Replacing 70-300 IS USM for birds and wildlife

There's also the 120-300 Sigma but that's probably a bit pricey for the OP's needs

DreDaze wrote in post #15081992
i'm not sure how useful they'd be, being MF only...the sigma's would do better AF speed wise than the 400mm with a 1.4TC on it...and with a 2X TC i doubt you'd get any AF at all, so you'd be stuck MF'ing wildlife, which to me sounds like a 2% keeper rate...

I think your estimate may be a bit low. Until I went digital in 2009, everything I shot was manual focus. If my keeper rate were that low, I would have given up this hobby 40 years ago. Perhaps MF is a lost skill. Admittedly, it is more difficult with today's DSLRs.

Your are correct about MF, though. For spontaneous shots, that is a problem. If I were using 500-800 mm lens on wildlife, I would do some preliminary work to know where they are going to be when, and setup accordingly. That makes MF a bit easier, even if the whole situation is inconvenient.

Snydremark wrote in post #15082009
There's pretty much never enough reach when talking birds; but, IMO, the 100-400 is the best, general birding lens without stepping up to the big guns. The 400 f/5.6 is great for in-flight shots, but the flexibility of the zoom, IS and closer minimum focus distance (@6ft vs @12ft) just beats it out, for me, as it can be used for wildlife and other applications where the subject is/can be inside of the prime's MFD.

Can we all agree then, that the 100-400L would best suit the OP's needs? It is the longest lens I can afford. I am sure that applies to a lot of us.

Thanks for taking the time to type in the very thoughtful responses, everyone!

And Tschrief, the 500 and 800 primes are just out of the question, money wise for me. I am an amateur, maybe making it out to the wetlands twice a month with my son and sinking 10 grand into a lens for a very narrow purpose is something that a professional wildlife photographer (or someone a lot more serious about it than I am) could justify, but not me.

Basically, the choices are between a 100-400L plus an extender and either MF or tape and slow AF, or the sigma 150-500 for a little extra range. The quality of the 100-400L is of course without question. I have read through the 150-500 sigma thread in the lens archive section and it is pretty schizophrenic - either people clearly peg it a notch down below the 100-400, or say that it is equivalent especially if stepped down to f/8 or smaller. The photos look pretty good, which is why I was keeping it in consideration.

I will ponder over it some more. My heart tells me to get the 100-400L and revel in the thrill of my first L glass.. , but every time I look at the 150-500 thread, my tiny part of my brain that is counting the value to the dollar perks up and starts asking questions...

I have been there, done that, got the t-shirt, sold the t-shirt and bought it again...so to speak. I had a 70-300, great lens no doubt but I needed better. I got the 100-400. It is good but I wanted longer, you always will. Sold it and bought the Sigma based on people's views and reviews. It is a sharp lens, n douobt, best at f8 of course but wide open it could not match the 100-400. Also worth noting is the Sigma becomes an f6.3 lens from 300mm onwards! The OS is a bit clunky, but works well, better than the 100-400's once it gets going. BUT. It is a heavy lens. I have never had a simga on which I liked HSM, it just pales against USM. For BIFs it scored a zero in my book (yes, all those 150-500 users out there with BIF shots will probably now post them, along with some blurry oversharpened shots with a TC). So I sent it back to Amazon, as we can here in Europe, for a full refund. I now own the 100-400 once again. It is sharper than my first copy, wide open, no doubt, sharp as a sharp thing on sharpening day. It is light weight, compact and just brilliant for travelling. 400mm is not enough, but I also have a 500 f4, my main bird/wild lens and often that is not enough

On a crop camera 400mm = 640mm.... if that is not enough then you can buy a TC but depending on you body it may or may not auto focus even taped. I never got my 7D to work for example.

Scrumhalf wrote in post #15082045
Thanks for taking the time to type in the very thoughtful responses, everyone!

And Tschrief, the 500 and 800 primes are just out of the question, money wise for me. I am an amateur, maybe making it out to the wetlands twice a month with my son and sinking 10 grand into a lens for a very narrow purpose is something that a professional wildlife photographer (or someone a lot more serious about it than I am) could justify, but not me.

Basically, the choices are between a 100-400L plus an extender and either MF or tape and slow AF, or the sigma 150-500 for a little extra range. The quality of the 100-400L is of course without question. I have read through the 150-500 sigma thread in the lens archive section and it is pretty schizophrenic - either people clearly peg it a notch down below the 100-400, or say that it is equivalent especially if stepped down to f/8 or smaller. The photos look pretty good, which is why I was keeping it in consideration.

I will ponder over it some more. My heart tells me to get the 100-400L and revel in the thrill of my first L glass.. , but every time I look at the 150-500 thread, my tiny part of my brain that is counting the value to the dollar perks up and starts asking questions...

I agree. 500mm+ primes are way out of my league, also. You may have one more lens to consider. Do some research on the Sigma 120-400. I have seen reviewers who prefer its vagaries and flaws to those of the 100-400L. Before anyone gets started, all lenses have vagaries and flaws. If I remember correctly, the 120-400 IS system is a lot better than the 100-400L. And it is sharper in the 120-200 range than the 100-400L. One reviewer claimed that the 120-400 is sharper at 300mm than the Canon 300mm f/4 IS. His words, not mine. I never tried the 120-400. I own the 100-400L and have to agree, its IS system is not very helpful. It is better than nothing, and it is good at less than 300mm. At 400 you are almost better off to turn it off, and use a faster (1/800+) shutter speed. The lens noticeably focuses faster with it shut off. I primarily use it for daylight sports (grandchildren, nephews, nieces, etc.) so IS=OFF and 1/1000 is right up my alley.

Edit: In my earlier post, I just didn't think of the Sigma 120-400.

Scrumhalf wrote in post #15082045
Basically, the choices are between a 100-400L plus an extender and either MF or tape and slow AF

Before you go down this route I'd recommend borrowing/renting a 1.4x TC and trying it out on your 70-300. That way you'll soon discover that it's an impractical solution for shooting birds, and a virtually unusable solution for shooting birds in flight.

The next thing I'd recommend it to go through the 'Birds' forum here on PotN and check out the gear used for some of the better images. That way you'll be able to discover for yourself that '400mm is not long enough for birds' claim is by no means true. Yes, a longer lens is almost always desirable, but it's still possible to get good shots with something shorter.

there's also the sigma 120-300OS with TC...that'd give you AF at 600mm...i imagine it's big and heavy, i think that's hard to avoid once you start going long...and it is more expensive than the other options listed