Best way to focus 20D

[Bsmooth]

I am having a difficult time focusing my 20D also as i use the center square alone to focus.Some of the shots are in focus and a lot are not.I used to use a split screen on my film cameras and always had great success,at least with the focusing anyway.Is there a good way to consistantly get good well focused shots?

Also do you think by using more depth of field would I have more success?Let me know your thoughts on this as I am getting slightly frustrated by many out of focus shots. Thanks

[ohenry]

Too shallow a depth of field can give the perception of the shot being out of focus. Any examples of your problem? What lens are you using and what settings do you normally shoot at?

[Marshall]

Certainly a larger d.o.f.would help as achieved by a higher f stop. I use the centre focus mainly, on my 20d. no problems if due care is taken with f stop used.Do a series of tests.

[SkipD]

I am having a difficult time focusing my 20D also as i use the center square alone to focus.I also use the center point alone, and have found that there are times when the target that the camera is trying to focus on doesn't have the right type of edges that it needs to focus on. If the target has edges in it but the camera still doesn't acquire focus properly, I have found that turning the camera about 45 degrees to the right or left (around the axis of the lens, not pointing at another target), it will acquire focus.

You will need to experiment a bit to get comfortable with how it works.

Also - your choice of lens may have a lot to do with how well the autofocus will work. Lenses with smaller maximum apertures (higher minimum f- numbers) may not focus as well in lower light situations. All of my lenses have f2.8 max apertures and I still find a situation now and again where autofocus doesn't quite work properly.

With a USM lens that allows you to turn the focus ring even with auto focus on, it's a snap to tweak the focus manually to deal with the problem situations.

[Bsmooth]

I've had the problem mostly with the Canon 18-55 lens.Although once in awhile I have the problem with my Canon 70-200F4 too. I shall have to post the photo,but it was a light colored leaf against a background of snow.It was a very deicate looking shot,but it was ruined by being out of focus.Can the 18-55 lens be manual focused while the switch is still in the autofocus mode? The problem being no split screen which would be a great help. I shall have to post the shot.By the way whats a good size to post here;640x480?

[CyberDyneSystems]

Set custom function 4 to "1",... set AF to "AI Servo" and leave it that way.

Use a single AF point ALLWAYS unless you are trying track a moving subject against an uncluttered background,. in which case all 9 AF points may be of some help.

[Chuckpic]

Set custom function 4 to "1",... set AF to "AI Servo" and leave it that way.

Use a single AF point ALLWAYS unless you are trying track a moving subject against an uncluttered background,. in which case all 9 AF points may be of some help.

I have been using your C.Fn-04 advice on my 20D since reading it in another thread. Great advice.Have you found it useful to set to 3 instead of 1 at any time?

With your above advice using TV mode for action like in rodeo photography which would you choose? Also which metering mode would you use in that combination and how often would you re-focus and re-meter?

Much appreciate your ideas.

Thank you.

[cmM]

Thankfully, the focus points on the 20D can be selected pretty easily using the joystick. I mainly use center point as well. The biggest challanges as far as focus goes for me is shooting in low light (large apertures such as f/1.8 ) people... no AI servo... sometimes I need to recompose. So I use One shot focus, but take the shot as soon as it focuses, so there's no time for the objects in focus (eyes) to move out of my depth of field. That usually works.
Now when I'm shooting sports or birds,etc... AI servo all the way ;)

[foley71]

Forgive my slowness here, but I want to make sure I understand. Are you all saying that if your shooting sports, for example, you simply select the center focus point and try to make sure you get the action in that area?

I shoot with a DRebel -- does selecting one area in the focus prism deactivate al servo? I'm guessing not.

Thanks for the help.

Jeff
www.foleypics.smugmug.com (http://www.foleypics.smugmug.com)

[drisley]

On the DRebel AI Servo is only active in sports mode.
Selecting single point focus does not deactivate servo in that mode.

[foley71]

Allegedly, on the DRebel, it also automatically switches between "one shot AF and al servo AF according to the subject status." Regardless, sounds like people are shooting moving subjects with the center AF portion selected. Is that right?


Jeff
www.foleypics.smugmug.com (http://www.foleypics.smugmug.com)

[cmM]

Allegedly, on the DRebel, it also automatically switches between "one shot AF and al servo AF according to the subject status."
That's AI Focus (when the camera switches to AI serve as soon as it detects movement).

AI servo mode is the autofocus mode where the camera "expects" movement and it tracks continuously.

However, focus modes cannot be selected on the 300D

[foley71]

OK, so let's say you're shooting sports in an arena and you need an ISO of 1600 ... The "Sports" mode on DRebel won't go higher than 400, correct? So best advice for still getting decent, focused action is ...

Would you say work in Av, set the appeture as high as you can and keep the AF in the center? BTW, I'll be facing this situation in a week-and-a-half, and I'll most be using an EF 50mm 1.8 and an EF 100mm 2.0.

Thanks for any help. I'm just trying to avoid having to dump all my sports photos.

On that note, I wish I'd discovered this site before I bought the Rebel. I shoot mostly sports and I clearly didn't do enough research.

Oh well, I'm sure there are ways to make the DRebel do fairly well in sports. And I also enjoy the non-action moments in sports (sidelines shots, etc.).

Anyhow, like I said, any tips are appreciated.

Jeff
www.foleypics.smugmug.com (http://www.foleypics.smugmug.com)

[drisley]

You are correct. Sports mode only goes to ISO400, and you can't select AI Servo in the other modes normally.
However, there are a few firmware hacks that let you use full time AI Servo, but the camera wont fire.You have to quickly lift your finger off the button and depress to fire a shot with the camera in Servo mode with the hack. I used this method for a while, and after getting tired of it, I sprung for the 20D.
AI Focus is a bit of a gimic. I accidentally had my 20D set to that mode while shooting basketball, and boy did it miss alot of shots as Servo mode never seemed to kick in properly. I guess it's ok for day to day shooting, or maybe even portraits, but for sports, it is too unpredictable.

[cmM]

Oh well, I'm sure there are ways to make the DRebel do fairly well in sports. And I also enjoy the non-action moments in sports (sidelines shots, etc.).

Sure there are ways ... Check out the sports gallery on my website (not that im bragging or anything :-P), all of those shots are taken with the drebel... Funny I never shot any sports with the 20D since i got it :)

[Bsmooth]

Not to get too far away from what I was talking about,here is an example of what I mean with focus.The picture was taken at F7.1 at 1/500 shutter speed using the regular 18-55 with the center focus point at the center of the leaf.

[Kostyanych]

Set custom function 4 to "1",... set AF to "AI Servo" and leave it that way.



Does it mean I will lose FEL-button on my 20D? :)

[CurtPick]

Not to sound like I know what I am talking about but I would dump the 18-55 lens. I never liked mine and sold it. I had the same problems. You can get around $60 on ebay or fredmiranda.com. Take that and get the 50mm 1.8 Mark II. I knwo. It wont be a "wide angle" but that lens will just frustrate you.
Looking at your photo it appears to be back focusing. Look at the lower right of the plant. You will notice that just underneath the leaf the snow is in focus between the to right leafs. Now I am not saying this as fact. But Try a test on a ruler. Make sure you use a Tripod. Set the ruler at 45 degrees. Take a picture of the 6" mark. Look at the picture to see where your focus sweet spot is for that lens. I would venture to say your focus sweet spot is somewhere from 1/8" to 1/4" to the right of your foucus point. ( thats laymen terms for not centered ! LOL )
Then do the same test with the 70-200. If they are both off. Then let someone else do it ( just to see if its the photographer ! LOL ) . If its still bad then send your camera in for calibration.

[Bsmooth]

I actually did the exact test you mentioned and here are the results.I actually focused at the 5" mark

[CurtPick]

Ok thats not quite correct.
Set the ruler on its side. At a 45 degree angle from the Camera and try it again.
Make sure the camera is on the same plain as the ruler.
And stop the lens down as far as it will go. I believe that one is f3.5.

[Salleke]

Set custom function 4 to "1",... set AF to "AI Servo" and leave it that way.

Use a single AF point ALLWAYS unless you are trying track a moving subject against an uncluttered background,. in which case all 9 AF points may be of some help.

My 20D is allways set on one AF point. But how can setting CF 4-1 improve autofocus? It splits AF en AE, but does it realy make pictures sharper?

Can i leave AF to AI Servo allways even if i don't use CF 4-1 to improve AF?

Thanks for your advice.

[Jon]

The discussion on this was split off to here (http://photography-on-the.net/forum/showthread.php?t=46965). Basically, it means that if what you want to focus on isn't right at one of the focussing points when you've composed the picture, you'll still be able to lock the focus correctly, then meter separately. It's also helpful if the subject may be drifting in and out of the focussing point (say you're panning with a car, bird, or athlete).