The free-play is there when the drive from the focus wheel isn't being transmitted to the focusing lens and you notice it because of two things. With your eyes you notice that the focus point doesn't move if you rock the focus wheel backwards and forwards within the free-play section. With your fingers you notice when the drive resumes at either end of the free-play section because there is a sudden increase in the 'stiffness' of the focus wheel as it now begins to transmit the drive down to the focusing lens.
Stiffen up the action of the focus wheel and this disguises the presence of the sudden increase in stiffness and thus can cover up the presence of a small amount of free-play. If the focus wheel is very free-rotating even small amounts of free-play are noticeable.
Lee
Lee,
As I said to JABW, it's more than just a perceptual component, or generalisation. In this particular mechanical design, there is a correlation which has an inverse relationship.
You described the operational observation somewhat accurately, except you left out the Mark I eyeball! When you are holding the bins in your hand and rocking the focus wheel back and forth and looking at the focus wheel turning (sometimes a mm or two) and not feeling any engagement movement (or watching the focus lens group not moving if looking down the objectives) is quite annoying!
There are things that can be done:
* Swap the bin
* Get a bin with more suitable 'stiffness/play' characteristics for your climatic zone
* Adjust the unit's mechanics as I described
* Forget about it (this may take some time!)
Serious about that last point. The kissin' cousin Zen-Ray ED3 has slightly worse play overall. My particular unit has a silky smooth light action (very reminiscent of Zeiss/Nikon), but has a lot of play (more than I would like and definitely not Zeiss/Nikon like). As we have people here seeking to emigrate to hades in search of somewhere cooler, then perhaps I could have done with a unit with more tension/less play.
This backlash used to annoy the living bejayzus outta me ! Grrrrr ! After living with it for ~8 years now, I hardly give it a second thought. The bin's better points such as:
* hands down best ergonomics in the business
* lighter than a Zeiss SF
* bright, neutral view
* outstanding CA control
* very wide fov
* nice quasi 3D effect
* rugged enough to just chuck em in the car
* cheap as chips so outstanding value.
So focus play that used to be a deal breaker is now a non-issue ......
Chosun :gh: