focus?

[biggin]

what do most of you guys as far as the setting for focus on the 20d, average(all 9zones)or just the center zone?

[robertwgross]

Tell me what you mean by "average (all 9 zones)."

My 20D does not have that feature.

---Bob Gross---

[tim]

He means focus points Bob.

Most people around here will use the centre point most of the time. I never use more than one focus point at a time, it slows focus and reduces your control if the camera chooses the focus point for you. I use other focus points when i'm shooting theatre, because if you focus/recompose with a wide aperture your focus comes out wrong.

[lmelendez]

I use center point focus most of the time.

Leo.

[jfrancho]

I use one of the extreme outer points, then recompose. The reason is that in creative modes, on my 300d, metering is center weighted or partial. I take a reading first, then lock my focus, compose and snap. I'm sure most of this process is overkill, and may not always work, but it only takes a fraction of a second.

[robertwgross]

He means focus points Bob.

Average focus points?

My 20D still does not have that feature.

---Bob Gross---

[sixshot]

Center point the majority of the time.

[GyRob]

I use centre as its faster and i want to know were the focus point is .
Rob.

[tim]

Average focus points?

My 20D still does not have that feature.

It's a reasonably obvious generic term for evaluative, IMO. It does choose the best focus points, and kinda chooses the average focus point between them.

[biggin]

Thanks for all the replies. I am new to the 20d and I am going to the mountains this weekend where there will be lots of photo ops so I am trying to get to know the camera as much and as fast as possible!

[tim]

Make sure you read the manual, with the camera beside you, then play with it. Next, read the manual again. After you're done, play some more, and read the manual. It took me a few readings to understand it all.

[robertwgross]

It's a reasonably obvious generic term for evaluative, IMO. It does choose the best focus points, and kinda chooses the average focus point between them.

Tim, you are completely confusing evaluative metering with some autofocus mode.

---Bob Gross---

[glangston]

Center point. Pictures were sharper than evaluative...see. p. 67 to learn how to toggle the point with the multi-controller (small toggle button)

[PacAce]

I use one of the extreme outer points, then recompose. The reason is that in creative modes, on my 300d, metering is center weighted or partial. I take a reading first, then lock my focus, compose and snap. I'm sure most of this process is overkill, and may not always work, but it only takes a fraction of a second.
Your 300D must be different from everybody else's 300D because in the Creative modes, everybody else's (non-hacked) 300D always uses Evaluative metering except in Manual mode.

But, be that as it may, assuming that the metering is center-weighted or partial, how does moving the extreme outer point change anything? In CWA or partial metering modes, none of the AF points are used in determining exposure so I fail to see how using the outer AF points changes anything. What am I missing?



At rate, I try to stick to using the middle AF point because it is the most accurate point of all the AF points. However, I do use the other AF points when I don't want to or can not recompose my shot. In AI Servo mode, however, I tend to use the Auto AF point selection mode because I want to use all the available AF points when i am tracking a moving object. I do have my camera set up so that I can use the "*" button for AF auto select and the "X" button to only use the center AF point and can easily switch from one to the other.

[SkipD]

I use center point only or manual focus with my 20D. I like to be able to predict what's going to happen instead of being surprised.

[jfrancho]

Your 300D must be different from everybody else's 300D because in the Creative modes, everybody else's (non-hacked) 300D always uses Evaluative metering except in Manual mode.

But, be that as it may, assuming that the metering is center-weighted or partial, how does moving the extreme outer point change anything? In CWA or partial metering modes, none of the AF points are used in determining exposure so I fail to see how using the outer AF points changes anything. What am I missing?



At rate, I try to stick to using the middle AF point because it is the most accurate point of all the AF points. However, I do use the other AF points when I don't want to or can not recompose my shot. In AI Servo mode, however, I tend to use the Auto AF point selection mode because I want to use all the available AF points when i am tracking a moving object. I do have my camera set up so that I can use the "*" button for AF auto select and the "X" button to only use the center AF point and can easily switch from one to the other.No guy, mine is the same as everyone else's. Sorry I forgot to clarify, it was late, this is using exposure lock too. That sets the camera to Partial in crative modes. In M, metering is center weighted. In evaluative metering, the camera tends to place emphasis on the focus point (personal observation, maybe someone can confirm it) and that doesn't usually give me predictable results in high contrast lighting. Metering can be found on page 84 in the manual.

[DReb-MO]

Tell me what you mean by "average (all 9 zones)."

My 20D does not have that feature.

---Bob Gross---

PITA... I am pretty sure you understood the question but just can't resist being a... I don't have to say it. :rolleyes:

[jfrancho]

PITA = Pacific International Trapshooting Association ?
or Pacific Islands Telecommunications Association ?
or Palestinian Information Technology Association ?
or People for the Intelligent Treatment of Animals ?
I guess I'm being a PITA.

[tim]

Pita is a kind of bread ;)

[bauerman]

Bob Gross - again you knew what the guy meant - but had to go the sarcastic route in your reply.......what gives?

[robertwgross]

Bob Gross - again you knew what the guy meant - but had to go the sarcastic route in your reply.......what gives?

No, you are dead wrong. "Average (all 9 zones)" just does not make any sense in the autofocus realm. Does it make sense to you?

There are too many people confusing autofocus with metering and then regurgitating it again. This just confuses the hell out of newbies.

---Bob Gross---

[bauerman]

Yes - but I also know that you could have gleaned from his post that he meant keep all nine points active and let the camera choose or just set it to the center point. Other people understood the meaning of the post and gave helpful answers rather than stating - "wow, my camera does not have that neato feature.."......If you are concerned about the newbies - post the correct information rather than pithy one liners - I would assume that would be more helpful to them.

[robertwgross]

Yes - but I also know that you could have gleaned from his post that he meant keep all nine points active and let the camera choose or just set it to the center point. Other people understood the meaning of the post and gave helpful answers rather than stating - "wow, my camera does not have that neato feature.."......If you are concerned about the newbies - post the correct information rather than pithy one liners - I would assume that would be more helpful to them.

You misquoted me.

No, I didn't glean from his post.

---Bob Gross---

[jfrancho]

Is anyone even trying to help anyone here?

[tim]

Not any more, I think the question's been answered, though I was helping on the last page.

[PacAce]

Not any more, I think the question's been answered, though I was helping on the last page.
What was the original question, anyway? :mrgreen:

[robertwgross]

Tim, don't you think you were confusing autofocus modes with metering modes? Those are two different things.

---Bob Gross---

[lancea]

I tend to leave my 20D on average ;) focusing mode, but will quickly switch to choosing a single point where required (i.e. to use a more suitable point in the shot). I rarely use centre focus.

[robertwgross]

I tend to leave my 20D on average ;) focusing mode

Do you mean Automatic AF point selection?

---Bob Gross---

[FlyingPete]

Now if this post is indeed about focus points…

I used to have eye control for my Focus points on my Film SLR, I was so used to that, that I ended up just using the centre point on my 20D and recomposing. That is still my default, but in some circumstances, especially with a tripod, I will manually select other focus points to save moving the camera.

Auto Focus point selection can be dangerous in some circumstances as the camera focuses on the wrong thing and it is not always that obvious through the view finder that the correct subject is slightly out of focus.

BTW, just ‘discovered’ AI Servo a couple of weeks ago, it really works!

[Wavy C]

When I first got my 20D back I just kept the default setting of the nine focus points active and let the auto-select feature do its job. The result - lots of oof pictures. So much so that I was very disappointed witht he camera. My little Olympus 5050 point and shoot was just so much better and more accurate when focusing.

Then I started to realise that I was taking most pictures indoors in winter with the lens wide open. The shallow dof made focusing critical. I switched to using the middle point only and noticed an immediate improvement.

But still not perfect - especially with portraits. I was using the focus and recompose method of half pressing the shutter to get the middle point to focus on the subject's eyes and then moving the camera to frame the shot as I wanted. This was the problem. When you think about it, if you had a piece of string between the end of your lens and the person's eyes, then move the camera to point at the chin, the string will no longer reach. Therefore the eyes will be oof (if you are using a wide apeture).

I first noticed this while fooling around one evening and taking a picture of a cup sitting on a patterned table, looking down from about 45 degrees. I focused on a motif on the front of the cup. Afterwards I noticed that the motif was in focus, but the patterned table at the bottom of the cup was not. Instead the pattern on the table well in front of the cup was in focus. This surprised me, but when I thought of the piece of string to measure distance it was obvious what was happening.

Now I am getting better results, but still notice the occasional subject where autofocus simply does not work. In these you have to use manual focus. That's ok, but annoying if you don't see something is oof at the time and can't go back and reshoot later. (I'll try and post an example later).

[lancea]

Do you mean Automatic AF point selection?
You're playing the straight man excellently :mrgreen: , but just in case you're not: yes. I do.