Is there a way to lock focus on the D90. I find at times, I want the focus at infinity or at some other distance for long periods of time. I have tried leaving it in manual focus but I bump the darn thing. After reading about locking focus (the three different ways) none of them seem permanent.
Those three solutions on page 57 are what I had read in other places but the manual confirms those as solutions. While reading those they all seem to temporary to the situation, once the buttons are released the lock is gone.
George's advice seems sound. Now, the challenge is remember that it is on manual. When you pick up your camera and it seems to be not behaving the way you want. I've seen that on other threads here. Terry.
"The Nikon did the work; I just happened to be behind it at the time." TP
Sounds exciting! Tape seems like a reasonable option. Of the two sorts of 3M blue tape, the one for delicate surfaces has the more aggressive adhesive (go figure) and has proved to be more likely to be left behind. The 14day stuff seems more likely not to disfigure your lens. Depending on the lens, wrapping some material like paper towel or glove leather grain toward the lens around the focus ring and body and then tightening it with painter's tape might do. (Aside: leather has two surfaces; grain and flesh. In leather circles, the flesh is the part toward the inside of the animal, the grain is the outside. Virtually all leather garments, shoes, etc are made with the grain outside.) Or, you might still be able to get broccoli or some such bunched vegetable with the wide, heavy rubber bands. For some lens barrels, they might be able to do a good job of providing drag without adhesive. An 'O'-ring perhaps?
A non AF-S AF lens (camera drive - you really do have to be brusque to move the focus, 'bumping' would have little effect) would be more likely to stay locked at a focus point (presumably just short of infinity or are we talking hyperfocal, here?) set to AF but with the thumb button set to AF-ON (f4, AF-ON - also removes AF from the shutter button), AF set to AF-C.
Is storm chasing a life sport? Not sure I'd like to try it.
Storm chasing is fun. The key is being safe and then finally getting in a good spot to take pictures of either the macro storm structure or the mirco storm structure (tornadoes and hail.) Some times the macro structure is the the best.
The photos I've seen are of some pretty astounding heavy weather. Good luck with the staying safe part of the endeavor.
The more I think about it the less I like putting any sort of adhesive in direct contact with the lens. Changing focus, if it meant taking tape off, would be too big a deal to be convenient. Hence the suggestions for clean and durable alternatives.
There's another (sub)option, it turns out. If you have or can get the use of a non-AF-S lens like my Micro Nikkor 105 2.8D that sports a device (in this case a ring with a lock button) specifically for setting the lens to AF or MF, then, with the lens set to AF and the camera set with the AF-ON relegated only to the thumb button, the camera is effectively in focus lock since the focus ring has been decoupled from the focussing mechanism. No amount of twiddling will change the focus setting - only pressing the thumb button. True, it's not a zoom...
Putting drag on a camera drive AF lens that doesn't decouple would, I suspect, endanger the camera's AF motor and gearing. The lens that took this shot (24-85, 2.8-4D) has a focus ring that does not decouple and is virtually impossible to turn when the camera drive is engaged. If it is bad form to wrench the focus ring while engaged, it must be equally bad form to restrain the focus ring while the camera is trying to focus.
This wouldn't matter as much for an AF-S lens since the focus ring is connected to the focus drive through a slip mechanism. There, any drag would work and I would regard as preferable drag that did not involve putting tape directly on the lens.