GH3 and RAW timelapse issue

[GHman]

I'm sorry for my poor english, but I'll try to explain the best I can.

I have noticed a weird problem with RAW timelapse on my GH3. I recently started using RAW images for timelapse because I can recover more detail from underexposed areas in post and get a wider dynamic range. Take a look at this video:

 

https://vimeo.com/66920197

You can see two timelapse tests that have been done with all manual settings (exposure, white balance, shutter speed and ISO). ISO levels are 125 for the first test and 200 for the outdoor timelapse. The clips marked with "A" are the RAW sequences straight from the camera, the ones marked with "B" have been modified in exposure with Camera RAW. As you can see, there is a noticeable color shift between some pictures: some of them tend to blue/green creating an ugly color flickering. This problem is evident in underexposed areas, especially after increasing exposure, whether I have sunlight or artificial light. I generally use a deflicker plugin for removing aperture flicker in a timelapse, but this solution can't work for color changes like this.

This is another timelapse test made in a room with a few light to better demonstrate the issue:

[attachment=521:noise color shift.jpg]

Picture 1 : RAW files before increasing exposure.  

Picture 2:  Exposure increased a bit for all the shots, apparently everything's fine.

Picture 3 : Further exposure increase reveals a shot with a much different color.

Picture 4 : The blue shot compared to the others.

 

If you want to replicate the issue:

1) Set all settings manually (WB,ISO,aperture,shutter speed).

2) Make a timelapse in a room with a few light in order to obtain very underexposed images.

3) Shoot at least 50/100 pictures.

4) Check the RAW files and increase exposure even if you can see noticeable banding.

Can you see some pictures with an evident color shift in the sequence?

 

I have tried changing lens, but the problem has still happened. I tried many other software for editing raw files, but the color shift is still there. Sometimes the color shift can affects lot's of RAW photos, sometimes only a few why apparently no precise reason. I tried correcting manually the frames with shifted colors with no success.

This is sad because the color flicker ruins the opportunity of using RAW for timelapse on the GH3. 

[dahlfors]

Hmmm. Check the raw files and see if all of them reports the same info for white balance. I'd report this to Panasonic as well, since it might be an issue that Panasonic could fix by updating firmware.

[GHman]

Hmmm. Check the raw files and see if all of them reports the same info for white balance. I'd report this to Panasonic as well, since it might be an issue that Panasonic could fix by updating firmware.

 

I have done several tests, all of them with the same identical settings. WB is the same for every single frame and as you can see, color is the same for more bright ares, and color shift can bee noticed only in underxeposed areas.

 

https://vimeo.com/67382669

 

In the above test, I have tried using slower shutter speed, however nothing changed. I really don't know what to think. An issue, or a regular camera limit?

[mikeyeung5]

Can you use video to do time lapse ?

[HiroProtagonist]

I am getting the same issue. I've only noticed it in exposures where you have to lift it quite a bit. There doesn't seem to be any regularity to it...

 

It's not white balance. There seems to be missing info in the affected images. I've upped the saturation and exposure in the screenshot of my library so you can see it more clearly. White balance was set to daylight, set to auto in post (but the issue persists in all temps). The green triangle is a shadow clipping warning. Which is interesting. 

 

My camera was early in the run... Do you think that might have something to do with it? Haven't installed the new firmware. 

 

I heard somewhere about a program that adjusts exposure/WB flicker for time-lapse photos. Anyone heard of it? Maybe that will work as a hold over. 

 

Let's send a link to this thread (and others like it) to panasonic. Built in timelapse was a big selling point for me. Haha. 

 

[dahlfors]

I've done timelapse videos with my Nikon cameras, in movie format as well as with RAW and jpeg sequences - this is not a "regular camera issue".

 

If all settings are locked to manual, it looks more like a firmware bug or sensor readout issue when seeing those histograms - or some issue in certain production batches. Contact Panasonic to see what they think.

 

 

Oh btw, I see one of your notes that I missed the last time:

"2) Make a timelapse in a room with a few light in order to obtain underexposed images with shutter speed 1/40 or higher."

 

Do you mean faster shutter speeds than 1/40 by "higher"?

- In general when people make time lapses they smooth out the motion by using long shutter speeds with ND filters. Except making the motion feel smoother, this also even out any kind of light flickering indoors, as well as averages out the light outdoors, which can be useful during cloudy days when light changes. Try using an ND filter and keep the shutter speed around half of the length of the delay between shots (this rule doesn't work out for really long delays between frames). 

[GHman]

I am getting the same issue. I've only noticed it in exposures where you have to lift it quite a bit. There doesn't seem to be any regularity to it...

 

It's not white balance. There seems to be missing info in the affected images. I've upped the saturation and exposure in the screenshot of my library so you can see it more clearly. White balance was set to daylight, set to auto in post (but the issue persists in all temps). The green triangle is a shadow clipping warning. Which is interesting. 

 

My camera was early in the run... Do you think that might have something to do with it? Haven't installed the new firmware. 

 

I heard somewhere about a program that adjusts exposure/WB flicker for time-lapse photos. Anyone heard of it? Maybe that will work as a hold over. 

 

Let's send a link to this thread (and others like it) to panasonic. Built in timelapse was a big selling point for me. Haha. 

 

 

Thank you for having done a test. Your timelapse too demonstrates that this is not an issue related with my camera but maybe a common issue of GH3.

I have the latest body firmware (1.1).

 

 

I've done timelapse videos with my Nikon cameras, in movie format as well as with RAW and jpeg sequences - this is not a "regular camera issue".

 

If all settings are locked to manual, it looks more like a firmware bug or sensor readout issue when seeing those histograms - or some issue in certain production batches. Contact Panasonic to see what they think.

 

 

Oh btw, I see one of your notes that I missed the last time:

"2) Make a timelapse in a room with a few light in order to obtain underexposed images with shutter speed 1/40 or higher."

 

Do you mean faster shutter speeds than 1/40 by "higher"?

- In general when people make time lapses they smooth out the motion by using long shutter speeds with ND filters. Except making the motion feel smoother, this also even out any kind of light flickering indoors, as well as averages out the light outdoors, which can be useful during cloudy days when light changes. Try using an ND filter and keep the shutter speed around half of the length of the delay between shots (this rule doesn't work out for really long delays between frames). 

 

Sorry for my english, I wanted to say "faster shutter speeds than 1/40".

However, after wrighting the firs post I have done several tests. As you can see in test 3 video, the issue can affect raw files even with slower shutter speed. So, I will edit the first post since it's not necessary to use faster shutter speeds. It looks like it's necessary to have very dark areas and increase it's exposure in post, but the shutter speed looks like to have a few relevance for this issue. 

 

I have tried doing a raw timelapse in the opposite direction: instead of underexposing shady areas, I have overexposed the sky. In post then, I have reduced the exposure, and the result looks like good. I have done only a few test for now, but it look like that overexposed frames can help reducing color flicker in shadows. But I need more time and tests to be sure that this solution can be helpful for every situation.

[/p/]

Guess I'll shoot in .jpg then..