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10-06-2011, 07:04 PM   #16
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Sometimes I do switch to CF rather than using all the camera's set points, but it depends upon the lens as to what I use. I do think it makes a difference actually. Center focus seems to work quite well with some of my shorter lenses, but using it with my 75-300MM long lenses makes for a vignette focus effect I don't really like much. I'm a lot lazier about setting my own focus lately I will admit though. I don't trust my eyes as much as I trust the camera's AF lately and I have a hard time distinguishing which is better, how many points of focus to use anyway. Most of them except for focusing dead center look the same to me really most of the time.

10-06-2011, 09:24 PM   #17
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QuoteOriginally posted by magkelly Quote
Center focus seems to work quite well with some of my shorter lenses, but using it with my 75-300MM long lenses makes for a vignette focus effect I don't really like much.
I'm curious what you mean by that, because using additional focus points will do nothing to bring more of your shot into focus, it will just tell you if more of your shot is in focus. So, do you mean you're focusing differently without that additional feedback from the camera, or something else?

To stay on topic, I generally use center point and AF-S, unless birding, where I'll use AF-C until I go crazy enough to switch to MF entirely. I find that using 5 or 11 points makes it too easy for the camera to use an undesirable point to "steal" the focus from what I'm going for, but that could be partly user error. If the points were small points, instead of large zones, it would be a lot easier to use. Figuring out where within a "point" the camera has actually locked onto can be difficult, and when several points are in play, even more so.
10-06-2011, 10:55 PM   #18
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Centre-spot AF and AF-S 95% of the time. Exceptions maybe while shooting small birds, where I'll go AF-C, and street where I may go 5-point AF depending on the lens.

I've never manually set a focus point in my life.
10-07-2011, 12:43 AM   #19
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QuoteOriginally posted by Philoslothical Quote
I'm curious what you mean by that, because using additional focus points will do nothing to bring more of your shot into focus, it will just tell you if more of your shot is in focus. So, do you mean you're focusing differently without that additional feedback from the camera, or something else?

To stay on topic, I generally use center point and AF-S, unless birding, where I'll use AF-C until I go crazy enough to switch to MF entirely. I find that using 5 or 11 points makes it too easy for the camera to use an undesirable point to "steal" the focus from what I'm going for, but that could be partly user error. If the points were small points, instead of large zones, it would be a lot easier to use. Figuring out where within a "point" the camera has actually locked onto can be difficult, and when several points are in play, even more so.
A while back I changed the setting from the AF-S to AF-C on my K-x for a while just to try it out. I usually use manual focus most of the time but I've been having eye issues lately. Like a lot of people as I hit middle age the muscles in my eyes are relaxing and my vision is shifting a lot. My ability to focus is taking a hit, particularly close up, but also it's been changing a lot in terms of my script in general. My eyes can't seem to decide what they are going to do. It's been so bad that my eye doctor basically told me to wait a year to see what they are going to do permanently because I'm having to change my script so often it's almost ludicrous. I'll change it and literally the next month my eyes will shift and I won't be able to see at all through the "new" glasses. I've been through 3 pairs already this year and I just can't afford to keep switching. I have a medical condition that may also be causing part of it, but either way, my eyes are driving me nuts, changing all the time.

I've been playing with AF more trying to wait my eyes out. Someone here was actually talking about how much better it was to use AF-C with AF so I thought I'd give it a go. The shorter lenses old and new worked fine, but with both of my AF lenses the 28-200 and the 75-300 I got this effect where everything in the center is crystal clear but there was almost a circular blur almost like a vignette around the center which was focused just fine. I switched it back and suddenly that effect was gone on both lenses. I'm sorry I think I wrote that wrong in the post I did before but I meant the AF lenses, not my manual Vivitar 75-300. I'm tired and not typing very straight, long week. I'm sleep deprived right now.

I'm pretty new to switching focus points, and also to switching from AF-S to AF-C but I didn't really understand why that happened only with the 2 long lenses and not with my shorter ones. In any case I decided that AF-S worked better for me for the most part. I pretty much let the camera handle the focusing in AF now and I use the basic # of points, factory default. I still like to change iso, aperture, and film speed, but the camera on AF-S is definitely doing a better job of focusing lately than I am so I figure why mess with that?

I was actually meaning to ask about the radial blur thing, but I've been busy with other things and I suppose it slipped my mind until I saw this thread.


Last edited by magkelly; 10-07-2011 at 12:55 AM.
10-07-2011, 12:52 AM   #20
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It sounds like a weirdness of those two lenses, but I can't offer any real explanation of it. Never encountered that before. I've caused some vignetting when doing stuff like reverse stacking lenses, but never seen an OOF ring around the center of a shot, unless the area around the center was farther away from the subject.

I'd agree that AF-S seems a lot more useful. AF-C might be good for tracking something large enough, like a car, but it gets maddening when it keeps catching on branches when chasing a bird. Really, in situations like that, I just give up on AF, switch to MF, miss a good portion of shots (normal for birds anyway) but it's much less frustrating.
10-07-2011, 07:02 AM   #21
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As with almost everyone, I use AF.s and CF+recompose method. This is the way I'm most comfortable with, and how I used since my film cameras. I remember fondly my days with my first AF camera, the Minolta Maxxum !
10-07-2011, 07:07 AM   #22
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I almost always use AF-S with center focus and recompose. I do use AF-C for sports, but not always. On a tripod CF&R doesn't work, so I focus manually. There was a poll here once, maybe two-three years ago, that showed approximately 80% of respondents use CF&R.

AF-A is a mess with quick shift lenses. Sometimes it fights for control when you're trying to focus manually.

Last edited by audiobomber; 10-07-2011 at 07:29 AM.
10-07-2011, 02:39 PM   #23
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While most people use CF and recompose, which I do that quite often; however, I do have to be careful in recomposing as it changes the angle of view (by tilting the camera) and thus distorting the subject. I think there is a good reason why they let you choose the focus point as an option. If you ever wonder why some people appear short in the photo, that is because the focus is in the eyes and then the camera is tilted downward to cover the entire body.

11-21-2011, 09:17 AM   #24
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Could someone please direct me to a good tutorial on the various focus modes available to the K-r user, I am anxious to learn and short on experience. Knowing what, when, and where to use each would sure help me out a lot. Thanks.
11-21-2011, 09:24 AM   #25
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Like everyone else I use AF-S and centre point almost all the time. If it's something moving (kid running at me, usually) I go to AF-C. If it's something moving erratically I go to AF-C and auto select points, but it doesn't really work; if the movement is too erratic for me to follow with the centre point, the camera hasn't got a chance. I do sometimes pick a point too - tend to shoot portrait a lot, so I use the focus point on the right (which becomes the top one when I hold the camera portrait) so it roughly aligns with the subject's face.
11-21-2011, 10:23 AM   #26
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Another option is to set MF, stop-down for thicker DOF, and zone- or hyper-focus. If I know the action|subject(s) will be in a certain distance range, that's my preference. None of this oh-no-what's-in-focus? stress.
11-21-2011, 12:59 PM   #27
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Wow! It's good to see so many people use AF.S. I talk with a lot of Canikon users and they have no idea what I'm referring to.

I try to use the adjustable focus points sometimes but I find they interfere with other settings in the camera so I do the CF and recompose as well.
11-21-2011, 01:43 PM   #28
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QuoteOriginally posted by Kricket Quote
Wow! It's good to see so many people use AF.S
I have to as it is part of the tech that allows for CIF ("Catch-In-Focus")





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11-21-2011, 02:35 PM   #29
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Just wanted to be sure that I understand when you guys mentioned "center point focus then recompose" do you really by that:

1) Have focus point to be in the center (by default it's the center)
2) Focus at the subject
3) Recompose by moving the camera away from the subject while half-pressing the shutter button
4) Subject in agreement with rule of third or whatever rule you use, then press shutter button

Is that the case? That's what I'm doing but I always wonder because of step #3, the subject is no longer in focus, especially with fast aperture where DOF is very thin. Am I missing anything?
11-21-2011, 02:44 PM   #30
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QuoteOriginally posted by ducdao Quote
Am I missing anything?
Are you keeping the same exact (or near exact) distance between the camera and the subject after focusing? Example, after focusing, when you re-frame while half pressing shutter to hold focus, are you:

A: Moving Left/Right
B: Pivoting the subject while keeping the same distance
C: Moving Forward/Backward any?

If "A", there should be no issue as long as the actual distance is the same for the line of focus ***
If "B", there should be no issues as pivoting means no matter where you re-position you would be the same distance as originally focused ***
If "C", there's your issue *** (that is if you are having this issue)




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