soft focus problems with 70-200 2.8 lens

[anguslincoln]

I am wondering if I am expecting too much image clarity and focus from my 70-200 mm 2.8 lens. I have been shooting a lot of birds with it from as close as 2 meters out to 50 meters.I have some fantastic results, but focusing seems to be inconsistant . I use it hand held mostly with good support at fairly high shutter speed when the natural light supports it. I was hoping to have less soft focus at the longer distances of 20+ meters. Is this lense capable of sharp focus at those distances if propper exposures are used ?

[RobertTheFat]

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@ebiggs1 wrote:

I am going to break a rule to not argue a point wiht other forum users but you seem to be a pretty reasonable guy.

Thanks. Did you see that I've just become a "Frequent Contributor"?

Cameras that can generate the insanely high shutter speed of 1/8000 have by design mirrors that move very much faster than older bodies that could not reach that speed.  There is no point in being super fast for a 1/1000 or even 1/2000 shutter.

You don't want a camera that opens it's mirror and waits for a fraction of a second for the mirror to stop rebounding when you want or need 1/8000 sec.  A mirror can take as long a 1/30 to stop rebounding.  The camera is shaking all this time.

Is 1/8000 better than 1/80? Absolutely but it in itself is not the answer.  The answer has several aspects, not shutter speed alone.

As in all electronics IS is varible.  It will works better at a 1-stop disadvantage than it will at a 4-stop.  That is just the way it is.

When the manufactuer says the lens has a 4-stop IS feature, they are really stretching the spec.  Does it work at 4-stops, yeah, but is it as good as at 1-stop. No, it is not.

The IS function should be turned off on a tripod and even a monopod.  The IS can actually work against you as most lenses have no idea wheter they ae being hand held or not.  Now if you don't want to turn yours off, please, feel free to leave it on and shoot away.

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Well, I just bought the new 16-35mm f/4L IS lens (not even out of the box yet). You can't turn off the IS, so I hope it knows whether it's hand-held or on a tripod! (As it happens, I have three tripods and a monopod, but I rarely have occasion to use any of them. So maybe it won't matter.)

[Stephen]

Hey guys!

For the last few years, some of our lenses actually do know whether they're on a tripod or not, so if you leave the IS on, and the lens doesn't detect movement, it'll automatically turn off the IS. I won't pretend to know how it works (maybe an accelerometer), but if you want to geek out, I'd be willing to bet our Tech Support folks know exactly how it works and which lenses have the feature, and they'd love to talk to you about it!

If you wanted to talk to them, they're at 800-OK-CANON

[cale_kat]

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@ebiggs1 wrote:

Big telephotos have a learning curve. The bigger tele, the longer that learning curve will be.  And 1/8000 is not the answer.

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@ebiggs1 wrote:

Is 1/8000 better than 1/80? Absolutely but it in itself is not the answer.  The answer has several aspects, not shutter speed alone.

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Sounds like you'd like to have it both ways. Not the answer or maybe part of the answer. I'd like to know which.

[ebiggs1]

"Well, I just bought the new 16-35mm f/4L IS lens (not even out of the box yet). You can't turn off the IS, so I hope it knows whether it's hand-held or on a tripod! (As it happens, I have three tripods and a monopod, but I rarely have occasion to use any of them. So maybe it won't matter. 🙂 "

Well, Bob from Boston, I bet it is new enough that it does have the intelegent IS.  It is a great lens, BTW, and you will love it.

Actually the vast majority of lenses that do have IS do not know when to turn themselves off.  Despite the post by the Canon rep.  The fact of the matter is a significant number of photographers use lenses made by other manufactures and their lenses have no clue.  It is a wonder that any of them work at all. 

I doubt IS on a 16-35mm is as big a helper as it is on a 500mm lens.  That must be taken into consideration.

My recommendation to you is the try it both ways.  Get out your biggest tele put it on a tripod and shoot (a lot of photos).

Keep track.  Back in the day we had to learn by trial and error as there was no internet to tell us every little nuance of photography.

And I still believe it is the best way to learn.  If you don't like my thoughts on the subject, you will quickly decide for yourself.

It's what makes photography so interesting, isn't it?  

I am turning green with eny  of your new 16-35mm, please let me know how you like it.

[ebiggs1]

"Did you see that I've just become a "Frequent Contributor"?"

Congratualtions.  I didn't see it but I do now! 

[bento2]

Stephen,

What about a list of those that DO turn off the IS when on a tripod. I get varying answers depending who I talk to at Canon in Australia.

My 100-400L doesn't appear to turn off. When on a tripod, the Focus point slowly wanders around - guess this is the result of feed-back from the sensor?

[ebiggs1]

"My 100-400L doesn't appear to turn off."

It doesn't.  More don't that do. 

[Stephen]

Hi bento!

I've spoken with one of our senior techs very briefly, and he says your lens is one that you do, in fact, have to flip the switch.

He said that while we don't have a list of lenses that automatically turn off, generally speaking it is usually the super telephoto lenses. He mentioned anything smaller than the EF 100-400 L, you'd have to flip the switch. 

While I know this might not be the news you were hoping to hear, I hope it helps out some!

[bento2]

Thanks Stephen! Helps out a lot by clearing up the issue.

[ScottyP]

I don't think the tripod will help with these images. Even without IS the minimum reciprocal shutter speed on 200mm's is 1/320 second on a crop body. Counting IS you are probably able to handhold reliably at considerably slower speed.

The OP already stated he knows shutter speed is important and offers 1/600th as a starting shutter speed. Since tripods only address camera shake, not subject motion blur, if he is shooting a shutter that fast then camera shake is irrelevant. Birds are fidgety even on foot, so slow shutter tripod work is out of the question due to subject motion blur.