Struggling with BIF - "focus on whatever is nearest?"

[TheGaffer]

I want a "Focus on whatever is nearest" mode.

Last weekend, I had my first stab at BIF. I spent the weekend at Skomer.

It's not what I usualy do, so I don't have a classic birding kit. I was using a 1DsIII with a 200mm f2.0 and 2x converter, giving me an effective 200mm f/4.

It seemed like excellent conditions for learning - bright light and a never ending supply of puffins flying past to practice on.

I had the camera set up with centre focus with surrounding helpers, AI-servo controlled by my thumb, so I figured that I was all set.

But it proved almost impossible. Puffins are incredibly small, darty little things. It was just about all I could do to keep the thing in the viewfinder, let alone nailing the focus. On every pass, I would slip off the bird onto the cliff face behind and never get the bird back.

Taking against a blue sky was easy. You can be miles out of focus, point in the right direction and the camera will find and track the target. But against a background, I just don't have the skill. I tried taking the 2x off but that makes the target even smaller, which doesn't seem to help.

Bucketloads of skill would help but I think that the camera could do more to help me. I just need a setting which says "look at all 45 focus points and focus on whatever is nearest"

Is there such a setting? Or am I being unreasonable?

Andrew

[Ken Nielsen]

The camera will not help you. You need to help yourself. I'm in the same boat that you are in: learning by doing. It takes a lot of doing. Shoot each day over a month, and then two months shoot every morning and go ponder the results. You will begin to notice improvement. Post your best here, even if it is a blur, that way, the experts can comment and give you specifics based on what you are getting.

Best,

Ken

[TheGaffer]

Post your best here, even if it is a blur, that way, the experts can comment and give you specifics based on what you are getting.


The best ones are showing promise:

This one was easy - he came in across the blue sky.

http://www.tug.com/blog/20090616_Skomer/400/136I9306.jpg

I got this one because he was close and slowing down to land:

http://www.tug.com/blog/20090616_Skomer/400/136I8546.jpg

And this is the best of the nearly impossible full speed flight against the cliff.

http://www.tug.com/blog/20090616_Skomer/400/136I8552.jpg

I'll certainly do it differently next time, I threw away two or three stops in PP on the last two but the real problem is pass after pass of focusing on the cliffs.

Andrew

[Ken Nielsen]

The best ones are showing promise:

See. You are doing great, with nothing but improvement to look forward to.

Keep up the good work,


Ken

[joayne]

I think you made a mis-type as with a 200mm 2.0 with the 2x converter gives you 400mm at 4.0.

Using the converter slows the ability to focus quickly and the little puffins are quick and darty so you will always be just a spot behind.

I use center focus point, AI - Servo mode and multiple shot mode. I get a fair keeper rate, but it has taken me a couple years of shooting on a weekly basis at a wetlands. I get a little excited and tend to bang the shutter button rather that squeeze it causing a bit of camera shake. Tripods with gimbel heads make a world of difference. Also I see you shooting at f/4 which doesn't give you much room for focusing errors.. I shoot at f/8 and above.

Practice... ... and Good Luck!

Oh, I shoot with the 100-400 L and a 300mm Prime with a 1.4 converter all on a crop body 30D for just a bit extra reach :)

[BradM]

Check your custom functions, I believe it is the same as the 1D3; C.fn III-2 and make sure it is set to slow or moderately slow. The settings description leads one to believe it should be set to fast to make the AF more sensitive however this setting is to inform the camera how quickly you want it to pick up a new subject that may come into the frame, like the background, slow it down and and the camera will stay on the subject more often.

You may also want to change C.fn III-5 to 1 if it is not already set there. What this does is slow the hunting is a lost focus situation and speed up to the re-acquisition of the subject when it drops out of focus. This can lead to a few more ooof situations but reduces the aggravation of getting it to reacquire.

Hopefully these help the most but to be honest even though the glass is fast the 2x will slow down the AF system so you also need to be sure to try to work those subjects that the camera can best predict there path. In my experience it is usually those subjects coming in at a slight oblique angle over straight on or crossing.

As to stopping down to increase dof and pull more of the subject into focus is one technique but of course has drawbacks like slower shutter speeds and harder bokeh but it can work, better is to just be sure that the AF point is on the head instead of the wing, this really becomes an issue with subjects larger than the little puffins.

There is another custom function that can help keep the AF point on the head if for example the wing covers the head and the AF will shift slightly and then go back to the head. C.Fn III-8-1 or -2, it is best to also set C.Fn III-4-1 so the camera will continue to track the main subject.

[canonloader]

I set C.Fn-17 to 1 a couple weeks ago and it fixed a lot of AF BIF problems I was having.

Set to Option 1, the 7 AF sensors immediately around the selected AF point are also activated.

Option 2 increases this to 13 points.

What Option 1 does is it uses the center focus point "as long as it is on the bird". When it wanders off cause your waving around like the conductor at the Philharmonic, then the 6 points around the center one will become active. This really helps me keep focus on the bird, as proven by all the great in-flight shots of Herons I got from a moving boat last weekend. It works, give it a try.