PDA

View Full Version : Back focus technique vs. metering



Tiago Caravana
03-22-2014, 05:46 PM
Hello,

I've been reading a lot about this BF technique and it really makes sense to me. But considering the basic adjustments that I normally use in bird photography - Aperture Prioritity and spot metering - I lose the metering accuracy on the bird when I recompose.

Can U please help me with this?

Daniel Cadieux
03-24-2014, 04:51 AM
Not sure which camera model you have, but when I setup back-button focus in Custom Functions it switches the shutter button to lock metering when half depressed. That should solve your problem. Using manual exposure would help too.

Tiago Caravana
03-25-2014, 02:51 AM
Thank you David :S3:!
My cameras are the Nikon D4 and D7100, I'll see if they have that functionality.
I understood previously that using manual exposure is the way to go (Jim Neiger explains it well in its book), but other than in controlled situations, I'm not there yet

Miguel Palaviccini
03-26-2014, 07:07 PM
Hi Tiago,

I know that the D800 has AE-lock when holding down the shutter half way, so I'd bet the D4 and D7100 do as well.

Do you use spot metering for birds in flight? I'd be a bit hesitant (but mainly bc I can't keep fast moving birds right in the middle the entire time).

Tiago Caravana
03-27-2014, 05:35 PM
Hi Tiago,

I know that the D800 has AE-lock when holding down the shutter half way, so I'd bet the D4 and D7100 do as well.

Do you use spot metering for birds in flight? I'd be a bit hesitant (but mainly bc I can't keep fast moving birds right in the middle the entire time).

Hi Miguel,

Thank you for the feedback :S3:

Yes in heterogeneous backgrouds I use spot metering for BIFs, because this way the camera isn't tricked by the background.

Jim Neiger
03-27-2014, 07:46 PM
Hi Miguel,

Thank you for the feedback :S3:

Yes in heterogeneous backgrouds I use spot metering for BIFs, because this way the camera isn't tricked by the background.

Tiago,

Spot metering for BIF is very unreliable. Every time the spot meter hits an unintended spot either on the bg or on the subject, you may get an incorrect exposure. Manual exposure mode is the only reliable method for BIF on varied (heterogeneous) bgs.

Tiago Caravana
03-28-2014, 02:06 AM
Tiago,

Spot metering for BIF is very unreliable. Every time the spot meter hits an unintended spot either on the bg or on the subject, you may get an incorrect exposure. Manual exposure mode is the only reliable method for BIF on varied (heterogeneous) bgs.

Thank you Jim! Alter my post yesterday I've went to see the camera settings chapter in your book and was going to post your view on this. But nothing better than having a post from the Master itself :)

I'm really going to train manual exposure and all you're advices but there's a learning period to it and as I was getting good results with my techniques the transition is not immediate. My main goal now is action shots, thus I need to be able to quickly change things in manual exposure.

Dan Brown
03-28-2014, 09:21 AM
LEARN MANUAL EXPOSURE! This is the best for action. If you absolutely can't learn manual, switch from aperture priority (where the camera is selecting the shutter speed) to auto ISO, this will allow you to set a high shutter speed that stays high which is very important for action. Auto ISO operates the same as aperture priority with your Nikons in that you can use exposure compensation, so you can adjust for darks or lights. BUT, ONCE AGAIN, LEARN MANUAL EXPOSURE!