Sigma 120-300mm F2.8 w/ lens extender vs. Tamron 150-600mm

[victor_ng2]

<p>Hi,<br>

I am a Canon user & I need a long lens for wild life photography. Of course L lens is good but out of my reach for the money. I'm thinking about buying Sigma 120-300mm F2.8 w/ 2.0 lens extender vs. Tamron 150-600mm, and I have 3 questions:<br>

1) Regardless of anything else, between Sigma 120-300 with 2.0 lens extender & Tamron 150-600 lens, which one will give you a better quality picture?</p>

<p>2) Regard everything, including the weight which Sigma is a lot heavier than Tamron (7lbs vs. 4lbs), which one is a better choice?</p>

<p>3) Besides Sigma's heavy weight, honestly, I like Sigma more because the lens stays @ a fixed length when you zoom in & out vs. Tamron will be longer when you zoom in. This prevents dirt get into your lens significantly. How about you, what do you think?</p>

<p>Thanks.</p>

[Dieter Schaefer]

<p>The 2x TC will deteriorate the optical performance of the Sigma quite a bit - whether it is then still significantly above the level of the Tamron is something you need to evaluate yourself by renting both and comparing. My experience with TCs is that a 1.4x will take the lens from excellent to very good; a 1.7x or 2x reduces that down to a mere good. Personally, I would only get the Sigma if adding the TC is an occasional thing but not if the TC would always be on; the heavy size and the quite substantially higher cost of the Sigma aren't warranted then.<br>

I went through precisely the same process - the three candidates were the Sigma 120-300/2.8, used Nikon 200-400/4, and the Nikon 80-400/4.5-5.6G. I ended up with the later precisely because I didn't want to have a TC mounted almost permanently (Sigma), and didn't want to deal with the price and weight of the 200-400/4 (not a lens I would like to hand-hold for extended periods of time).</p>