choosing between EF 70-200/f4 L IS vs f2.8 L. need Help

Hi all, I'm new to this forum and consider myself a newbie in photography developing some serious interest in this hobby. I'm looking to add a 70-200mm lens to my 7D+15-85 kit hence the question.
I did some research and am currently leaning toward the f4 version for its IS and light weight. On the other hand, f2.8 is a full stop faster. The price difference is negligible. So i think it boils down to whether this one stop aperture is worth every other merit the f4 version has.
I shoot a bit of everything. I will add a couple of primes over time but 70-200mm FL has its priority.
Any comment is highly appreciated.

Unless you are considering the mk II f/2.8IS, I would get the f/4 IS.

What will your MAIN use for the lens be?

If you're going to be shooting indoors (something like a basketball game) and just can't get away with not having 2.8, then go with the 2.8.

In all other situations, the f/4 IS is a much better performer...sharper, lighter weight, has IS...

I'll definitely be adding the F4 IS to my bag in the future...I'll just lean on the fact that I can crank up the ISO on my 5D2 to make up for the lack of 2.8

F4 fo sho.

It is one of those lenses that just feel right.

The f/2.8 weighs twice as much as the f/4.0. Go to a local camera shop and handle both, then decide.

I have both and the 7D.When I used them on the 40D,the f2.8 was always my sports lens (if it was indoor or going to the evening),the f4 for everything else.The 7D has shifted this due to the higher useable ISO (1-2 stops).Now I use the f2.8 only if I know the lighting is going to be really bad and the f4 alot more often.It's gotten to the point that I may sell/trade the 2.8 for a 135l.I recommend the f4 because you have the 7D and can gain SS with the ISO's.My 2.8 hardly gets used anymore now-to big and heavy,gets unwanted attention,and it doesn't have IS.The f4 is alot smaller and lighter,get's little attention,and has 4 stop IS.The main thing I like about the f2.8 is the shallower DOF,the f4 seems to have better contrast tho.They are both excellent for sharpness,the f4 takes the TC better.

On the 7D (crop) I doubt you'll use it much indoors due to the FL being pretty long. As someone pointed out, if you're doing basketball or something like that, then you may want to consider the 2.8, but that's about it.

For my 7D I went with the f/4 and have yet to be in a situation where I really felt like I needed the extra stop. This includes many days of shooting in the shade, early morning, and under cloudy skies. Also, I just didn't like the weight of the 2.8 for something that I wanted to carry around a lot and take backpacking and things like that. I feel like I should point out that for all other FL's I use a 2.8 zoom or fast prime because I do tend to want the extra aperture, so I believe that says even more about my choice to go with the f/4 here.

Summary: I'm VERY happy with my f/4 on my 7D. You could also consider complementing it with the 85 f/1.8 if you're concerned about low light or want some extra DOF control on the short end.

thank you all for the input. I rarely do indoor sports. I'd say ~80% of my shots are outdoors, so i think that settles it. thank you eddy and COkid - you've been extremely helpful. 85 f/1.8 or siggy 50 f/1.4 will be my next purchase. maybe next year. until then i'd like to enjoy shooting with my 70-200mm

I had the f/2.8, disliked the weight and lack of IS, sold it, bought the f4 IS and have never looked back. The f4 IS is a wonderful lens. You're going to love it.

Blah, I wouldn't exactly pay almost 2x the price for just IS, over the non-IS. It just doesn't seem right to me. Learn to handhold

and f/2.8 can always be f/4, while f/4 can't be f/2.8. Thinner DOF is also fun.

forthewinwin wrote in post #10136583
Blah, I wouldn't exactly pay almost 2x the price for just IS, over the non-IS. It just doesn't seem right to me. Learn to handhold

and f/2.8 can always be f/4, while f/4 can't be f/2.8. Thinner DOF is also fun.

I wondered if the IS was worth double the price. Thank you!

lovebug wrote in post #10136742
I wondered if the IS was worth double the price. Thank you!

Well to me, Ide rather spend that extra $400 or so into a 50 1.4. I think that would make me happier in the long run.

The only situation I would find myself chipping in for IS would be when I absolutely can't stand carrying the bulkier, heavier f/2.8 (which to me honestly isn't very heavy) and want to max out my 70-200 potential in a lightweight package and I already have all my other lenses Ide need for other stuff. Otherwise, f/2.8 would easily make up for the required increase in shutter speed in dimmer light.

And f/2.8 works out better for sports, where IS doesn't help.

If you're going to shoot things where you can use the IS to compensate for low light, go for the f/4 IS. If you're going to be shooting action, or plan on using a 2x TC, go for the 2.8 non-IS. I honestly haven't noticed the weight difference between the f/4 and the f/2.8, but then again, I use a mono-pod.

forthewinwin wrote in post #10136833
Well to me, Ide rather spend that extra $400 or so into a 50 1.4. I think that would make me happier in the long run.

The only situation I would find myself chipping in for IS would be when I absolutely can't stand carrying the bulkier, heavier f/2.8 (which to me honestly isn't very heavy) and want to max out my 70-200 potential in a lightweight package and I already have all my other lenses Ide need for other stuff. Otherwise, f/2.8 would easily make up for the required increase in shutter speed in dimmer light.

And f/2.8 works out better for sports, where IS doesn't help.

First of all, if your equipment list is accurate you really can't comment on the pros and cons if the 2 lenses since you have neither. Either one of these lenses would cost more than all of your equipment combined.

Now for the OP: get the f/4L IS. Having used bog extensively I can tell you it's a much better lens for a vast majority of uses. If you shoot am lot of night sports or indoor sports with bad lighting the 2.8 would be helpful but the vast increase in weight and size and the lack of IS are too big a difference. The f4 is also *much* sharper.

Being someone who can handhold very well (at 200mm on crop body I can take a shot at 1/50 pretty reliably without a problem and have done it lower) the IS is still remarkably helpful. The IS in the f4 is the best I've ever seen (canon says 4 full stops). I've taken a shot at 200mm at 1/3 of a second with no visible shake.

Oh...and everybody is different. Just because you'd like the 50mm 1.4 doesn't mean everyone will.