A good alternative to look at is maybe the 55 250, good range decent IQ and excellent value for money... [snip]
The EF-S 55-250mm IS? From the reviews I have read, it's not a bad lens for the price but it's really kit lens quality and I think I'm looking for something a step up -- this is really a once-in-a-lifetime opportunity. Besides, considering that I already own the 18-135mm IS, the EF 70-300mm IS isn't really that much more money than the 55-250mm, gets higher scores in all the reviews I have read, and gives me a total coverage between the two lenses of 18-300mm, rather than 18-250mm.
Consider a Sigma 150-500mm OS lens. It is relatively light and has VR (called OS). [snip]
Nice shot.
As great as it would be to be able to do facial close-ups animals at long range, I really don't think I need 500mm on my 1.6x crop sensor T3i. Don't get me wrong, having a super tele like this would be nice, and if I could carry the 150-500mm
and a 70-200mm f/4 IS as a shorter range/lower light complement, this would be great. But given the weight limits I am dealing with, I don't think this will work. We're also going to be doing a fair amount of walking safari. I'm a pretty big guy and still in fairly good shape, but there are limits to how much gear I want to put on my back anywhere I might need to quickly put distance between myself and an angry hippo.
If anybody cares or wants to comment further, here is what I'm thinking based on advice and research to date:
I will bring my 18-135mm IS for occasional wider shots and also as a walk-around for when we're doing the tourist thing in towns. In addition to this, I am considering:
(a) Renting or maybe even buying a used 70-300mm f/4-5.6L. I like this option because I would only have to change lenses occasionally when I want to go below 70mm. Less lens changing means less dust issues, and less chance I'll miss a fleeting opportunity because I have the wrong lens mounted.
(b) Renting or buying a used 70-200 f/4 IS, and pairing it with the 1.4x extender. This is the lightest option, and compared to option (a) gives me slightly wider aperture up to 200mm. To take advantage of this, though, I'm going to have to open up the body more often to mount and unmount the extender.
(c) Renting a 70-200mm f/2.8 IS and a 1.4x extender. Pretty big and heavy, but with the extender it's nearly a one-lens solution and I think I can manage a lens of this size and weight if I don't have to carry much else. A lot of wildlife is most active at dawn and dusk, so having the option of shooting at f/2.8 out to 200mm could be very handy.
(d) 70-200mm f/4 IS as (b) above, but rent a 300mm f/4 prime instead of a 1.4x extender. Carrying both of these starts to push the weight limits, but neither of these lenses is all that heavy, so I think I could make it work... I do like the idea of having the 300mm prime to play with, as this would give me better performance at 300mm than any other option.
I've got a few months before I need to make a final decision, so I'm in no hurry. For now, my plan is to keep my eye out for good used deals, and find some excuses to rent some of the above equipment for a weekend and give stuff a try before I make any decisions.
Cheers,
EQ17