For those skimming, just look at the bold stuff.

I'm going to be heading to the Omaha zoo and only have a Tamron 17-50 for my 30d...which I am not happy with the IQ of that lens past 12-15ft or so, but that's for later.

I'm stuck between the 70-200 F2.8 IS and the 300F4 IS. For the most part, I'll have that tele lens on the camera, but will 300mm be too much for some of my closer shots?

Because I only have that one lens up to 50mm, going to 300mm is a big jump! And I think the 70-200 would be a better bet.

My second concern. My shots I take with my Tamron look great so long as they're all fairly close (less than 10-12ft away) beyond that, nothings really in focus. If I focus on something 2-3 ft away it's really very crisp, but if I try to focus on something 15 or more ft away, everything has a bit of a blur to it regardless what the F-stop is at.

Is that a lens issue or body issue? I hope it's only in the lens because I don't want to find out that I will have blurry pictures at the zoo with either telephoto lens.

Thanks for any info guys.

 

Ok, well, I'll add my .$02...

Im not sure how sharp that 300 is going to be past 200mm. From what I've noticed, most of the 300s in a decent price range arent tack sharp at all past 200, and leave a lot to be desired. I'd go with the 70-200, stictly for the f2.8 IMO.

About your focus problem, are we talking tripod use or handheld? what shutterspeed? ISO?

 

Well the 300mm lens is 300mm and that's it. No zoom to it at all, so I'm kind'a confused about what you meant by "past 200"

The Tamron issue (even if on a tripod) is regardless of what ISO, shutter speed, f-stop, or zoom. Keeping all constant - for example 100 ISO, 1/80, f4 and 50mm - shots taken at 2-5 ft away are real nice and crispy, lots of detail. Now, focus on something 20ft away and everything that's "in focus" is not crispy and it has a noticable amount of blur to it in comparison to what I was focusing on much closer. (Real noticable when cropping images)

I'll have to take some examples probably huh?

 

Woooops, read right over that detail! I was thinking you were comparing 2 telephotos with similar focal lengths, I completely skipped the fact that you posted a 300 prime lol.

Man, that changes things a bit, primes are great but I really dont know how much use I'd get from a prime 300mm lens, so I couldnt give you a fair opinion.

On the tamron issue, yeah some examples would be great, but it sounds like just a lens quality issue to me.

 

I'd want to carry a zoom at a zoo where you are limited to where you can stand. There's going to be plenty of places where 300mm will be way too narrow FOV and you won't be able to back up far enough. Even if you can back up, then you will have to deal with passerby walking in front of you.

 

Both of those lenses assuming you are talking about the L versions are excellent performers. The zoom may be better suited to you since you have limited other lenses to choose from. Here is a suggestion pick up the 70-200mm is and than pick up or rent a 1.4x. This will give you more flexibility from one lens. You will be shooting in daylight so the one stop of light you lose by attaching the 1.4x will not even be a factor.

For what it is worth I own both of those lenses in non-is form. The 300mm F4L is arguably one of the sharpest lenses in all of canons arsenal. I use mine often and it never lets me down. Stellar stellar lens!

here is a bang up no pp shot from it shot in less than ideal light

 

70-200mm + 1.4x is an excellent idea and something I had thought about, but wondered if it would degrade my picture any.

I'm going to rent both, but I fall in love with the 70-200 F2.8 IS, which is a lens I've wanted, I may buy one later. I'd rather rent it and use it before buying in case I get disappointed like I am with my Tamron lens...except the Canon L lens will have a lot higher buyers remorse if I don't like it.

 

I have the sony equivalent 70200 G SSM and it is fantastic. You can always do a bit of cropping to get the reach you need.

 

The 1.4x will not degrade your pic when mated to the 70-200 2.8l I would go a step further and say you prob cant even see the difference.

 

Bounced flash off the ceiling is less than ideal light? Looks like it's working decently well to me.