photodoc16

I was about to convert my 7DII to BBF when I watched a video that mentioned, on this camera, you could not separate the focus from the metering function. Is this true and, if so, how to these two functions interact?
Thank you, Hogs
Photodoc16

IBM

It's no different than focusing wth your shutter , we'll it's different in a good way .you hold down the back button make sure it's set on continues focus ,, put your black dot on the bird and snap away or hold the shutter down , and follow bird and see how many you get in
One go , if the bird is sitting in a tree , hold back button down tell it's in focus then you can let go and and shoot all day long witout refocusing on that spot , you will only have to focus again if bird jumps to another branch then focus once and shoot tell it jumps to a different tree , it will become second nature to do in about a hour of practise , an there is no cost like zapping of a roll of film

Longshadow Loc: Audubon, PA, United States

I'm puzzled as to why they would say that. Having them separate means you don't have to worry about the focus point(s) hitting sky or tree limbs, depending on your composition. I love having focus and metering functions separate! (They don't really interact, other than both functions are performed with one button.)

Nalu Loc: Southern Arizona

Whoever made that video is wrong!

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I'd like to see the video but I am going to guess that what the video was stating is the focus point that is used for BBF will also be used for metering, which may be true.

Wingpilot Loc: Wasilla. Ak

I don't know if the Canon system is any different from Nikon's, regarding BBF and AE lock, but here's how my D7200 is set up. I set it up for back button focus, and the shutter button to AE lock, meaning as long as the button is held down half way, the exposure is locked. Otherwise, I suspect your only other alternative is to set the back button to AE lock and use the shutter button for focusing. But then you have to hold the shutter button down to keep your focus--so long as you are in AF single, not AE-C. Or I could be completely out to lunch on this.

photodoc16

Hogs,
The "guy who made that video" WAS wrong. I switched to BBF and, indeed, the metering function remains with the shutter button while the focus is now assigned to the AF-ON button. Now comes the experimental stage. I must admit that some of the hype surrounding this maneuver seems to be a stretch and many of the you tube videos are awful. However, I will see what happens.
Thank you all for your help,
Photodoc16 (or PD16)

amfoto1 Loc: San Jose, Calif. USA

It's super easy to set up BBF on 7DII... That video is incorrect.

In fact, with the factory defaults BBF is basically already set up. The AF On button on the rear of your camera, under your thumb, will start auto focus. But so will a half-press on the shutter release. So to truly "do BBF", all you need to do is go into the button assignment/customization menu and disable AF at the shutter release button. The shutter release setup the very first item under on that menu page and once you've navigated to it, simply change it to the middle setting (I think it's labelled "Metering").

Done. That's all there is to it. You're now "doing BBF".

In fact, metering (and image stabilization) will still start either when you half-press the shutter release or when you press the AF On button on the rear of the camera. That's fine and what you normally will want the camera to do.

It can sometimes be desirable to do, so if you want the camera to stop metering and changing the settings when in the auto exposure modes, use the separate AE Lock button, which is right next to the AF On button.

One of the primary reasons to use BBF is to be able to use AI Servo as your default focus mode setting, with both stationary and moving subjects.

Without BBF, there are times when AI Servo can be a problem, such as if using a "focus and recompose" technique. With BBF enabled, you activate AI Servo AF by pressing the button with your thumb and once focus is achieved on a stationary subject, if you want to recompose, lift thumb pressure off the button so that focus remains set on the subject and recompose as you see fit.

Having the camera in AI Servo mode all the time and using BBF lets you be ready for anything... moving or stationary, focusing & recomposing or not.

One advantage to AI Servo is that many zoom lenses today are varifocal, meaning they don't exactly maintain focus when you change the focal length setting. If you are using One Shot, you have to remember to stop focusing and restart it after any zooming. If you are instead using AI Servo, it will automatically and instantly correct the focus is the lens doesn't maintain it when zooming.

If you use Spot Metering, keep in mind that it sn't linked to the active AF point. It remains at the center (as defined by an engraved circle on the focus screen) on the 7DII, as with most Canon cameras.

However, if using Evaluative, the metering will put extra emphasis at your active AF point(s), sort of assuming that's the primary subject and most important part of the image area to meter.

This is similar to, but not exactly the same as AF-linked Spot Metering (which 1D-series cameras have, though it is limited to a reduced number of AF points in some models).