GH13 overexposing

M

MarcusWolschon

Active member
Situation:
One GH13 in on full auto and doing a wide shot while I'm operating a second GH13 to do
closeups.
=> can't do much on the camera doing the wide shots.
A performer in bright spots in the middle, surrounded by an audience that's basically dark.
The brightness constantly changes as spots change color or get replaced by an ambient
light for a moderator between performances.
=> automatic exposure required
The performer is not always in the center of the frame.
=> prefering the center for exposure automatics is not enough

Any idea how I could get the GH13 that runs unattended to prefer underexposing the audience
for not overexposing the performer? Currently it likes to stay in the middle and overexpose
the performer in spotlight while at the same time underexposing the audience.
Any way to limit the dynamics?
I guess I could use manual aperture and go down an f-stop or two, to prevent the overexposing
but then I would have to manually interfere all the time as the light changes.
Same goes for using the dial for exposure-correction in automatic mode.
 
I can try that next time I have such a situation. Let's see how it works out. Thanks!

The difference between between some kilowatts of spotlights (on performer) and ambient light (performer, moderator talking in front of audience) between the performances is maybe 2-3 f-stops.
Some questions to your proposal, so I understand the reasoning and what outcome to expect:
* Did you make the experience that it is noticeable or not noticeable when the metering adjusts the aperture or ISO (because we just fixed the exposure to 1/50th)?
An f-stop is quite a harsh step compared to a continuous, smooth change in exposure time.
I did not try fixing exposure time manually while filming. I guess I should experiment with that. Good idea!
* I estimate 1/50th may be way to long for someone in multiple kilowatts of spotlights moving rapidly.
What level of motion blur would you expect with 1/50th and a fast dancer for a 25fps (PAL) shot?
* Wouldn't spot mean, that I need someone to handle the camera when the dancer leaves the center of the frame and the spotlight?
He is much brighter or darker then the empty floor in the very center of the wide shot frame.
(That's why I had the unattended camera in matrix mode instead of spot)

I don't have much experience with filming anything illuminated by high power spotlights and the resulting harsh dynamics between the darkest and the brightest areas in the same frame.
Nor with doing multi - camera shots without multiple camera men (to make the resulting video at least slightly more interesting then your every day hold-a-camcorder-for-2-hours-from-the-audience shot.).
That's why I'm asking, to get some insight into how more experienced people deal with it.
 
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The shutter speed you use will depend on whether you're shooting in a 50Hz country or a 60Hz. The lights will tend to pulse or fluctuate with the hertz rate of electricity applied to them. So, you want to lock down the shutter speed to match the Hz rate of the lights. Also, if 1/50-60th is to slow-meaning your light sources are very bright, you will need to use Neutral Density filters to reduce the light getting into the camera, while maintaining a stable F/stop. If your actors moves around a bit on stage, try "center-weighted" metering for correct exposure. Another thing to try is a manual focuses, manual aperture lens with an adapter. Still shooing in Shutter Priority, you adjust the aperture for the amount of light you have and desired depth of field. The camera then can only change the ISO(you want to make sure that the increments in the menu is set to 1/3 stops-not the default 1-stop).
Bottom line is; the GH camera's don't do well as remote camera's, unless you really have a good controlled situation, and know what you are doing.

I would recommend you read more area's of the forum, and watch some "how-to" video's on You Tube, to gain the knowledge necessary for basic operation of the camera, and film making. There is a wealth of information on the internet. You will need to test/practice, a lot.
 
I think you are trying to do something that is not possible or even recommended.
First let's state that most viewers do not appreciate or enjoy watching footage shot by a camera that is automatically compensating for changing lighting. This is the sign of amateur home video. In most situations like this, a crew would setup lighting with the cameras in mind, making sure there wasn't too much contrast in the scene for the camera and style of video. If you can't adjust the actual physical lighting because its not your set, then you are stuck with the difficult decision of setting exposure to work for the most common levels. This means that sometimes the subject will be overexposed and sometimes under as they move around. That's fine and way better to watch than leaving the camera on Auto.

I use the spot meter to lock exposure. I place the little "+" on the brightest part of the subject for which I am setting exposure. You may lose some highlights to clipping occasionally or some extreme shadows especially in a very high contrast scene, but that's life! We can't always see into every shadow. Think of your image as a game of light and dark, play with it and don't worry about having everything 'perfectly' exposed and visible, ESPECIALLY when you can't do anything physically on the set to control the lighting!
 
Problem is that the main actor was moving out of the spotlight and not just for a second or two and that the table with the important jury was not as flooded with light as the center of the stage was.
I tried around and I'm no longer shure spot metering would help since subject and camera are moving. It adjusts nice and slow but that choosen spot will simply be somewhere in the audience when the talent or camera moves.
(Moving the wide-show camera to have either talent or jury in view is the only thing I can do while I'm busy operating the second camera for closeups.)

I fear the only way around would be to have 2 cameras with different exposure settings on the same tripod for the wide shots then?

There was an official video crew but as they are years behind in releasing their videos I can't tell what they did against this issue as they supposedly worked closely with the light crew who set this up.
(They where using video cameras in a way higher price range instead of repurposed photo equipment like we do though.)
 
no, we're not suggesting you use the spot meter with auto-exposure. we're suggesting you do NOT use auto-exposure. higher priced cameras won't solve the problem. the problem is only solved by working with the light crew, by actually adjusting the light that is hitting your subjects.
 
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