Adjustment to new lens

[mgc]

Hi folks,
I recently bought a Tamron 18-200mm lens for my Canon 1000D, to give me a bit more range than the kit lens offers. The Tamron seems like a good lens, but I have noticed that my shots often seem to be very bright, verging on overexposed, using the camera's own exposure settings. I have found that I get the best shots when underexposing by around 1/3 to 1 full stop down.

This isn't a big deal as such, but I'm curious as to why it should be. Is this something I should expect with a lens like this, and if so, what causes it?

Thanks for any advice,
G

[autofocus]

Try this little experiment. Keeping everything constant shoot the same subject with this and your other lens. On both lenses make sure your zoom is set to the same place, the lighting is the same, same ISO, focus and meter off the same spot on the subject, same shutter speed and F/Stop...in other words, change nothing but the lens, and see what happens. Let us know the results...I wouldn't image you'll see a dramatic difference between the two, but it'll be a good test.

[mgc]

Thanks auto-focus,
I'll experiment and compare the difference. I just wondered if it was a known effect of such a lens.