack of stop in both ends of the focusing range.

It's a joy to manual focus with the 24-70 and not so with the two 35's.

Therefore i hope that future lenses is least as good as the 24-70 in manual focusing mode .

This is all about manual focusing.

Re: Manual focus

Bieomax — Wed, 16 Apr 2014 09:20:57 GMT

i suspect that some of it is down to lens design, and some what down to how the lens is to be used.

if doing macro work i'd prefer the longer throw which will give the greater degree of accuracy to get focus spot on.

I dont know how much is actually done by wire on these lenses in regards to focussing (i'll have to have a look in the service manuals) but if they are still like the SSM/SAM for the Amount camera's then it still comes down to a motor with a cog on moving a tube with a toothed gear running along the outer edge, then it still comes down to how much movement is needed in the tubes guide slots to move the elements around.

now if sony started to mount the elements on piezo electric rods similar to the Amounts Image Stabilisation then they could maybe have a custom setting for how sensative/ how much throw the focussing action is since the elements will be moved forward and back on electric current.

topic Manual focus in Alpha & NEX interchangeable lens cameras

Manual focus

Re: Manual focus