7D Mark II Surprise Exposure & WB shift

I've taken hundreds of shots with my 7D2 over the last few weeks of youth basketball in the same gym (lighting), same camera setup, and same lens (135mm f2.0). The results have been great. I shot AF using AL SERVO/ Hi Speed frame rate and at a burst of 2-6 frame/burst. However last week I started to notice a problem. A noticeable shift between shots while no change in lighting that could effect exposure or AWB. Does anyone have any ideas what might have caused this? Please see included meta data and photos. No post processing applied only converted RAW to JPG using Light Room 5.7

It looks like you are showing two sequential photos, taken at high FPS. The only change in the EXIF is the ISO (were you running AutoISO?). Then, it is likely the current frequency (60 hz).

sagebrush wrote in post #17474939
............... A noticeable shift between shots while no change in lighting that could effect exposure or AWB. Does anyone have any ideas what might have caused this? ...............

There is a change in lighting that is not visible to the human eye. Those gymnasium lights are flickering at about 60 (or 120?) cycles per second and that causes variation in both color temperature and light intensity.

If you didn't notice it before you were either very lucky or shooting at a slower shutter speed.

There really is no solution other than shooting a a slower shutting speed or correcting each frame in post processing.

Check your "SHOOT4" settings on the camera and see what your "Anti-Flicker Shoot" setting is. If set to "Disable" then change to "Enable" and try again.

Anti-Flicker, when enabled, seems to control the issue you described pretty well.

Correct. I shot using AutoISO due to the sudden background change that can occur. And yes the ISO change between frames did change the expose but why the White Balance?

I set the lens wide open and shutter speed to 1/400 to freeze the action (most of the time). So your thinking the 60Hz electric power source to the gym lighting is causing this. Any other ideas out there??

Use the anti-flicker feature of the 7D2.

What Mike said. But also, in most school gyms there's a mix of different types of light: high-pressure mercury, halogen, florescent, standard incandescent, even natural daylight from windows. The brightness and color balance can vary at any instant, and even within an individual frame.

The human eye and brain adapts, the eye constantly adjusts without conscious effort, the brain analyzes the individual elements and determines what's white versus red versus yellow and interprets the scene, even different parts of a scene. The camera runs on programming that adjust to an averaged view of the scene, and can't interpret what should be there, it only averages the light and color that falls within its metering pattern. The photographer's job is to turn the camera's "vision" into his own human interpretation.

It appears that the manual settings you're using are good, perhaps I'd dial-in +1/2 to +2/3 stop EC. Then let the camera decide the appropriate ISO and you deal with the color correction in post.

Lupo-Lobo wrote in post #17474979
Check your "SHOOT4" settings on the camera and see what your "Anti-Flicker Shoot" setting is. If set to "Disable" then change to "Enable" and try again.

Anti-Flicker, when enabled, seems to control the issue you described pretty well.

Good call! I forgot that the new 7D II has this new Anti-Flicker Mode. More info about it here: http://www.the-digital-picture.com …News-Post.aspx?News=13866

Is there any down side to always keeping anti-flicker enabled for outdoors too?

sagebrush wrote in post #17474992
Is there any down side to always keeping anti-flicker enabled for outdoors too?

I turned my anti-flicker on when the body was new and it has been on ever since. I haven't noticed any problems.

But the camera says it could delay the shutter. Maybe that's why I've been missing those BIF shots!

sagebrush wrote in post #17474992
Is there any down side to always keeping anti-flicker enabled for outdoors too?

Not outdoors but keep in mind what canon reports with the anti-flicker option enabled 'the shutter release lag time may be longer. Also, the continuous shooting speed may become slightly slower, and the shooting interval may become irregular'. I messed around with the anti-flicker a little and did experience the irregular shooting interval mentioned. Ultimately I decided to keep it disabled because I'd rather deal with a little extra PP than having the camera act irregularly at a critical time.

nqjudo wrote in post #17475013
Not outdoors but keep in mind what canon reports with the anti-flicker option enabled 'the shutter release lag time may be longer. Also, the continuous shooting speed may become slightly slower, and the shooting interval may become irregular'. I messed around with the anti-flicker a little and did experience the irregular shooting interval mentioned. Ultimately I decided to keep it disabled because I'd rather deal with a little extra PP than having the camera act irregularly at a critical time.

Well, at slower shutter speeds, you can get varying white balance in a picture, which is not easy to fix.

Thanks to all for your welcomed feedback.

I shoot wildlife and BIF just about all the time so will keep Anti-flicker off until the next opportunity I have for Indoor Sports.

The way I read it, the Anti-flicker kicks in only if flicker is detected. If it kicks in, you need it. If you don't need it, it will not kick in.

In addition, the 'cycle' is 1/100th or 1/120th of a second. The camera will delay a shot by a fraction of that fraction of a second. At the most half, means 1/200th delay. I don't think that there is a man alive that has reflexes that fast (including Mr. Hamilton flying low in Oz!... ) I don't think delay will be an issue, it may offset the timing of a high FPS series, but so what?

Archibald wrote in post #17475032
Well, at slower shutter speeds, you can get varying white balance in a picture, which is not easy to fix.

With all the know how and tech around that enables is to fix issues of varying WB, different light sources, etc. it is indeed very easy to fix. A lot easier that re-creating a missed shot anyway.