135L - I can't get a sharp shot no matter what :(

[ddt0725]

Just looking at 1 picture its hard to pin it down. A person really needs a series of pictures at each setting to determine if it is hitting or not. Another thing is even though say the picture with Natures Recipe appears to be dead on, I know that that the positioning of your camera is skewed and not square to the table. Same thing with the lenses. You can see the DOF trail off sideways up and down in the pics.


You should be using AF single point, single shot to test with. Since you do not have a lensalign, maybe lay a ruler down on the table next to the item you are shooting. It might help getting a feel of what is going on.


With the 500mm F4L on the 5D, which is extremely accurate (the most accurate lens I own) at 0 I had Front Focus of 12, On Focus of 21 and Back Focus of 3 in the series. Even the most accurate lens combinations are going to drift front to back a little. You got to hit the right average at the setting that works.


If its not to late to send it back, I wouldn't hesitate sending it and getting a different copy. We pay to much for our equipment for it not to perform the way we expect. Another copy might do better, or not.

Hi Rick -


Believe me I have taken numerous shots of each subject at all settings from +5 thru +18. These I think are the best, although I have not gone thru all of them yet. Most it is really hard to see a difference in +14 to +15. Also, I was wondering if it was normal for a lens to do really good at one setting then all of a sudden not so much. I'm also wondering if +14 ends up being the setting, should I really keep a lens that needs that much of an adjustment. After spending soooo much time getting it there, to send it back for another copy to go thru it again isn't very appealing to me either. B&H extending their return time frame due to the holidays so I am able to return it anytime before January 17th.


Happy Holidays!
Denise

[GarzaCapitalist]

www.michaelthementor.com/.../index.php

[GarzaCapitalist]

www.google.com/webhp





it may be obvious,or not the issue, but have you upgraded the firmware?


Drivers & Software
Details - 7D Firmware Update Version 1.2.3

[elmo_2006]

Hi Denise...


In my humble opinion, may I suggest that you return said lens and ask for a replacement or a refund. Chances are that you may have second thoughts about this lens if you decide to keep it. I personally see no reason as to why anyone would have to *figit* with a brand new lens to get it to work properly. Sure there are some lenses that require this correction, but an *L* series lens?!? I think I

[neuroanatomist]

I have to disagree about

[HDNitehawk]

I'm also wondering if +14 ends up being the setting, should I really keep a lens that needs that much of an adjustment

Of all the big primes I have had, all were very close out of the box new. If they required anything it was very little. In my way of thinking the lens should be usable out of the box, with maybe a few minor adjustments to correct and make it even better.


What would bother me about a plus 14, is that you are almost to the end of the scale that direction. What if you wanted to set the lens up later to Back Focus? I don't know why a person might want to do something like that, but you wouldn't have much of an adjustment to do that option. In my mind I keep relating this back to sighting in my rifles, I have bought scopes that I ran out of vertical or horizontal adjustment. Then what do you do? With firearms its get a new scope, take it to a gunsmith or get shims. Its a pain. For a fast prime I would start having my doubts after plus 10.


I would expect a little better performance out of the box. I would be just as you are now, debating about sending it back. If it were a zoom lens or wide lens I might be less likely to send it back. With a larger prime I would be more likely, accuracy is to important with the larger tele primes.

[ddt0725]

I have decided to return the lens on Monday. I was thinking of just getting a refund but since I already have bought a Genus ND Fader filter for it, I might as well try another copy.


From very early this morning,here are afew of the last photos taken with this lens before I pack it up this afternoon...










Thanks to all of you for helping me out with this! Hopefully, the next copy will be awesome!

Denise

[neuroanatomist]

If ti focuses properly with contrast detect (Live View), and also focuses properly with +14 AFMA, the lens itself is fine. I can't foresee a reason to intentionally want to set a lens to backfocus. But, it does make sense to return it - if the next body you buy is also 'off' in the same direction, at that point the lens may exceed the +20 possible with AFMA.

[wickerprints]

A lens that needs a significant amount of microadjustment (say, more than +/- 5), in my opinion, is a miscalibrated lens. That is the most likely explanation. Nearly all of the lenses I have ever used have not needed any adjustment, in that they are most accurate at 0. A few lenses were off by no more than about +/- 3, and even then, the results were not consistent. In other words, even for a lens needing no calibration, the AF system doesn

[Andy Stringer]

Denise, the shots at +14 look about right, but I understand if you are disappointed that the lens needed such a large adjustment, and you are right to return it if you're not entirely delighted with it.

I thought the following sentence from tkerr's link is worth highlighting to everyone following this topic:

http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html]
It's important to realise that any system of parts with individual tolerances can exhibit significant variance if the assorted 'errors' all stack up in one direction (they can just cancel out too).

I think it's possible that your 7D may have a focus calibration issue, but your other lenses almost cancel this out. With your 7D + 135L combination, the errors add together instead of cancelling. It's impossible for us to say how much of the +14 is due to the body and how much is due to the lens. Both your 7D and 135L are probably within their individual focus tolerance (very few are not) but you can't be sure about the 135L. You might have issues with the lens on another body, or with an extender fitted, or when trying to sell it. As you don't have another camera body to try it on, I agree that an exchange is the right thing to do. I respectfully disagree with those who suggested that an exchange was the first thing you should try, even though you have now decided to follow that course.

On the positive side, hopefully you've learned a bit more about micro adjustment and the challenges of photography with an ultra thin depth of field. It isn't easy using this lens wide open but the results are well worth the effort.