AF Microadjustment question

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dinners

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Quick question that I'm sure somebody can answer......

I was looking at some snaps that I took at the weekend using a Canon 1D3 and on the rear screen info I noticed that the AF+/- was showing +7 for all the shots taken with my Canon-EF-24-105mm-f-4-L-IS-USM

The only lens I've registered on my 1D3 is a Canon EF 100-400 f/4.5-5.6L IS which is showing AF+/- as being 0 as I've never felt the need to adjust it.

So why is the 24-105 set at +7 ?

If the previous owner of the 1D3 had a 24-105 which he AF adjusted to +7 would the camera then assume my 24-105 was that same lens ?
 
I think it would - from Canon's detailed look:

A few important points about the Adjust by Lens feature:

• The camera can distinguish between different models of Canon EF lenses, but it cannot read serial numbers and distinguish between two samples of the exact same lens. In other words, it can tell if you have the 70-200mm f/2.8L or 70-200mm f/2.8L IS II lens attached. However, it cannot distinguish one 70-200mm f/2.8L IS II lens from another.​
 
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Thanks Brian

C.Fn III -7

So despite being able to register 20 different lenses I couldn't have two different versions of the same lens micro adjusted differently.
 
That sounds right to me.
 
AF hasn't really been an issue with the lens at +7 as I've mainly used the lens for landscapes but I'll be doing more portraits where AF accuracy is more important.

I'll just reset the AF back to zero for the 24-105, test and adjust again as required.

It must me a pain for people who may be required to use different copies of the same lens.

Unless newer cameras can identify individual lenses.
 
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Just looked at the 5D3 instructions. On that body you can register up to 40 lenses and for zoom lenses you can apparently set the adjustment separately for both the wide and the telephoto end. For the issue you mention it is possible for the camera to read the serial number of the lens and adjust them accordingly, which would allow you to have more than one copy of a lens. However, I suspect that it would only work with newer lenses as it also says that if an asterisk appears before the serial number then you cannot register several copies of the same lens.

Will have to check mine out now...
 
Yep

5D3 allows you to microadjust for the short AND long end of a zoom.

1D3 allows a single +/- value to be applied to the zoom as a whole. For my 24-105 I'd set it towards the longer end.
 
The 1D3 MA was specific to a focal length or zoom range and that's all it knew...a 300/2.8 and a 300/4 would use the same MA value (bizarrely). Later bodies read the lens serial number (done for agencies with multiple copies of lenses) and that's the same point where zooms could have different settings for wide and telephoto ends.

Bob
 
Canon Bob said:
The 1D3 MA was specific to a focal length or zoom range and that's all it knew...a 300/2.8 and a 300/4 would use the same MA value (bizarrely). Later bodies read the lens serial number (done for agencies with multiple copies of lenses) and that's the same point where zooms could have different settings for wide and telephoto ends.

Bob
Click to expand...

That first part would be a pain although for a hobbyist like me it's less of an issue given my lens collection.
 
dinners said:
That first part would be a pain although for a hobbyist like me it's less of an issue given my lens collection.
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It was a pain. I have a 200/2 and 200/2.8 along with a 300/2.8 and 300/4.

Bob
 
It seems a natural assumption that the people designing a new software feature for an expensive high end camera would consult a few knowledgeable photographers while doing the design. I get the impression that in practice this is often not the case. Weird. However, it's a welcome change in the DSLR world that at least the most expensive models with the most sophisticated AF systems are offering ever improved facilities for correcting the errors in auto focusing. In the early days not only was the AF not so good, but they dumped the old-fashioned aids to manual focus that the film SLRs had.
 
the 1D3 was one of the first cameras with the M/A feature so its a bit basic ,just reset as needed and go from there
 
I'm thinking of pulling the trigger on this software but I only have 1DX bodies, is it worth paying the extra for the Pro version as I believe the 1DX is not fully auto?
 
The 1Dx isn't fully automatic, Jim, and you still need to enter values when prompted (it's a limitation with Canon's SDK and not a Reikan issue). If you only want AFMA calculation then any version will suffice. If you fancy some of the analysis tools and details of AF repeatability along with aperture sharpness appraisal then I'd go for the Full Monty.

Bob
 
Cheers Bob :)
 
dinners said:
So despite being able to register 20 different lenses I couldn't have two different versions of the same lens micro adjusted differently.
Click to expand...
Bythesea said:
Just looked at the 5D3 instructions.... it is possible for the camera to read the serial number of the lens and adjust them accordingly, which would allow you to have more than one copy of a lens. However, I suspect that it would only work with newer lenses as it also says that if an asterisk appears before the serial number then you cannot register several copies of the same lens.
Click to expand...
Canon Bob said:
Later bodies read the lens serial number (done for agencies with multiple copies of lenses)
Click to expand...
Guys, I think it's worth pointing out that, until recently, Canon lenses didn't have their serial numbers encoded in them electronically. That underlies all the observations you've made.

I don't know exactly when Canon started doing this with their newer designs of lenses. I know for certain that the 24-70mm f/2.8 Mk II has the serial number encoded electronically, because it's available in the EXIF data and last year I was able to get a fraud prosecution on that basis. So I surmise that all Canon designs newer than the 24-70 II have this feature, and maybe some slightly older designs do too. I'll have to investigate properly some day and make a list.
 
That's true, Stewart, only lenses produced in the past 3 years (give or take) seem to have the embedded serial number. The lens type has been there much longer and the body is able to pick this up for MA purposes. So, it's possible to have MA values for two lenses of the same focal length (unlike the earlier incarnation of MA) as long as they're different models (IS or non-IS, MkI or MkII, different max aperture etc) but two lenses of the same model may be a problem based on age. For most single users this is probably sufficient but you might need to be alert if you're in the habit of picking a lens off the shelf for you personal outings.

Bob
 
StewartR said:
Guys, I think it's worth pointing out that, until recently, Canon lenses didn't have their serial numbers encoded in them electronically. That underlies all the observations you've made.

I don't know exactly when Canon started doing this with their newer designs of lenses. I know for certain that the 24-70mm f/2.8 Mk II has the serial number encoded electronically, because it's available in the EXIF data and last year I was able to get a fraud prosecution on that basis. So I surmise that all Canon designs newer than the 24-70 II have this feature, and maybe some slightly older designs do too. I'll have to investigate properly some day and make a list.
Click to expand...

My new 100-400 L II doesn't.
 
I've just calibrated my lenses on my 7D2. This allows calibration of zooms at both focal length ends:

10-18mm ef-s w=0, t=0
17-55mm ef-s w=+11, t=+14
100-400mm L II w=-1, t=+1

I was quite surprised by the 17-55mm, but I did a field calibration and the dot-match technique and both gave very similar results.
 
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