TAMRON SP AF200-500mm F/5-6.3 Di LD [IF]

[oldtool]

Bob,  Have you compaired the IQ of the TAMRON SP AF200-500mm F/5-6.3 Di LD [IF]  against the EF 70-399mm IS USM lens?  I have the Canon and  am considering the Tamron and wondering if I should keep the Canon or sell it.  Am wondering how they compair. 

[KeithB]

Do you mean the 70 - 300?

It seems to me that these are completely different lenses with little overlap.  The 70 - 300 is a moderately wide telephoto that complements a "normal" zoom lens.  (i.e., I have the 17-85 and the 70-300 extends that nicely)  If I got rid of the 70 - 300 and added a 200 - 500, I would add a lot of reach, but leave a big hole in the 85-200 mm range.

What do you want the lens for?  If you just need more reach than by all means replace the 70-300 with the 200-500.  If you want a more general purpose lens than you should probably keep the 70-300.

IF you *need* 500 mm, It seems to me that adding a 1.4 extender on the 300 will get you to 420, at a much lower cost, though with some reduction in IQ.  I have the Tamron for mine and it seems to work pretty well in bright light.

[Bob Atkins]

I've shot with both lenses and reviewed both of them here, though I've never shot with them side by side using the same camera.

Here's the 200-500 review - http://www.bobatkins.com/photography/reviews/tamron_200_500b.html

I'd agree the Tamron 200-500 and Canon 70-300IS are different lenses which serve different purposes and so I'd keep them both. Above 300mm the Tamron will give you better results than attempting to put TCs on the 70-300IS, and you'll get autofocus. On the other hand the 70-300IS is image stabilized, which will probably give you a distinct advantage if you are handholding the lens, plus it has almost a completely difference range of focal lengths making it more useful for general photography (not to mention that it's smaller).

[KeithB]

Bob:  Will autofocus work at f/6.3?

[Bob Atkins]

Yes. Tamron and Sigma seem to have some way of fooling the EOS AF system into working at f6.3. I think somehow they "lie" to the camera!

Canon don't do this, so you'll see at all their lenses are f5.6 and faster. Some time back Sigma actually has an f7.2 lens that they managed to fool the camera with.

It's possible that AF might not be quite as good as with an f5.6 lens, though the extra 1/3 stop really doesn't make much difference most of the time. If could be slightly less accurate in low light or with a very low contrast subject.

I did test the Tamron 200-500 and I didn't notice any problems with AF at 500mm and f6.3