Dramatic colour change halfway through clip

[Andrew Leigh]

Hi,

I'm busy editing a wedding, I have a clip that is over 5 min with no starts or stops. At one point the colour changes dramatically from warm reds / oranges to a green tinge. Almost like the effect when white balance is not set correctly. The colours do come back slightly over time but never return to what they were.

Any ideas as to what I could have done to get this effect?


Cheers
Andrew

[Ken Tanaka]

You'll have to tell us much more about how you shot the footage. What exposure mode did you use? What white balance method did you use? Do you recall the shutter speed you used? Did you vary it during the clip? What type of lighting was in the room?

[Don Palomaki]

And did you pan, or zoom in/out on a subject with a strong dominant color. Did the outdor lighting change if natural light was used - e.g., go from bright sun to heavy clouds?

[Andrew Leigh]

Apolgies for the lack of info,

The clip was shot some about 18 months when I was "practising" camera technique. You might ask why it's taken so long to edit the wedding? It was footage never intended for later work or production into a "wedding video". I am now putting some of the footage together practicing editing techniques.

Needless to say it will be difficult to remember what was done other than;

- at that stage I am positive I would have been shooting in the auto mode (whitebox with the A). Had this not been the case they only other way I shoot is aperture priority with the lowest aperture number I could have used (in this instance). Can't be more specific sorry.

- I have always had the white balance set to automatic (A). I reset the white balance (by default) when moving inside after taking external establishing shots. I changed tape at this point to film the service. This by the way was the first time I have used Panasonic Linear Plus tapes, always used Sony before that.

- the chapel was for the most part naturally lit through large windows being clear and stained glass, I used no artificial light.

- there was a backlighting issue when zoomed out, don't know if the AE shift was activated, would doubt it. Zoomed in removed any backlighting issues and the previous shots were fine for at least 30 sec before the change.

- the shot was a tight frame of the best mans bald head with no zooming.

That's about it.

PS: Is there any way to check on the tape what the settings were at the time of shooting?

Thanks for the help.

Cheers
Andrew

[Rob Lohman]

It will be basically impossible to tell what went "wrong" in this
case. My best bet would be that you left some setting on auto-
matic and the camera changed it for some reason.

[Andrew Leigh]

Hi Rob,

we have missed each other halfway between posts. I incorrectly posted and then needed to edit.

I have just recalled that when I did my sons wedding video the entire service portion had a slight green cast that needed to be fixed in post. Establishing shots were O.K. as were the reception shots.

How could I have forgot that one, the wife was fuming.

I will be the first to admit that it is possible to not set something correctly. With WB I got into a habit in the early days in the Kruger National Park of switching the XL-1 off after each shot. This caused other problems like missing shots waiting for the XL-1 to "bootup". I quickly learnt that in the early morning and evening hours the light changes so rapidly my early footage definitely suffered WB problems. This is a habit that stays with me so I think we could rule out WB although it was my first thought.

Also every wedding I have done has three tapes.
- Establishing shots where the XL-1 is on and off all the time resetting the WB by default. (Never had problems here)
- The second tape is for the service, is always changed inside the chapel for the WB. Once the service starts the XL-1 stays on and filming for the duration of the service or the tape. This is to sequence a second camcorder if required.
- The final tape is the reception (never had problems here)


Any other thoughts?

Cheers
Andrew

[Rob Lohman]

Indeed, I missed your full post. I still think it would be hard to
reconstruct and you confirmed my basic thought that probably
some auto settings was getting in the way.

If you put the tape in the camera and play it back on a TV you
can switch the amount of information that is displayed with your
remote control that came with the camera. One setting should
include recording settings as well indeed.

Good luck!

[Andrew Leigh]

Thanks Rob,

I will just be a lot more careful to take note of the process I follow the next time to see if the problem re-occurs and how this could be averted.

I will check it out on the TV for interest sake.


Cheers
Andrew

[Dean Sensui]

Andrew...

Your color cast problem could be due to the camera trying to compensate for a particular dominant color in the scene.

For example, if the church had a huge stained-glass window that had a lot of magenta in it, the camera would try to "fix" that by shifting in the opposite direction: Green.

The best solution for this is to use a manual white balance. You'll have to determine the best place to get the right white balance, and that can be done by doing a manual white balance and seeing what it does in your viewfinder. Not perfect, but close enough.

Also, the best solution for back light problems is setting up the camera in a position that avoids backlight.

The second best solution, other than using powerful lights to overcome the backlight, is using a manual exposure setting. Backlight can fool the camera into exposing for the background and turning your subjects into silhouettes. To avoid that, set your exposure manually -- the background will get blown out but your foreground will remain visible.

As you can see, operating the camera manually can help you avoid a lot of headaches later. What's nice about video is you get immediate feedback on what you're shooting and can instantly determine if you have a problem developing.

With film, you don't see the problem until after the developing... :-)

Dean Sensui
Base Two Productions

[Kieran Clayton]

If you have the white balance set to auto that might be the problem. Set up the camera with it in auto and wave a saturated colour near the lens and the colour balance will change. It could be that someone walked past the camera wearing a bright colour and it tried to compensate.

kieran