[GibbyTheMole]

Hi there.

Any consensus on which is optically better between the Tamron & Sigma AF 18-200mm zooms? They're both about the same price, just curious about quality differences.

Cheers,
Bobbo :-)

[yusuf]

I have no experience with Tamron but Sigma 18-200 is pretty good. Here is two pics I shot with Sigma 18-200mm

https://www.pentaxforums.com/forums/post-your-photos/95359-streets-street-kids.html

[psychdoc]

I have the sigma 18-200 but no experience with the Tamron. The biggest problem for me is that as you go longer this thing is really slow and you are likely to get blurred shots of anything with movement. Image quality is also poor towards the longer end. But fair enough for ordinary travel shots. I expect both brands would have the same problem and you can bump up the ISO on your camera. I only use it if I am travelling somewhere where I cannot do not want to change lenses.

[hcc]

Both the Tamron 18-200mm and Sigma 18-200mm are old lenses, somehow 1st geenration all-around lenses.

The Tamron 18-250mm (and its sibbling Pentax DA18-250mm) superseeded the 18-200mm. The 18-250mm is a great all-rounder and a major improvement from the 18-200mm. (See reviews in the Lens Review, at www.slrgear.com and ww.photozone.de.) Unfortunately the 18-250mm is now longer manufactured but you can still find some excellent 2nd hand lenses.

The Sigma 18-200mm was recentlty replaced by the 18-250mm OS HSM. A little expensive but some good user review in a few threads.

Hope that the comments will help..

[GibbyTheMole]

psychdoc:

How long can you go before the IQ starts to fall off?

hcc

Truth be told, I'd rather have the 18-250. But the going rate for the 18-250 is around $500 USD, vs. $240 for the 18-200.

[KxBlaze]

The Tamron 18-200 can be had for $189 from BH. Deal is good till the end of the year. I have the Tamron and am happy with it. The IQ is better than I expected but a little soft at >150mm and the AF is pretty slow at times. All in all though, for the focal length, the convenience, and the $ it is well worth it.

[psychdoc]

psychdoc:

How long can you go before the IQ starts to fall off?

hcc

Truth be told, I'd rather have the 18-250. But the going rate for the 18-250 is around $500 USD, vs. $240 for the 18-200.

I have not looked at the actual numbers. I guess I used it for so long that I kind-of-know from experience when I am shooting as to whether the subject is too far off or too fast for the lens. I think I almost never use more than 150. I use the 18-about 100. But that is partly out of shooting style too. If you like the long end more than the short end of the zoom I am not sure this is the lens for you.

[psychdoc]

P.S: The above is an example from the shorter end. Did not do anything other than cropping outside the camera.

[shnikus]

You can easliy find a gently used sample of DA 18-250 for under $400 if you keep an eye on eBay and Craigslist adds. I recently bought one for $350 in mint condition.