Out Of Focus


Status
Not open for further replies.

fubar6

New Member
Dec 16, 2005
26
0
0
#1
I've taken these shots today (more than 80) and the results were out of focus shots when shooting in a frontal position, ie when subject is coming towards me. I'm using both AL Servo and single shots (shutter speed 1/400,1/500) without any success. Side shots are OK except those that I shook the camera.

By looking at these shots,
1) Do I have a problem lens.
2) Camera processor slow, could not keep up with subject's approach speed to send to lens for focusing.
3) Human error.

Thanks in advance for your feedback, Bernard



IMG]http://i42.photobucket.com/albums/e305/fubar_6/IMG_4345.jpg[/IMG]



 

fubar6

New Member
Dec 16, 2005
26
0
0
#4
Sorry for the error on the pictures.
 

#7
Seems like your background is focused, while the subject is not. Could be that your focusing at infinity. Your exif info shows an aperture of f2.8 and f4.5. This will narrow your depth of field. Try focusing on the subject and shoot.
 

espn

Deregistered
Dec 20, 2002
21,905
0
0
Planet Nikon
#8
It's a user controlling camera issue, understand why the camera focuses behind instead of on the subject, also understand the limitation of the AF of the system and over come it.

The user must understand the equipment to work it to the best.
 

sk.images

New Member
Dec 9, 2005
1,244
0
0
www.pbase.com
#9
^^^^ What he said ^^^^

I'm guessing that your composing, waiting for the subject to come into frame and then taking the shot. If you've already go the shutter pressed half-way then this will never work. Change your AF to AI Servo and track the subject, make sure to keep the centre AF point on the subject at all times for this.
 

fubar6

New Member
Dec 16, 2005
26
0
0
#10
kelccm said:
What kind of camera are you using? I think it could be more of your focusing techniques.
Its a Canon 350D with a Sigma 70-200
 

Snoweagle

Senior Member
Jan 26, 2005
14,002
0
0
Pasir Ris, Singapore
#11
I also have experienced issues such as this. Sometimes it's a bit hard getting the cam to constantly focus on the subject (maybe due to my hands) and resulting in blurness.

It seems like in this case, the focus is locked on the background.
 

fubar6

New Member
Dec 16, 2005
26
0
0
#12
cyber_m0nkey said:
^^^^ What he said ^^^^

I'm guessing that your composing, waiting for the subject to come into frame and then taking the shot. If you've already go the shutter pressed half-way then this will never work. Change your AF to AI Servo and track the subject, make sure to keep the centre AF point on the subject at all times for this.
Tried both. single shot and AI Servo, even use bust to track subject shooting multiple shots. The picture you see is resized and not cropped, so subject is in the middle of frame yet its not in focus.
 

fubar6

New Member
Dec 16, 2005
26
0
0
#13
blive said:
Seems like your background is focused, while the subject is not. Could be that your focusing at infinity. Your exif info shows an aperture of f2.8 and f4.5. This will narrow your depth of field. Try focusing on the subject and shoot.
these photos were taken yesterday, after a thunder storm and at around 5.30 ~ 6.00 pm with a cloudy sky and the sun setting fast, that is why the f stop is so wide. But these were not the only shots taken. I've also taken with smaller aperture when the condition were more ideal(on another day) but with the same result. I did
focus on subject, these pictures are resized and not cropped, subject is in the middle and I've switched to centre focusing.
 

zac08

Senior Member
Feb 21, 2005
11,755
0
0
East
#14
Try pre-focusing on the spot before the target arrives onto the scene. Else you'd need a good cam with continuous focusing to achieve what you intend to do...
 

fubar6

New Member
Dec 16, 2005
26
0
0
#15
zac08 said:
Try pre-focusing on the spot before the target arrives onto the scene. Else you'd need a good cam with continuous focusing to achieve what you intend to do...
So what you mean, it could be a camera issue. Ie processor being slow.
Problem is(pre-focusing) that subject movement is erratic and may not track the place where I pre-focus. BTW "a good cam", is the 30D ok or will I have to go higher?
 

zac08

Senior Member
Feb 21, 2005
11,755
0
0
East
#16
fubar6 said:
So what you mean, it could be a camera issue. Ie processor being slow.
Problem is(pre-focusing) that subject movement is erratic and may not track the place where I pre-focus. BTW "a good cam", is the 30D ok or will I have to go higher?
Sorry, but I'm a Nikon user and would not know about which is the better cam for you in Canon models.

On the matter of pre-focusing, I believe the skiers would be following a fixed cable pull, so you would be able to get a good idea on the area where they will be appearing on the next pass. Using a slightly smaller aperture would also give you more room for error in terms of the focusing area. Btw, this means to use manual focus and fix it there...


Cheers,
 

Aug 27, 2004
336
0
16
#17
There are numerous possiblity to your prob but I am quite sure that the "slow" processor of the camera is not a problem.

Assuming that you have chosen the focus point to use as the one right in the center, it could be a case that you are focusing on a object that is "too small" in relation to the focusing area. Looking from the size of your subject, I believe that the face of the subject will not be able to cover the focusing area fully. Therefore, it could be case where the camera is not able to determine where u are trying to focus on and mistakely assumes that you are focusing on the background instead of the subject's face. Using large apperture will also make this problem more pronounced due to thin DOF. When using large appertures, it is critical to tell the camera explicitly which point you wan it to focus on.

If you not able to estimate where the subject will track and hence pre-focus, than ur best option is to track the object with your cam and only shoot when u feel that u have the object in focus and in the correct composition.

If you seriously believe that this is not the problem, than it could be that the lens needs to be calibrated. But as you say, your side shots are fine, so this is unlikely the problem.

End of the day, it is very likely a technique issue. There is no "slow" camera, it is the brain behind the camera. Do not conclude so quickly that you need to get a "better" camera so quickly, else you might well be getting a 1DMkIIN before long
 

MDZ2

New Member
Feb 23, 2005
306
0
0
Eastern Part
#18
Some time ago, I was playing around with my sisters 350D as well and had, on occasion, encountered the same problem. For me, it was because the camera had a tough time deciding on which focus point to use. If I remember correctly, there are about 5 rectangle boxes in the view finder and the camera decides which is the most appropriate at the time.
To counter this problem, I set the camera to use only the center rectangle (I am not sure exactly how I did it). After that problem was solved. I think that if the subject is too small compared to the rest of the frame, the camera chooses the largest area or number of objects that fall on a certain focal plane. I am guessing of course.
Hope this helps.
 

syazkal

New Member
Apr 7, 2004
668
0
0
PSR
#19
Ren_Hao said:
There are numerous possiblity to your prob but I am quite sure that the "slow" processor of the camera is not a problem.

Assuming that you have chosen the focus point to use as the one right in the center, it could be a case that you are focusing on a object that is "too small" in relation to the focusing area. Looking from the size of your subject, I believe that the face of the subject will not be able to cover the focusing area fully. Therefore, it could be case where the camera is not able to determine where u are trying to focus on and mistakely assumes that you are focusing on the background instead of the subject's face. Using large apperture will also make this problem more pronounced due to thin DOF. When using large appertures, it is critical to tell the camera explicitly which point you wan it to focus on.

If you not able to estimate where the subject will track and hence pre-focus, than ur best option is to track the object with your cam and only shoot when u feel that u have the object in focus and in the correct composition.

If you seriously believe that this is not the problem, than it could be that the lens needs to be calibrated. But as you say, your side shots are fine, so this is unlikely the problem.

End of the day, it is very likely a technique issue. There is no "slow" camera, it is the brain behind the camera. Do not conclude so quickly that you need to get a "better" camera so quickly, else you might well be getting a 1DMkIIN before long

:thumbsup: :thumbsup: :thumbsup:

Good advice......:thumbsup:
 

justarius

Senior Member
Nov 9, 2003
1,226
0
36
Northeast
Visit site
#20
A workaround for your problem is to predetermine where is the best angle you want your shot, determine where the skier is likely to be; gauge the distance, and then set your lens to manual focus and focus it at your estimated distance. That way, whatever complain (if any) about your camera's autofocussing capability is taken out of the question. If you know the hyperfocal distance of your lens, then you could try that also.;)
 

Status
Not open for further replies.
Top Bottom