35L backfocusing consistently

FM Forum Rules
Canon SLRs, primes, and zooms lenses reviews

FM Forums \| Canon-mount SLRs \| Join Upload & Sell	Search Used
1 2 end

Archive 2010 · 35L backfocusing consistently

Jacob D
Offline
Upload & Sell: Off

p.1 #1 · 35L backfocusing consistently

My 35L has suddenly started consistently back focusing. By consistently I mean just that. I noticed it today in a series of 12 shots, set up a couple of other tests and confirmed it. I'm sending it in to Canon, has anyone ever experienced something like this with the 35L or another lens? What is the typical cause? Was Canon able to fix it to your satisfaction?

Thanks.

Jan 22, 2010 at 03:29 AM

BennyR
Offline
Upload & Sell: On

p.1 #2 · 35L backfocusing consistently

My 85 1.8 was back-focusing terribly and consistently. I did the micro adjust on a 5D2 and not only is it better now but it improved the focusing on a 30D also which doesn't have the adjust feature. I also adjusted the 35L as it was back focusing slightly.

Jan 22, 2010 at 04:15 AM

Jacob D
Offline
Upload & Sell: Off

p.1 #3 · 35L backfocusing consistently

I don't have MA on my 5D, also the lens just suddenly started behaving this way. I wonder if one of the elements somehow shifted inside.

Jan 22, 2010 at 05:43 AM

Daan B
Offline
Dedicated FM
Upload & Sell: Off

p.1 #4 · 35L backfocusing consistently

On what camera?
What AF point was used? One Shot or Servo?
What aperture was used?
What lighting conditions?
What kind of subject? How big/small? Static or moving?

Jan 22, 2010 at 01:45 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #5 · 35L backfocusing consistently

5D, center AF, f2, low~moderate light, static subject, person, objects, etc...

like I mentioned this is a sudden development... makes me wonder if one of my kids got hold of the lens...

Jan 22, 2010 at 05:46 PM

jhom
Offline
Dedicated FM
Upload & Sell: Off

p.1 #6 · 35L backfocusing consistently

Send the 35 in for calibration. In my case, it took several tries to get it right. My 35 was bad straight out of the box. Your problem may be different because it was working.

Jan 22, 2010 at 06:09 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #7 · 35L backfocusing consistently

Here's one of the first shots I noticed it on. I was sitting at my desk doing some work when my son wandered over to peek outside. I picked up my camera to snap a few shots... he wasn't moving (much) and neither was I. This was taken @ f2, iso800, 1/100. Every shot in this series his face is OOF meanwhile the window and printer below him are nice and sharp. Later that day I set up a test on the kitchen table with direct overhead light and see the same issue photographing a single piece of tile sitting on the table.

Please forgive the quality here, cropped from screen shot at 50%.

This image is copyrighted by the owner

Prior to this the lens has been just about perfect.

This image is copyrighted by the owner

Jan 22, 2010 at 06:46 PM

fotografur
Offline
Dedicated FM
Upload & Sell: Off

p.1 #8 · 35L backfocusing consistently

BennyR wrote:
My 85 1.8 was back-focusing terribly and consistently. I did the micro adjust on a 5D2 and not only is it better now but it improved the focusing on a 30D also which doesn't have the adjust feature. I also adjusted the 35L as it was back focusing slightly.

I don't understand how this would improve the focusing on your 30D

I may be dumd about this though

Jan 22, 2010 at 08:20 PM

Max10
Offline
Upload & Sell: Off

p.1 #9 · 35L backfocusing consistently

Apparently the OP and BennyR are talking about some 'mechanical shift' in their lenses.

I never experienced/ heard about such cases.

Jan 22, 2010 at 10:55 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #10 · 35L backfocusing consistently

I just re-read what Benny wrote... although I don't have a body with MA I'm sure it doesn't "do" anything to the lens, the MA setting is more like an offset on the AF motor driver... so MA on your 5DII won't mean anything when using your 30D.

(right?)

Jan 22, 2010 at 11:00 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #11 · 35L backfocusing consistently

By the way, I sent my lens to Canon today. I'll post an update when I get it back.

Jan 22, 2010 at 11:46 PM

Jun Zhou
Offline
Upload & Sell: On

p.1 #12 · 35L backfocusing consistently

Jacob D wrote:
By the way, I sent my lens to Canon today. I'll post an update when I get it back.

wish you are lucky. I sent my 35L 4 times in a month to get a adjustment. first 3 times didnt solve any problem on the AF, then I sent both body and lens to Canon, and they eventually fixed problem,

Jan 23, 2010 at 12:41 AM

booja
Offline
Upload & Sell: Off

p.1 #13 · 35L backfocusing consistently

i got my 35L brand new from adorama and i have to put it at +15 on the adjustment... sucks

Jan 23, 2010 at 07:46 AM

Daan B
Offline
Dedicated FM
Upload & Sell: Off

p.1 #14 · 35L backfocusing consistently

The OOF effect in the pic of the boy by the window may well be caused by the strong side/backlighting. This does strange things to Canon's AF.

Jan 23, 2010 at 02:12 PM

mineymole
Online
Dedicated FM
Upload & Sell: On

p.1 #15 · 35L backfocusing consistently

would love to hear what canon does to your 35L and how much it costs as I am having the same difficulty with my 35L since purchasing the 7D.

Jan 23, 2010 at 02:35 PM

Mr. Clean
Offline
Upload & Sell: Off

p.1 #16 · 35L backfocusing consistently

Jacob D wrote:
My 35L has suddenly started consistently back focusing. By consistently I mean just that. I noticed it today in a series of 12 shots, set up a couple of other tests and confirmed it. I'm sending it in to Canon, has anyone ever experienced something like this with the 35L or another lens? What is the typical cause? Was Canon able to fix it to your satisfaction?

Thanks.
I posted in another thread here too but mine (both the Mark III and the 35L) just went off to Canon. 5D2 + 35L = greatness, 1D Mark III + 35L = OOF crap.

Feb 02, 2010 at 07:17 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #17 · 35L backfocusing consistently

Mr. Clean wrote:
Jacob D wrote:
My 35L has suddenly started consistently back focusing. By consistently I mean just that. I noticed it today in a series of 12 shots, set up a couple of other tests and confirmed it. I'm sending it in to Canon, has anyone ever experienced something like this with the 35L or another lens? What is the typical cause? Was Canon able to fix it to your satisfaction?

Thanks.
I posted in another thread here too but mine (both the Mark III and the 35L) just went off to Canon. 5D2 + 35L = greatness, 1D Mark III + 35L = OOF crap.

I have heard of the 35L + 1d3 issue, that's an odd one for sure. In my case I've been using it on the same body (5D) all this time then all of a sudden the focus issue appeared. Due to a Fed Ex debacle my lens was just delivered to Canon last Friday (I'm lucky it was not lost in the system). Canon just "received" it today and accepted the repair. So I'm anxiously awaiting the next email from them.... Hopefully it will be back in my hands soon I already miss it and could have used it a few times.

Feb 02, 2010 at 10:37 PM

Jun Zhou
Offline
Upload & Sell: On

p.1 #18 · 35L backfocusing consistently

my 35L+1D3 work perfect now, pin sharp at wide open

Feb 02, 2010 at 10:49 PM

Jacob D
Offline
Upload & Sell: Off

p.1 #19 · 35L backfocusing consistently

My lens came back today, the work order was very vague so who knows what exactly went on... after a few quick tests it is definitely better but I feel that it's still back focusing.

I'm really under the weather right now and exhausted. Maybe later this week I'll have some time to put a test together and check it out.

Feb 09, 2010 at 02:30 AM

mttran
Offline
Dedicated FM
Upload & Sell: Off

p.1 #20 · 35L backfocusing consistently

I am sure your 5D AF false and not the 35L. 5Dx can't focus right if you have hi contrast back ground while using fast lens @ f2.8 or larger.

Feb 09, 2010 at 02:37 AM

1 2 end
FM Forums \| Canon-mount SLRs \| Join Upload & Sell 1 2 end