Back-button focus for Birds (Page 2): Yes, this works quite well. That is how I normally do autofocus when in my floating blind. Sometimes birds are still, and other times swimming...

John Gerlach Loc: Island Park, Idaho

bleirer wrote:

Focus lock is also possible in servo mode by re-assigning a button to disable AF (AF-ON ironically is the best choice). You keep the shutter on the usual half press in servo mode but when it is time to recompose press the af-on and it acts as focus lock, keep it pressed while you take the shot, release it and you are back to servo mode.

Yes, this works quite well. That is how I normally do autofocus when in my floating blind. Sometimes birds are still, and other times swimming toward me. Due to the angle I have to hold my arms in the float, it is more difficult to use back-button focus, so I keep it on the shutter, but should I get a still subject, then I force myself to press in the AF-on button to lock focus.

bleirer

John Gerlach wrote:

Yes, this works quite well. That is how I normally do autofocus when in my floating blind. Sometimes birds are still, and other times swimming toward me. Due to the angle I have to hold my arms in the float, it is more difficult to use back-button focus, so I keep it on the shutter, but should I get a still subject, then I force myself to press in the AF-on button to lock focus.

It has all the advantages of regular BBF in my mind, and takes care of some of the downsides, like having to hold your thumb on continuously.

OllieFCR

John Gerlach wrote:

It is too bad Canon does not put AF point along the margin of the image where the head of my subject sometimes is.

You can move the focus point wherever you like on the 7D Mark II and most other Canon DSLR's with the multi-controller.

Notorious T.O.D. Loc: Harrisburg, North Carolina

I use BBF and AI Servo 99.99 percent of the time...

mborn Loc: Massachusetts

John Gerlach wrote:

I continually switch between a back-button focus method and having autofocus on the shutter button. It all depends on the situation. For all action photos where you need continuous focus all the time, I find it is simpler to keep the autofocus on the shutter button as then I don't have to fuss with the back-button AF-On button or the button to the right of it as I typically assign that to back button too. I do not have any problem with half-pressing the shutter button to force autofocus and then pressing it all the way down to shoot images.

But, for the harlequin ducks and the sandhill crane in Yellowstone during May, I selected back-button. The harlequins mostly swam and dove, but movement was nothing like flying birds. At times they held still while perched on rocks in the Le Hardy Rapids. For swimming birds, I held the back-button down while keeping the active AF point on its head as best I could - not easy when they move erratically and then dive out of sight. With a duck holding still, I put the active AF point on its head, push the AF-On button down, the lens focuses on the head, let up on the AF-on button to lock focus, recompose and shoot keeping the focus on the bird's head.

When I do have the autofocus assigned to the shutter button, I find using my right thumb to move the active AF point around is effective, but often there is no active AF point where the head of the bird is near the edge of the frame like the sandhill crane. Then back-button works well as the active AF point does not need to be on the target when back-button is used properly. Sometimes I also assign the AF-ON button to stop continuous autofocus when it is held down. I am doing that more and more when using my floating blind from Mr. JanGear. There are numerous other angles to back-button, so perhaps it is time for me to write another article on the topic for Nature Photographer - the magazine I have written a column in for more than 20 years. By the way, I also like to use the Touch screen autofocus in live view with my Canon 5D Mark IV and it does not work unless I have autofocus assigned to the shutter button. And it is convenient to assign back-button to two buttons on the rear of the camera that have a different autofocus point array. Then I can select a single AF point or a small cluster of active AF points just by the back-button option I decide to use. www.gerlachnaturephoto.com

I continually switch between a back-button focus m... (show quote)

martinfisherphoto Loc: Lake Placid Florida

I assign auto focus continuous and metering to my back button and only shutter release for the shutter button. This makes life so easy. If subject is moving keep BB pressed if subject is not moving release BB as you're already focused and metered on subject.

Cwilson341 Loc: Central Florida

Awesome photos, John, and very helpful information!

bleirer

martinfisherphoto wrote:

I assign auto focus continuous and metering to my back button and only shutter release for the shutter button. This makes life so easy. If subject is moving keep BB pressed if subject is not moving release BB as you're already focused and metered on subject.

Just curious, can you manual focus when you release your thumb, if needed?

whitehall Loc: Canada

bleirer wrote:

Focus lock is also possible in servo mode by re-assigning a button to disable AF (AF-ON ironically is the best choice). You keep the shutter on the usual half press in servo mode but when it is time to recompose press the af-on and it acts as focus lock, keep it pressed while you take the shot, release it and you are back to servo mode.

To follow up does bb work if one uses a remote trigger?

wapiti Loc: round rock, texas

speters wrote:

I haven't used the shutter button in probably 20 years, I only use BBF and I use it for everything, I never switch anything around, but that's just me

bleirer

whitehall wrote:

To follow up does bb work if one uses a remote trigger?

Good question, my camera has a phone app for remote operation, but I haven't really explored it, maybe somebody else knows?

foathog Loc: Greensboro, NC

Notorious T.O.D. wrote:

I use BBF and AI Servo 99.99 percent of the time...

Me too. Have found NO reason to switch.

peterg Loc: Santa Rosa, CA

On my Nikon D850, I set one rear-camera button to BBF group area. Activate with my thumb. I set a front-camera button to single point focus. Activate with my index finger. My Nikon focus "bible" is Steve Perry's "Secrets to the Nikon Autofocus System" book.

suntouched Loc: Sierra Vista AZ

John- thanks for the post. It validates for me that the focusing via the shutter button still has its time and place as well as BBF. Most of the proponents of BBF state something to the effect of " I changed to BBF and never looked back" whereas it makes more sense to me to use both methods depending on the situation. Sweet shots!!

martinfisherphoto Loc: Lake Placid Florida

bleirer wrote:

Just curious, can you manual focus when you release your thumb, if needed?

Yes, I have the lens set so I can override the auto focus just by grabbing the lens focus ring and adjusting the slightest amount. Several setting options on the nikons.