amfoto1 Loc: San Jose, Calif. USA

The Canon 100-400mm f4.5-5.6L IS USM Mark II is an excellent lens, but may not be "long enough" for a lot of birders. Lensrentals.com loves to take things apart, just to see what's inside, and when they did that with the Mark II they called it the best-built zoom they'd ever seen. It's also got excellent image quality throughout the range. It's not cheap or lightweight, by any means, but it's smaller than the 150-600mm lenses. The 100-400mm is about 3.5 lb. and close to 4" in diameter.... noticeably bigger and heavier than 70-200/2.8 and 300/4 lenses that I use. It's also not internal zooming, so it grows considerably longer when zoomed to longer focal lengths. Still, image quality is excellent, stabilization is the latest and greatest and it's pretty fast focusing. It's got a zoom tension control ring that's nice to prevent "zoom creep" when carrying it, or can be set just to provide some drag on the zoom or to let it move as freely as possible.

The original Canon 100-400mm is a push/pull zoom, which some folks since zooming with a push/pull is very fast. The Mark II is a more typical two-ring (zoom and focus) design. Personally I prefer the latter... but some people prefer the push/pull for Birds in Flight, air shows and some other fast action shooting. The original 100-400mm can still be found new sometimes, and is widely available used.

There are actually four different 150-600mm you might want to consider: two different Sigma and two different Tamron (the latter are older and newest versions of the lens)

The Sigma 150-600mm "C" is less expensive, as is the Tamron SP 150-600mm (either the new version or the original)...

The Sigma 150-600mm "S" (Sport) version is very close to the same price as the Canon 100-400 II... and is a lot bigger and heavier (105mm filters, versus 77mm)... but probably the best performer of the 4 different third party lenses.

As mentioned in a couple previous responses, with any of these lenses, adding a 1.4X teleconverter will cause your 7D to stop autofocusing. The 7D is "f5.6 limited", meaning it needs a minimum of f5.6..... when you add 1.4X to any lens, you lose one stop of light. The 100-400mm with 1.4X added "becomes" an effective 140-560mm f6.3-f8, for example. (80D, 7D Mark II, more recent 5D-series and 1D-series cameras are "f8" capable. They can autofocus an f5.6 lens with 1.4X or an f4 lens with 2X... although, depending upon lens and camera, autofocus may be limited in some ways.)

Now, there are work-arounds for this. You can just focus manually.... But your viewfinder will be darker and modern DSLRs simply aren't designed for manual focusing. Another possiblity... It's possible to tape up a couple of the contacts on the teleconverter, so that the camera is fooled, doesn't know it's installed and will still try to autofocus. In all but the very best lighting conditions, AF will be slower and tend to hunt more... and will probably fail in lower light conditions. If you are interested in giving this a try, Google for info about how to tape up the 1.4X's contacts. I'm sure someone out there on the Internet has posted photos showing how it's done. (Note: your image EXIF metadata also will report focal length incorrectly, as if only the lens were on the camera.)

You might want to consider renting and experimenting with one or more of these lenses, before purchasing. If you don't already have one, you are likely to want a sturdy tripod to use with any of them, too. Or at least a monopod. All these lenses can be handheld briefly... but you're not likely to want to do so for very long. Even with stabilization in all of them, a tripod or monopod also might make for sharper shots sometimes. It ain't easy getting a steady shot with these extremely long telephotos.

There's no such thing as a "long enough" lens for birding. No matter how long focal length you've got, there's always some subject that's just a little too far away.

Have fun shopping!

imagemeister Loc: mid east Florida

PNagy Loc: Missouri City, Texas

Thanks.

jeep_daddy Loc: Prescott AZ

I have to tell you, the new 100-400 mark II is the best zoom in that range money can buy. I had the old one and there is no comparison. A friend and I went to Safari Park in CA a few weeks ago and she brought her old 100-400 and we traded back and forth for the day. There is such an improvement on the new lens that she ordered one as soon as we got home. That said, I to know people with the Tamron 150-600 lenses. They are probably in the same class as the older Canon 100-400. No, they will not work with the teleconverter. Nor will the old 100-400. But the new 100-400 will work with the 1.4x teleconverter on most of the newer Canon bodies like the 7D Mk II, 80D, 5D IV etc. It MIGHT work on some of the other bodies, but if it does, you'll probably only get a single focus point. You also better make sure that you invest in the Mark III teleconverter if you haven't already.

cameranut Loc: North Carolina

If I had it to do over I would spend a bit more and get the Canon with extender. I bought a Sigma 150-500 a few years ago and regret it now. It does not auto focus at all. If you are trying to get birds in flight, or just birds in some form of movement, you need the auto focus and sharpness of the Canon. I don't know about the newer versions of Sigma but I have a feeling you would be happier with Canon. Trying to get a bird in flight while holding a very heavy camera/lens combination and operate a manual focus wheel------ all adds up to a lot of deleted shots.

jimmya Loc: Phoenix

Canon is well known for producing excellent lenses for their cameras and remember, even in this economy, you do still get what you pay for.
Good luck

Camera buyer Loc: Las Vegas

I shoot performers on stage and have the Canon 100-400mm lens, model 1. I like the push pull zoom feature and is incredibly sharp. I shoot at ISO 6400 and at 1/500th at full aperture, and get amazing results. I'm sure you can get a good deal on the earlier version.
I hand hold the lens on either my Canon 6D or 5D MkII. Occasionally I'll use a monopod.

starlifter Loc: Towson, MD

Soooo many opions.

SharpShooter Loc: NorCal

When the dust actually settles, no, not that many options.
You wanna see how narrow the options are, just look at what Pros use.
It's a pretty short list!!
SS

Haydon

You might check out the following link if you're interested in the Canon lens. LensRentals tore it down and made the accessement that wasn't by user ownership bias or by assumptions. They are a professional service that provides an interesting product and do ALL there servicing.

https://www.lensrentals.com/blog/2015/02/canon-100-400-is-l-mk-ii-teardown-best-built-lens-ever/

Here is was Roger had to say in a quick sum up:

I know I can’t really, without showing you dozens of other lenses, do a good job of impressing you with just how robustly engineered this lens is. I will say that the insides look more like what we’d expect to see in a 500mm f/4 or 600mm f/4 lens, rather than a telezoom. It’s by far the most heavily engineered zoom lens Aaron and I have ever seen; and we’ve seen the insides of dozens of lenses in this range.

dave.m

I have the Tamron 150-600 (V1, a V2 has recently been released) and use with an EOS 6D and sometimes with my backup body, a 100D

I don't know how it compares with the Canon 100-400 or the Sigma 150-600, but I think its a great lens. I typically use it for birds and at airshows where the zoom range and max zoom is really useful. Also it means that if trying to travel light (a relative term :) I can typically get away with 3 lenses - the 28-105, 70-200, 150-600.

Some observations - if using a 7D the effective focal length is x1.6 or a whopping 240-960!, you will need a monopod/ tripod or use a high shutter speed even with image stabilisation to get sharper images. I tend to use a monopod as its less cumbersome to carry and use and less likely to be kiced by passers by in an airshow crowd.

Confirming a previous comment, a x1.4 converter won't autofocus with my 6D or 100D - both need an aperture of f6 or better and at 600mm it is f6.3 to start with.

Interesting comment above on cropping 600mm view from 400mm image - never thought to test that but hey, the 150-600 is a lot cheaper and I'm very happy with the results I get, easily enlarging to A3+ (19") on Epson R3000 even after some cropping.

Don't know how it works in your neck of the woods, but mostly get from a locan specialist Canon camera store. There is room to argue about price, but the benefitis of testing the actual lenses outside using a monopod, and the great pre-and after sales service more than make up for the slightly higher price. Perhpas your local store may allow the same pre sale testing of the models you are interested in?

Here are a couple of examples both at 600mm, both cropped. The kingfisher is at f/6.3 the Vulcan and Red Arrows at f13. I shoot raw, extract jpeg for a quick look (using the free 'quick jpeg from cr2'), typically apply lens correction and colour balance (if reqd) in ACR, and post in Photoshop. Use Topaz denoise if required, resize to 360ppi to match printer output, and sharpen with Nik.