What do people mean when they say 'stiff focus'?

G

Gilo25

Established
Local time
1:43 PM
Joined
Dec 27, 2007
Messages
107
A stiff focus is often referred to as a problem a lens may present. However how stiff should a focus be, to be really classified as a defect? As far as I know lenses' focus rings vary in terms of softness (or stiffness). Some are very soft, and easy to turn, some are harder. I often find that newer lenses' focus rings are sometimes harder to turn. So I am wondering how this is normally defined.
 
I have never had a lens that was hard to focus that was supposed to be that way. For example the CV lenses I have owned were a bit "tighter" (I think that is a better descriptor) than my Minolta 40 M-Rokkor bit neither of them are "stiff" like a lens that has hardened grease in the focusing helical. Stiff would be a defect and some will tell you to drip some naptha into the focusing helical to loosen up the grease but the only real fix is to disassemble the lens and replace the grease after scraping it out. A CLA on the lens would include this. To sum up my idea of the definition: Stiff is a problem that need to be fixed, tighter or looser is basically dependant on the way the lens is designed and the thickness (weight) of the grease used in the focusing helical. Hope this helps.
 
I have a Minolta Rokkor 35 f1.8 that is so hard that you need all 5 fingers to turn it... :bang:
 
I think a decent focus on a lens would be to be able to turn the ring with two fingers.

Troubles occur with RF lenses that have one, two, or three helicoid. Hardened grease may be a problem because excessive mechanical strengths can damage the threads and/or the components of the hélicoïd.
 
The Summircron C 40mm is a lens that is often stiff to focus when compared with M mount lenses with conventional cams. I dont consider it a fault though just a trait of this particular lens.
 
Stiff focus generally means the lens needs to be re-lubed. Usually Stiff and uneven go hand-in-hand. Some lenses require a lot of thick grease to focus correctly- several FSU lenses are like this. But, Some lenses that are freshly CLA'd need some time to loosen up a bit.
 
Depends on the mass of the lens, depends if it has double helicoil (on a telephoto) or single. Brian, do you lube all helicoils with the same grease? I would say, a small wideangle needs a more sticky lube than a one-pound telephoto lens. Otherwise the wideangle would turn too soft or the telephoto too stiff. It's a subjective matter anyway. Anyway, if it scratches on the foscussing way, that's too stiff..!
 
i agree, it depends on your opinion and the amount of stiffness/tightness. one of the reasons i went for a bronica over a hasselblad, other than money, is that the lens are easier to focus, however i have a canon lense thats so loose it focuses out when ever you turn the camera face down.

moderation and personal preference
 
You must log in or register to reply here.
Back
Top Bottom