Slow AF 135L f2.0

USAIR

Just picked up the 135L f2.0.
I had the lens for a week so not very long.
One thing I noticed is that I missed lots of shots because on no AF lock in low light.

In the same low light conditions with the 70-200L f2.8 I have no problems with AF.
But with the 135 in the same light big difference.
The IQ is much better with the 135 then the 70-200 but AF much worse.

My question...is this normal ? or should I send the lens back for a new one ?...like I said its only a week old.

Using it on the 5D mark II

Thanks
Fred

divamum

Definitely NOT normal for my 135L - one of the fastest-focusing lenses in my bag, even in low light. That said, with my 7d I do sometimes lose focus accuracy in low contrast conditions, but I've always attributed that to the camera rather than the lens.

ziggy53

My Canon EF 135mm, f2L USM will not accurately focus in close proximity to the subject. I need around 8 or more feet from the subject in order for the subject to be sharp. Otherwise, AF is very accurate and swift.

Using a flash which has an AF Assist light can dramatically improve AF accuracy in low light.

USAIR

Thanks guys for the help.

It was low light and also low contrast conditions.
The distance was about 3-4 feet and it was my fast moving 2 year old grand daughter.
I normally use my 70-200 in these conditions and it has no problems locking on.
I love that lens for portraits.


So I guess some more testing is in order...I just hate to sent the lens back if there is nothing is wrong.

Thanks
Fred

USAIR

Still playing around but I think I am leaning towards sending this lens back.
For a new one that is.

Fred

angevin1

USAIR wrote: »

Still playing around but I think I am leaning towards sending this lens back.
For a new one that is.

Fred

I also have this lens and it has been a keeper for me. AF low light? What does that mean, ie: give us some idea of the light conditions via the EXIF data, please. Also not to forget the center focus point is about the only reliable focus point for the 5Dmk2. It has taken some getting used to since I switched to Canon, in toto. But I agree, if it is possible, try another one!

USAIR

Here's an example very low light shot inside at dusk using center focus point.
She just won't hold still.:D
Would have had more keepers but the lens just would not lock on.

135mm
ISO 200
1/100 @ f 2.0


2 speed lights one to the left and another behind her.
Both sitting on the floor.

Fred

angevin1

Cute Kid.

I don't think a different lens is going to fix this problem, viz., Moving kid, f/2, 4ft distance, 1/100th. The DOF is entirely too thin to allow precision focusing at that distance to subject AND that subject moving omnidirectional.

nak

f 2.0 at 4 feet? 3 feet is the minimum focus distance for that lens, so your DOF is razor thin - have you looked into the focus adjustment in your camera for the lens?

The lens to lens variations and camera to camera variations can be corrected this way.

USAIR

nak wrote: »

f 2.0 at 4 feet? 3 feet is the minimum focus distance for that lens, so your DOF is razor thin - have you looked into the focus adjustment in your camera for the lens?

The lens to lens variations and camera to camera variations can be corrected this way.

Thank everyone

This was brought up in another forum...I am really talking about AF Lock...my post was not clear.

And I am looking at the manual for focus adjustments.

I am also testing to...and I just think I need more time with this lens.

I let you guys know what I do

Thanks
Fred

angevin1

USAIR wrote: »

Thank everyone

...I am really talking about AF Lock...my post was not clear.

No, I think you made that clear Fred. But what I cannot wrap my head around is why AF lock on a moving subject? On my D700 there was an AF system that would follow a Subject once locked on and it wasn't near capable of handling a typical busy child at four or 5 ft. distance. So Why do you think AF lock is the problem versus DOF & Subj.-Distance/movement?

At any rate, if I wanted to actually have a chance at stopping the child mid-motion, I'd up the Shutter speed to sync speed (to heck with ambient) AND increase the ISO/Aperture as well. And In fact I'd probably use a different lens entirely based on this situation. My thinking being a portrait lens is better suited for portraits and not mobile kids, especially at f/2 & 4ft.

I actually used my 135 f/2 @ f/2 recently for a commercial shoot and because I had a trained actor, she was able to stay in the field of focus with her eyes ( the focal point) even though I was shooting a movie. (I was entirely too close [per rules] but had to be based on the story-board) Very hard to do for a subject.

USAIR

angevin1 wrote: »

No, I think you made that clear Fred. But what I cannot wrap my head around is why AF lock on a moving subject? On my D700 there was an AF system that would follow a Subject once locked on and it wasn't near capable of handling a typical busy child at four or 5 ft. distance. So Why do you think AF lock is the problem versus DOF & Subj.-Distance/movement?

At any rate, if I wanted to actually have a chance at stopping the child mid-motion, I'd up the Shutter speed to sync speed (to heck with ambient) AND increase the ISO/Aperture as well. And In fact I'd probably use a different lens entirely based on this situation. My thinking being a portrait lens is better suited for portraits and not mobile kids, especially at f/2 & 4ft.

I actually used my 135 f/2 @ f/2 recently for a commercial shoot and because I had a trained actor, she was able to stay in the field of focus with her eyes ( the focal point) even though I was shooting a movie. (I was entirely too close [per rules] but had to be based on the story-board) Very hard to do for a subject.

Thanks for the help.

I think you are correct it is not the best lens for this situation.
The reason I chose this lens is it is new it just came UPS so it's a new toy.:D

I think it is the hype I have heard over the years of what a great lens it is had a lot to do with it.
So I had some preconception of it's capabilities.
I think I was just a little surprised it did not lock on in that scene.
Just not a good test.

I did a little test the other night the same time of day and the same light.
I hung that shirt on a chair and took a reading..
ISO 200
1/4 @ f2.0
That was ambient light reading not flash reading.
I guess that gives you a idea how dark it was.

Now as far as AF lock on the shirt it was still hard but was able to get lock on the edge of the cupcake on the shirt.
Also when I shoot her I focus on the eyes not her shirt.

I have some local guy who offered to meet with me and we can compare 135s.
I think this will put this to rest.
I am now thinking the lens is OK I just expected more then I should.

Thanks again and we will see what happens.

Fred

PS: I do think so far this lens is a great lens.

USAIR

OK update on this...

Had a local photographer come over today with his 135.
We both had problems with focus on the yellow shirt.

It seems the dimly lit scene and low contrast was the problem.
So my lens is fine.

I did use his 5D Mark III and to me it seemed to focus little faster then my Mark II did.

Anyway thanks everyone for the help.

Fred