Looking for a Long Lens

Plenty of them show them self on this site. are you one of them?

Talley wrote in post #17719988
Canon recommends using IS even for sports or other high shutter situations as it helps stabilize the image so the AF can lock on easier

Try it for yourself - it doesn't! It does stabilise the image in the viewfinder once the IS is up and running, only THEN can your AF work, but in that brief time your subject may well have disappeared! If the subject is moving then Canon suggest using mode 2 which is fine if it's moving in the right plane (eg. a car on a track) unfortunately animals don't do this - so your AF will be fighting the IS which impairs AF tracking.
In addition there is an extra piece of glass in the focal path that does nothing for IQ (remember all the arguments about whether to filter or not?).
I advocate turning IS off (unless shutter speeds REALLY demand it) because it has given me a higher success rate, frankly on my longer lenses (300 and 800mm) I have no use for IS and would happily pay a little extra not to have it.

Just my experiences.

johnf3f wrote in post #17720605
In addition there is an extra piece of glass in the focal path that does nothing for IQ (remember all the arguments about whether to filter or not?).

It's still there if you have IS on or off. Guess it also depends on the quality of each lens element: as say the 70-200mm 2.8L II is sharper then the 70-200mm 2.8 non IS (even though it has more elements). I never thought of it, but you've got a point about the amount of time it takes to activate. I still like it for panning shots: have found it works well with cycling. I've also noticed every lens is a bit different in IS activation speed....my 100mm macro is perhaps the slowest. But I'd rather have it since I'd rather get it going and track focus (and IS can be a good feature for macro shots). Different strokes for different folks, and it's best to have a range of choices!

davesrose wrote in post #17720636
It's still there if you have IS on or off. Guess it also depends on the quality of each lens element: as say the 70-200mm 2.8L II is sharper then the 70-200mm 2.8 non IS (even though it has more elements). I never thought of it, but you've got a point about the amount of time it takes to activate. I still like it for panning shots: have found it works well with cycling. I've also noticed every lens is a bit different in IS activation speed....my 100mm macro is perhaps the slowest. But I'd rather have it since I'd rather get it going and track focus (and IS can be a good feature for macro shots). Different strokes for different folks, and it's best to have a range of choices!

I did also say that I would "would happily pay a little extra not to have it", that is for IS not to be fitted in the first place. My Macro lens doesn't have IS but I can see that IS may be handy for this sort of thing.
The OP was looking at this from a Sports and Wildlife point of view and for these uses I have found IS to be a hindrance. Were I shooting indoors (where tripods are not allowed) then IS can be a godsend, I just keep forgetting to turn it on in these situations! Still the picture look fine so I am not worried.

johnf3f wrote in post #17720648
The OP was looking at this from a Sports and Wildlife point of view and for these uses I have found IS to be a hindrance. Were I shooting indoors (where tripods are not allowed) then IS can be a godsend, I just keep forgetting to turn it on in these situations! Still the picture look fine so I am not worried.

Yep, but motocross and other sports can benefit from IS and panning tracks. I can see that if you're birding and need to be "quick on the draw" that tracking is less important then an immediate shot. And IS macro can be good for hand holding and trying to get insect wildlife Just goes to show there's no one "best" lens or a single technique in getting the shot.

Got the lens but to dark inside to really see what it can do since photos are 12800 iso, they look quite sharp for sure. But AF hard to tell. The lens feels great in the hands for me built really nice, I wonder what the Sport feels like...

the sport feels heavy ...congrats on the lens

05Xrunner wrote in post #17717460
I will bet most of these people saying the sigma will have problems are canon fanboys. I never owned the 120-300 but always read it was a fantastic lens. I used to own the 100-400v1 and sold it few years back. Got a sigma 150-600C in the spring and it is my favorite lens. Most of the people who put down the sigma lens are fanboys and never even used one before to make any real judgement. My vote would be the 120-300 or the 150-600. If budget tight get the 150-600C. It's IQ is pretty much equal according to sigma. Mine is very sharp wide open. It just isn't built as tough for nasty weather.

Statements like " I'll bet" " I never owned" "I read" " most people who put down the sigma lens are fanboys" have no factual basis and add nothing to this forum. This really has nothing to do with whether or not someone is a "fanboy" or not. I actually think the sigma 120-300 is a very good lens. If that makes me some kind of fanboy then so be it.

awww dont cry about a true statement. There are PLENTY of canon fanboys on this site that will put down the sigma as much as they can because its not a canon. 2 come off top of my head as Thorrulz and Ed Rader. So dont cry like they dont exist. They are the first ones to say negative things about them without even using them to spread BS

I see this thread has gotten a bit out there, but yes there are Canon Fanboys, who cares. Testing the lens out, its sharp no way around that at all. AF seems a bit slow but will have to see how it does tracking. Rented a 1.4 af there seems a bit slower but sharpness is there but running into a few problems both with and without tele. I have fine tuned the lens in my 1D and got it so subjects from me to about 150-200 feet are sharp but if I foucs on something farther then that they are soft and out of focus.

RussellJ wrote in post #17721858
I see this thread has gotten a bit out there, but yes there are Canon Fanboys, who cares. Testing the lens out, its sharp no way around that at all. AF seems a bit slow but will have to see how it does tracking. Rented a 1.4 af there seems a bit slower but sharpness is there but running into a few problems both with and without tele. I have fine tuned the lens in my 1D and got it so subjects from me to about 150-200 feet are sharp but if I foucs on something farther then that they are soft and out of focus.

I guess you might need the help of the USB dock then. That allows for MFA at multiple focal lengths and distances. I pick up my 150-600 C at WEX tomorrow. I figured that I would try the lens on my 50D first, and see how it went, with only the single MFA option. Then if I need to make further adjustments I can get a dock and do the full (IIRC) 4×4 MFA settings.

Really looking forwards to the last airshow of the year at the Shuttleworth Collection next Sunday, with the new lens to play with, much nicer than renting. It is supposed to be the very last display for the Vulcan bomber. I guess that will be one aircraft that I won't be needing the full 600mm for.

Alan

I'm pretty sure the OP mentioned earlier that they had gotten a 120-300 OS (non-sport) so unfortunately the dock is not going to be helpful

Just got my 120-300 OS NON Sport lens, loving it so far but only took it to the zoo for some testing today. Both using a Canon 1.4 EX Needed to really fix the lens micro focus by around -18 in camera though to get it this sharp so I dont know if I should just keep it this way or send it in to be looked at. Nothing else wrong very happy so far.

Sorry missed that it was the non sport, my memory is real bad sometimes.

Alan