Hey guys,I'm getting a new Sigma lens from amazon.com but I'm not sure if it is the correct lens. Here's the link : http://www.amazon.com/Sigma18-200mm-3-5-6-3-Stabilizer-Warranty/dp/B003v504J8/ref=sr_1_14?ie=UTF8&s=electronics&qid=1282537244&sr=8-14

It says that it would Auto Focus on my D40 but it doesn't say it has the "HSM".

HSM - "HSM (Hyper-Sonic Motor) ensures a quiet & high-speed auto focus"

yes it will AF .. just not as fast and as quiet as the HSM version i suppose

Thank you for your reply sir. So even if I buy a Sigma lens with out the HSM function its ok as long as it AF? Or is there a particular lens that needs the HSM for it to work with my Nikon D40

Some Sigma lenses doesn't indicate "HSM" but it has built-in AF motor in it (such as their 70-300mm). If it doesn't say HSM and yet the seller claims it to AF on a non-AF body, much better if you can test. Otherwise, since you're buying remotely, I suggest look for the HSM variant instead.

Thanks for the info Sir.Yohan. What about this lens : http://www.amazon.com/Sigma-18mm-Stabilizer-Cameras-Professional/dp/B002TK7D6S/ref=sr_1_1?s=electronics&ie=UTF8&qid=1282323782&sr=1-1

I'm sorry if im asking this questions, I'm a Newbie I have been learning photography for about 4 months now.

Thanks for the info Sir.Yohan. What about this lens : http://www.amazon.com/Sigma-18mm-Stabilizer-Cameras-Professional/dp/B002TK7D6S/ref=sr_1_1?s=electronics&ie=UTF8&qid=1282323782&sr=1-1

I'm sorry if im asking this questions, I'm a Newbie I have been learning photography for about 4 months now.

yes sir.. it will auto-focus on D40.. i have one like that and it auto-focuses on my D3000.. hope this helps.. :)

^ from the link you gave, yes that will surely AF on your D40 (since it did say HSM too).

Thanks for your answers guys, I already ordered the lens from Amazon and hoping to receive it next week.