How many use the 'back button focus' feature on the DSLR's?
If not, why not :)....not a new function...but beneficial!

Jim

Can you describe in a little more detail how it works?

To put it simply Kort...I;'m sure many Canon users know this!!!

MaIn focus shutter/button uses both focus/ exposes the frame!.

Back  focus does what it says!!!...only focuses!
Only till you PRESS the 'shutter' does it expose the frame!
Damn sight faster in focusing!!!
Ask any Pro tog :-)
More keepers than 'loosers'!

As I mentioned, not a new thing, but it does take time to re-adjust
as one needs two fingers to use!

FYI, its CF (Custom Function(CF)...4.3

imo..why not use the functions offered if its beneficial :-)

Do you mean the * Button?

Button, shutter....whatever you want to call it!

Give it a try Radlafx!

ps...back focus is the STAR symbol on rear!

Yeah good one Jim it is a great way to stop action and stops the focus working overtime once you have got used to it..

Lets say, the 10D, 1D2 and 5D all have this enabled...wouldnt have them any diff!

Real cool, thanks I didn't know which CF# to use (i was using 4.1). Does it work in AI servo mode?

Does it work in AI servo mode

prob the most used in what I do, so yes it does:)

isnt that the AE lock/focus lock for one shot mode/flash exposure reading test for flash photography button?  If so - yes i do use it occasionally - although i tend to shift the focus point instead as i find the only real use of the * is to aid in composition of an offcenteredly focused shot.

You can use it for that (as you know)...but... also used for above. Need to go into Custom Functions to set it though.
As per manual:  the * button, to start /stop AF. The exposure is set at the moment the picture is taken, Thus, the focusing and exposure will always be at the optimum point.

Jim

I need to figure out how to do this with my 400D(Rebel XTI)

Thanks for the tip..That's why I love this forum..so much great information

Attached Link: http://www.dpreview.com/reviews/canoneos400d/page7.asp

The main purpose is that the  * button focuses, when the shutter is then pressed, it then exposes, as opposed to the shutter doing both!

Stay with it, you will find more keepers than 'loosers' :-)

You guys are awesome:)

Cheers muchly Nameless, I'll give it a try.

With Nikon there is a similar function, you choose what the button does in the menu.  I use for exposure lock mostly.  I might try for focus and see how it works.

Thats why CF's are their for...to be used for 'setting' up the cam for your needs!

Nameless, I've set my CF as you suggest and been trying it the last few days and, I LOVE IT! 

It's still taking some thought, not second nature yet, but I'm enjoying work with it this way.
Thanks for the heads-up!!!!

A few days after I got my Markll I discovered the back button in the menu and I have never gone back to the the traditional "Half Press" focus method.....in action shots it's a must....a great feature and ease of use is sensible....

Aloha Jim

Attached Link: C|net

Seen quite a lot of shots from pro togs...stunning and tough to beat imo :)

In the process atm at putting the 1D2 into almost nr silent mode :-)

In the process atm at putting the 1D2 into almost nr silent mode :-)

Sorted :-)

Had to go out an get a firewire cable...cam to PC...now, I have access to Personal Custom Functions (enables one to further customise camera settings :)

"How many use the 'back button focus' feature on the DSLR's?
If not, why not :)....not a new function...but beneficial!"

Yep, all the time! Especially in very low light situations when the bloody cam won't focus!

Very cool info. :) I'm still trying to learn more of the technical side to taking pictures. I read about it in my book, but I just didn't take the time to sit down and understand what I read. Too eager to start taking pics I guess. sigh

I'm going to try this today and see if it improves my focus any. :) Thank you!

edit: Hmmm...still not exactly sure how it works, but I'm trying....please don't make fun of me, I will be the first to admit I'm a bit technically challenged. lol

Seriously handy info, I'm def gonna give it a try! Thanx

The beauty with this function Damia is that you can choose your exact point of focus in a sec! Pretty cool!

Okay, I hate to do this, but I'm a bit confused. So at the risk of sounding like a complete airhead, I want to see if I can get this cleared up in my mind.
 I set the CF to what Jim said. Okay, so now it focuses with that little ***** button. But it doesn't focus where I want, so that means I use the other button that sets your focus point, choose your focuse point, and the red light square is on, then push the * button to focus on that point, then the shutter? Sounds confusing, but is that how it works? (in very simple words lol)

I can not work it out either. I am sure I am doing something wrong, because other canon users say cool and thanks for a tip...so on. I don't get it.  I do it as Damia, see nodifferent.

seeya  Tunde

Jim is not around ...  So I will respond to his thread

Custom function 4 (page 156  for 5D (your manual? look in Custom functions section ). It controls how you initiate autofocus on the camera. Normally the camera tries to autofocus when you push the shutter release half way down (CF4.0). In this mode the * button on the back of the camera works as exposure lock.

Custom function 4.1 reverses these functions. Autofocus is initiated by pressing the * button on the back of the camera and exposure lock is obtained buy half depressing the shutter release. Custom function 4.3 is the same as 4.1 except that exposure lock is disabled.

The way I use 4.1/4.3 is to leave the camera in AI Servo all the time. As long as I have the * pressed in the camera continuously autofocuses. As soon as I release the * button the camera stops focusing. So, pressing the * briefly gives me "One Shot AF", holding the * button down gives me continuous AF tracking. If I want to focus lock / recompose then I put my AF point over the select target press the * button briefly and then release it and recompose the shot. If I then want to focus on a moving target I just hold the * button down and get instant AI Servo AF. No mucking around changing focus modes and no worrying if I have set the wrong one by mistake. Using the camera this way is the favourite trick of  wildlife and sports photographers or photo journalists. Once you get used to it, it's incredibly flexible. Like most things when you do something new it takes time to practice to get it right!! Best advice it to try and practice on readily available birds like Gulls who dont move too fast..

I'm not sure we're talking about the same thing here. On the Canon 30D, the * button is for exposure lock. To select your point of focus, you have to press the button next to it, a square with 5 little squares in it. Once you've pressed that one, all you have to do is to select your point of focus by using 1: the wheel or 2: the 'lil thingie that moves in every direction. Select your point of focus and press the shutter. To go back to autofocus, simply push the 'lil thingie to the same point of focus again and all the points will lit, indicating that you're back in autofocus. Not sure I'm being very clear here though.....

Thanks Danny for a respond, I give another try....well I do it untill I  get it right. 

seeya  Tunde

Okay, I think I got it. :) Pascale, I do know exactly what you're talking about. My 20D has that also. It was the way to use that particular custom function that I wasn't clear on. I think I have it now. I tried it as Dan said, and for my type of photos so far it doesn't work as well. I'll be sure to do it that way for action stuff though. :)

Unfortunately, a lot of my problem is once I get the subject in focus, I end up moving a tiny bit before taking the picture.....or I move the camera when I snap the picture. sigh I'm one of those who needs a tripod constantly, but don't want to lug it around when I'm just shooting in the yard. Hinders my movement. Oh well.

Thanks for the explanations! Helped a lot. I'll let you know if it helped my focus problems at all. lol

How about a monopod instead? Much lighter and easier to carry around!  Just an idea!

Yes! I've thought about the monopod. I just have to wait until I can spare a bit to buy one. :)

Some really cheap ones here: [ www.warehouseexpress.com/

](http://www.warehouseexpress.com/?/binsandscopes/tripods/manfrotto.html)