# FoCal – Long / Fast Lens Calibration



## mackguyver (Feb 24, 2014)

*Updated with revised procedure (in blue) January 3, 2017*

I've noticed a fair number of posts on using FoCal, so I thought I'd share my technique. I’ve been using FoCal since it was in beta and over the course of time, through lots of trial & error, I’ve figured out how to reliably calibrate long lenses and fast lenses. Here’s how I do it:

*Use Automatic Focus Calibration (previously known as "Manual Mode")*: The automated mode has never given me reliable results, at least with fast or long lenses. It takes longer, seems to take an inordinate number of extra shots, is not repeatable, and does not result in very good results. For lenses slower than f/2.8, it works really well, though, if your camera supports it.
*Do Not Use Back Button AF*: As Neuroanatomist helped me discover, Back Button AF does not (reliably or at all) record the AFMA value in the EXIF metadata.

Target Preparation
1.	Use the PDF file and print it on matte heavyweight paper at the highest quality settings your printer allows
2.	For best results, mount the target on stiff cardboard – I use the protector sheet of cardboard that comes with the paper and use 3M 6090 photo mounting spray to glue them together

Calibration Target Set Up
1.	Use your most stable tripod/head combination, legs not extended, and set up roughly 20x to 30x focal length (i.e. 8-12 meters for a 400mm lens) from where you plan to mount the target. I have found that this is the sweet spot – it keeps the target big enough to obtain excellent results and is close enough to average shooting distance and infinity to be accurate in the field. I’ve also found that f/1.2 lenses work best around 20x.
2.	Add weight to the tripod – I use a 20lb sandbag
3.	Line up the front of your lens to it is as close to parallel to the target as possible. If available, use your camera’s level feature to get the camera perfectly level. A bubble level will do if your camera doesn’t have this feature. 
4.	Mount the target so it lines up with the center of the target matching the center of the viewfinder. A second person is helpful but not necessary. This usually takes a few tries.
5.	Make any minute adjustments (while keeping the camera perfectly level) to get the center point perfectly aligned with the center of the target.
6.	Lock the tripod head down tightly
7.	Light the target – the brighter the better. I use 2 x Paul C. Buff Einstein lights (with 8” high output reflectors) with the modelling light turned on Full power. The lights should be angled at roughly 30-45 degrees off axis from the target and the target should be lit as evenly as possible.

Camera Set Up
1.	Use the viewfinder cover to block light from entering the viewfinder
2.	Set camera to:
•	Aperture Priority Mode
•	Wide open aperture
•	ISO 100
•	Auto White Balance
•	RAW
•	+1 EV
•	Spot metering
•	Timer/remote mode
•	Set shutter control to activate AF & AE (this may be disabled if you usually use back-button AF)
•	Center point AF
•	Mirror-lock up enabled
•	Disable IS on the lens
•	Also, if you have a newer model, make sure AF is enabled for your focus-by-wire lenses like the 85 f/1.2 II

Calibration
1.	Record the current Auto-focus Microadjustment value (AFMA) for the lens
2.	Set the AFMA to -20
3.	Defocus the lens (towards infinity or minimum focus distance [MFD]) – it doesn’t matter which you use, but I’ve found that using a consistent direction helps
4.	Using a cable release or better yet, a wireless remote (like the RC-1 or RC-6), set to 2 or 10 second delay, press the remote shutter button to autofocus the lens and lock up the mirror. After 2 or 10s, the shutter will trip
5.	Defocus and take a second shot (2 shots minimum should be used)
6.	Repeat steps 3-5 and take shots with the following series of AFMA values: -20, -15, -10, -5, 0, 5, 10, 15, 20 -20, -18, -16, -14, -12, the following x2 (defocus opposite directions) -10 through +10, then +12, +14, +16, +18, +20. Note: the vast majority of lenses fall within -10 to +10, and doing this upfront saves time doing a follow-up calibration.

Analysis and Re-Calibration (if needed)
1.	Remove the memory card, download the photos to your PC/Mac
2.	Launch FoCal, select the Calibration tab and then choose "Automatic Focus Calibration"
3.	Click on Add Files and select the shots you just took
4.	When they appear, make sure the AFMA values appear correctly (they should) and that you took all of the shots required
5.	Click on Select All
6.	Enable “Target Optimization”. Unless you have the lens mounted on a copy stand or a SERIOUS tripod, the camera/lens will move very slightly as you adjust AFMA values - Target Optimization will adjust for that
7.	Click Analyze – wait for results
8.	After you obtain the results, *if the results fall out of the -10 to +10 range*, go back and take AFMA shots around the predicted value – i.e. if FoCal says it’s +12, take two additional shots at +11, +12, +13, and +14
9.	Return to your PC, download these new files – re-run the analysis with the original files + the new ones.
10.	The results will now be as accurate as possible.
11.	Save the Report – good to have for later reference
12.	Return to camera, set AFMA to FoCal recommended value

Optional Steps
1.	Measure target size (in mm) of the strip at the top of the target – input into preferences
2.	Determine the white balance of your lights (Einstein modelling lights are 5200K) and input that into the white balance setting


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## ahab1372 (Feb 24, 2014)

+1
although I prefer to take more additional shots in the first run instead of going through a second round


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## mackguyver (Feb 24, 2014)

ahab1372 said:


> +1
> although I prefer to take more additional shots in the first run instead of going through a second round


Thanks, and I often do that, too, especially if I've calibrated the lens before and know roughly where it will end up. As FoCal has improved, however, I have found that shots beyond the 5 point spread are often unnecessary. More often than not, I find that the extra shots result in the same calibration, especially for lenses f/2.8 or slower. For my f/1.2 & 1.4 lenses, I have frequently taken shots at plus & minus 5 AFMA values to get the best results. AFMA on these lenses not only makes the image sharper, it reduces CA.


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## neuroanatomist (Feb 24, 2014)

Thanks for posting!



ahab1372 said:


> +1
> although I prefer to take more additional shots in the first run instead of going through a second round



Me, too. Note that you can use back button AF, as long as you're holding the AF-ON button when you press the shutter to activate the timer. 

Definitely get as much light as possible on the target. Light levels in 11-12 EV range or higher give more consistent results.


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## PhotoConceptsDT (Feb 24, 2014)

Great info. I've been pondering getting FoCal for my kit. I am also looking at the new Tamron 150-600. My question is whether I need the pro version if FoCal as that lens is greater than 400mm. I'm okay with doing all the stuff manually. Your thoughts?

Thanks!


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## mackguyver (Feb 24, 2014)

PhotoConceptsDT said:


> Great info. I've been pondering getting FoCal for my kit. I am also looking at the new Tamron 150-600. My question is whether I need the pro version if FoCal as that lens is greater than 400mm. I'm okay with doing all the stuff manually. Your thoughts?
> 
> Thanks!


Thanks and yes, for that lens you'll need the Pro version if you want to calibrate lenses over 400mm (the plus version works for lenses up to and including 400mm):
http://www.reikan.co.uk/focalweb/index.php/versions/version-comparison/


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## R1-7D (Feb 24, 2014)

This is great information. I too have noticed that FoCal doesn't work too well in auto/semiauto modes for fast lenses. I've never had the guts to try all manual, but I think I will give it a shot when the weather warms up here (don't have enough light or space in my house for adequate testing). 


Thanks for all the effort you've put into this!


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## mackguyver (Feb 24, 2014)

R1-7D said:


> This is great information. I too have noticed that FoCal doesn't work too well in auto/semiauto modes for fast lenses. I've never had the guts to try all manual, but I think I will give it a shot when the weather warms up here (don't have enough light or space in my house for adequate testing).
> 
> 
> Thanks for all the effort you've put into this!


It sounds a lot harder than it actually is and once you try manual, you'll see that it's actually a lot faster because you can generally calibrate each lens in about 20-26 shots and while FoCal doesn't process instantly in Manual Mode, there's no more waiting for the USB cable transfers and slow RAW processing. I calibrated my 300 f/2.8 IS II and both extenders on my 5DII and 5DIII bodies yesterday in about 20-25 minutes. I came back and knocked out my new 50 f/1.2 on both bodies in about 10 minutes. In full auto mode on my 5DII, it's usually 20+ minutes for a f/1.2 lens at which point it is giving "Poor" results and I usually stop it because it's racked up 30-40 shots or more.

Also, I often take shots for numerous lenses at once and then "Analyze" them on the PC in one sitting. The only trick is *remembering* to go back and put those lenses back on and set their AFMA values one-by-one.

One time I forgot and I was in the field shooting when I noticed all of my shots looked like crap and were horribly out of focus. Must have bumped the diopter, right? Nope, not that, hmmm, better check AFMA - oh, it's set to +20, oops!!!


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## Famateur (Feb 24, 2014)

MackGuyver,

Thank you so much for taking the time to post your FoCal method. It's actually quite reassuring to me as I've had inconsistent results trying to calibrate my EF-S 17-55 F2.8 IS with my 70D (so much so, actually, that I've started to wonder if I have an issue with either the lens or the body). Granted, my lens is not nearly as fast as your F1.2, but it was nice to see that while results of the automated process were "poor" for your lens, you were much more successful via this manual method.

As soon as I come up with a better/brighter light source (maybe a couple of those 500W halogen work lights from my shop?), I'm going to follow your FoCal recipe to see how it goes. The 20lb sandbag is a great idea, too -- especially with my cheapo tripod.

I'm much more enthused to go give FoCal another try. Thanks again!


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## mackguyver (Feb 24, 2014)

Famateur said:


> MackGuyver,
> 
> Thank you so much for taking the time to post your FoCal method. It's actually quite reassuring to me as I've had inconsistent results trying to calibrate my EF-S 17-55 F2.8 IS with my 70D (so much so, actually, that I've started to wonder if I have an issue with either the lens or the body). Granted, my lens is not nearly as fast as your F1.2, but it was nice to see that while results of the automated process were "poor" for your lens, you were much more successful via this manual method.
> 
> ...


I'm happy to hear that you have enjoyed my post and you're very welcome. I have also had issues calibrating f/2.8 lenses in full-auto mode - so I'm not surprised by the issues you've had with the 17-55 2.8 IS. As Neuro said, adding more light is usually the best thing you can do (those shop lights should work well), followed by a stable tripod, and in my experience using Manual mode. Getting a bit closer to the target really helps, too, as it gives FoCal more pixels to work with - around 25x should work well at f/2.8. Initially I tried 50x (Canon's manual AFMA process recommendation) and found it didn't work well at all. I moved closer and got great results. I was afraid they would affect the real-world autofocus, but that hasn't been the case, at least from 20x and further.


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## Raptors (Feb 25, 2014)

Mackguyver,

I too would like to thank you for taking the time to post your FoCal method. I have used the LensAlign
MKII, but never getting consistent results...that's why I am seriously thinking about buying FoCal. 

I have a few questions, regarding calibrating zoom lenses. I have the 1DX and would be calibrating my
200-400mm 1.4X...I do know that you can calibrate at both ends of the zoom range, but would FoCal 
recognize when I engage the internal 1.4x as well as the external 1.4x? 

Thanks


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## mackguyver (Feb 25, 2014)

Raptors said:


> Mackguyver,
> 
> I too would like to thank you for taking the time to post your FoCal method. I have used the LensAlign
> MKII, but never getting consistent results...that's why I am seriously thinking about buying FoCal.
> ...


Raptors, I am happy to pass along things I learn and yes, FoCal would recognize the lens via the EXIF data, and would give you the calibration for any focal length you choose. I'm guessing the 1DX treats this as two lenses in the AFMA settings, right? I see that DxO does that, so I'm betting that the camera sees a 200-400 1.4x and a 200-400 with 1.4 engaged or something like that and there are separate AFMA settings for each at W & T. If that's correct, then FoCal would work the same way.


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## Badger (Feb 27, 2014)

Thanks for posting! I'm a relatively new FoCal user and I have been thrilled with the results!
Always happy to learn how the pros do it.


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## Raptors (Mar 9, 2014)

mackguyver said:



> Raptors said:
> 
> 
> > Mackguyver,
> ...



Mackguyver,

Thanks...sorry for the delay, I have been out of the city for a couple of weeks. With the 1DX, the camera is able to save independent AFMA values for use w/ or w/o the built-in extender, as well as w/ or w/o the external 1.4x. Here are the 4 different profiles from the camera.

1) AFMA, focal length 200-400mm
2) AFMA with the built-in extender, focal length 280-560mm
3) AMFA with the built-in 1.4x extender and the external 1.4x, focal length 292-784mm
4) AMFA with just the external 1.4x, focal length 280-560mm

For the target set up, you recommend roughly 20x to 30x focal length. What is the procedure for zoom lenses? As I can calibrate at both ends of the zoom range, I gather you need to change the distance to target for each focal length?

Sorry for all the questions...thanks in advance
Raptors


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## mackguyver (Mar 10, 2014)

Raptors said:


> mackguyver said:
> 
> 
> > Raptors said:
> ...


I guess I didn't cover zoom lenses or think about all of the combinations when you add in (external) extenders, but that makes sense in terms of the number of possible profiles for the 200-400 1.4x (with or without the internal 1.4x and external 1.4x). 

To answer your question, yes, you need to move the camera for the Wide and Telephoto measurements, and a wise man will take photos with every camera body he owns before moving the set up. Ask me how I know that .


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## Raptors (Mar 11, 2014)

mackguyver said:


> Raptors said:
> 
> 
> > mackguyver said:
> ...



Thanks Mackguyver...as I'm going to need a fair amount of space, I will have to wait till it stops snowing!!! 

Thanks again for all your time and effort


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## mackguyver (Mar 11, 2014)

Raptors said:


> Thanks Mackguyver...as I'm going to need a fair amount of space, I will have to wait till it stops snowing!!!
> 
> Thanks again for all your time and effort


I'm happy to help and I hope it warms up for you soon!


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## hovland (Apr 18, 2014)

Thanks mackguyver.
Just what I needed after some inconsistent results trying to calibrate my 135L.
I’m also new to focal, so you guide helps a lot


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## mackguyver (Apr 18, 2014)

hovland said:


> Thanks mackguyver.
> Just what I needed after some inconsistent results trying to calibrate my 135L.
> I’m also new to focal, so you guide helps a lot


I'm glad it's helpful and I also had trouble calibrating my 135L until I got better about how I set up and used FoCal.


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## mackguyver (Jan 3, 2017)

FYI, I have updated this post based on some refinements made over the last year or so. As many of you may have new lenses from the holidays, I wanted to share this. Also, if you have any questions, please let me know here.


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## Maiaibing (Jan 3, 2017)

mackguyver said:


> FYI, I have updated this post based on some refinements made over the last year or so. As many of you may have new lenses from the holidays, I wanted to share this. Also, if you have any questions, please let me know here.



Thanks for your efforts. Canon recommends 50x FL to target; you suggest 20x to 30x. I usually go with Canon - what's your suggestion based on?


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## neuroanatomist (Jan 3, 2017)

Maiaibing said:


> Thanks for your efforts. Canon recommends 50x FL to target; you suggest 20x to 30x. I usually go with Canon - what's your suggestion based on?



Reikan recommend 50x at shorter FLs, and a reduced multiplier at longer FLs.

http://s449182328.websitehome.co.uk/focal/dl//Docs/FoCal%20Test%20Distance_1.1.pdf


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## mackguyver (Jan 3, 2017)

neuroanatomist said:


> Maiaibing said:
> 
> 
> > Thanks for your efforts. Canon recommends 50x FL to target; you suggest 20x to 30x. I usually go with Canon - what's your suggestion based on?
> ...


It's based on my experience calibrating multiple fast (f/1.2-1.4) lenses. I have purchased the larger Focal target from Reikan and that has helped with the shorter lenses, particularly the 11-24.


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## Viggo (Jan 3, 2017)

I did not know that the manual shots could be analyzed by FoCal, I will absolutely try this when I get my 200mm back from service. Thanks!


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## mackguyver (Jan 4, 2017)

Viggo said:


> I did not know that the manual shots could be analyzed by FoCal, I will absolutely try this when I get my 200mm back from service. Thanks!


Yes, it's so much faster to take the shots yourself. Definitely give it a try.


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## neuroanatomist (Jan 4, 2017)

mackguyver said:


> Viggo said:
> 
> 
> > I did not know that the manual shots could be analyzed by FoCal, I will absolutely try this when I get my 200mm back from service. Thanks!
> ...



The other advantages to manual are 1) you can oversample (relative to FoCal's algorithm) if desired, and 2) you can calibrate a new model that FoCal doesn't yet support. I started using manual mode when I got my 1D X (it was a few months until FoCal support, and even then it was semi-manual), and found it better and easier, so I never went back.


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## Ah-Keong (Jan 4, 2017)

thanks for the guide! ;D


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## 1251division (Jan 4, 2017)

Yes, thank you all for the FoCal usage tips. This is a great step-by-step guide, and very handy to bookmark. I've been thinking about picking up FoCal as well. I've read the mixed reviews, but have concluded that this is the best tool available for the job.

A somewhat tangential topic, but there was a recent thread discussing whether or not or to what extent high-quality filters affect IQ. Has anyone ever run the APERTURE SHARPNESS test within FoCal on a lens with and without a given filter? https://www.reikan.co.uk/focalweb/index.php/tests/aperture-sharpness/

If you have, I'd be curious to hear about your results and observations.

(Personally "I don't always use filters, but when I do..." I use B+W XS-Pro Clear MRC-Nano 007 filters. On my 24-70ii 82mm; visually, I notice almost no difference and results are very sharp; however on my 70-200ii 77mm, there is a noticeable fall-off in IQ between w/ and w/out filter.) I was wondering if this before/after comparison would be useful in assessing a specific filter's quality in general and was looking forward to testing it out once I get the software.

Thanks!


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## Maiaibing (Jan 4, 2017)

mackguyver said:


> Calibration Target Set Up
> Analysis and Re-Calibration (if needed)
> 1.	Remove the memory card, download the photos to your PC/Mac
> *2.	Launch FoCal, select Tools>Manual Mode
> ...



Looked at this, but cannot see any Manual Mode option.


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## Valvebounce (Jan 4, 2017)

Hi Maiaibing 
There is something funny with this, like manual won't show up if the camera is connected to the USB or similar, I don't have FoCal here so can't check, but it is not the easiest option to find. 
I think this has been mentioned in a thread before if you know how to make the forum search provide you with any useful results! It never works for me. :-[

Cheers, Graham. 



Maiaibing said:


> mackguyver said:
> 
> 
> > Calibration Target Set Up
> ...


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## LordofTackle (Jan 4, 2017)

Maiaibing said:


> mackguyver said:
> 
> 
> > Calibration Target Set Up
> ...



Hi Maiaibing,

I agree, it's a bit tough to find/ill-named.
You need to go to "Calibration" and then choose "Automatic Focus Calibration". In the opening window you can then specify which pictures should be analyzed by clicking "Add files". As Graham pointed out, you need to have your camera *disconnected*. 

At least thats the way on my mac with the newest Focal version.

-Sebastian


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## mackguyver (Jan 4, 2017)

LordofTackle said:


> Maiaibing said:
> 
> 
> > mackguyver said:
> ...



Sebastian, thank you for this - it used to be called Manual mode and the new name is a bit confusing to say the least. I will update the main post.


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## Maiaibing (Jan 4, 2017)

LordofTackle said:


> Maiaibing said:
> 
> 
> > mackguyver said:
> ...



Thanks! That's what I tried doing. Just thought I was missing out of something!


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## Maiaibing (Jan 4, 2017)

hovland said:


> Thanks mackguyver.
> Just what I needed after some inconsistent results trying to calibrate my 135L.
> I’m also new to focal, so you guide helps a lot



Hmmm. I'm also having trouble nailing my 135L to my 5DSR. Rechecked today using this methodology. Changed the setting from -11 to -10. A close call between the two settings.


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## mackguyver (Jan 4, 2017)

Maiaibing said:


> hovland said:
> 
> 
> > Thanks mackguyver.
> ...


Yeah, I always had a tough time calibrating my 135L and ultimately sent it in to Canon to have it aligned and calibrated. After that, it was consistent, but perhaps there's something about that lens that's prone to getting knocked out of alignment. I still regret selling that lens


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## Viggo (Jan 11, 2017)

So I'm trying the manual method for the first time, and I turned off BBF and used the normal shutter. Everything went great, and then loaded the images and both and older pc and my iMac shows all files as "+1", any tips?


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## kaihp (Jan 11, 2017)

Viggo said:


> So I'm trying the manual method for the first time, and I turned off BBF and used the normal shutter. Everything went great, and then loaded the images and both and older pc and my iMac shows all files as "+1", any tips?



If the AFMA isn't recorded in the EXIF (due to BBF or live-view), it will not show up at all. That it's fixed at +1 sounds to be as that it _is_ getting noticed & recorded, but somehow the AFMA isn't being updated. try putting the card back into the camera and preview the images with the information displayed. It should tell you the AFMA there.


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## Viggo (Jan 11, 2017)

kaihp said:


> Viggo said:
> 
> 
> > So I'm trying the manual method for the first time, and I turned off BBF and used the normal shutter. Everything went great, and then loaded the images and both and older pc and my iMac shows all files as "+1", any tips?
> ...



I tried that in the later run, and with the 35 the displayed showed the afma every time, but not in FoCal. However! The 200 set to any afma value does not show up on camera! Never ever have I seen a lens camera combo where the camera fails to display the selected afma.


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## Valvebounce (Jan 12, 2017)

Hi Viggo. 
Do you have lens corrections aberration turned on on your camera (can't remember which camera you are trying to do) but this is known to cause issues, mine was whilst tethered, a message saying *"A shot was taken but no focus points reported focus confirmation. You should ensure you are using single point AF mode and that you have an appropriate focus point selected on the camera".*
The newer versions of FoCal have a new message suggesting lens corrections as the culprit, but I'm guessing you would only get these messages whilst tethered. 
Also, contact Reikan for help, they are great, I got a response in less than a day! 

I hope you get to the bottom of this. 

Cheers, Graham.


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## Viggo (Jan 12, 2017)

Valvebounce said:


> Hi Viggo.
> Do you have lens corrections aberration turned on on your camera (can't remember which camera you are trying to do) but this is known to cause issues, mine was whilst tethered, a message saying *"A shot was taken but no focus points reported focus confirmation. You should ensure you are using single point AF mode and that you have an appropriate focus point selected on the camera".*
> The newer versions of FoCal have a new message suggesting lens corrections as the culprit, but I'm guessing you would only get these messages whilst tethered.
> Also, contact Reikan for help, they are great, I got a response in less than a day!
> ...



Thanks! I have a 1dx2 (yeeeesh, I bought it) and have vignetting and ca correction on. I will turn them off and try again ! Will report back here on my findings.


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## sedwards (Jan 12, 2017)

I had a similar issue when using manual mode and it turned out Focal was reading the first character of each file name as the afma number. In my case I was using a 1DsIII and had set the filename to 1ds + the consecutive number. No idea if that is your issue but something to look at.


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## kaihp (Jan 12, 2017)

sedwards said:


> I had a similar issue when using manual mode and it turned out Focal was reading the first character of each file name as the afma number. In my case I was using a 1DsIII and had set the filename to 1ds + the consecutive number. No idea if that is your issue but something to look at.



Now that you mention it, I ran into this one as well. I see the underlying idea (which is neat) but that FoCal doesn't warn out about this is ... less than ideal IMHO.



Viggo said:


> Thanks! I have a 1dx2 (yeeeesh, I bought it) and have vignetting and ca correction on. I will turn them off and try again ! Will report back here on my findings.



Congrats! hopefully the 1Dx2 will serve you well without gremlins for years to come.


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## Viggo (Jan 12, 2017)

kaihp said:


> sedwards said:
> 
> 
> > I had a similar issue when using manual mode and it turned out Focal was reading the first character of each file name as the afma number. In my case I was using a 1DsIII and had set the filename to 1ds + the consecutive number. No idea if that is your issue but something to look at.
> ...



Thanks! Yeah, fingers crossed! 8)


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## Viggo (Jan 12, 2017)

I've got a great tip from FoCal about the issue described above:

"In older versions of Focal, if your file name starts with a number, that number will displayed as the afma value. Simply change the file names starting with a letter and the issue should be resolved."


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## mackguyver (Jan 26, 2017)

Viggo said:


> I've got a great tip from FoCal about the issue described above:
> 
> "In older versions of Focal, if your file name starts with a number, that number will displayed as the afma value. Simply change the file names starting with a letter and the issue should be resolved."



That's pretty crazy, but thanks for sharing this as I'm not on the current version, either.


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## Viggo (Jan 26, 2017)

*Re: FoCal – Long / Fast Lens Calibration *



mackguyver said:


> Viggo said:
> 
> 
> > I've got a great tip from FoCal about the issue described above:
> ...



Thing is FoCal gives me a constant front focus even in manual mode so I can't really use it for anything but ballpark and go out and test. Luckily the 1dx2 makes it possible due to extremely consistent quality of focus to find the correct value in the field.


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## mackguyver (Jan 27, 2017)

*Re: FoCal – Long / Fast Lens Calibration *



Viggo said:


> mackguyver said:
> 
> 
> > Viggo said:
> ...


That's unfortunate to hear as I have had really good luck with it, particularly with the f/1.2 lenses. Speaking of which, it does seems to take CA into account, which is great for the 50L & 85L, but it does so at the expense of peak sharpness (& optimal focus?). Perhaps that's the issue?


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## Viggo (Jan 27, 2017)

*Re: FoCal – Long / Fast Lens Calibration *



mackguyver said:


> Viggo said:
> 
> 
> > mackguyver said:
> ...



Could be, because it's any type of light source in target or any lens/camera combo. And it started after a specific update to the software and has been like that ever since. It gives about +4 points front focus, but sometimes more
Or less. But it's always in front, never behind or dead on.


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## [email protected] (Jan 27, 2017)

One note to throw in re: target size: 
You can print your own target from the included images that come with the software. If you have a very large printer (like the ubiquitous Pixma 100), you can print a really large one. There is a setting in the Focal preferences that allows you to measure the width of the target and input that, thus letting the software know what size target it's seeing and adjust accordingly. That has helped me a great deal while AFMA'ing on focal lengths of 400+ while still getting a decent distance to target. 

Haven't tried manual myself, but I will next time. -tig


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## Viggo (Jan 28, 2017)

[email protected] said:


> One note to throw in re: target size:
> You can print your own target from the included images that come with the software. If you have a very large printer (like the ubiquitous Pixma 100), you can print a really large one. There is a setting in the Focal preferences that allows you to measure the width of the target and input that, thus letting the software know what size target it's seeing and adjust accordingly. That has helped me a great deal while AFMA'ing on focal lengths of 400+ while still getting a decent distance to target.
> 
> Haven't tried manual myself, but I will next time. -tig



Indeed you can! I tried and used a print with the older versions, and even though it was very shiny it was 100% accurate. 

I bought the official target (210mm) from FoCal, maybe that's my problem


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## mackguyver (Feb 3, 2017)

Viggo said:


> [email protected] said:
> 
> 
> > One note to throw in re: target size:
> ...


I bought it, too, expecting it to be a fair amount better than one I had printed and mounted to Gator Board. It wasn't. It's still a nice target and the plastic backing is easier to deal with, but if anyone is thinking about buying one and has at least a decent printer (laser or inkjet), I wouldn't buy it. Just print the target using the PDF so you can scale it as Tiggy suggests and then use some 3M Super 77 spray or similar adhesive to mount it to some foam board from Walmart/Target/grocery store.


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## Viggo (Feb 3, 2017)

mackguyver said:


> Viggo said:
> 
> 
> > [email protected] said:
> ...



You didn't notice any frontfocus results with the official target, compared to the one printed by yourself?


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## mackguyver (Feb 3, 2017)

Viggo said:


> mackguyver said:
> 
> 
> > Viggo said:
> ...


No, it seems to work just the same as my own targets have. I will say that the biggest key in using FoCal for me has been the light level on the target. The brighter, the better it seems.


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## Viggo (Feb 3, 2017)

mackguyver said:


> Viggo said:
> 
> 
> > mackguyver said:
> ...



Thanks! Yeah, I've been using the same lamp since the first time. Even tried in direct sunlight.


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