300mm f/4 or 400mm f/5.6 for sports?

I shoot sports, and have a 1D3 and 1D4, and as the title says, I am looking at either the 300mm f/4 or the 400f/5.6. Since I have a 1.4 extender, I will be using it for a bit extra reach when needed. The thing is if I use the extender on the 400, it puts me at f/8, which I guess isn't too bad outdoors, which this lens will only be used. But if I use the extender on the 300, it puts me at 420 while being at f/5.6.

And I DON'T want the 100-400, had it, but didn't like it.

I will only be able to afford about $1,000 or so.

Any advantages/disadvantag​es of either? Thoughts?

Thanks!!!

I can't help much with your specific question, but the "Slim Jim" 400 is an excellent lens that has exceptionally fast focusing which might be good for your sports shots. Today, I noticed a near new one for sale on Craigslist (Space Coast, Florida) for $800 which might fit your budget.

RVer wrote in post #14152996
I can't help much with your specific question, but the "Slim Jim" 400 is an excellent lens that has exceptionally fast focusing which might be good for your sports shots. Today, I noticed a near new one for sale on Craigslist (Space Coast, Florida) for $800 which might fit your budget.

"Slim Jim" 400? Never heard of that, sorry. Is it a nickname for a Canon lens, or something else?

I debated between both lenses and opted for the 400mm due to the focal length. There are a lot of pros for the 300mm but for my needs the 400mm made more sense.

I went with the 300/4 IS and use it with and without 1.4X. That gives me two focal lengths to work with, rather than just one. And, for me, the IS makes it a better lens for handholding.

The 400/5.6 is a fine lens, but the whole reason I got the 300mm was for handheld use (I already had 300/2.8 IS an 500/4 IS for those times when I can use a tripod or monopod). With a non-IS 400mm lens, I'd want to use a tripod or monopod most of the time.... especially since most of the time I'm using 7D... 1.6X crop, so to handhold reliably I'd need to keep to 1/500 or 1/640 or higher with the 400mm.

300 + 1.4X...

effstop wrote in post #14153100
I debated between both lenses and opted for the 400mm due to the focal length. There are a lot of pros for the 300mm but for my needs the 400mm made more sense.

Debating now.. lol...

For summer sports, it's mostly High School - baseball, softball, soccer, then football in the fall, but the football games are mostly at night, and field lighting around here sucks, so wondering if f/4 would be a difference.

I also shoot auto racing, and will be getting to a local motocross track this summer as well. So will the extra reach win over the lower aperture? Damned if I know that right now..

amfoto1 wrote in post #14153128
I went with the 300/4 IS and use it with and without 1.4X. That gives me two focal lengths to work with, rather than just one. And, for me, the IS makes it a better lens for handholding.

The 400/5.6 is a fine lens, but the whole reason I got the 300mm was for handheld use (I already had 300/2.8 IS an 500/4 IS for those times when I can use a tripod or monopod). With a non-IS 400mm lens, I'd want to use a tripod or monopod most of the time.... especially since most of the time I'm using 7D... 1.6X crop, so to handhold reliably I'd need to keep to 1/500 or 1/640 or higher with the 400mm.

Good points. I will most likely be using this lens with a monopod, so I'm thinking IS won't matter much. I have a 70-200 Mark II, and used it for a basketball game hand-held, and it pretty much sucked. Got way too heavy way too quick.

RVer wrote in post #14152996
I can't help much with your specific question, but the "Slim Jim" 400 is an excellent lens that has exceptionally fast focusing which might be good for your sports shots. Today, I noticed a near new one for sale on Craigslist (Space Coast, Florida) for $800 which might fit your budget.

Ok, looked up the ad, guess you were meaning the 400 f/5.6... Sorry, never heard it called "Slim Jim". Why is it called that?

kenjancef wrote in post #14153139
Good points. I will most likely be using this lens with a monopod, so I'm thinking IS won't matter much. I have a 70-200 Mark II, and used it for a basketball game hand-held, and it pretty much sucked. Got way too heavy way too quick.

You get used to it.... I use 70-200/2.8 IS on one 7D and, a lot of the time, 300/4 on a second one. Camera bag has 12-25 and 24-70 in it, plus two 580EX in case they are needed, teleconverter and a few other things. Often 6 to 8 hour shoots, sometime longer... Rarely is a monopod possible... but I take a break and set things down every chance I get.

The 300/4 isn't much larger or heavier than the 70-200/2.8. Maybe a little, but I think it uses the same lens case.

I'm so confused... If I get the 300, I'll bet I get in a situation that I would have wanted the extra reach. If I get the 400, I might wish I had the lower aperture and IS...

But then... if I use the 1.4x extender with the 300, I get 420mm with IS, and if I use it with the 400, I'd be shooting f/8, so that might be a reason to go with the 300.

Personally, I think you would get far more use out of the 300 f4 for sports. You would have the option of that extra stop of light at 300mm which will be greatly appreciated for games under stadium lights or you could use your extender for better reach when light isn't as much of an issue. For the most part, you shouldn't find that you'll need much reach beyond 400mm very often if you're able to get to the sidelines of whatever sport you're shooting and when you do, some slight cropping can bring you right into the action without much loss of IQ.

jra wrote in post #14153224
Personally, I think you would get far more use out of the 300 f4 for sports. You would have the option of that extra stop of light at 300mm which will be greatly appreciated for games under stadium lights or you could use your extender for better reach when light isn't as much of an issue. For the most part, you shouldn't find that you'll need much reach beyond 400mm very often if you're able to get to the sidelines of whatever sport you're shooting.

Yea, this is true... so I think I am leaning towards the 300...

The IS on the 300 could come in handy for motorsports. Panning with a low shutter speed, the IS in mode 2(panning) can steady things for you.

Get the 300, with the 1.4X TC you have two useable lenses from it for sports:
300/4
420/5.6

If you get the 400/5.6, you have just a 400/5.6 and you have a long gap from your 70-200 to 400.
The 400/5.6 with 1.4X TC is useless for sports.
And I don't see running the 70-200 with the 1.4X TC and then the 400/5.6 naked as a great option as the AF speed of the 70-200 seems to suffer a lot with the TC compared to the 300/4.

I've got the 300, it's very good but I'm looking to pick up the 400 to shoot birds with. The only sports I've shot are the late fall surfing competitions (Vans) on the north shore, and I've rented the 600mm F4 IS for them.