Lumix GH6 and AUTO ISO

[Adriano Moroni]

Hello, excuse my ignorance, I need some info about AUTO ISO. Setting the 180° rule and blocking the exposure, I don't think there are sudden changes in brightness and darker areas lit up as day, resulting in a rather unpleasant video. By locking the exposure, AUTO ISO does all the rest and I think it does it very well, even for a professional video. Don't answer me: "if you like it like this... do what you like". I would like to understand better. Thank you.

[Ron Evans]

Exposure is set by shutter speed, iris ( aperture) and gain on the sensor( ISO ). On the GH6 if you set shutter to "angle " it will always set to 180 rule so shutter is fixed then for each frame rate. That leaves you with two things to set exposure. Iris and gain. If you set your iris to get the depth of field you want ( in your case maybe f5.6 or f8 ) you only have gain left to get the exposure. Also have ND filter if it is too bright of course . In auto ISO ( gain ) the camera will set the gain level to meet the exposure ( governed by how you have set exposure sensing ie centre, full frame etc ) also you can bias this with AE shift control. It is better always set a gain limit if you are going to use auto ISO that way the camera will not use all the available gain and then introduce grain/noise. One advantage of auto ISO is the camera has much finer control over the gain level than manual control. Think of large changes with iris or even ND filter and fine control with camera controlling auto gain. This is how I often shoot in the theatre with my GH6 and GH5S.

[Adriano Moroni]

Thanks for your interesting reply. I think AUTO ISO is a good option for your theater work, but perhaps much less for me because I only shoot where there are sunny days. Sharp shadows and lots of contrast on people. I shoot at any time, I don't wait for precise moments of the day to get the best results. I'm afraid AUTO ISO isn't for me, because for example, it might make a shadow in a scene look too bright, etc.

[Pete Cofrancesco]

Normally the best use for auto iso is outdoors since the light is constantly changing and you have no control over it. Where as indoors the light can be control and general remain the same unless you're next to a window or filming a theater performance. I generally stay away from auto unless it's run and gun where getting the shot is more important than maintaining perfect exposure. The issue with auto exposure is if you or your subject is moving, the background is changing, or your zooming, this can cause the exposure to shift even if the light remains the same. There is no hard and fast rules, depending on the situation you use what works best.

[Ron Evans]

Originally Posted by Adriano Moroni

Thanks for your interesting reply. I think AUTO ISO is a good option for your theater work, but perhaps much less for me because I only shoot where there are sunny days. Sharp shadows and lots of contrast on people. I shoot at any time, I don't wait for precise moments of the day to get the best results. I'm afraid AUTO ISO isn't for me, because for example, it might make a shadow in a scene look too bright, etc.

You need to really control auto gain. Cannot just leave it without setting max value for each situation. Don't think of it as auto exposure think of it as automatic adjustment within a fine range that you set. That means when light changes too quick for you to adjust the autogain will. How you set the exposure range will control how it changes. If you have the setting of exposure range set to a box in the middle that will be the only thing controlling the adjustment. A shadow off to the side will not be affected. For instance if you want the exposure of the people in the shot to be correct then they will control the exposure of everything else in the frame. I actually think it might work very well for you if you learn how to set levels etc.

[Doug Jensen]

Originally Posted by Pete Cofrancesco

Normally the best use for auto iso is outdoors since the light is constantly changing and you have no control over it.

No, that is not right. If you are outdoors in daylight there is almost always TOO much light even for the camera's base (lowest) ISO or Gain. Raising the ISO up just exacerbates the problem of there being too much light. The only way your method would work is if the other exposure settings are really off the wall. Such as stopping the lens down to f/22, cranking the sutter speed up to ungodly numbers, or adding a ton ND. All bad decisions.

Just to be clear, however, I'm strongly against ANY use of auto-exposure. But auto-ISO is particularly useless outdoors in daylight.

My advice to the OP is to learn to set exposure manually and then questions like this don't even need to be asked. Somehow I have managed to shoot for 40 years without ever using auto-exposure. If I can do it, anyone can.

[Adriano Moroni]

Originally Posted by Doug Jensen

My advice to the OP is to learn to set exposure manually and then questions like this don't even need to be asked. Somehow I have managed to shoot for 40 years without ever using auto-exposure. If I can do it, anyone can.

But you don't even know why I asked this question. Anyway you are right, because I had to explain it, but someone here knows my work and for this reason I forgot to write it.
Of course I don't want to always use AUTO ISO, but sometimes I have the need. In fact I configured the GH6 also in AUTO ISO, AF and 180°, etc. like Ron Evans wrote, then I saved it as a personal further profile.
Sometimes, when I shoot, I don't even have time to focus and I can't change other parameters too!!!
PS: I always leave a VND mounted on the lens.

[Doug Jensen]

No time to set exposure? That's impossible. How does everyone else manage to do it, but you can't? It's just a matter of getting the camera configured properly so that judging and setting the exposure takes just a couple of seconds. If you continue with attitude that you are incapable of running the camera on manual, then you will never be able to run the camera on manual. Change your attitude and master your camera. YOU can do it.. I believe in you, even if you don't believe in yourself.

[Adriano Moroni]

Maybe you didn't read my post correctly, but maybe I wrote it wrong, I don't know. But it's not like you say. I always use the GH6 manual and want to continue using it manual, so I know it takes 2-3 seconds to set the exposure and 3-4 seconds to focus. But sometimes the scene that I have to shoot fades away in 7-8 seconds .