Need Tips (focusing)

[swampler]

Sounds like it's hunting focus. Probably so if there's not much light.

[E-Man]

Originally Posted by swampler

This could be part of your problem. The 30D cams are designed to AF with f/5.6 or faster (smaller number) lenses. That 100-400 at f/6.7 is outside of the 30D's spec for AF.

Steve, I was going to point out this very same issue. If your 100-400 is fully extended, it goes to f6.7, which prevents the AF from working.

Also, I have experienced similar camera performance when tracking one subject and then shifting to another subject (or even just a momentary loss of the subject you are tracking) making the camera "hunt," which then makes it almost impossible to re-acquire focus lock on a moving target until the "moment of interest" has passed. I'm still struggling with this form of operator error myself Practice, practice, practice...

[gryphonslair99]

Originally Posted by swampler

How would it focus more quickly? The camera will always use the maximum aperture for focusing and close the aperture blades down only when the shot is taken (or the DOF preview button is pressed).

Sorry, my explaination was probably lacking. It's not so much faster focusing as a compensation. If you are shooting action and your depth of field is 6 feet and you change subjects you have 6 feet of in focus area. If however you shoot with a very small aperture you may have 40 or 60 feet in focus, maybe more. When you switch and click rapidly you increase the chances that the new action is still inside the area of focus (dof).

Not the way I would want to do it, but it will increase your keeper rate.

[gryphonslair99]

Originally Posted by obtr32

Right... gryphonslair, I understand all that. Remember, I normally shoot in manual...only occasionally I go with the autos...IE...TV, AV and the likes.

What my problem is, when I "unlock" from the action and then "re-lock" onto a new one...why does the camera choose the back wall first?

I'm talking when two of the action shots are almost the same distance away...but in diffrent a direction...

Here is the proses ..I'm following a player in servo and then someone falls just to the right....I stop pressing all the buttons...point the camera dead center of the new action....restart the the focus proses...and then wait for the focus to start from the back wall to the subject....

If the new action is close to the same action I was shooting at....you would think that the lens wouldn't have that much to move....however...it seems that once you stop the focus proses...it goes stupid.....

It might just be the lens....but I notice this a lot. Not only in sports. When I shoot portrait, I watch the proses...and there too....the background comes into focus first before the subject...

That's great....but when you got less then a second to get the shoot...I don't have the time to wait for the camera to decide...

That is focus hunt. The new camera is now trying to focus on the contrast. It has a 50/50 chance of getting it right. It may be a manufacturing design of Canon that it when it hunts it starts deep and comes back. If it started shallow and then deepened it would still only give you that 50/50 chance.

[Rodeoshooter]

I shoot rodeo all the time. In the dark, in sun and shade often times at the same ride. Every weekend I shoot up to 5,000 images. I have less than 1 percent out of focus.

I think your problem is the lenses you are using. You didn't mention what the Canon lens is but noting it is a variable apature I would guess it is a EF lens but is it USM? The cheaper lenses and bodies don't have the focusing speed of the 1D or 1DS nor the "L" series lenses.

Just MHO but I would guess it is the answer to your issue.

Spend money for better results.

Originally Posted by obtr32

Sorry...had to work.

Um...I have played around a little with the focusing points. Lately, I have been using a focusing point that would be center...but now that I'm reading this, I'm thing of changing....

Sometimes, out of frustration, I do let the camera decide...but not very often. I've been finding out that the "autos" setting haven't been working for me. When I say "autos" I mean the auto and portrait settings...

With E-man's suggestion of the lens focusing on the nears object first...I'm having the problem of focusing on the farthest first...

For some reason, I can't seem to shoot well in the sports setting. The place that I shoot is very dark...and I find it easier to shoot when I got control over shutter and aperture....

What do you guys think about moving the focusing point down (center)? Would that keep it off the back wall?

Oh...the two that I like to use is a Canon 17-85 f/4-5.6 and a Promaster 100-400 5.6-6.7....

[swampler]

Originally Posted by gryphonslair99

Sorry, my explaination was probably lacking. It's not so much faster focusing as a compensation. If you are shooting action and your depth of field is 6 feet and you change subjects you have 6 feet of in focus area. If however you shoot with a very small aperture you may have 40 or 60 feet in focus, maybe more. When you switch and click rapidly you increase the chances that the new action is still inside the area of focus (dof).

Not the way I would want to do it, but it will increase your keeper rate.

I would agree with that! In fact, I had to stop down my 85 f/1.8 to f/2.8 to compensate until I got it calibrated, and even then it wasn't a very good solution, but I couldn't stop down more and get a decent shutter speed.

[obtr32]

Right....and that is my exact problem...

That too is my complaint...

Like I said, I was sitting right next to a guy and I'm pretty sure we were close to the same settings...even our lens was pretty close to the same...

Do other brand cameras have a shorter...um..."focus hunt time"?

So my question is...other then getting more light..is there anything that I can do to reduce the focus hunt?

P