# Can't quite dial in AFMA on my 70-200 f4L IS w/1.4x and 5d3



## cdn_photog (Jun 10, 2014)

I have been struggling to get really clear photos from my 70-200 with the 1.4xIII extender so I tried to dial in AFMA on the weekend. I know there will be some image degradation when you add an extender, but that is not what I am asking about. I tried to keep this as apples-to-apples as possible, test shots were done indoors, on a tripod, with 10 second delay timer & mirror lock up, using a remote cable release, IS turned off, so there should be no movement. But try as I might, I can't get the shots taken through the viewfinder to focus quite as sharp as live view. I used FoCal, and also did some shots on either side of the suggested AFMA setting, and the best I could come up with is shown, with a setting of -2. Am I missing something here, or is this about as good as I can expect?

These images are 100% crop, not adjusted at all, just converted from RAW to JPG and then cropped. 

Larger, uncropped versions are https://www.dropbox.com/s/4za1f2452khry6l/5D3_3770.jpg and https://www.dropbox.com/s/5f2ocshddkx747h/5D3_3776.jpg.

Thank you for your help.


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## neuroanatomist (Jun 10, 2014)

AF isn't perfect. But with a properly AFMA'd lens, the sharpest of five each Live View and VF AF should be equivalent. If they're not, there might be an issue with camera and/or lens (or TC in your case).


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## cdn_photog (Jun 10, 2014)

Thanks neuro. But if it is an issue with the camera, lens, and/or extender, wouldn't both images be the same? i.e. show the same defect? It seems to me that I almost need a 0.5 adjustment as 1 either way made the image worse. Although I'm not even sure if this is a front/back focusing problem. The lines on the ruler in front of and behind the 9 don't seem any sharper than on the 9 itself.


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## neuroanatomist (Jun 10, 2014)

Have you tested other lenses?


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## cdn_photog (Jun 10, 2014)

This is the only combination that I am struggling with. I used FoCal on my others (100L macro, 24-105L, and 35 f2.0 IS) and they all seem to be working as expected. The 70-200 on its own seems to be working fine too.


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## neuroanatomist (Jun 10, 2014)

Odd! Any access to another TC-compatible lens?


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## cdn_photog (Jun 10, 2014)

Not really, but I could always rent one. Maybe I should try to rent a different 70-200 f4L IS to see if the same thing happens. If I rent anything better than what I already have that will likely lead to upgrading.

The result I got, with a bit of sharpening in software, was enough of an improvement over what I was getting that I was pretty happy with it. Until I saw how much better the live view version is. I usually photograph outside, birds, animals, etc, so using live view is not a practical option most of the time.


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## cdn_photog (Jun 10, 2014)

I just did some more quick test shots. Using the 70-200 at 200; 24-105 at 105; and 100L macro. The shots taken with live view vs viewfinder look to be very consistent in terms of sharpness. So it must be something to do with the extender. Odd.


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## neuroanatomist (Jun 10, 2014)

Which version of the 1.4x?


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## cdn_photog (Jun 10, 2014)

The 1.4 extender is version 3. Purchased last year, as was the 70-200 f4L IS.


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## horshack (Jun 10, 2014)

Make sure when you AFMA you're using the extreme ends of the focal range (70mm and 200mm) and set the AFMA for each end appropriately. Any attempts to AFMA with the zoom in between those extremes will produce unpredictable results since the 5DM3 firmware interpolates the AF tune value between the AFMA values of the extreme ends. Additionally, I would give DotTune a shot: DotTune: Autofocus fine tuning in under 5 minutes


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## neuroanatomist (Jun 10, 2014)

I know the MkIII extenders have AF algorithms optimized for the MkII supertele lenses (that's why I swapped my MkII versions of the 1.4x and 2x for the MkIII versions after getting the 600/4L IS II). I wonder if there's a negative consequence for older lenses? 

At some point in the near future, I'll try to compare live view and VF for a couple of my TC compatible older lenses (perhaps the 70-200/2.8L IS II and the 135L).


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## cdn_photog (Jun 10, 2014)

That is an interesting point. I should rent a v2 1.4x extender along with the 70-200 f4L IS and test all the combinations. It looks like I can get both.


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## cdn_photog (Jun 10, 2014)

Thanks horshack. I think I have the AFMA at the best possible setting, based on multiple tests, it just isn't quite as sharp as when focusing with Live View.


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## neuroanatomist (Jun 10, 2014)

horshack said:


> Make sure when you AFMA you're using the extreme ends of the focal range (70mm and 200mm) and set the AFMA for each end appropriately. Any attempts to AFMA with the zoom in between those extremes will produce unpredictable results since the 5DM3 firmware interpolates the AF tune value between the AFMA values of the extreme ends.



Unpredictable results? No. It's a simple linear regression, very predictable. Here are my confirmatory data, tested with 4 different lenses set to W = -10 and T = +10:







I find it's useful to test intermediate focal lengths for a zoom lens. All you need to do is set both W and T values to the same adjustment, so no interpolation is performed. Personally, I test 1-3 intermediate FLs, depending on the zoom range (1 FL for ~2x zooms like the 16-35, 2 FLs for ~3x zooms like the 24-70, 3 FLs for zooms with broader ranges). Not that AFMAs can be set for intermediate FLs, but if they don't fall on the regression line the lens should be returned or sent to Canon. For example, my 24-70/2.8L II needs zero at 24mm and +5 at 70mm, and tests at 35mm and 50mm give AFMA values right on the regression line.


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## Mt Spokane Photography (Jun 10, 2014)

Extenders can be bad, I'd call Canon and ask them for advice, they can test your extender on their reference 70-200mm lens with a 5D MK III to see if they find the same result.


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## horshack (Jun 10, 2014)

cdn_photog said:


> Thanks horshack. I think I have the AFMA at the best possible setting, based on multiple tests, it just isn't quite as sharp as when focusing with Live View.


The DOF increments associated with each AF tune increment are pretty thin, so if you're not getting AF results that match LV then that might suggest you haven't arrived at the optimal tune value just yet. In your testing, is every AF photo consistently not as sharp as your LV at your arrived tune value, or is it that there is shot-to-shot variability at your tune value? Do you see the problem at all focal lengths on the zoom?


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## cdn_photog (Jun 10, 2014)

@mt spokane - thanks. I will try renting a v2 extender and a different copy of the lens to see if that makes any difference. If my combo is the only one with this issue then I probably will have to send it in.

@horshack - I have tried AFMA settings on either side of this setting and this is the best one, with consistent results. I didn't test other focal lengths because if I have the extender on the lens is always at 200mm.


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## mackguyver (Jun 10, 2014)

cdn_photog said:


> This is the only combination that I am struggling with. I used FoCal on my others (100L macro, 24-105L, and 35 f2.0 IS) and they all seem to be working as expected. The 70-200 on its own seems to be working fine too.


I had that combination (now the 2.8 IS II) and have never had any issues with f/4 lenses, they tend to be the easiest to calibrate with FoCal. Here are some tips - first, I assume IS is off, right? If so, are you at the right distance? I find that closer to 25x is better than 50x. Focal says that as well for telephotos. Be sure to use LOTS of light - the more light on the target (from roughly 30-45 degrees) the better as it speeds up shutter speeds and improves the accuracy. The other possibility is your support - the tripod needs to be really solid (preferably weighted down) with a good head when you calibrate the 5D3 and other bodies without full auto that use MSC mode. At 280mm, even very slight movement from adjusting the AFMA on the camera is plenty to throw it off. Be sure to turn on "Target Optimisation" setting if you have a Pro license as this really helps when using MSC mode. Hopefully some of those tips might help, but let us know if you still have issues as I've had at least one lens (a 135 f/2) that wouldn't calibrate. I had to send it to Canon for a calibration, but I think light or movement are probably the issue here.


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## Valvebounce (Jun 11, 2014)

Hi Cdn photog.
Please don't take this the wrong way, but did you attach them in the specified order, lens to convertor then combination to body? If not this may have a bearing on the adjustment.

Hope you get this sorted. 

Cheers Graham.


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## cdn_photog (Jun 11, 2014)

@mackguyver - Thanks for the tip about lighting. I think I had the camera locked down pretty tight on the tripod, but probably could have used more light. I will try that. IS was off. I was shooting from about 20 feet, 25x 280mm is ~23 feet so not quite where I need to be but that is the longest stretch of hallway I have.

@valvebounce - I'm sure I attached the extender to the lens first, and will make sure I do when I try again.

I emailed Canon and they recommended cleaning the contacts before giving up and sending it in for service, so there are still a few variables I need to eliminate. Thanks all for the tips & advice.


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## mackguyver (Jun 11, 2014)

cdn_photog said:


> @mackguyver - Thanks for the tip about lighting. I think I had the camera locked down pretty tight on the tripod, but probably could have used more light. I will try that. IS was off. I was shooting from about 20 feet, 25x 280mm is ~23 feet so not quite where I need to be but that is the longest stretch of hallway I have.
> /quote]
> 20 feet should be totally fine, but adding light will help a lot. It seems to be the key to getting good results with FoCal from my and many other's experience. Also, note that the extender to lens then combo to body thing only matters if you are attaching the lens with the camera TURNED ON. If it's off, the camera won't know the order . I almost always leave the extender on my body when I'm changing lenses in the field to keep dust from getting into the body. As long as the camera is off, I've never had an issue when I've turned it back on, and I've done this for many years.


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## Valvebounce (Jun 11, 2014)

Hi Mackguyver. 
That is a good point to know, I was repeating what I read in the manual, never tried it the other way, but I guess it makes sense that the camera wouldn't know, or would it? The viewfinder stays powered with the camera switched off, how much other stuff is powered whilst off, GPS on 6D?
I wonder if the lens contacts are still listening when the power is off, just thinking out loud now? 
I guess if your experience is that it doesn't make a difference with the camera off you may well be correct. Just in case I will continue to follow the order in the book as I only have one lens that the 2x III fits so I am adding or removing the extender whenever I touch it. If I get another lens that the extender fits I may revisit this theory.

Cheers Graham.



mackguyver said:


> Also, note that the extender to lens then combo to body thing only matters if you are attaching the lens with the camera TURNED ON. If it's off, the camera won't know the order . I almost always leave the extender on my body when I'm changing lenses in the field to keep dust from getting into the body. As long as the camera is off, I've never had an issue when I've turned it back on, and I've done this for many years.


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## mackguyver (Jun 11, 2014)

Valvebounce said:


> Hi Mackguyver.
> That is a good point to know, I was repeating what I read in the manual, never tried it the other way, but I guess it makes sense that the camera wouldn't know, or would it? The viewfinder stays powered with the camera switched off, how much other stuff is powered whilst off, GPS on 6D?
> I wonder if the lens contacts are still listening when the power is off, just thinking out loud now?
> I guess if your experience is that it doesn't make a difference with the camera off you may well be correct. Just in case I will continue to follow the order in the book as I only have one lens that the 2x III fits so I am adding or removing the extender whenever I touch it. If I get another lens that the extender fits I may revisit this theory.
> ...


Graham, all I can say is that it seemed a bit silly to me (when the camera was turned off) so I started doing leaving the extender on when changing lenses - usually a supertelephoto to 70-200 or vice versa and I've never had any issues. 

When I've left the camera on and done it, the camera definitely gets mad, however . It happens as soon as you screw the extender in or take the lens attached to the camera off the extender. With the battery in, there's definitely some juice running through the camera, but it doesn't seem to affect this, mainly because it seems to throw metering and/or aperture control off, and I'm pretty sure that's disabled while the power switch is in the off position.


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## East Wind Photography (Jun 11, 2014)

Well lots of advice from everyone. However i will say that afma will not work as expected with the setup that you have. The camera will ultimately use the ruler in some af calculations.

The best way without buying reikan focal (and i have never had much luck with Focal) is to tape a full sheet of news print on a wall and take 5 shots at each major afma setting 0 5 10 15 20 and 25 as well as the negative ranges. Use 100% view on a computer to evaluate the images. Once you determine the clearest ones then you can do then same + and - for every afma step 5 up and 5 down from that major setting.

Dont eval on the lcd screen or you will never get it right.

Another factor is to focus at the farthest distance your setup will allow. Some lenses also have different afma settings depending on your focus distance. Quite annoying.


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## Valvebounce (Jun 12, 2014)

Hi Mackguyver. 
Thanks for the extra clarification. When I get my supertele lens I will probably have forgotten all about this but I can hope! 

Cheers Graham.



mackguyver said:


> Graham, all I can say is that it seemed a bit silly to me (when the camera was turned off) so I started doing leaving the extender on when changing lenses - usually a supertelephoto to 70-200 or vice versa and I've never had any issues.
> 
> When I've left the camera on and done it, the camera definitely gets mad, however . It happens as soon as you screw the extender in or take the lens attached to the camera off the extender. With the battery in, there's definitely some juice running through the camera, but it doesn't seem to affect this, mainly because it seems to throw metering and/or aperture control off, and I'm pretty sure that's disabled while the power switch is in the off position.


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## cdn_photog (Jun 14, 2014)

I had a chance to try again. I cleaned the contacts per Canon's advice, hung my camera bag from the tripod for extra stability, and used better lighting. It was a big improvement over the first attempt (at the same AFMA setting, so that wasn't the problem). Still not 100%, but probably 98% so I am happy with that. Just goes to show how many little details there are that affect picture quality. Thanks again for all the advice & tips.


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## mrzero (Jun 15, 2014)

Valvebounce said:


> The viewfinder stays powered with the camera switched off, how much other stuff is powered whilst off, GPS on 6D?



The viewfinder in a traditional SLR or DSLR is a prism that reflects the light being transmitting through the lens and bounced off the internal mirror. Hence, no power is required. The GPS on the 6D stays on while the camera is powered off so that it can keep updating its own location, unless the GPS is deactivated first.


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## Valvebounce (Jun 15, 2014)

Hi Mrzero. 
Just for your edification, look through the viewfinder with the power off then drop the battery out and watch the light level through the viewfinder drop. This is the proof that the LCD display overlay for the viewfinder is powered. 

Cheers Graham.



mrzero said:


> Valvebounce said:
> 
> 
> > The viewfinder stays powered with the camera switched off, how much other stuff is powered whilst off, GPS on 6D?
> ...


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## mackguyver (Jun 16, 2014)

cdn_photog said:


> I had a chance to try again. I cleaned the contacts per Canon's advice, hung my camera bag from the tripod for extra stability, and used better lighting. It was a big improvement over the first attempt (at the same AFMA setting, so that wasn't the problem). Still not 100%, but probably 98% so I am happy with that. Just goes to show how many little details there are that affect picture quality. Thanks again for all the advice & tips.


CDN, I'm happy to hear that and if you'd like to see some more tips on FoCal use, check out this thread I created a while back, which I should have posted a link to earlier:
http://www.canonrumors.com/forum/index.php?topic=19742.0


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## cdn_photog (Jun 16, 2014)

Thanks mackguyver.


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