View Full Version : AF points comparison

08-27-2007, 11:08 PM
hey fellas,

i am on the verge of buying a DSLR....

i have zeroed in on the following models:

1. oly e 510
2. canon rebel xti
3. nikon d80

all these cameras have diff AF points -> 3,9 and 11 respectively.....

how does this affect the photography.....i have a soft corner for the oly brand as i have been using olies for a while now.....does the 3 point AF of the oly any less in terms of , if i can put it this way, performance......

please help me out...

thanks a ton

08-28-2007, 07:09 PM
A common habit is to focus using the center point and recompose the image. This works fine for fairly distant objects, but for closer subjects, say 10 feet or less, it can lead to out-of-focus shots. As an extreme example, put your finger 6 inches in front of the center of your monitor. Now pretend you want to focus on the corner of the monitor. The distance between your finger and the corner may be 8 or 10 inches. If you focus on the corner but recompose for the center, your shot will be out of focus. That is where the extra points come in handy - to compose THEN focus.

If your camera is on a tripod, the extra points become even more useful because you can't move the camera around.

I've only used other AF points a few times. Personally I think 3 is the minimum, but 11 is overkill.

The number of AF points would be way down on my decision-making list.

08-31-2007, 02:57 AM
Using all focus points comes into play when trying to track a fast moving subject, and then it does make a difference.

3 is not a lot, especially since they are just on one horizontal line.

But, that is nt the biggest drawback of the E-510. Its 4:3 image format, small and noisy sensor and the fly by wire manual focussing are bigger annoyances in my opinion.

08-31-2007, 04:42 AM
for tracking moving objects like coldy suggested its important. but more importantly if you do tripod work like special K mentioned, the # of AF points is very important.

i want as many AF as i can get when shooting macro in particular. the more points the more control you have over the framing and composition of your subject. there are many, times shooting macro where i have had to comprimise my composition cos the focal point is not in the place i want it. on these occasions, you either have to alter your composition of use MF.

if your not going to do those things, i don't necessarily think its super important. for normal everyday shooting, i would use the central AF point say 75% of the time.