A while ago I bought the 35/1.4. This was one of the lenses I dreamt about for a long time. However, after getting it I was less than thrilled. It didn't seem to be sharp as it was suppose to be. However, as I knew its DoF is supposed to be paper-thin (one of the main reasons I bought it for), I kept on experimenting.

Well, yesterday I got the answer. It's not the lens, it's me. It's me that can't get this damn focus plain in the right place. However, I plea for mitigating circumstances: DoF is ridiculously thin. Look at this picture. Only part of the eye and eye lashes are within the DoF. This is going to be challenging.

Happy shooting,
Yakim.

100% crop. No PP.

Edited by Yakim Peled on Jan 19, 2008 at 10:45 AM GMT

The same crop with sharpening applied.

Wow yeah, you can see why AF picked that area, specifically. That is some amazingly thin DOF!

Looks like it's gonna take some work to master AF with that lens!

Yes - that is what you get a f1.4 - no matter which lens. Amazing isn't it...
If you want more DoF then go to f4 or more and see what you think. There was light available -- the shutter speed was 1/750 sec so you could have used a variety of f stops and compared the results.

I'll try it on the 1D. I think my chances of getting it right might improve. I need any AF help I can get.

Happy shooting,
Yakim.

Graham, I bought it for the f/1.4. For slower apertures I'll use other lenses. However, getting it right is so difficult its frustrating. I don't remember having that problem with other fast lenses I had (28/1.8, 50/1.8, 50/1.4, 85/1.8). Maybe I was not shooting that close.

Happy shooting,
Yakim.

hey, that's nothing! try the 50mm 1.2, and then, to top it off the 85mm 1.2. DOF is so narrow, you have to focus on a single eyelash...

Maybe, but this is just a wild idea, you should not focus so much on sharpness. (HAH! Sorry, bad pun, I know.)

I think the shot you've shown is great and the very shallow DoF doesn't bother me at all. The shot doesn't need more of the face sharp in a Count-The-Individual-Hairs way.

Edited by Tentacle on Jan 19, 2008 at 02:27 PM GMT (Reason: horrible typo *blush*)

Yakim,

Looks like distance is the primary culprit here. A similiar composition (although different perspective) can be obtained using higher focal lengths with greater depth of field. This is probably why you haven't seen the same problems with a 50mm/85mm.

The point of using the 35/1.4 or any wider angle/larger aperture lens, in my opinion, is for low light photos where you need a wider angle, or for simply any photo where you need to include more in the photo. For your photo above, which is a closeup candid portrait, I would have reached for my 85/1.8 or 70-200 f/2.8L IS and probably shot at around f/2.8 or f/4 and not have to step as close. This would ensure that the subject is entirely in focus, while the background still has a nice creamy bokeh effect.

Agree with Jimmy's post.

Yakim- thanks for sharing.

Just a thought: I found my 35f1.4 front-focussed quite a bit in tests with my 1Diii. After microadjusting +17 it focuses perfectly on my target at f1.4. Of all my lenses, this is the one needing the most adjustment. Also, there is nothing in front of the subject's eye in the center of the image, but if there was, I'd guess you'd see evidence of front focusing.

I think it's hard to see where the sharp area starts in your sample. Mayby you should try some tests shoting a ruler at eg. 45 degree. This will give you an idea of what DoF to expect and also if the focus is off.

Edited by J Andersen on Jan 19, 2008 at 02:58 PM GMT

shrink1 wrote:
hey, that's nothing! try the 50mm 1.2, and then, to top it off the 85mm 1.2. DOF is so narrow, you have to focus on a single eyelash...


With my 85 1.2 I have to foucs on the front of an eyelash to have the far side of the same lash in focus

Yakim Peled wrote: It's not the lens, it's me.

Yakim,

I'm full of admiration for the fact that:

a) you didn't automatically rush to print with the assumption that the problem must be with the lens; and that

b) you were man enough to admit your eventual findings.

We need more of that...

DOF at 2 feet with the 35L wide open is ~1/2 inch. DOF at 6 feet with the 85L is ~1 inch and more like ~1.5 inch with the 85/1.8. I agree with Jimmy on this one. Pull out a short tele for this type of portrait. Or stop the 35L down a bit, at least. That said, I have a feeling that the boy's family would like that picture a lot.

Yakim, I think you like being on the edge of everything

Jimmy Ho wrote:
Yakim,

Looks like distance is the primary culprit here. A similiar composition (although different perspective) can be obtained using higher focal lengths with greater depth of field. This is probably why you haven't seen the same problems with a 50mm/85mm.

The point of using the 35/1.4 or any wider angle/larger aperture lens, in my opinion, is for low light photos where you need a wider angle, or for simply any photo where you need to include more in the photo. For your photo above, which is a closeup candid portrait, I would have reached for my 85/1.8 or 70-200 f/2.8L IS and probably shot at around f/2.8 or f/4 and not have to step as close. This would ensure that the subject is entirely in focus, while the background still has a nice creamy bokeh effect.

Yakim,

As I'm sure you have figured out, you will not be successful by focusing and recomposing at f/1.4. Have you tried focusing manually? Not that the variables this introduces are any less prone to error.... If nothing else, this supports the strategy of taking lots of shots to increase the likelihood of getting what you want .

Yakim Peled wrote:
Well, yesterday I got the answer. It's not the lens, it's me.
Yakim.


Thankfully not another "my lens is backfocusing" post.

I am also challenged when I use this lens, but I wouldn't give it up for anything.

Good post, Yakim.

Yakim, I see a 50 f/1.0 in your future.

I may be stating the obvious here, but if the object of your exposure is perpendicular to you (as is this child's face) you will want more depth of field...

Yakim
Are you aware there are online resources that tell you the DOF you are working with given the shooting variables? : http://www.dofmaster.com/dofjs.html

Expoimaging makes some pocket guides I picked up recently but haven't had a chance to use yet. They look a little complex, but I am hoping that after a few uses the DOF calculations get a little more reflexive for me.

Focusing manually with a 40D? You must be joking. Yes, I tried that and it's next to impossible even in daylight. The viewfinder is so tiny....

I'll try to see if it has FF/BF but I must say that normal shooting (and not extreme ones like this, wide open up close) suggests it is fine in that regard.

About changing lenses, the 35/1.4 and 100/2.8 are my walk-around lenses and while I could switch, in this case I wanted the "look" of a wide angle lens up close (remember Robert Capa?).

I think that the right course of action is to close it to f/2 or f/2.8 when I'm close and f/1.4 when I'm far. That is just common sense and I'm sure it will reduce my OOF rate but I hate to do it. After all, I paid so much to use it wide open. I hate the laws of physics....

Happy shooting,
Yakim.

f1.4 requires a careful choice of subject.

b) you were man enough to admit your eventual findings.

We need more of that...

Excuse me here, but I too admitted a while ago that I started having erectile dysfunction problems (after finding out my imaginary Canon 1D Mark III has AF issues) and yet, no one came up to me and patted me on the back complementing me on how manly man I was...

Yakim Peled wrote:
Graham, I bought it for the f/1.4. For slower apertures I'll use other lenses. However, getting it right is so difficult its frustrating. I don't remember having that problem with other fast lenses I had (28/1.8, 50/1.8, 50/1.4, 85/1.8). Maybe I was not shooting that close.

Happy shooting,
Yakim.





I know the 35 is fabulous at 1.4, but don't miss out on all its other apertures. It is more than a one trick pony.

Shane