Reading mode: Light Dark

OOF 50mm 1.4 on 20D

Go to last post
P

Peter Dhaeze

Active member
Messages
85
Reaction score
0
Location
NL
Hi,

A week ago I bought a EF 50mm 1.4 for my 20D to use for studio headshots and general low light situations. I use AF, but 50% of the pictures is totaly OOF at f/1.4. Mostly when shooting under an angle or when subjects has depth.

Send it back as DOA and got back other new lens. Has the same problem. Retailer says I have to shoot with MF, but I can not manualfocus accurate on eye of model at 10-15 ft with 'small' viewfinder of the 20D.

Send it to Canon repair center and they adjust AF of camera and lens. The problem is still there.

Has anyone knows the problem and how to solve it?

Thanks,

Peter

PS. There is also a lot of CA at f/1.4
 
are you shooting at 1.4? Its a little soft at 1.4 anyway and yes the lens is known for its CA.

You've sent it back and forth a couple times. I find it hard that they could have missed fixing it (Althought there have been horror stories here about lens repair 2-3-4 times w/o actually fixing the problem and in the end getting the lens replaced).

Have you sat down and tested on say a stationary object like a book with text? To make sure it actually is back or front focusing and it isn't camera movement/subject movement? Because at f1.4-f2.8 there still just isn't much give in terms of DOF.

--
Charles -300D -
http://www.pbase.com/h4rdluck/ (Pbase Supporter)
 
Wide-open, your depth of field will be paper-thin. Be very careful about where you put the AF point and use the center point only, and you should get very accurate focus. But it does take a certain amount of practice.

Petteri
--
Me on photography: [ http://www.prime-junta.tk/ ]
Me on politics: [ http://p-on-p.blogspot.com/ ]
 
Hi,

I shot a brick wall in an angle of 45 degrees and the focuspoint is 4 ft behind focuspoint. ISO100, f/1.4 and 1/4000s. So camerashake is out of the question.

I shot a daisy from tripod on 2 ft at f/1.4 ISO100 and picture is fully OOF. I know f/1.4 is soft and at small distances the DOF is only 5mm, but nothing sharp is crazy.

Peter
 
I was trying to focus on his pupil. I got accurate AF in 19 of 20. This is a 100% crop from the 20D and 50/1.4 at f1.4:



Lee Jay
 
Petteri Sulonen said:
Wide-open, your depth of field will be paper-thin. Be very careful
about where you put the AF point and use the center point only, and
you should get very accurate focus. But it does take a certain
amount of practice.
Click to expand...
I have never been able to understand what to practice? I put the center AF point on the subject I want to focus on, then when the AF locks on I press the shutter. Can you explain what the heck needs practicing?

Dietmar
Petteri Sulonen said:
Petteri
--
Me on photography: [ http://www.prime-junta.tk/ ]
Me on politics: [ http://p-on-p.blogspot.com/ ]
Click to expand...
 
Dietmar Fichter said:
I have never been able to understand what to practice? I put the
center AF point on the subject I want to focus on, then when the AF
locks on I press the shutter. Can you explain what the heck needs
practicing?
Click to expand...
Don't move the camera fore or aft after focus lock is achieved, don't expect AF to lock on a flat (no contrast) subject, do expect AF to lock on something outside of the little box if that item is higher in contrast than whatever is at the center of the box and it is within 1 box dimension from the box, learn which way the contrast must be for the AF box you are using (different on 20D and 10D-Rebels, by the way). Plenty of things to learn/practice.

Lee Jay
 
Peter,

Why are you shooting headshots at f1.4? You'll need at least f3.5 to get both eyes in focus.

-Scott
Peter Dhaeze said:
Hi,

A week ago I bought a EF 50mm 1.4 for my 20D to use for studio
headshots and general low light situations. I use AF, but 50% of
the pictures is totaly OOF at f/1.4. Mostly when shooting under an
angle or when subjects has depth.
Send it back as DOA and got back other new lens. Has the same
problem. Retailer says I have to shoot with MF, but I can not
manualfocus accurate on eye of model at 10-15 ft with 'small'
viewfinder of the 20D.
Send it to Canon repair center and they adjust AF of camera and
lens. The problem is still there.

Has anyone knows the problem and how to solve it?

Thanks,

Peter

PS. There is also a lot of CA at f/1.4
Click to expand...
 


Lee Jay
 
I am FULLY aware of all the things you mentioned, that is not an issue with me.

Dietmar
ljfinger said:
Dietmar Fichter said:
I have never been able to understand what to practice? I put the
center AF point on the subject I want to focus on, then when the AF
locks on I press the shutter. Can you explain what the heck needs
practicing?
Click to expand...
Don't move the camera fore or aft after focus lock is achieved,
don't expect AF to lock on a flat (no contrast) subject, do expect
AF to lock on something outside of the little box if that item is
higher in contrast than whatever is at the center of the box and it
is within 1 box dimension from the box, learn which way the
contrast must be for the AF box you are using (different on 20D and
10D-Rebels, by the way). Plenty of things to learn/practice.

Lee Jay
Click to expand...
 
As someone else mentioned the DOF is very very thin, less than an inch wide at f/1.4. If you focus on the tip of there nose the eyes could be pretty soft and the ears are OOF bad.
Practice, practice, practice, because at f/1.4 focus is very important.
BOL
_
Joe
 
Dietmar Fichter said:
I am FULLY aware of all the things you mentioned, that is not an
issue with me.
Click to expand...
Great. Then you've already practiced or you wouldn't know this stuff!

Lee Jay
 
Maybe the camera and lens should be taken to Canon together for adjustment. Not sure what your results are like with other lenses. If they're nowhere near as fast as this one, focussing problems may not be as obvious.

I use this lens quite a lot, and it's certainly not razor-sharp wide open--I only use f1.4 under really low light or when shallow DOF 'makes' the picture.

After some early disappointing results, I tend to cover myself by getting multiple shots. I set the drive to single shot, single AF/centre point only and take a sequence, triggering a new AF lock for each frame. And hold the camera steady as if the shutter speed was way too slow.

Si.
 
That only works if your subject is in the exact center of the frame, and it's contrasty enough to give a strong signal. The practice bit comes from identifying where to focus, focusing there, and recomposing in a way that doesn't throw it OOF again (or using some alternative technique to get the same result, such as fluidly switching AF points etc.).

Petteri
--
Me on photography: [ http://www.prime-junta.tk/ ]
Me on politics: [ http://p-on-p.blogspot.com/ ]
 
Lee-

I understand the concept, and I have a 50 1.4 myself. However, even the picture you show does not benefit from being shot at f1.4, it would have still been a better picture if more of the face was in focus. The same goes for model and actors headshots-they are pretty useless if you cant clearly see all the features on their face.

-Scott
ljfinger said:


Lee Jay
Click to expand...
 
Scott G Spellman said:
Lee-

I understand the concept, and I have a 50 1.4 myself. However,
even the picture you show does not benefit from being shot at f1.4,
it would have still been a better picture if more of the face was
in focus. The same goes for model and actors headshots-they are
pretty useless if you cant clearly see all the features on their
face.
Click to expand...
I disagree here. IMO the lack of in-focus-ness elsewhere in the photo draws your eye strongly to the child's eye. All the rest can be considered extraneous in this particular case and thus benefits from being blurred. It's a less-is-more approach. Publicity shots of models & actors are a different thing. There the (often famous) face as a whole is usually the focal point and such photos encourage you to explore different facial features. I'd say neither approach is intrinsically better than the other. Which one to use depends on the subject matter and what you as the photographer want people to look at.

-Dave-
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top