Back Button Focusing
Oct 19, 2016 13:25:21 #
davefales wrote:
The subject of BBF has been discussed many times here. There is a wealth of info available for you to search.
I use BBF and find the major challenge is when you hand your camera to someone else and tell them to use BBF. (Some times the photographer wants proof he/she was there too.)
I use BBF and find the major challenge is when you hand your camera to someone else and tell them to use BBF. (Some times the photographer wants proof he/she was there too.)
Don't know how other cameras operate ( Nikon, Sony, etc ) but with my Canon Rebels one needs to only set the camera to either the "A" or "P" mode on the dial and the auto-focus is back onto the shutter button, like a regular camera. Kinda turns the DSLR into an expensive "P & S". When you return the dial to "M" "Tv" etc the auto-focus reverts back to BBF. I have no problem handing my camera to an innocent bystander to take a quick pic of me and my better half while on a trip.
Ron
Oct 19, 2016 13:44:53 #
LittleRed wrote:
Don't know how other cameras operate ( Nikon, Sony... (show quote)
My Nikon doesn't work that way. If it's set to BBF, it's still on BBF in auto mode
Oct 19, 2016 17:34:08 #
No,the only time you have to keep the BBF button pressed while taking a pic is when the subject is moving,that's why you have to set BBF on continous mode. Jim Bianco
Oct 19, 2016 18:45:05 #
Jim Bianco wrote:
No,the only time you have to keep the BBF button pressed while taking a pic is when the subject is moving,that's why you have to set BBF on continous mode. Jim Bianco
Don't confuse the OP. You don't set the BBF on anything. You set the CAMERA on continuous AF. On Nikon, it's called AF-C. Then you set a button on the back of the camera to AF-ON. 2 simple changes.
Then, you just have to remember that your focus button is on the back. Set it and forget it as long as your subject doesn't move. When you're ready, press the shutter button. If they start moving, press & hold the back button to keep them in focus. No need to change anything else.
Watch the videos posted by Jerry. It will all become Crystal clear.
Oct 19, 2016 19:12:52 #
rmalarz wrote:
It's a button I'm still trying to understand why they even bothered putting that on a camera. Tried it, don't like it. Personal opinion and YMMV. The shutter release button pressed 1/2 down will activate auto focus.
--Bob
--Bob
I agree. I tried it for a week and just could not get used to it. I'm left-eyed and that made it harder.
Oct 20, 2016 13:54:49 #
I understand setting the camera for BBF and pressing once for a stationary subject and holding for moving subjects but how does all of this affect auto-exposure?
Oct 20, 2016 16:20:55 #
Geegee wrote:
I understand setting the camera for BBF and pressing once for a stationary subject and holding for moving subjects but how does all of this affect auto-exposure?
It's just separating auto focus from the shutter release. Autofocus is done by the camera. Manual focus is done by adjusting the ring around the lens yourself to obtain focus. I hope I answered your question. It's not auto exposure
Oct 20, 2016 20:27:12 #
GrandmaG wrote:
It's just separating auto focus from the shutter release. Autofocus is done by the camera. Manual focus is done by adjusting the ring around the lens yourself to obtain focus. I hope I answered your question. It's not auto exposure
I know but when you release the shutter auto focus is activated. Using backfocus separates focusing from exposure. I am no clear as to how exposure is affected.
Oct 21, 2016 06:29:01 #
For example when shooting BIF your metering continues to change as you follow the bird, unless of coarse your settings are in manual mode.
Geegee wrote:
I know but when you release the shutter auto focus is activated. Using backfocus separates focusing from exposure. I am no clear as to how exposure is affected.
Oct 21, 2016 07:15:42 #
Geegee wrote:
I know but when you release the shutter auto focus is activated. Using backfocus separates focusing from exposure. I am no clear as to how exposure is affected.
Releasing the shutter does NOT activate the focus when you are using BBF ( the back button does the focus & then you take the picture), nor does it separate focus from exposure. You are making this way more complicated than it is. Exposure is completely separate from focusing. BBF separates focusing from accuating the shutter to take the picture. The exposure triangle determines the exposure 1)aperture 2)shutter speed 3) ISO. Read Bryan Peterson's book, "Understanding Exposure"" this is a whole different topic and not at all to do with the original question.
There are some very good explanations on this thread as well as some excellent videos. Maybe they can explain it better than I.
Oct 21, 2016 12:47:34 #
martinfisherphoto wrote:
For example when shooting BIF your metering continues to change as you follow the bird, unless of coarse your settings are in manual mode.
Thank you masrtinfisherphoto. That is what I wanted to know.
Oct 21, 2016 17:00:04 #
collhart wrote:
Once you achieve focus do you have to keep the back button focus depressed when you take the picture?
If I understand correctly, NO, only if your subject moves, tell me if I am wrong please.
Oct 21, 2016 17:25:29 #
Oct 21, 2016 19:06:37 #
When using back button focus, which is basically, "auto focus continuous" not only does your camera continue to focus but your exposure changes as well. For example if your in Aperture priority and have a fixed ISO your shutter speed will change as you follow the bird thru different lighting. So on and so forth. Personally I use manual for the most part now, but used aperture priority for the longest time with Spot metering to set the exposure..In combination, Using only the Center focus point, which help to Always keep the bird as the primary focus point plus Metered part of the photo.
GrandmaG wrote:
Releasing the shutter does NOT activate the focus ... (show quote)
Oct 22, 2016 14:10:37 #
martinfisherphoto wrote:
When using back button focus, which is basically, ... (show quote)
I did not know that the exposure changed in Aperture Priority mode while using BBF. I usually shout in manual, so you're saying that exposure doesn't change when using Manual? What if you're in Manual with auto ISO turned on; does the exposure change then?
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.