View Full Version : GH5(s) autoexposure


Noa Put
June 15th, 2018, 06:31 AM
I always dial in my exposure manually on the camera's that I controll but I have a few weddings this year with outdoor ceremonies where I want to try out the autoexposure functionality of my gh5s as it will be partially unmanned during a ceremony. It's especially in partially cloudy conditions where the sun appears and disappears all the time that setting exposure is very difficult, untill now I always have set the exposure when the sun is shining and just let it underexpose when the sun goes into hiding behind a cloud, I can always correct underexpsoure to a certain extent but with overexposure it's often impossible to correct this.

I just have been testing in the garden by setting the camera to aperture priority because I don't want that to change and iso was set to auto, I also set the ev to -1 and the camera seemed to controll expsoure changes very well.

Does anyone else might have some more tips?

Ron Evans
June 15th, 2018, 06:58 AM
I use my GH5 in the theatre unattended and operate just like I did the small Sony's for full stage shot. I set mine to shutter priority at 1/60 because I want the motion blur to be the same on all the cameras, auto gain with gain limit of 12db and set compensation to about -2 to -3. Like you I can correct underexposure a lot but do not want to over expose. I use the 12-60 Leica so frame the stage and then use touch focus to setup focus. Works well. I am shooting UHD60P by the way all the time on the GH5. Also use the app to control from my Samsung tablet so can start and stop or check touch focus from my camera position. I have tried full manual using the app too but unfortunately there is no smooth parameter change like a normal camcorder. Changing any of the parameter is a step, something that would be nice to get in a firmware update. The auto gain does however change smoothly so is the preferred parameter to be in auto for the smooth changing.

Noa Put
June 15th, 2018, 08:08 AM
Thx for the reply, in my case the iso should not increase and it's important that the dof stays the same as I will be shooting between 40-150mm so changes in aperture would be very visible but I might decrease the ev to -2 as the exposure in my test looked spot on but as you said a minor underexposure is more easily corrected then over exposure.

I"m going to run some more tests before I use it next week, currently I set the camera to aperture mode using teh big dial on top, as this is normally for shooting stills, is there anything else that needs to e considered? Does the camera behave the same as when that dial is set to the video icon?

Ron Evans
June 15th, 2018, 08:33 AM
I should add that because I am in the theatre and its a little dark with lens ramping the lens is wide open at about f3.7 and of course stays there so really the exposure is controlled by the auto gain.

Ron Evans
June 15th, 2018, 08:40 AM
The dial on the top that is for still has no control over video. You need to set the video mode separately. I would create a custom preset for what you want and use the dial to select that when you want it. How to set the PASM settings when in Creative Video Mode. - DC-GH5, DC-G9 - Panasonic Canada (http://eng-ca.faq.panasonic.com/app/answers/detail/a_id/43105/kw/43105/session/L2F2LzEvdGltZS8xNTI5MDczNTQwL3NpZC9mVWxsV3VvZkxQSlBGcm85NU5uSHFrbE9ybTR5RVc1c1RUVGpBRTJrdnZZMlZGcGQ5 SzJuNzNuNF9SNV9EZ005ZWI0SHNXbnQyZlhZTk5QZkdhNzNIMyU3RVJON1hITkdjM1dCJTdFQ0xzUk9yUUptZ3ZTbXdnM0VyTVJ3 JTIxJTIx).

Ron Evans
June 15th, 2018, 08:48 AM
This is a good source for GH5 info LUMIX DC-GH5 Training Guide - Panasonic Canada (http://eng-ca.faq.panasonic.com/app/answers/detail/a_id/43117/~/lumix-dc-gh5-training-guide#FEATURESFUNCTIONS)

Noa Put
June 15th, 2018, 12:17 PM
Thx Ron, I need to do my homework on teh GH5, so many possibilities yet I have covered only a small fraction of what it can do.

Ron Evans
June 15th, 2018, 02:18 PM
You could try setting in full manual. Set iris and shutter for what you want, set gain to auto with a limit and use the exposure compensation to set how dark or light you want the scene. It should then maintain this with auto gain.

Noa Put
June 15th, 2018, 02:33 PM
In my case that won't work as I plan to use auto exposure only on Sunny outdoor ceremonies meaning the iso will be at it's lowest all the time, it's the shutter I need to ramp up or down as the aperture stays locked.

Ron Evans
June 15th, 2018, 04:29 PM
It should work the same if you fix iris and gain and let the camera control shutter speed. Set the exposure compensation to taste !!

EDIT: Having thought about it I really do not like shutter varying for video so you could use a fixed shutter and use an ND to force the camera to use some gain. The GH5 is very usable up to 12db so setting it so that it at most would use 6db and let the camera use auto gain as I described. You would get the DOF you want and not have varying shutter speed that will cause motion blur differences.

Noa Put
June 16th, 2018, 02:36 AM
I"m planning on using a nd outside anyway so it could be that the iso will be raised at some point but I don't mind that the shutter raises either, I"m just shooting talking heads so there is very little movement in the frame, a changing shutter is something that you hardly notice in such a case. Going to perform some more tests the following days.

Ron Evans
June 16th, 2018, 08:18 AM
Not sure if the shutter is variable in aperture priority but the gain I know is smooth changing so not noticeable when the exposure compensation is changed. Will be interested to find out if the changes are smooth because even with no movement an abrupt change would be noticeable.

Enrique Orozco Robles
June 18th, 2018, 01:18 PM
Altought not a GH5 user, I have had very nice results with my G7 filming in shutter priority (60 for indoors, 125 outdoors) and ISO in auto mode ... I began to use this when filming with my gymbal with a 25 lens and also with focus continuous mode enabled ... the autofocus is a little slow, so I have to make slow movements with my gymbal letting the G7 make the aperture changes for itself ... with a little practice, very good results so far ..

my 2 cents... kind regards

Noa Put
June 18th, 2018, 03:53 PM
Not sure if the shutter is variable in aperture priority

Did some more testing and it looks variable, at least I don't see any sudden jumps and exposure changes are smooth. I feel a bit more confident to try it at a wedding.

Peter Riding
June 20th, 2018, 08:55 AM
I'm not familiar with the GH5 but perhaps there is a similar method to that which I use with my two Canon 5D Mark IV's and 5DS-R. for video.

I set the cams on full manual for shutter and for aperture. Then I set the ISO to auto, and crucially it is possible on these cams (not earlier ones like 5DII and III) to use exposure compensation via the auto-ISO up to plus or minus 3 stops in 1/3rd steps n.b. it doesn't affect the shutter or aperture.

Typically for indoor I set the shutter to 1/50th for obvious reasons and the aperture to f5.6 to have sufficient depth of field. The auto-ISO looks after itself. Often I set auto-ISO compensation to +1 over, depends on circumstances. The shutter and the aperture don't change so the clips don't alter midway.

However outside, like one I'm shooting later this week, 1/50th is often far too slow even with auto-ISO. I could use my variable neutral density filters but for wedding purposes I prefer to just bump up the shutter speed. But if sunlight is very bright one moment and subjects backlit or with specular highlights one moment then not the next its far trickier as you know.

Pete

Ron Evans
June 20th, 2018, 07:09 PM
I use a similar approach with my GH5 and GH5S in the theatre. Setting aperture and shutter speed, auto gain, gain limit and use compensation to set the brightness I want in the image. Essentially clamping the exposure in a range when unattended.

Tom Van den Berghe
December 11th, 2019, 11:55 AM
I have the GH5s with the 14-140mm lens. I set it on autofocus for theatre (wide shot) but I noticed I hunts regularly.

Or is manual focus and peaking a better option? (don't know if you can peak the whole stage)

Ron Evans
December 11th, 2019, 12:44 PM
I always have focus set to manual and use touch focus to set the focus. This is especially important in the theatre because of the lights changing. I use the 12-60 on my GH5 and also like you the 14-140 on my GH5S. Since I use the Ninja V also I can watch to see if exposure is OK using false colour.

Tom Van den Berghe
December 11th, 2019, 01:40 PM
thx Ron for your quick answer. But the GH5S stands normally close to the side of the stage so I can't touch focus it when the show starts. Can you be a bit more specific?

Pete Cofrancesco
December 11th, 2019, 01:53 PM
You can’t leave a camera up close unmanned set to auto focus. It’s not the right type of camera. Traditional eng cameras are used because of their large dof. Before the performance start manually focus is set to the middle of the stage and is unchanged throughout. If the camera is up front and to the side it will be impossible to get everything in focus. If you leave it in auto focus the camera will hunt.

Ron Evans
December 11th, 2019, 06:37 PM
I shoot from the back for most of my shoots with just different framing. Both GH5 and GH5S have good WIFi app so you could just use that to touch focus when show starts. I often run my cameras with the WiFi app it is easy to use and controls almost everything on the camera.

Tom Van den Berghe
December 15th, 2019, 12:35 PM
thx Ron for the tip with the wifi. never used it before. I had again a theatre this weekend but didn't had much time to test out the app. Again the GH5S was near stage on the side and I could see the image
on my phone attached into the manfrotto smartphone clamp

I used face detection this time and so far I saw my footage on my pc I didn't see any "hunting".