Reply to Canon450D;
I shoot RAW or Fine Jpeg using my D90 + Tamron 18-270mm. I like sharp photos, I get good-enough sharpness using F8.0 and with shutter speed above 1/250 sec. I usually like to shoot stationary, inert objects. I think the Tamron cannot handle fast moving objects that well, unless you crank up the ISO (Perhaps ISO 800 or higher) in order to give you a shutter speed of 1/250 sec or faster when using F8.0 in less than ideal lighting conditions. But then again, the auto-focus speed of this Tamron, like any other superzoom lens, sucks!
By the way, I realised that PhotoShop CS4 can open JPEG files using RAW mode, and that's cool! You can tweak a lot more using RAW mode first. I have photos blown up to 1920x1200x72 and they are still very sharp. See Bird's Nest below (Sorry, I think Flicker only allows me to display 1024x640 size photo maximum);
Reply to Nikon users attempting to shoot using LV video mode;
The D90 does not autofocus when shooting with LV video mode - you have to manually focus the lens, any lens. Autofocus is dead in LV video mode. I hardly use the LV video mode these days. It's just a novelty really.
Reply to ctm1968 and other D40 or D60 users;
I am not sure whether this Tamron lens will work with cameras without a built-in motor to drive the lens. D60 and D40 do not have built-in motor to drive lenses, D40 and D60 users should check out lenses with built-in drive such as Nikkor lenses equipped with SWM (silent wave motor) or equivalent, like the hypersonic motor (HSM) of the Sigma lenses. I never bothered to check the Tamron lens as both my cameras can drive motorless lenses. Sorry.
Eddie