[liukaitc]

Viewed lot market sales here. I find the price of used one on sigma 18-250, tamron 18-250, pentax 18-250 is pretty much same. about 380 bucks.
sigma one sounds has the latest technology. but it is heavier than pentax/tamron one.

[Jasvox]

The Tamron/Pentax 18-250 seem to have the most consistently positive reviews for any mega-zoom lens in recent years, including the Sigma. No need to pay extra for technology that does not help create a better photograph. If I was looking to buy one of these, I'd check out the forum marketplace here and glance at feedback scores and history of the seller. I have bought and sold several things here and have had only positive experiences.

Jason

[picobeach]

Used the Tamron 18-200 today for the first time with my K-5. I'm more-than-pleased with it and a bargain price makes this lens a natural.
See what you think:
http://www.photoshow.com/watch/Vf2ps5Ac

Chers,
jb

[hcc]

The Tamron/Pentax 18-250 seem to have the most consistently positive reviews for any mega-zoom lens in recent years, including the Sigma. No need to pay extra for technology that does not help create a better photograph. If I was looking to buy one of these, I'd check out the forum marketplace here and glance at feedback scores and history of the seller. I have bought and sold several things here and have had only positive experiences.

Jason

Adorama had two used 18-250mm last week and KEH had one used 18-250mm last week, all around US$360 which is a reasonable price for a lens in excellent condition (E+). You might find cheaper on the Forum marketlace...

I full agree with Jason that the DA18-250mm is a great lens. The focal length range is outstanding, despite some compromise in terms of IQ. Mine has been well-used and it remains my 'workhorse' lens.

[dstar]

I have Pentax 18-250 its right very good lens ,but after few months i start experience
severe creep problem and keep constantly lens on the lock position i talk with pentax service they try help ,but after few weeks all back.
May be not big deal but its only one problem. Tamron out from this problem