leftj Loc: Texas

But you are condescending, not just considered to be. When it comes to your sense of self, your cup runneth over which is another way of saying you're full of yourself.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

"You might well think that, I couldn't possibly comment." - Francis Urquhart.

leftj Loc: Texas

A quote from a fictional character. How fitting.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Well, at least you understood the reference. None of us are perfect, including your good self, as a review of anyone's posts will show.

Perhaps the question should be more about intent, motivation, and the resulting effect.

leftj Loc: Texas

Actually the question was regarding BBF and shutter speed.

RRS Loc: Not sure

It appears that with the composition that your focus point was on the young ladies sitting against the wall. You can move the focus point to the right in the view finder and maintain the same composition and your focus point would then be on your grand daughter. There are several ways to accomplish this shot.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Ya think? I was responding to your comment.

The OP's question was not about BBF and shutter speed as you suggest, despite the title. It was about the quality of results he was getting from the techniques he was attempting to use, and the coordination of those separate functions.

Focus points, exposure, shutter speed, aperture and composition all affect the final image. Independent of anything else, that's four or more separate variables that need to be balanced and coordinated which is not easy to do.

An understanding of each of those aspects and their influence on the final image is important if the desired result is to be acheived.

It is clear from viewing the image posted by the OP and from parsing his question that he understands the principle issues but has not yet mastered coordinating them, which is not easy to do in such circumstances when there are so many variables in play.

There isn't really a quick fix to the OP's problem. The long fix is to understand each function, practice with them independently, and then how they work in combination.

It is not dissimilar to being able to drive a powerful rear wheel drive, stick shift vehicle on snowy mountain roads. Many people end up in the ditch as a direct result of insufficient understanding of the circumstances and the choices that they make.

leftj Loc: Texas

I think you would probably be better off on a driving forum.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Ya think? I sometimes wonder about that!

anneabc

It's certainly not just Hoggers that have been so wonderful with advice. It's Youtube videos.

amfoto1 Loc: San Jose, Calif. USA

There's your problem.

After achieving focus and BEFORE you RECOMPOSE, you have to release the back button you're using for focus. If you don't, the camera will re-focus on whatever is covered by the active AF point(s).

Think of back button focusing as giving you a means of starting and stopping AF separately from the shutter release button.

BBF is popular with sports photographers, in particular, because of situations just like that in your photo. Shooting sports, there's simply no time to change the AF point, as some others have suggested. BBF is the ONLY way to effectively use "focus and recompose" technique when using a continuous focus mode (AF-C, in the case of Nikon) such as is pretty much required for sports or any other type of action photography.

It has nothing at all to do with shutter speed, as mentioned in the title of your post.

anneabc

Thanks, amfoto1, so what I've been doing is holding the bbf button down when recomposing.
Now, does this rule apply to stationary subjects also while recomposing? AF-S?

leftj Loc: Texas

If you're on "one shot" auto focus BBF will not refocus unless you release and then press it again.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I think you have got the concept now. It isn't really about BBF so much as what each button or function performs. BBF is not the same as continuous or servo focus. It is simply which button activates a function. Press / release captures focus, but doesn't change it until pressed and captured again. No need to refocus if the distance does not change. If the subject is moving, continuous refocusing makes sense, so holding the focus button down makes sense. The same applies to metering / exposure. If using spot metering then locking the exposure and then recomposing is a choice. Changing the composition will clearly make a difference to those things.

Essentially you are choosing to control the focus points and metering points of the image, rather than letting the camera do it for you. Focus, exposure and composition are separate things that you need to control if you wish to take control yourself. These things are not easy, and understanding how any type of automation works is important if you wish to be the person that controls the decision process. Automation isn't a bad thing, quite the contrary, but if you don't understand what it does then it can become very confusing.

Ask Mark Zuckerberg!

Mary Kate Loc: NYC

Dear boy, I do not pontificate. Besides your rambling diatribe was not directed towards me. It was in response to someone else with a question.