FF: Change gear drive size for easier focusing?

[hempo22]

Hi all

I'm looking for a way to focus easier in the 7 feet to infinity area. That area is tiny on DSLR lenses! So I'm looking to replace the gear drive between the lens gear and the gear box. CoolLCD got a few:



But since English isn't my first language I'm a bit confused when reading the description: "The Larger Gear Drive (44.8mm diameter) is necessory if you want to adjust your lens faster than ratio 1:1"

I want to be able to turn the knob more in order to not be have the precision of a fraction of an inch. Does this mean I need a smaller gear drive or larger?

 

[yoclay]

A smaller gear means that you will have to rotate the follow focus more to go the same distance as a larger gear. Thus it will offer more rotational space for fine tune adjustments in the 7ft to Infinity area. However, it also means that you may have to rotate excessively in the less than 7ft area. Choose wisely.

 

[hempo22]

Thanks, yoclay! Of course I will be testing. I just got my hands on an LA7200 anamorphic adapter dirt cheap ($500!), so testing have to be done with that too since it changes framing a lot. One more question:

I've also begun building a vintage Nikon prime set, and I need new focus gears for them and I'm tied between Cinematics' Redrock Micro-styled ones or zip ties. My D-Focus will reach both, but will the increased diameter with the Cinematics affect the focus throw for me as well?

 

[Samuel H]

yes: increased diameter on your lens gears means you have to turn the FF more to get the same change in focus

you might want to use zip tie gears on the long-throw lenses, and redrock-micro-styled gears on the short-throw lenses, to partially neutralize the difference

 

[hempo22]

Thanks Samuel

I only got one lens right now, Tamron 17-50 with gears similar to zip tie because of big filter size. And on that on it's a really short throw. Not even a 90 degrees. The old AI/AIS Nikons is closer to 180 if I remember correctly, on that shoot we used jag35 universal lens gear and a remote focus with reverse direction and calibrated it to a whole 360 turn on the remote. All lenses work with the same calibration as long as I put the focus to the end position before changing lenses and connected them with the lense set to infinity. So they should match pretty much perfectly.