photogenix wrote:
At the Camera Clinic in Collingwood, Melbourne, the starting price would be about $180 for a straight-forward calibration for a Canon lens on a Canon body. (great service btw). But yours does not look straight forward (can't imagine it's straight forward going from a coke bottle to an L series!) - definitely more than back/front focusing going on - I see smearing, echoing, ugh. And it's hard to say how much it will end-up being as whatever they do, it will be an interactive process, tweaking this and tweaking that until it looks better. For what you're after, I don't think you'll be able to get a quote, but you could perhaps ask them to put a cap on the labour charge (ie: say you're only willing to pay up to $x) and pick up the lens in whatever state they got it in by that point. You would be best to take your body in with it so the calibration matches your camera too....Show more →
Frankly, your "can" shots don't show any front - or backfocus to me !
As a matter a fact, it doesn't show ANY focus at all !?
Something's wrong for sure !
You should be able to get a more or less sharp area shooting @ f1.4 when using a shutter speed of, let's say 1/250th, taking well lit pictures of a newspaper or so .....
( I mention 1/250th to exclude moving errors, NOT that the lens isn't capable to focus at much lower speeds !)
I have a love/hate relationship with my 35/1.4. Mine constantly and consistently front focuses at f/1.4 and I have to set my microadjust to +20 to compensate. I have sent it back to Canon (mostly at their request) 4x, and it's still not fixed. The latest response was that the lens was "well within specifications". I laughed. Seems funny that a $1300 professional lens that will not focus properly on a non micro-adjust body could be considered "well within specifications"... Oh well... f/1.8 it is I guess!
If I didn't have so much invested in Canon glass, I'd be seriously looking at alternatives. With all the flaming hoop jumping I've had to endure with the servo auto focus issues on the Mark III bodies, I typically tell new shooters to go with Nikon...
testing focus with a target that isn't parallel to the sensor plane will not yield consistent results, and is not a good way to diagnose/micro adjust a lens. chuck westfall said this in a past tech notes issue, the date of which i can't remember.
My 30L is nice and sharp, sure it sharpens a wee bit more if I stop down. But wide open, and allowing for it's thin DOF...it's more than sharp enough on my 5DII.
But it's not all plain sailing. My copy is either spot on focus at MFD but slightly off at infinity or vice-versa. Micro Adjustment effects the lens across it's whole focus range and can't in-proportionally adjust at different focusing distances.
I guess Canon have room for improvement with Micro Adjust 2.0.
I think that one of the issues that the digital capture has brought us all is the ability to scrutinise in PS at 100%...which is pretty extream and harsh on gear.
abam wrote:
testing focus with a target that isn't parallel to the sensor plane will not yield consistent results, and is not a good way to diagnose/micro adjust a lens. chuck westfall said this in a past tech notes issue, the date of which i can't remember.
Oh really ?
But in a way it should, no ?
Lot's a subjects are not parallel to the sensor plane !
Two cans in a row or a person 3/4 view, focusing on one eye ... what's the difference ?
The UPS guy literally just delivered my new 35L from B&H so I have to test it out. Sorry to hear about your focusing problem and I hope it's something simple but your post couldn't have come at a better time for me. I will utilize the recommendations for this post to verify the sharpness of my lens.
Rather than start another thread, I'm just going to post this here, as I think it relates... hope that's okay!
I just got my 35L back from Canon, after going in for the second time for focus issues. (this lens has been like this since I purchased it back in March of this year...) I sent my 5D in with it so they could be calibrated to one another.
When it came back I tested them on the cans again, and it was absolutely perfect! Soooo psyched about that! (Thank you Canon, NJ)
Then, I decided to check it out on my new 7D which arrived while the 5D and lenses were being serviced. Wouldn't you know it, it was back focusing terribly on the 7D I decided to try my other lenses on the 7D but thankfully, they were all perfect. So, I had my first experience with Micro-adjusting a lens using the 7D.... What an awesome feature! I adjusted just three small stops and it's spot on like the rest of them.
What I don't understand is, how can all of my lenses work fine on both bodies, but the 35L needs adjusting? I'm psyched to start shooting things besides cans, regardless, and knowing everything is working really well again!!
Princeli wrote:
What I don't understand is, how can all of my lenses work fine on both bodies, but the 35L needs adjusting? I'm psyched to start shooting things besides cans, regardless, and knowing everything is working really well again!!
It's because DOF is very thin so it exposes the loose tolerances used in manufacture
I have owned two 35L's in my life. The first one I bought used and it front focused. The seller was kind enough to give me back my money. The second I bought brand new from B&H. It is killer sharp from wide open to whatever.
Well I sent off the lens and my body to Canon Australia, and i just received them both back, and its all goodness!
They did the repair free of charge at no cost to myself even though it was out of warranty, it took roughly 3 weeks to complete. and the work completed as per statement of service reads:
"Dismantled, recalibrated optical alignment, reassembled, cleaned, checked and tested. Also calibrated best focus. Note: It is normal for this lens to be softer below f2.8" end quote
So all in all very happy with that. After reading that i thought i'd do my own test to confirm and from the first shot that i took i knew it was a goody!
Anyhow here are the comparisons, after it was repaired by Canon on the Left of Screen and prior to repair on the Right of Screen.
I followed the same testing regime as before (mirror lockup, manual focus, tripod, remote release ISO 100 etc) however the distance was not that same, but close enough for my liking. Anyhow i am happy with the results.
Sounds like they did a collimation/lens element realignment, it certainly needed it
You were very lucky to get that free of charge, that would normally have costed upwards of $300! (Labour Rate B for when something has to be taken apart)
Thanks for relaying the findings, it's great that duds can be fixed through other means when calibration doesn't help, performance looks up to par now, and those f/1.4 crops show good detail and should sharpen up nicely
Wow ..great pics...my 35mm L is pretty bad ( huge front focus)...looks like Canon Canada is not skilled enough to fix it they keep giving me the '' fixed lens'' ....but with the same front focus.....already 6 weeks of frustration.
Thanks Guys, pretty stoked with the overall results with Canon Australia. I think their service department is pretty good here, i have never personally had a bad experience with them thus far, in fact they have exceeded expectations really. In fact i think they have totally overhauled the way their service department operates here, so kudos to them.
Sobax wrote:
Wow ..great pics...my 35mm L is pretty bad ( huge front focus)...looks like Canon Canada is not skilled enough to fix it they keep giving me the '' fixed lens'' ....but with the same front focus.....already 6 weeks of frustration.
Have you micro adjusted to your 50D? I had mine calibrated to my 5D and still had to micro adjust to my 7D... and finally, it's amazing!
I decided to try my other lenses on the 7D but thankfully, they were all perfect. So, I had my first experience with Micro-adjusting a lens using the 7D.... What an awesome feature! I adjusted just three small stops and it's spot on like the rest of them.
