Focus & Re-Compose - not good idea?

[Glenn NK]

Wide apertures?

Fixed.

That was posted at 12:03 am my time - I was a bit weary.

[Colin Southern]

Colin,

Don't get me wrong - I'm not arguing with you at all. I'm just trying to make sure I understand. I want to make sure I'm learning the techniques that will help me get better photos. If learning how to quickly move my AF points around will produce better results than MF, then I will put energy into that. I was just under the assumption that MF would get me the same results.

In my case, a lot of my work is done with macro - how does that change things (if at all)?

Thanks for the info. I'll definitely be trying my own experiments with this in the near future to see how my results go.

- Bill

Hi Bill,

I'll give you a "good" example ...

In December I shot a learning workshop and subsequent concert for Yulia (www.yulia.co.nz) (<- Free plug!). The concert was somewhat restrictive, so I had the bulk of my gear in the car, and just the camera / tripod / 70-200/2.8IS and 1.4x extender plus a few other odds and sods. Shot the concert - everything was fine until one of the performers grabbed me and said "Yulia's asked if you can come do some fan shots" - oops - hadn't though of that. It's really the realm of my 24-70, but that was in the car (too far away) - tried the 70-200 - not even close - only other lens with me was the 16-35/2.8. Had a flash too.

Light was low low low - so maxed out the ISO - chose the widest aperture I thought I could get away with (getting a bit flustered at this point -- I'd kept the star waiting 2 to 3 minutes) - not to worry - all set now - smile - and ...

... darn lens won't autofocus. Check the obvious - set to AF - check the camera - camera off and on etc - no joy. CR^P. One option remaining - Manual Focus. So did my best - my VERY best - but when I zoomed in, I could see that they just weren't sharp.

In the end I took a step back - smiled - "sorry - small technical hitch" - thought the problem through - and traced it to the fact that I hadn't twisted the lens enough on the mount. Problem solved - repeat. And a lesson learned under pressure.

So what I learned was that under pressure - for me - MF was a dismal failure despite my best effort. Can images be effectively focused manually? Of course so - but I'd challenge anyone to get better accuracy than a correctly functioning AF under normal conditions - and speedwise the AF is going to win hands down. The thing to remember in situations like I was in, justt just "one or two keepers" is a dismal failure - EVERY fan shot had to be a keeper - failure was not an option.

Just my thoughts anyway.

[LeoLeo]

Gents,
A very interesting discussion. 85% of the time I'm using the center focus point, and recompose. I do have some focus issues because of this, but not so much. It depends, as allways, of type of shooting (action, portret, lanscape, so on).

Also, a kit lens will not have MF override, and sensitivity of MF on those lenses in ....arguable, compared with "pro lenses".
I do have a different point of view ( sightlly ), about the first artice (link). There is a misunderstanding of focal plane. Focusing on one point, and recompose, you will get a spheric surface of focus points (the same distance of all points to center). Of course, technical construction of lenses will tempt to strach that spere to plane, but wider angle will have more "trouble" compared with a narrow angle. Also, this is very depending between distance to subject and subject size.

Yes, is better to use the appropiate focus point to your subject, but bending the rules might become handy sometimes (not breaking, bending)

Leo

[IanCD]

Here's another focus screen link: http://www.focusingscreen.com/index.php?cPath=22_92
...and a useful thread at PhotoZone where manual focus and different focus screens were discussed: http://forum.photozone.de/index.php?...-af-necessary/
Ian

[vladimir]

<...> concert for Yulia (www.yulia.co.nz) (<- Free plug!).

OMG! That Yulia is unbelievable!
Her pictures in her web site are incredible!
Thanks for sharing!

[Colin Southern]

OMG! That Yulia is unbelievable!
Her pictures in her web site are incredible!
Thanks for sharing!

Thanks

And believe it or not, they're the un-retouched versions (look for sensor dust spots in the top right of all the images)

[Noice]

Am I naive in wondering why this solution ever came into common usage when manual focus is available? I mean is the camera's AF that much superior to manual focus that it is even better to use AF and move the camera rather than use MF?

I've always had trouble understanding how people have pushed this idea... as Glenn points out, it is simply trigonometry... You change the angle, you change the distance; you change the distance, you change where the focal plane lands... and in all but a very *very* limited set of circumstances, that just isn't going to work the way you want.

I think when Glenn said about 'wide apertures' he meant that the problem is exacerbated when you have a very narrow DoF. If you move the focal plane and your DoF is already razor thin, the chances of being able to move it from one spot to another are just as thin as the DoF.

But I digress... and not to hijack a thread, but can someone tell me whether I am wrong to flip to MF when I feel AF isn't picking up on the point I want it to use? Should I get better about moving my AF points around instead?

- Bill

personally, i use this focus + re-compose as my main solution solely cause i photograph largely in low light. i dont own higher end cameras like you guys so the AF in mine isnt the greatest. AF hunting really annoys me so i resort in using the center AF (which is usually the most accurate AF to my knowledge) and find the brightest/ higher contrast area to focus on which wouldnt be so far from the original composition of the shot. i find it works well for me.
also, trying to MF in lowlight is eye straining.

i am guilty of learning photography through the digital systems (shoot>look through screen>adjust) but i have always pushed myself to learn the fundamentals. hell, i even try photographing off the hip just using the the distance scale for fun/practice.