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on Jan 19, 2020 13:22:11 GMT
Posted: Jan 19, 2020 13:22:11 GMT
I just ran across these things (whatever they are) -- inadvertently -- and as usual, their website tells me absolutely nothing about what they are, what they are used for, let alone, why I should buy any of them. Here are their products for some of Yashica's lenses:
Can anyone tell me, hopefully in a few words, what are these things?  ? |
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on Jan 19, 2020 13:34:13 GMT
Last Edit: Jan 19, 2020 13:36:47 GMT by biggles3
They are exactly what they say - follow focus gears. They are for use with movie cameras - the gears are attached to your stills lens and they mesh with external gears on the movie camera that help the camera operator to follow focus when needed. As follow focusing requires very smooth and subtle movement, the use of direct gearing is always going to be more accurate than manual focusing.
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on Jan 19, 2020 13:39:17 GMT
Last Edit: Jan 19, 2020 13:57:09 GMT by xkaes
Thanks. I don't need to know how they work, but are these of any use/help to a still photographer?
Let me give an example.
I have a very nice Vivitar 21mm f3.5. The focusing ring turns about 3/4th around to get to one foot. Easy focusing despite its wide angle.
I also have a very nice Minolta 28mm f2.0. The focusing ring turns about 1/4th around to get to one foot. Not as easy focusing.
Would something like this solve my problem?
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on Jan 19, 2020 14:18:17 GMT
Posted: Jan 19, 2020 14:18:17 GMT
Generally those follow focus rings are of no practical benefit to a stills photographer - and they're uncomfortable to use. That being said, you might find the extra circumference allows you to fine focus more easily on the Rokkor 28mm lens.
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on Jan 19, 2020 19:14:26 GMT
Posted: Jan 19, 2020 19:14:26 GMT
Aside from the uses already mentioned, they do offer at least one other function. They can provide a way to set a physical focus stop... a settable position that you rack the focus to, so as not to miss the optimal focus point. You don't over-rotate the focus ring beyond, or need to pay attention to where the point is. You can't rotate beyond the temporarily set stop block, and go out of focus and need to reverse it back into focus.
Not essential for still work, but obviously saves from doing video/filming retakes, since the camera can 'hit its mark' in one attempt. That might still be of limited use for still work - if - you need a repeatable focus position that's always going to be accurate.
I remember reading something about adding an external gearbox to change the ratio of the focus throw too, but I doubt that would be useful for still work with the extra 'stuff' attached to the lens barrel.
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on Jan 20, 2020 14:36:50 GMT
Posted: Jan 20, 2020 14:36:50 GMT
This reminds me of an old Kiron 80-200mm(?) zoom that allowed you to set a close and a far focusing stop to make action shots faster -- as in a tennis match.
Another possible use for this "follow focus gear" thingy would be to quickly set the hyper-focal distance mark on a lens without looking.
Still, for me, it's not worth the price of admission.
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on Jan 26, 2020 4:05:48 GMT
Posted: Jan 26, 2020 4:05:48 GMT
Some focus gears also have the option of a handle with a knob end which would come in handy when shooting in extreme cold with gloves on.
PF
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