steven789,
IS should be off when you mount on tripod, unless it is the new generation of image-stabilized telephoto lens that does work on tripod for panning.

alex u getting tamron 17-50 VC? but i tot u got the 24-70mm canon L lens edi rite?

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Added on October 6, 2010, 6:59 amfark... my lens just arrived i found out its not a good unit.. HOW????
inside the lens like loose loose. i shake the lens inside elements can move de??? and i shake i will hear sound gulong gulong inside the lens. but after i fix into camera and switch on, then no sound... after i switch off, i shake got sound... whY????? does this happen to tamron?

the inner elements just feel like falling off when i terbalik-an the lens... wth...

DEMO OF IT

MY OLD KIT LENS PERFECT SHAPE
this one taken using that 17-50mm sigma, showing that it can work perfectly. just that the sound of OS can hear. can focus everything good, but when i shake abit the gulong sound come. WTH!

Since when?

haha..want poison me? where to check the price list for canon gear

http://www.bobatkins.com/smf/index.php/topic,769.0.html

ini comfort me the most. i may not wanna send it over to exchange anymore i guess. but i will see what the dealer and sigma say about this. and what uncle Ian said is true also, got warranty 4 years. if spoil then send for warranty stil sempat. but anyway, just hope they say this is normal and it applies to all lenses with OS. then i lega edi.

So far, everything seems to work fine with the lens. tested in low light situation and find that focus wasnt that fast, IQ not too good in low lights. But it doesnt really matter now as long as its fine..
tested some close up, it really performs cuz it can really go pretty close. note that i say close up, not macro..
sharpness, is excellent 
built quality quite sturdy n heavy.. size big enuf and offer better ergonomics.
OS works fine. turn it off or on the image still not shaky. dunno y, maybe my hand too steady? so i decided not to test further anymore.

i just wanna share some of the pictures i took with the lens when i run some testings on it. Cheers 
Wow.... those are OOC?
Poisonous sial... damn poisonous.
It's bloody expensive in Taiwan though... ~RM2.3K for 3rd party lens... a bit hard to stomach. Maybe I'll wait till more people bring it in and price to fall

what is OOC?
yea, the sharpness is really good. now i can feel it already. haha.
at f2.8 is really sharp. tested several position and style, still sharp. the sharpness ithink can compare with tamron edi

http://www.bobatkins.com/smf/index.php/topic,769.0.html

ini comfort me the most. i may not wanna send it over to exchange anymore i guess. but i will see what the dealer and sigma say about this. and what uncle Ian said is true also, got warranty 4 years. if spoil then send for warranty stil sempat. but anyway, just hope they say this is normal and it applies to all lenses with OS. then i lega edi.

So far, everything seems to work fine with the lens. tested in low light situation and find that focus wasnt that fast, IQ not too good in low lights. But it doesnt really matter now as long as its fine..
tested some close up, it really performs cuz it can really go pretty close. note that i say close up, not macro..
sharpness, is excellent 
built quality quite sturdy n heavy.. size big enuf and offer better ergonomics.
OS works fine. turn it off or on the image still not shaky. dunno y, maybe my hand too steady? so i decided not to test further anymore.

i just wanna share some of the pictures i took with the lens when i run some testings on it. Cheers 
sharp copy bro

any idea how was it compare with tamron 17-50 VC?
I was deciding between these 2 as well

How much price difference ya between these two models?

I'm still happy with my Tammy for the price I paid.

Taiwan price.... all grey market price

Tammy VC --> ~RM1.4K
Siggy OS --> ~RM2.3K

Expensive sial.

Taiwan price.... all grey market price

Tammy VC --> ~RM1.4K
Siggy OS --> ~RM2.3K

Expensive sial.

I bet Malaysia is more expensive. Cannot consider at all. If buying that I'll get a used L lens.

Ya lar.. giler mahal for a Sigma.

But buy L just for red ring also not worth it lor.

17-40 only f4 and no IS
24-105 not wide enough for crop + heavy

Aikss... decision decisions....