Back-Button AF

[MX5]

Re: Back-Button AF

I take advantage in two situations ...

1. When something unexpected is likely to come into shot and throw everything (focus) off (birding, air shows etc).

2. When you need to focus off-centre but can’t be bothered to set an off centre focus point because the next shot requires it elsewhere ...

[eeyore]

Re: Back-Button AF

Glad to see/read that my sense of humour is appreciated!

Although not directly related to the theme, ( but themes always digress a bit) I have just a few thoughts to add...
As put in my signature, I'm a proud user of the 350D, and it doesn't have the back focus, as well as a sensor clean, 9 +focus points, and many of the newer functions! In this way it is quite a basic camera, but more complicated than a Kodak Instamatic 126 cartridge film, (1980's model), a twin lens reflex, a canonet rangefinder, ( a beautiful camera), EOS 500, EOS 5. ( I've used all of the above).

But as we all know, technology moves quickly as always, newer things to add to the camera and depending on what you do it may or may not be useful... and with that said, we managed quite well in the past without mobiles, but these days, what would life be like without it? ( However, in this case if you don't have a mobile, it really can be life threatening!!)

I wonder if there could ever be a version of a 'digital' Polaroid camera ... and I digress now, but just to add one more thing as I have mentioned Polaroid cameras...
(being cheeky again ) If one really wants a picture 'straight from the camera', perhaps one should stick to the Polaroid, because literally, THAT really WAS straight from the camera!!!!

[Canon-Fodder!]

Re: Back-Button AF

I wonder if there could ever be a version of a 'digital' Polaroid camera ...

Seek - and ye shall find...

[MX5]

Re: Back-Button AF

Richard ... The Digital Poloroid is called something like PoGo if I recall (seriously) ... more a 'printer' than a 'camera' though.

[Canon-Fodder!]

Re: Back-Button AF

On a serious note... thanks to all for the input here...

Having tried & failed with Back-button AF, (I enjoy wildlife, birds, airshows etc...) I'm inspired to give it a long-haul shot...

[eeyore]

Re: Back-Button AF

I might have known!
"Crop pics before printing, add borders, remove red-eye and print dates." (quoted from the above link from Canon Fodder). Not technically 'straight from the camera', then!

[Millie]

Re: Back-Button AF

First I going to add small tip about the exposure lock * button.

If you keep your finger on the * button it keeps the exposure settiings locked.

When you want to meter again, tap the menu button to reset (you'll see the asterisk in the viewfinder disapear immediateley).

..............................................
Back to the back AF
For the life of me I can figure out how the AF is locked except bieng locked to a focal plane.

Please explain again, I feel like the thick kid in the class, slow on the uptake.

Should anyone be kind enough to help, please state what focussng mode you're using.

Millie

[Bobby Canon]

Re: Back-Button AF

Interesting thread. I have just set my camera up to back button focussing. I have promised myself to leave it there for at least a couple of weeks to see how .....or indeed if.....I become accustomed to it. It would seem to me that leaving it that way, even while using one shot mode, should not cause any problems once you are accustomed to it.

[Woolley]

Re: Back-Button AF

Something I've heard of and wondered if I should try. Colin's excellent description tells me I should avoid it because it's exactly the opposite of what I often have fixed in my head. I take a lot of pictures of theatre shows where it's important to lock the exposure before recomposing since there's such a huge difference in light between one area and another. I'm fairly confident I'll never master this technique!

[briansquibb]

Re: Back-Button AF

I took some pictures of a school play and was constantly using the exposure lock.

ot into a simple routine:

- exposure lock on face
- half press for focus lock
- compose and fire

Ended up with about 8/10 correct exposures

pretty good for me as I haven't much experience in low light shooting

[Millie]

Re: Back-Button AF

- exposure lock on face
- half press for focus lock
- compose and fire

What if the stage lighting changes, or the person moves into different light ?
Or during re-composing, the subject moves forward or back, they'lll be OOF, the degree to which they’re OOF will depend on your AV.

Any thoughts ?

Millie

[briansquibb]

Re: Back-Button AF

Do it quick is the answer

I agree with what you are saying, and yes I was getting about 2/10 failure through focus or exposure issues. However 8/10 was good.

I was taking pictures at iso1600 to get maximun DOF - about f5.6 on average. I focused on the face for exposure and found that didn't change too much. I was using the Sigma 105 to increase the DOF as I was further away.

[Woolley]

Re: Back-Button AF

Much the same here. Depending on the quality of light I'll often go for manual now, but you still have to live on your wits. Biggest problem is lighting directors who go for arty strong colours: http://picasaweb.google.co.uk/MusComCo/WestSideStory#