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**Mark Ralph** · 2007-07-21, 19:09

Unless you are shooting in low light turn IS off. I can't see why these type of shots you refer to cause any more trouble than shooting anything else. When you say "Trying to capture" are they blurry, underexposed ?

**colinkeightley** · 2007-07-21, 19:18

I have a focusing problem with my 100-400IS everytime I switch on the IS I only get around 1 in 5 shots in focus thats when used with a 400D body

**Mark Ralph** · 2007-07-21, 19:33

It's not on AIServo is it?

**colinkeightley** · 2007-07-21, 20:14

Mine is on 1 shot focus

**Mark Ralph** · 2007-07-21, 20:37

I have never been happy with the result of AIServo that's why I asked, I have had lots of blurry shots using it. Well with that ruled the only the that comes to mind is maybe your so fast with the shutter the frame is being captured at the moment the IS is activating.

**B7772ADL** · 2007-07-22, 09:24

I've always tended to stick to one shot as AI Servo produces inconsistent results on my 20d and that was using it with a 100-400 or a 70-200.

Steve: my JUNK terminology for this lens is totally tongue in cheek as i had a bad copy of the lens with many problems with it which has been documented many times in these forums. There are some good copies out there but there are also many people who have problems. Until you experience some of the other zooms in the L range you don't realise how mediocre the 100-400 is...it's simply an above average all rounder but it's not a superstar.

**steve** · 2007-07-22, 19:36

Follow Up on IS Canon Focusing Problem

Hey ""Thanks"" to all for the feedback. Let me follow up with more information.
Yes, I have it set on High Servo,,,,, 4 frames per sec. I don't want to miss a thing,,,ha,ha. Maybe that's the problem. You guys all take single pictures with these long zooms ??? Also I'm on continueous focus.. Pictures in low light are a mess, more light are a bit better.
I shot some yesterday and the panning shots were okay. I might get one clear pic out of 6 on high servo ( 4 frames per sec). I'm fine with that.
The pics coming at me were all fairly fuzzy and those should be the easiest to track and get good clear shots in my opinion.
I guess I should try the slower Servo, and single pictures, Huh ???
I got to tell you though, that IS Mode 1 for shots around the house where you're not panning is great. Almost like using a tripod,,,,,,

Thanks again,,,,,,,,,, Hey is there a Spotters Group in Cincinnati ??
Later,,,,,,,,,,,,,,,,, Steve

**dheald** · 2007-07-23, 05:41

Originally posted by colinkeightley

Mine is on 1 shot focus

That's why you only get one "focused" shot of a moving subject. One Shot means that the camera focuses on the subject and locks in that focus for that instance. That mode is well-suited for stationary subjects. AI Servo keeps the focus active to track moving subjects. AI Focus automatically selects either of the two other focus modes (AI Servo or One Shot). Try using either AI Servo or AI Focus.

Dean

**colinkeightley** · 2007-07-23, 11:40

Originally posted by dheald

That's why you only get one "focused" shot of a moving subject. One Shot means that the camera focuses on the subject and locks in that focus for that instance. That mode is well-suited for stationary subjects. AI Servo keeps the focus active to track moving subjects. AI Focus automatically selects either of the two other focus modes (AI Servo or One Shot). Try using either AI Servo or AI Focus.

Dean

But I only take 2 shots before refocusing for the next. I take a 2 shot burst then lift off.

**cja** · 2007-07-23, 14:09

You may have already ruled out the following factors as possible causes but if not they might be worth considering.

It would be interesting to know what shutter speed you are using for these shots and also which focusing points are selected. The f stop will also make a difference especially at the 400mm end of the range. At maximum zoom your depth of field will be reduced especially if you are using a wide aperture. If the camera is selecting a focus point that is not ideal then this will also have an effect. The camera might well be focusing on background or foreground objects rather than the aircraft or at least not on the best point of the aircraft to get the best depth of field. A slow shutter speed might also be a factor with an aircraft moving either directly towards you or away from you especially when you are filling the frame with the aircraft.

(You can check which focus point is selected for each picture by reviewing the image using the Canon Viewer Utility that I believe comes with Canon cameras.)

For all situations where the subject is moving I use AI Servo with IS mode 2. With an AC moving either away from or towards you, you may well still be panning slightly, so I would suggest you stick with mode 2, (unless the light is good enough to turn it off). For focusing I just select the centre spot to reduce the chance of inadvertently getting a miscued focussing point.

Marks comments re AI Servo are intersting and I would love to know if he uses Canon or another make.

**Mark Ralph** · 2007-07-23, 14:27

Originally posted by cja

Marks comments re AI Servo are intersting and I would love to know if he uses Canon or another make.

Yes Canon, I must add though. Using AI Servo was a whole lot worse on the 100-400 when compared to the EF300 F4 L IS.

I read the other week that the 100-400 L IS is not considered a true L lens possibly why AI Servo is not quite as effective when using this lens, I don't know just a thought.

**colinkeightley** · 2007-07-23, 15:11

I use centre focus point allways I use shutter priority at around 600th to 1000th and the main photos I had a problem with were at 100mm I get better results with the IS turned off I dont think Ive had a good photo with it at slow shutter speeds. At the moment I avoid using the 100-400 in favour of my good old Sigma 50-500 me and my dad camera share with 2 bodies and 2 lenses so it cant always be avoided I get excellent results with the sigma

**cja** · 2007-07-23, 15:31

I have never used 100-400 but I suspect most of the problems people have with it or more down to things like camera shake and depth of field issues. Despite what people say it does produce some great shots and at the end of the day I think composition is more important than the fine technical differences between these lenses. Having said that, if there is a difference in performance in IS and AF leading to out of focus or blurry images then people do need to be aware of the limitations..

**steve** · 2007-07-23, 23:39

Canon IS Focusing Again

Hey THANKS to CJA, Mark, Colin & James for the feedback. Well, after reading all the info and going back to the simple instruction manual for the Canon 30D, I found I set the auto focus on AlServo thinking that was the Continuous Focusing Mode,,,,,,,Duh,,,,,,,,, I also have a Nikon D200 and I think the Continuous Focusing on that is the 3rd option on the LCD screen, and the 3rd option on the Canon is AlServo. So,,,,,,,,,,,,,,,, I will change that to AlFocus the 2nd setting and try some pictures on single shot, use the Aperature Program and use F8 with speed around 1/400. I'll also try some multi shots at 3FPS, then see what the 5FPS does. 'll also try swithching the Focus Point from center to 9 point, and I'll try and compose better shots too.
I use this Canon 100-400 alot at 300-400mm. I'm always trying to get close with the shots, unless the planes are flying right over me, which is rare. The closer shots just show more detail, although focusing is tougher.
I've gotten some nice pics with the Nikon D200 and a cheap 300mm G lense. It's really all in the ability to move right with the plane. When you're panning quickly, it takes the shake out of the lense. When you slow down you can that lense shakin all over the place, thus the IS feature. It is a neat gimick, and it does work.
Okay, let me try some more shots and see what happens. One good thing about the local Airport is,,,,,, There's always tomorrow !!
ThAnKs again you guys,,,,,,,,,,,,,,,, Steve

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