7D Mk II Fails to Focus in AI-Servo

[riknash]

Anyone have an explanation what went wrong?

Using the 7D Mk II with the 200-400/4 (1.4x internal TC engaged), the AI-Servo failed to function. Depressing either the shutter half way or using the AF Back button multiple times failed to operate the AF focus motor on the lens. It simply did nothing. Since there was no time to check settings as the subject was going to disappear within seconds, I decided to depress the shutter button all the way to see what would happen. The camera operated the shutter in high speed mode and several images were taken, all significantly out of focus. Of the eleven consecutive images taken, the camera never once tried to correct the out of focus image.

As set on the camera,

- AI2: AI Servo Turned to focus priority.

AI Servo 1st image priority set to focus priority, the camera should not take a photo until focus is achieved. It wouldn't focus at all and quite readily took many out of focus photos. EXIF shows no AF points were in focus.

- Same setting was on AI Servo 2nd image priority, set to focus priority which shouldn't take any photos if not in focus.

AF4: Lens drive when AF impossible. This was set to OFF as recommended in the manual for super telephotos.

- Case 2 was selected on the camera for AI Servo AF Characteristics.

- The lens was checked and confirmed the AF was selected.

GPS was turned ON in the camera.

A single point was selected. No AF points appear in DPP "show focus points" menu option.


EXIF stripped out but detailed below

The lens must have been communicating with the camera for it to know the data which comes from the lens.

ExifTool Version Number : 9.77
File Name : 2J4A4436.JPG
Directory : D:/2014_12_10/no_focus
File Size : 7.2 MB
File Modification Date/Time : 2014:12:10 10:13:32-07:00
File Access Date/Time : 2014:12:13 21:43:09-07:00
File Creation Date/Time : 2014:12:10 21:11:49-07:00
File Permissions : rw-rw-rw-
File Type : JPEG
MIME Type : image/jpeg
Exif Byte Order : Little-endian (Intel, II)
Make : Canon
Camera Model Name : Canon EOS 7D Mark II
Orientation : Horizontal (normal)
X Resolution : 72
Y Resolution : 72
Resolution Unit : inches
Modify Date : 2014:12:10 10:13:32
Artist : Rick Nash
Y Cb Cr Positioning : Co-sited
Copyright :
Exposure Time : 1/1600
F Number : 5.6
Exposure Program : Manual
ISO : 6400
Sensitivity Type : Recommended Exposure Index
Recommended Exposure Index : 6400
Exif Version : 0230
Date/Time Original : 2014:12:10 10:13:32
Create Date : 2014:12:10 10:13:32
Components Configuration : Y, Cb, Cr, -
Shutter Speed Value : 1/1579
Aperture Value : 5.7
Flash : Off, Did not fire
Focal Length : 280.0 mm
Macro Mode : Normal
Self Timer : Off
Quality : Fine
Canon Flash Mode : Off
Continuous Drive : Continuous, High
Focus Mode : AI Servo AF
Record Mode : CR2+JPEG
Canon Image Size : Large
Easy Mode : Manual
Digital Zoom : None
Contrast : Normal
Saturation : Normal
Camera ISO : Auto
Metering Mode : Evaluative
Focus Range : Not Known
Canon Exposure Mode : Manual
Lens Type : Canon EF 200-400mm f/4L IS USM + 1.4x
Max Focal Length : 560 mm
Min Focal Length : 280 mm
Focal Units : 1/mm
Max Aperture : 5.7
Min Aperture : 45
Flash Activity : 0
Flash Bits : (none)
Zoom Source Width : 0
Zoom Target Width : 0
Manual Flash Output : n/a
Color Tone : Normal
SRAW Quality : n/a
Auto ISO : 100
Base ISO : 6400
Measured EV : 10.50
Target Aperture : 5.7
Target Exposure Time : 1/1625
Exposure Compensation : +1
White Balance : Auto
Slow Shutter : None
Shot Number In Continuous Burst : 0
Optical Zoom Code : n/a
Camera Temperature : 8 C
Flash Guide Number : 0
Flash Exposure Compensation : 0
Auto Exposure Bracketing : Off
AEB Bracket Value : 0
Control Mode : Camera Local Control
Measured EV 2 : 10.25
Bulb Duration : 0
Camera Type : EOS High-end
ND Filter : n/a
Canon Image Type : Canon EOS 7D Mark II
Canon Firmware Version : Firmware Version 1.0.2
Canon Model ID : EOS 7D Mark II
Thumbnail Image Valid Area : 0 159 7 112
AF Area Mode : Spot AF
Num AF Points : 65
Valid AF Points : 65
Canon Image Width : 5472
Canon Image Height : 3648
AF Image Width : 5472
AF Image Height : 3648
AF Area Widths : 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243
AF Area Heights : 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 24
3 243 243 243 243 243 243 243 243 243 243 243 243 243
AF Area X Positions : 279 0 -279 -559 -1093 -1397 -1700 -2004 -1397
-1700 -2004 2004 1700 1397 1093 559 1397 1093 559 279 0 -279 -559 -1093 -279 -55
9 -1093 -1397 -1700 -2004 2004 1700 -2004 2004 1700 1397 1093 559 279 0 559 279
0 -279 -559 -1093 -1397 -1700 -1093 -1397 -1700 -2004 2004 1700 1397 1093 1700 1
397 1093 559 279 0 -279 -559 2004
AF Area Y Positions : 776 776 776 776 631 631 631 631 315 315 315 63
1 631 631 631 776 315 315 388 388 388 388 388 315 0 0 0 0 0 0 315 315 -315 0 0 0
0 0 0 0 -388 -388 -388 -388 -388 -315 -315 -315 -631 -631 -631 -631 -315 -315 -
315 -315 -631 -631 -631 -776 -776 -776 -776 -776 -631
AF Points In Focus : (none)
AF Points Selected : 3
Time Zone : -06:00
Time Zone City : Denver
Daylight Savings : On
Bracket Mode : Off
Bracket Value : 0
Bracket Shot Number : 0
Raw Jpg Size : Large
WB Bracket Mode : Off
WB Bracket Value AB : 0
WB Bracket Value GM : 0
Live View Shooting : Off
Focus Distance Upper : 26.86 m
Focus Distance Lower : 21.51 m
Flash Exposure Lock : Off
Internal Serial Number : LA00xxxx0
Dust Removal Data : (Binary data 1024 bytes, use -b option to extr
act)
Crop Left Margin : 0
Crop Right Margin : 0
Crop Top Margin : 0
Crop Bottom Margin : 0
Exposure Level Increments : 1/3 Stop
ISO Speed Increments : 1/3 Stop
AEB Auto Cancel : On
AEB Sequence : 0,-,+
AEB Shot Count : 3 shots
Safety Shift : Disable
Shutter Speed Range : Disable; Hi 1/8192; Lo 32
Aperture Range : Disable; Closed 91; Open 1
Focusing Screen : Ec-CIV
Viewfinder Warnings : Monochrome, WB corrected, One-touch image qual
ity, [6]
Continuous Shooting Speed : Disable; Hi 10; Lo 3; 4
Custom Controls : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 254 255 0 3 112 48 0 0 0 0 0 0 0 0 0 0 0 20 80 0 0 0 7 3 0 255 255
255 0 255 255 255
Dial Direction Tv Av : Normal
Multi Function Lock : Off; Quick control dial
Add Aspect Ratio Info : Off
Default Erase Option : Cancel selected
Aspect Ratio : 3:2
Cropped Image Width : 5472
Cropped Image Height : 3648
Cropped Image Left : 0
Cropped Image Top : 0
Tone Curve : Standard
Sharpness : 3
Sharpness Frequency : n/a
Sensor Red Level : 0
Sensor Blue Level : 0
White Balance Red : 0
White Balance Blue : 0
Color Temperature : 5200
Picture Style : Standard
Digital Gain : 0
WB Shift AB : 0
WB Shift GM : 0
Measured RGGB : 445 1024 1024 715
VRD Offset : 0
Sensor Width : 5568
Sensor Height : 3708
Sensor Left Border : 84
Sensor Top Border : 50
Sensor Right Border : 5555
Sensor Bottom Border : 3697
Black Mask Left Border : 0
Black Mask Top Border : 0
Black Mask Right Border : 0
Black Mask Bottom Border : 0
Color Data Version : 11 (7DmkII)
WB RGGB Levels As Shot : 2362 1024 1024 1432
Color Temp As Shot : 6981
WB RGGB Levels Auto : 2362 1024 1024 1432
Color Temp Auto : 6981
WB RGGB Levels Measured : 2362 1024 1024 1432
Color Temp Measured : 6981
WB RGGB Levels Daylight : 1978 1024 1024 1626
Color Temp Daylight : 5200
WB RGGB Levels Shade : 2289 1024 1024 1394
Color Temp Shade : 7000
WB RGGB Levels Cloudy : 2131 1024 1024 1507
Color Temp Cloudy : 6000
WB RGGB Levels Tungsten : 1398 1024 1024 2346
Color Temp Tungsten : 3200
WB RGGB Levels Fluorescent : 1730 1024 1024 2255
Color Temp Fluorescent : 3736
WB RGGB Levels Kelvin : 1978 1024 1024 1626
Color Temp Kelvin : 5200
WB RGGB Levels Flash : 2198 1024 1024 1477
Color Temp Flash : 6327
Average Black Level : 2047 2047 2047 2047
Raw Measured RGGB : 208409 483339 478062 342940
Per Channel Black Level : 2047 2046 2047 2047
Normal White Level : 14580
Specular White Level : 15092
Linearity Upper Margin : 10000
Custom Picture Style File Name :
AF Micro Adj Mode : Adjust by lens
AF Micro Adj Value : 3
Warning : Invalid VignettingCorrUnknown2 data
Peripheral Lighting Setting : On
Chromatic Aberration Setting : On
Auto Lighting Optimizer : Off
User Comment :
Sub Sec Time : 23
Sub Sec Time Original : 23
Sub Sec Time Digitized : 23
Flashpix Version : 0100
Color Space : sRGB
Exif Image Width : 5472
Exif Image Height : 3648
Interoperability Index : R98 - DCF basic file (sRGB)
Interoperability Version : 0100
Focal Plane X Resolution : 6086.76307
Focal Plane Y Resolution : 6090.15025
Focal Plane Resolution Unit : inches
Custom Rendered : Normal
Exposure Mode : Manual
Scene Capture Type : Standard
Owner Name :
Serial Number : 02xxxxxxxx4
Lens Info : 280-560mm f/0
Lens Model : EF200-400mm f/4L IS USM EXT
Lens Serial Number : 13xxxxxxx5
GPS Version ID : 2.3.0.0
GPS Latitude Ref : North
GPS Longitude Ref : West
GPS Altitude Ref : Above Sea Level
GPS Time Stamp : 16:09:02.444
GPS Satellites : 21
GPS Status : Measurement Active
GPS Measure Mode : 3-Dimensional Measurement
GPS Dilution Of Precision : 6
GPS Img Direction Ref : Magnetic North
GPS Map Datum : WGS-84
GPS Date Stamp : 2014:12:10
Compression : JPEG (old-style)
Thumbnail Offset : 12216
Thumbnail Length : 9471
Rating : 0
Image Width : 5472
Image Height : 3648
Encoding Process : Baseline DCT, Huffman coding
Bits Per Sample : 8
Color Components : 3
Y Cb Cr Sub Sampling : YCbCr4:2:2 (2 1)
Aperture : 5.6
Drive Mode : Continuous Shooting
GPS Altitude : 817 m Above Sea Level
GPS Date/Time : 2014:12:10 16:09:02.444Z
GPS Latitude : 51 deg 17' 28.93" N
GPS Longitude : 115 deg 56' 44.56" W
GPS Position : 51 deg 17' 28.93" N, 115 deg 56' 44.56" W
Image Size : 5472x3648
Lens : 280.0 - 560.0 mm
Lens ID : Canon EF 200-400mm f/4L IS USM + 1.4x
Scale Factor To 35 mm Equivalent: 1.6
Shooting Mode : Manual
Shutter Speed : 1/1600
Create Date : 2014:12:10 10:13:32.23
Date/Time Original : 2014:12:10 10:13:32.23
Modify Date : 2014:12:10 10:13:32.23
Thumbnail Image : (Binary data 9471 bytes, use -b option to extr
act)
WB RGGB Levels : 2362 1024 1024 1432
Blue Balance : 1.398438
Circle Of Confusion : 0.019 mm
Field Of View : 4.7 deg
Focal Length : 280.0 mm (35 mm equivalent: 441.5 mm)
Hyperfocal Distance : 734.72 m
Lens : 280.0 - 560.0 mm (35 mm equivalent: 441.5 - 88
3.0 mm)
Light Value : 9.6
Red Balance : 2.306641

 

[Calliope]

Are you sure you had a good connection between the lens and camera? I had something similar happen once and when I removed and reconnected the lens it cleared up.

 

[Boomanbb]

What AF point did you have selected? If it were one of the ones on the low contrast snow combined with lens drive when auto focus impossible then that would be a reason why it did not focus. The AF point must be on an area of some contrast for things to work.

Ben

 

[Zeee]

What AF point did you have selected? If it were one of the ones on the low contrast snow combined with lens drive when auto focus impossible then that would be a reason why it did not focus. The AF point must be on an area of some contrast for things to work.

Ben

 

[Karl Gnter Wnsch]

AF4: Lens drive when AF impossible. This was set to OFF as recommended in the manual for super telephotos.

And there we have the culprit - there wasn't enough contrast under the focus point to make a focus decision so the lens drive was not engaged...

 

[DugT]

Does it work now in better light?

That has happened to me a couple of times with my 100-400mm lens. I detached the lens and the contacts looked ok so I re-attached it and then it worked. This has happened twice in about five years.

 

[riknash]

AF4: Lens drive when AF impossible. This was set to OFF as recommended in the manual for super telephotos.

And there we have the culprit - there wasn't enough contrast under the focus point to make a focus decision so the lens drive was not engaged...

Oh, your saying, the 7D Mk II AF system isn't any good in that light with superteles? The camera was manually set at 1/1600 at f/5.6 and the light meter in the camera chose auto ISO 1600 with a +1 EC in a treed forest with plenty of contrast from the moving animal against white snow, the dark metal fence contrasting the white snow along with line needles etc on the white snow. So the 7D Mark II talking to a supertele isn't any good under those conditions? I did try positioning the AF point on various objects when it failed to move the focus. It started working when I shut the camera off and turned it back on. By then the pine marten was long gone deep into the forest.

 

[riknash]

What AF point did you have selected? If it were one of the ones on the low contrast snow combined with lens drive when auto focus impossible then that would be a reason why it did not focus. The AF point must be on an area of some contrast for things to work.

Ben

 

[Karl Gnter Wnsch]

AF4: Lens drive when AF impossible. This was set to OFF as recommended in the manual for super telephotos.

And there we have the culprit - there wasn't enough contrast under the focus point to make a focus decision so the lens drive was not engaged...

Oh, your saying, the 7D Mk II AF system isn't any good in that light with superteles?

Quite the contrary. But you disabled it through your setting when the defocusing is too strong to make an immediate distance measurement...

So the 7D Mark II talking to a supertele isn't any good under those conditions? I did try positioning the AF point on various objects when it failed to move the focus. It started working when I shut the camera off and turned it back on. By then the pine marten was long gone deep into the forest.

You are jumping to all the wrong conclusions now. You disabled the AF yourself!

I suggest you reread the suggestion regarding the "Lens drive when AF impossible", I bet that this encompasses that you are supposed to use the preset AF distance on those supertelephoto lenses to get you into the ballpark of your subject first.

 

[riknash]

AF4: Lens drive when AF impossible. This was set to OFF as recommended in the manual for super telephotos.

And there we have the culprit - there wasn't enough contrast under the focus point to make a focus decision so the lens drive was not engaged...

Oh, your saying, the 7D Mk II AF system isn't any good in that light with superteles?

Quite the contrary. But you disabled it through your setting when the defocusing is too strong to make an immediate distance measurement...

Let's read it together...

Customizing AF Functions

Page 122

If focus cannot be achieved with autofocus, you can have the camera keep searching for the correct focus or have it stop searching.

ON: Continue focus search

If focus cannot be achieved with autofocus, the lens is driven to search for the correct focus.

OFF: Stop focus search

If autofocus starts and the focus is far off or if focus cannot be achieved, the lens drive stops. This prevents the lens from becoming grossly out of focus due to focus searching.

Note 24: Lens drive when AF impossible

Super telephoto lenses, etc., with a wide focusing drive range can become grossly out of focus during focus search, taking more time to achieve focus next time. Setting [Stop focus search] is recommended

So the 7D Mark II talking to a supertele isn't any good under those conditions? I did try positioning the AF point on various objects when it failed to move the focus. It started working when I shut the camera off and turned it back on. By then the pine marten was long gone deep into the forest.

You are jumping to all the wrong conclusions now. You disabled the AF yourself!

What does it mean when it says, "if focus cannot be achieved"? I think you are suggesting the camera won't even try to move the focus motor if the AF unit in the camera determines that focus is not possible? I think you are suggesting the low light, low contrast scene was responsible for the AF unit to not be able to find distance and direction information? If yes, then can you explain their recommendation for superteles? It doesn't make much sense. I'm sure a better more clear explanation would be useful for anyone who has pondered that recommendation.

I suggest you reread the suggestion regarding the "Lens drive when AF impossible", I bet that this encompasses that you are supposed to use the preset AF distance on those supertelephoto lenses to get you into the ballpark of your subject first.

I did reread the manual before posting. I didn't want to ignore the obvious. You haven't addressed the fact that the camera went merrily along and took the photos although its very clear in the manual that if focus was not achieved, it should not take any photos?

 

[riknash]

Does it work now in better light?

That has happened to me a couple of times with my 100-400mm lens. I detached the lens and the contacts looked ok so I re-attached it and then it worked. This has happened twice in about five years.

 

[riknash]

What AF point did you have selected? If it were one of the ones on the low contrast snow combined with lens drive when auto focus impossible then that would be a reason why it did not focus. The AF point must be on an area of some contrast for things to work.

Ben

 

[riknash]

Are you sure you had a good connection between the lens and camera? I had something similar happen once and when I removed and reconnected the lens it cleared up.

 

[Apewithacamera]

Just lighten it up a bit in PP and maybe sharpen it up a bit?

 

[Karl Gnter Wnsch]

What does it mean when it says, "if focus cannot be achieved"? I think you are suggesting the camera won't even try to move the focus motor if the AF unit in the camera determines that focus is not possible?

Correct. That has always been the problem of disabling focus search. If there is a strong defocusing so that the AF can't even determine the direction into which it has to move the focusing group AF won't even be attempted.

I think you are suggesting the low light, low contrast scene was responsible for the AF unit to not be able to find distance and direction information? If yes, then can you explain their recommendation for superteles?

The recommendation is made on the bases that you have been focusing at roughly the correct distance (that's why the supertelephoto lenses can recall a focus position on button press - to get you into that ballpark.

 

[meland]

Just lighten it up a bit in PP and maybe sharpen it up a bit?

Ha! There aren't many humorous comments on DPR but that was quite good.

 

[Apewithacamera]

;-)

 

[riknash]

Just lighten it up a bit in PP and maybe sharpen it up a bit?

LOL, ya, that'll do it.

 

[riknash]

What does it mean when it says, "if focus cannot be achieved"? I think you are suggesting the camera won't even try to move the focus motor if the AF unit in the camera determines that focus is not possible?

Correct. That has always been the problem of disabling focus search. If there is a strong defocusing so that the AF can't even determine the direction into which it has to move the focusing group AF won't even be attempted.

I think you are suggesting the low light, low contrast scene was responsible for the AF unit to not be able to find distance and direction information? If yes, then can you explain their recommendation for superteles?

The recommendation is made on the bases that you have been focusing at roughly the correct distance (that's why the supertelephoto lenses can recall a focus position on button press - to get you into that ballpark.

--
regards
Karl Günter Wünsch

I have since disabled it. You still haven't addressed why the camera took the photos anyways....????

Also, after shutting the camera off and on I then shot and easily achieved focus of the same scene (without the critter of course). I reasoned it couldn't have been a low contrast issue as the AF was now working. WTH ?

 

[Calliope]

Are you sure you had a good connection between the lens and camera? I had something similar happen once and when I removed and reconnected the lens it cleared up.