autofocus help!

[tyasa81]

hi guys... need some input.. basically i have a problem with autofocusing and can't decide which technique gives more consistent result...

basically i'm usually ok with focus with 2.8 lenses... i just got a 1.4 lens and suddenly i keep missing focus (the eyes aren't focus)... i have a d90... the center focus (x-type) is fine... but when i put my subject away from center (non x-type af) the af can't get accurate lock on the eye and thus comes half blurred picture that looks fine on back lcd but not on monitor...

so... basically i want to ask what do u do when you want to focus with non cross type af (any camera model but d90 is better)... i tried center focus and recompose, not so good since recomposing shift the focus enough so the eyes aren't sharp... tried selecting particular af and let it lock.. still not good since the af is not accurate ppl's faces (is this expected or is this camera/lens error?) but is fine for non living objects... getting very frustrated... since i have this problem mainly shooting portraits i'm hoping some of you with 1.4 lens can help with your most reliable method... what do you do?

shooting mostly my ninja kid..



f1.4
1/160 s
iso 400

[MrJones]

I usually select the AF point closest to the eye and recompose. that way the distance doesn't throw me out of focus completely.
your photo seems to be sharp so I'm not really sure where is the problem.

[tyasa81]

Hi MrJones, Thanx for replying... sorry the picture isn't showing the out of focus coz i used one that's actually in centered-focussed... i deleted most of the pictures that are out of focus but will take a look again later to see if i left some behind... just trying to get a feel on how others do their af with fast lenses and not directly related to any specific picture... thanx for your vote... and your explanation on how you usually af.. i have not tried your method and it'll be something new to try...

as for the others... it's an anonymous vote... so please select one you used if you dont feel like commenting

[tyasa81]

Guys... there's 96 views... and only MrJones bothered to leave a comment and a poll... at this rate by next week this thread will be buried... so please help...

here a pic of barely missed shot

1/60 f2.8 flash bounced... i put focus on the eye and it misses and focus is on the chair instead... had some focused on the background


f2 1/125s flash bounced... this one is weird... i focus on the woman's eyes and the focus end up on the chair/man behind... had some missed and focused on the wall but deleted those...

thanx for any help

[kristenh]

well, tyasa, i'm another one of those views and i hated to not respond, but i have the same problem. i generally use the center point focusing and recompose, but i have "ninja" kids as well and i miss the focus a lot. if you look at my thread here titled something like "why is the little guy not in focus here," a much more experienced photographer than i suggested that he usually does portraits at an aperture of 5.6 so as to keep the whole head sharp. i plan to try that this weekend. hope that helps; it's all i've got !

[RLucas]

I usually use single servo mode, center point, and recompose.
Are you using continuous focus? If so, wherever you move your chosen focus point will be refocused.
If you are using single servo mode, are you keeping the shutter button half pressed as you recompose?
It would help if you could guide us through your process.

[mar dela cruz]

hi tyasa. i use d90 too and use the single servo af in taking shots. more often than not, i use the center focus and recompose later while holding the shutter release button halfway.
i hope this somehow help you.

[tyasa81]

Hi guys... thank you so much for replying... so far i see that a lot of people are using center pt and recompose...

my way of doing it is to manually select the intended focus point on the face using af-c... i moved my af to the ae-l button and yes i do keep it pressed throughout the pressing of the shutter button... i'll try some of your suggested method and see if i can get better results... thank you so much for replying... it's nice to see other ppl's method and how i could learn with it... so far i've heard no one saying that it might be the lens/camera fault which is my biggest fear... if it is my technique i'm willing to learn and hopefully it'll get better in the future...

i'll try to use af-single servo manually select side af first since i've tried the center and recompose... but when you move too far, the angle is enough to give you soft eyes due to the slight distance change when you recompose..

*thumbs up* thanx all

[vjhoward]

Generally, if I am "chasing my kids" I will keep on center focus and recompose, or crop in post. If I have some time to setup the shot (5-10 seconds), then I will frame the shot and move the focus point to where I need it. I use a D300S that lets me do this really fast.

[aprillove20]

Well, I used to single servo mode.