One of the more noticeable things among using the larger lenses is "zoom creep."
Zoom Creep is a lens' tendency to slowly (or rapidly) extend or shorten, depending on the downward or upward tilt of the camera. It absolutely necessitates the use of two hands while using the lens and is problematic.
Several people have suggested different methods in dealing with this problem, my favorite being the use of a piece (or pieces) of "gaffer's tap" along the barrel of the lens, to "lock it" at the zoom length you have chosen for your shot. Gaffer's tape rarely leaves residue, unlike masking tape and such. Get a roll.
One of my favorite lenses, the Tokina AT-X 840 80-400mm f/4.5-5.6 suffers from this problem, so I do have some experience dealing with it. It is made entirely from metal and weighs a goodly amount. There are many other lenses that also have it, but in different degrees. I have found the more you use your zoom lens, the more you increase its chance of developing "zoom creep." Call it an "old age" problem. A handy idea would be for the manufacturer's to design an adjustable knurled screw that could provide additional pressure along the lens barrel, to retard this tendency. Cripes, I may just machine it myself. Heck, it's my lens. :rolleyes:
Anyway ... for the plastic lens barrels ... stick with the tape (pun intended ;))
I never had to deal with lens creep until recently. My SAL 75300 was less than 6 months old, and wasn't known for lens creep anyway, and the beercan has internal zooming.
However my recently purchased Canon 70-210 3.5-4.5 USM had terrible zoom creep out of the box. It was used, in like new condition, but if you tilted it up or down past about 80 degrees, the zoom would come down in a hurry. The only thing slowing it down at all was the time it took for air to exit the barrel.
I knew this was a common problem with this lens, and was mentioned in all the reviews. I figured it was worth dealing with, I really wanted a close replacement for my beloved beercan.
So, being impatient, frustrated, and brave/stupid, I started twisting screws. Turned out the zoom ring was held on by three screws, and under that were three screws that could be tightened to fix the zoom creep. I expect I will have to do this again every few months, but until I can sport the money for a lens with better build quality, it will do.
Hey, glad you fixed it. Wow I did not know the beercan had internal zoom! :D
Originally Posted by laydros
It's kinda funny, it has internal zooming, but not internal focusing, and the front element turned while focusing. Welcome to 1985.
Originally Posted by dr4gon
Originally Posted by DonSchap
That's funny that you mentioned gaffer's tape. I google'd "stop zoom creep" and found a website that offers silicone bands that are made specifically for zoom lenses. In one of their photos, it showed them using tape vs lens band, to stop zoom creep. I thought it was pretty clever. Here is a link to their site http://lensband.com
I thought 'zoom creep' was a pasty looking guy with a camera hanging out at a nude beach.