# Is my 70-200 2.8 mk.II back focussing?



## K-amps (Jan 16, 2012)

I took some shots at a party last night. Most of them were a bit out of focus which I don't mind in portraits of regular folks ... I learnt that the hard way!

But I was curious, if the lens is back focussing.

Exposure is manual, no flash, AF is spot center (5D classic) aimed at the eyes. @f2.8 . NO sharpening done, though some NR was applied in LR4.

The eyes are not as sharp, however some of the hair (a smidge behind her eye plane) are more in focus. See below her mouth on the right side that lock of hair seems to be more in focus.

What do you guys think? this 70-200 f2.8 mk.II is only a few weeks old and not fully broken in.

There's no MA on the 5Dc.


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## pwp (Jan 16, 2012)

It's quite possible that there is some back-focus going on there. But I'd like to know what shutter speed & focal length you were using...camera shake & motion blur are common culprits with soft files. Can you check this info?

If you want to properly assess potential back focus issues, run controlled tests rather than reacting to soft party photos. My 70-200 f/2.8isII back-focussed slightly which I was able to adjust on the 1-Series bodies but I don't think 5D has adjustments. 

Paul Wright


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## neuroanatomist (Jan 16, 2012)

To expand on Paul's post, also keep in mind that AF isn't perfect. If you take 10 shots, even with a perfectly adjusted lens, maybe 6 will be perfectly focused, another 2-3 will be off but not enough to ruin the shot, and 1-2 will be just plain off. So, careful testing is the only way to determine if you've actually got a problem, vs. random errors.


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## Fleetie (Jan 16, 2012)

Nice picture. But yes, it really does look like significant back-focus to me. I assume you were wide-open?


I took my 70-200mm f/2.8 L IS II out today.

I'm still at that early stage where I'm like "I'm gonna take nearly all my pics wide open, cos I'd didn't pay £2k for a lens to then stop it down!"! 

I'll grow out of it... Eventually! 


I suppose: Send body and lens off for calibration and wait; or Buy a 5D2 body with AFMA. Or return lens and lucky-dip again.

EDIT: Or, where possible, aim slightly in front; in this case, the tip of her nose, I guess. But that's an unsatisfactory solution, in many situations.


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## JR (Jan 16, 2012)

I agree with Paul and Neuro's comment on further and proper testing first, as well as understanding shutter speed for your shot. Myself when I first got the 70-200 I missed a few shots at longer focal lenght like 135-200 because shutter speed was not fast enought for my subject movement (IS cant help here). Hell when I got my 135L I even thought it was not sharp because using the auto ISO from the camera yield often 1/125 sec shutter speed which was not fast enought to freeze my shot! Now that learned that, I usually shoot not slower then 1/160 with my 135L and for the 70-200, I prefer shutter speed of 1/160 or 1/200 for focal lenght above 135mm, even if the lens has IS.

Of course I took several good in focus picture at slower speed, but I missed a bunch as well. Just something to consider I guess.


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## wickidwombat (Jan 16, 2012)

no AF micro dajust on the 5D classic?


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## neuroanatomist (Jan 16, 2012)

wickidwombat said:


> no AF micro dajust on the 5D classic?



Nope. 1D III was the first to have it. Others are 1DsIII, 5DII, 50D, 7D, 1D IV, and of course the 1D X (which improves the feature by allowing two adjustments for zooms).


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## wickidwombat (Jan 16, 2012)

neuroanatomist said:


> wickidwombat said:
> 
> 
> > no AF micro dajust on the 5D classic?
> ...



bummer.


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## Mt Spokane Photography (Jan 16, 2012)

Their are lots of possibllities, if you focus and recompose, if you lock focus by pressing the shutter halfway and then sway forward or backwards a small amount, if you are near minimum focus distance, most lenses will front focus, so its best to test it carefully with as many variables removed as possible.

Place it on a sturdy tripod, full aperture, ISO 100, and take several shots at about 25-50 * the focal length in use. Then go to the same focal length and distance used when taking the image and take 8 or 10 more.

Focus on a flat target so that you can be certain the camera selected the correct place to focus. The camera will often focus on the closest object, even if its not in the center of the point used.


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## K-amps (Jan 16, 2012)

Mt Spokane Photography said:


> Their are lots of possibllities, if you focus and recompose, if you lock focus by pressing the shutter halfway and then sway forward or backwards a small amount, if you are near minimum focus distance, most lenses will front focus, so its best to test it carefully with as many variables removed as possible.
> 
> Place it on a sturdy tripod, full aperture, ISO 100, and take several shots at about 25-50 * the focal length in use. Then go to the same focal length and distance used when taking the image and take 8 or 10 more.
> 
> Focus on a flat target so that you can be certain the camera selected the correct place to focus. The camera will often focus on the closest object, even if its not in the center of the point used.



Will do! Thank you to everyone who responded. Generally most of the pics I took were not as sharp as I would expect the mk.II to be, but then most of them were 1/30 to 1/40, so I agree, I might have locked the AF and swayed a bit, but not sure there was Camera blur in that shot otherwise none of her hair would be in focus.

Yes Fleetie, I shot wide open to get max OOF blur and lack of flash by choice.


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## Mt Spokane Photography (Jan 16, 2012)

K-amps said:


> Will do! Thank you to everyone who responded. Generally most of the pics I took were not as sharp as I would expect the mk.II to be, but then most of them were 1/30 to 1/40, so I agree, I might have locked the AF and swayed a bit, but not sure there was Camera blur in that shot otherwise none of her hair would be in focus.



I agree that your lens should be very sharp, even at max aperture, but if you get really close, the depth of field can be shallow enough so that only the nose, for example, will be in sharp focus.


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## drmikeinpdx (Jan 16, 2012)

Whenever you buy a new lens, I strongly recommend doing some controlled focus tests. In the case of a zoom lens, you need to test at 3 or 4 different focal lengths. Many zoom lenses have focus error that shifts at different points in the zoom range.


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## well_dunno (Jan 16, 2012)

I would use the focus test chart (available for download for free) and shoot on a tripod to see whether the focus/misfocus has any consistency.

I am relatively new to photography so probably nothing new to you guys... Either case, wanted to give feedback... 

Cheers!


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## K-amps (Jan 16, 2012)

Thanks again!

Prior to my Photography Hobby, I was an audiophile for about 20 years. There we had a concept of performance shift with usage, for example, speakers and amplifier had to be "Broken in" just like shoes etc to perform their best.

Is there such a thing with lenses? ???

I know my 70-300L has gotten better with usage... Is it just me?


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## JR (Jan 16, 2012)

K-amps said:


> Thanks again!
> 
> Prior to my Photography Hobby, I was an audiophile for about 20 years. There we had a concept of performance shift with usage, for example, speakers and amplifier had to be "Broken in" just like shoes etc to perform their best.
> 
> ...



lol! I am very familiar with your "broken in" audiophile concept being one myself and having an all tube system! Now as far as camera lenses are concern, I dont beleive this concept would apply. I dont see what could improve with use. I would suspect optical properties stay the same. I would be very curious to know for sure someone could confirm this here?


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## K-amps (Jan 16, 2012)

JR said:


> K-amps said:
> 
> 
> > Thanks again!
> ...



Yes, I would not expect glass/ optics to improve with usage (that would be akin to cables having magical properties  ); but I do think the focussing mechanisms get freed up some more (just like new pistons in a engine) and perhaps with less friction can focus better?


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## JR (Jan 16, 2012)

Humm...interesting...this sounds like a good question for our friend Neuro!


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## bornshooter (Jan 17, 2012)

JR said:


> K-amps said:
> 
> 
> > Thanks again!
> ...


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