Tamrons 1.4 tele extender

[Todd Caswell]

What is the difference between the standard model 129.00 and the Pro version 209.00?? Both are Auto focus.

Also,This would be used on a 70-200 F/4, I have used the 1.4 with good results on this lens but for the small difference in price will the 2.0 perform just as well as the 1.4? AF was a little slow with the 1.4, will the 2.0 be the same or will it be slower? Obviously Manual Focus is always an option .

[MN Shutterbug]

The 2.0 will not auto focus on this camera lens combo. The maximum aperture that will AF with a tele converter on a **D body is 5.6. Add the 2.0 to your 70-200 and you're at f8. You double the focal length and you double the aperture. Adding the 1.4 keeps you within the 5.6, which will AF.

[Steve Foss]

I don't know whether the price differences between the two Tamron TCs are due to build quality or glass quality, as I have not used them.

With the nice sharp Canon 70-200 series, a Canon 1.4 will not reduce image quality enough to really notice. With even the best brand 2x, you will notice a bit of degradation. The only non-Canon TC I have experience with is the Kenko pro 1.4 TC, and it was not quite as sharp as the Canons are.

X already pointed out the AF issue with the lens/2x combo. Only a Canon "1" series body will AF a combo with a max aperture of f8.

[finnbay]

Ditto on the 1.4X vs 2X teleconverters. Haven't used the Tamrons, but did use a Kenko Pro and was satisfied with that until I exploded it by dropping my camera and large lens off the top of a tripod on a -20 night a couple of winters ago. Decided to go with Canon's as a replacement.

[MuleShack]

Sorry to jump on here, but what is the gain of using a teleconverter on say a 200mm lens?

Does it increase the reach out to 340mm for the same lense? does it keep the same image quality?

Just curious as to the advantages/disadvantages. Obviously is is cheaper than buying a bigger lense...but?

[Steve Foss]

You lose one stop of aperture with the 1.4, but gain 40 percent of the native focal length of the lens, so your 200 f2.8 becomes a 280 f4. With the 2x you lose two stops and gain 100 percent of focal length, so your 200 f2.8 becomes a 400 f5.6.

Prime lenses are more sharp on their own than zooms, so using a 1.4 TC on a prime won't hurt image quality enough to matter. The 2x will show you some degradation, but not as much as it would on a zoom lens.

Cheap TCs are a waste of money, generally. This is really a case of getting what you pay for.

[Dbl]

Cheap TCs are a waste of money, generally. This is really a case of getting what you pay for.

Could not agree more with that statement! I've used a few cheaper Tamron's on manual focus lenses a number of years ago and they were OK at best. Didn't matter what it did to autofocus because I didn't have it, but I eventually stopped using it due to degradation in image quality.

The only one I use now is a 1.4 Canon. I just don't care for the results or the performance of the 2.0 but that is just my opinion. You really do get what you pay for.