Want a 400mm & have 2 options....

The 100-400 f/4.5 - 5.6 L IS for about $1200 and ../.. a 400mm Prime f/5.6 L with no IS for about $1100 ...

I know the 1-400 would be more 'versatile', and has IS, but - any idea of the quality of the shot at full zoom between these two ? Would the prime be a better quality without the IS over the 400 on the zoom lens with IS ? - with both about the same price, common sense would indicate I'd get more for my bang with the zoom, but then everyone tells me that Prime lenses are better.. I'm purchasing more for the 400mm length than anything else.

If it makes a diff, the lenses I already have are a Sigma 70-200 f/2.8 IS, and a Canon 75-300 IS.

Any experience out there ?

tks,

There are about a thousand threads on this comparison, not to mention extensive compare hits on Google. The prime is a tad sharper wide open. Stop down and the difference goes. I believe the prime is also lighter, but the zoom compressed is smaller. Search and you'll find extensive hits.

Versatility vs Speed(AF); really. I wouldn't trade my 100-400 for any other solution besides one of Canon's long, L primes, myself. Flexibility of focal lengths (for when the critters come up to check YOU out), closer minimum focus distance and IS trump the minor improvement in IQ and AF speed from the 400 5.6, for me.

I went for the prime. Lighter, sharper corner to corner, faster af and better bokeh.

Hideous MFD and less flexible but I tried a 100-400 and shot it at 400 all the time.

here's a comparison between both lenses:

http://www.pbase.com/l​iquidstone/100_400is

Snydremark wrote in post #15383495
Versatility vs Speed(AF); really. I wouldn't trade my 100-400 for any other solution besides one of Canon's long, L primes, myself. Flexibility of focal lengths (for when the critters come up to check YOU out), closer minimum focus distance and IS trump the minor improvement in IQ and AF speed from the 400 5.6, for me.

Same here on all points. The 100-400L's versatility trumps the minimal extra AF performance and IQ gained with the prime for me. Besides, the 100-400L gives me great results wide open at 400mm already.

When I bought the 400 it was another 50% more for the 100-400.

RobDickinson wrote in post #15383611
When I bought the 400 it was another 50% more for the 100-400.

Appreciate the responses .....

Actually, Amazon has the two priced as follows:

100-400 at $1290 and the 400 Prime at $1090 - both new.

I own the 100-400mm and absolutely LOVE it and it's my favorite lens. It all depends on what you are using it for, honestly. I shoot wildlife, sports and journalist style and i absolutely need the zoom. It is slightly softer at 5.6 in CERTAIN situations but when you stop it down to 6.3 or 7.1 it's all good.

I hear that the 400mm prime is a little faster focusing and is a little lighter but it's physically bigger when storing, it may not sound like a big deal but it is. I struggle to find bags that will fit the 100-400mm with the lens hood reversed, i could imagine the 400mm fixed is a nightmare at 3" longer than the 100-400mm. I can barely fit my 1D + 100-400mm in my lowepro stealthreporter 200aw with it sticking out just a little bit.. there is no way the prime is getting in there attached to a body.

Yeah; those sound about right

Depends on what you shoot. If birds in flight then 400mm prime all the way. 100-400L can't touch it. Prime is very sharp at f5.6. Zoom needs atleast f6.3/f7.1. Most copies zoom would need f8 to be as sharp as prime at f5.6. Trust me I had one of the best 100-400L and did some side by side testing with 400mm f5.6.

MFD of prime is longer but that never been a problem except one time for me in using these lenses for birds photography for two-three years.

Folks saying prime AF is little faster then zoom haven't used the prime IMHO. I tested 300mm f2.8 IS, 500mm f4 IS and 400mm prime is as good as any of those supertele costing $$$ more. Zoom is just ok. This was on 1 series body (1dmk2). You can shoot sports 100-400L with it and I have done it but primes kick butt in AF performance.

I loved everything else about my 100-400L though.

If you are a birder and are going to be at 400 mm all the time anyway, get the prime. If you want versatility that you can use for larger wildlife, trips to the zoo, etc., get the zoom.

Scrumhalf wrote in post #15384012
If you are a birder and are going to be at 400 mm all the time anyway, get the prime. If you want versatility that you can use for larger wildlife, trips to the zoo, etc., get the zoom.

Nice way to put it. Agree.

Scrumhalf wrote in post #15384012
If you are a birder and are going to be at 400 mm all the time anyway, get the prime. ...

The only way I feel this is even fully true, though, is if you are only shooting birds in flight; otherwise, stationary birds frequently hang out in shady/covered spots where having the IS on the 100-400 comes in pretty handy since you may not be able to keep your SS up, appropriately, for the prime.