Loose lens head on Tamron 17-50mm F/2.8

On a recent trip to Utah I brought my trusty combination of a Canon 60D and my favourite all-purpose lens, my Tamron 17-50mm F2.8 (non-VC.)

Part of my itinerary involved a backcountry ATV tour, and I had the camera gear in a padded case strapped to the Honda's rear cargo rack. By the end of the 4 hour tour, I noticed that the lens "head" on the Tamron was very loose and wobbly -- this is the part that holds the lens cap and filters.


The optics of the lens were still fine, the wobbly was only in the plastic end piece. After searching for a solution, it turns out this is a relatively common problem with this and other Tamron lenses, and the solution is quite simple.

Using a small jeweler's screwdriver, behing very careful to avoid damage to the optics, the following DIY fix is very quick and easy -- it took me under a minute.

Firefox Sluggish with newer AMD HD 4290 Video Driver

I recently upgraded my system video driver to address some video playback issues. In my case, I had been running the latest AMD 890X Chipset drivers with HD4290 GPU graphics support.

I am running Firefox 6 and FireFox 7. Prior to the video driver upgrade, Firefox ran smoothly and quickly. After upgrading to the latest HD 4290 drivers provided by Windows Update, I noticed Firefox seemed sluggish. My system is otherwise very fast (AMD 1090T X6 with 12GB of RAM and SSD) so the speed degredation seemed very related to the video driver update.

It wasn't "slow" but things like switching tabs suddenly had a very short, but noticeable, delay. Another symptom was that sometimes, when launched, Firefox would display a grey translucent screen with diagonal bars for a brief moment.

After some Google research, it became apparent that ability in recent versions of Firefox to detect and use "GPU acceleration" to speed up browsing, did not always improve things. So, in effect, disabling GPU acceleration in Forefox returned my browser to normal snappy speeds. The setting to change is:

• Open Firefox Tools::Options
• Go to Advanced
• Select the "General" tab
• Uncheck the option "Use hardware acceleration when available"

I tried various versions of the ATI Catalyst drivers for the HD4200 series GPU, but all seem to have the same slow Firefox behaviour when running with GPU hardware acceleration (I tried Catalyst 11.6, 11.7 and 11.9.)

EDIT 11apr2012: still a problem with Firefox 11 the latest Catalyst 12.3 drivers, grrr...

Many sights indicate this option needs to be unselected for "older" graphics processors, but it's odd that it affects the HD4290, which is a relatively recent onboard GPU solution that is certainly not out of date.

Oh well -- since I don't need advanced HTML5 support in Firefox yet, no problems leaving this hardware acceleration option off for now.