Topic: Tele extender advice (Read 6046 times)

cowboy · « **on:** July 08, 2007, 10:18:53 pm »

Can anyone advise me on a tele extender 1.4x or a 2x for a Tamron 70-300 used on an XTi. Is it a reasonable thing to do? Also have a Canon zoom 28-80mm. I haven't had much luck finding anything by searching. Any advice is helpful. I normally shoot using a tripod. Use is mixed because I am still exploring possibilities.

DarkPenguin · « **Reply #1 on:** July 08, 2007, 10:54:06 pm »

You'll lose AF with a TC and that tamron lens.

Goodlistener · « **Reply #2 on:** July 08, 2007, 11:04:12 pm »

The technical support people for Canon advized me to get a 70-200 zoom PLUS a 1.4 extender on Friday after the 4th of July. Their statement was that one keeps auto focus with the 1.4X extender, but not with the 2X extender. You loose one f stop with the 1.4 extender. I understand from other sources that you loose 2 f stops with a 2X extender.

Canon tech support tells me that the 75-200 f/f L telephoto will be more sharp with a 1.4X extender than the low end 75-300 EF-S lens that I have. Hope some of this is relevant to your situation.

DarkPenguin · « **Reply #3 on:** July 09, 2007, 12:30:55 am »

The 70-200f4 with TC will still AF as it is a constant f4. The tamron is f5.6 at the end of the zoom range. So it is already at the limit of AF at that point.

Oh, and the 70-200f4 with TC is an extremely effective combination. Get the IS version, tho, as it does get dark with the TC.

cowboy · « **Reply #4 on:** July 10, 2007, 12:52:27 am »

Thank you both for the info. It answered my questions and helped me plan a direction.

Goodlistener · « **Reply #5 on:** July 11, 2007, 12:00:28 am »

If you get a chance to post some of the shots you do with this combination and even better yet, explain them, that wodl be really great. Good luck on your trip.

Author Topic: Tele extender advice (Read 6046 times)

DarkPenguin

DarkPenguin