AF Points - DPChallenge Forums

08/20/2004 09:21:51 PM · #2

I use the central focus point almost exclusively. The focus and recompose routine can result in out of focus subjets under certain situations, in these situations I select the focus point until it is on the subject I want, then shoot.

dwterry

Canon EOS-1D Mark III

08/20/2004 09:29:43 PM · #3

The 300D has focus points like this:

6
1 2 3 4 5
7

I find that I am almost always on either 2 or 4, sometimes 6 or 7, and every now and then on 1 or 5.

About the only time I am ever on 3 is if I'm dealing with a fast moving object and that's about the only way I'm going to catch it in focus.

The thing is, you seldom get a good composition if you use the center AF point (unless you focus lock and then shoot). So you end up cropping the picture too much after the fact. So by using one of the other focus points I can get closer to the crop that I plan to have in the final picture and that leaves me with more pixels to blow up (err, enlarge).

Edit: Hmmm... my little pattern up above looked good in the editor. HTML just flattened it!

Message edited by author 2004-08-20 21:30:39.

08/20/2004 09:34:33 PM · #4

i dont think you're idea is 100%

focus lock is the way to compose, 1 less step to have to figure out.
if you know the center is always live - you can focus and lock in one motion, and know whats in focus.

EDIT: try manually focusing, and think of the options...

Message edited by author 2004-08-20 21:36:35.

Jacko

Canon EOS-20D

08/20/2004 09:38:12 PM · #5

I don't use the center AF exclusively. I will use the other ones while shooting macros since the DOF is very shallow. I tend to lock the centre focus then recompose if DOF is not a problem or an issue.

08/20/2004 09:51:02 PM · #6

with set up macros - why not manual?
i had better luck with humming birds with manual focus than any AF point...

Jacko

Canon EOS-20D

08/20/2004 09:55:23 PM · #7

I hardly ever shoot manual. I see no use in it.

Edit: I do use manual when I shoot with a reversed 50mm because the AF is not very functional.

Originally posted by soup:

with set up macros - why not manual?
i had better luck with humming birds with manual focus than any AF point...

Message edited by author 2004-08-20 21:57:36.

doctornick

Apple iPhone 13 Pro

Canon EF 24-105mm f/4.0L IS

08/20/2004 09:55:51 PM · #8

Originally posted by Jacko:

Focus recompose is the way to go most of the time, but there are situations where this will cause the subject to be out of focus and it is better to select the focus point closest to the subject.

zeuszen

Canon EOS-1Ds Mark II

08/20/2004 10:07:05 PM · #9

My default drive mode is [Continuous] with center focus. I spot-meter (correction 'partial'-meter) just about everything and, if the lens provides for it, focus manually after recomposing.

08/20/2004 10:25:41 PM · #10

yes yes - i am not crazy...
what lenses let you manual focus after a focus lock?
or do you let the AF get close to perfect, and then manually adjust>?

Message edited by author 2004-08-20 22:26:02.

doctornick

Apple iPhone 13 Pro

Canon EF 24-105mm f/4.0L IS

08/20/2004 10:31:34 PM · #11

Originally posted by soup:

yes yes - i am not crazy...
what lenses let you manual focus after a focus lock?
or do you let the AF get close to perfect, and then manually adjust>?

All Canon lenses with USM allow you to manually focus after focus lock.

Natator

Canon EOS-5D

08/20/2004 11:00:29 PM · #12

Originally posted by zeuszen:

My default drive mode is [Continuous] with center focus. I spot-meter (correction 'partial'-meter) just about everything and, if the lens provides for it, focus manually after recomposing.

Another good question there as well ....

What metering mode on the 10D and 300D do people use?

08/21/2004 01:30:14 AM · #13

i don't have any of those - thanks

Originally posted by doctornick:

All Canon lenses with USM allow you to manually focus after focus lock.

Jacko

Canon EOS-20D

Sony 16-50mm f/3.5-5.6 E-mount

08/21/2004 07:10:35 AM · #14

I'm so dumb I had to print the 3 metering mode icons on a small piece of paper and stick them to the bottom of my camera for reference. I kid you not. I use Evaluative a lot.

Originally posted by Natator:

What metering mode on the 10D and 300D do people use?

jmsetzler

Sony Alpha a6000

08/21/2004 07:31:11 AM · #15

Originally posted by Natator:

So, recently I have set my AF to be just the central single point, and then I recompose the shot after focussing.

That method works out in some cases and not in others. If you are working with a long lens at close range, this method will get you in trouble. I am finding it much simpler in these cases to use manual focus rather than AF.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

08/21/2004 08:45:55 AM · #16

Originally posted by doctornick:

All Canon lenses with USM allow you to manually focus after focus lock.

It's only the one's with a distance scale on the lens that allow you to do this. I have the 75-300 IS USM which doesn't have the scale and doesn't allow for this. My 28-135 on the other hand has a distance scale and allows adjustment to the focus after AF.

Message edited by author 2004-08-21 08:46:25.

EddyG

Canon EOS-1D Mark II

Canon EF 70-200mm f/2.8L IS USM

08/21/2004 09:07:06 AM · #17

Originally posted by cpanaioti:

It's only the one's with a distance scale on the lens that allow you to do this.

More correctly, it is only the Canon lenses with ring USM that allow full-time manual focusing. Canon also has USM lenses with micro-motor USM which is not even in the same league as ring USM (and is a marketing ploy by Canon to make their cheap lenses look more appealing). Once you've experienced how quick and quiet ring USM is, you'll look for that as a specific feature on your next lens. =] For more details, see here. You can tell if a Canon lens has ring USM by looking for the "FT-M" symbol when browsing their lens lineup web page:

The one exception that I'm aware of is the Canon 50mm/1.4, which doesn't have ring USM but does have a special clutch mechanism which allows full-time manual focusing.

Like Jacko, I never use manual focus, except when working with the reversed 50mm in extreme close-up situations. I always get better-focused pictures by letting the camera auto-focus.

Finally, for Canon DSLR's like the 10D and Digital Rebel, the center AF point is the "most sensitive" since it is a cross-type sensor, meaning it is sensitive to both horizontal and vertical contrast patterns. (The 10D/DRebel AF layout is shown here, which shows the "red squares" that are visible in the viewfinder, and then the size of the actual AF sensor at those locations.) One great way to set up your 10D is to select the center AF point as your "default" focusing method, and then assign the "Assist" button (to the left of the * button) to select your "Registered AF Point" (which can be all 7), which allows you to quickly switch back and forth between center AF only and any other AF point combination.

(For those recommending the focus-and-recompose approach, you may want to read Why Focus-Recompose Sucks. It is a big reason for "back focus".)

Message edited by author 2004-08-21 09:09:52.

TomH1000

Olympus E-3

Olympus 14-54mm f/2.8-3.5 Zuiko Digital Zoom

08/21/2004 09:24:56 AM · #18

Originally posted by doctornick:

Same here.