C100 Mk1 footage underexposed

[PHoward188]

Hi I've recently moved from a Canon XA10 to a Canon C100 Mk1.

Yesterday I was shooting a presentation with a Samyang 24mm T1.5 lens The C100 was CP locked. I kept an eye on the inbuilt light metre and kept it on the centre mark most of the time by adjusting the aperture keeping the ISO native at 850.

However, when I edit the rushes after applying a Canon Log lut all the footage is very underexposed with the highlights at well below 50 lumens. I can bring it up in post on what I might be doing wrong if anything?

Thanks in advance

Paul Howard

[Tim]

Hello PHoward188, 

I understand this must be frustrating and sorry that it occurs.  If you are finding the highlights underexposed, are you able to add additional exposure to the scene?   Does it only occur with this one particular lens attached?  

[PHoward188]

Hi thanks for your response. 

Obviously, I can compensate for the problem by putting more light on the sensor. But my question is why when the light meter is showing it is well exposed does the footage come out underexposed. Perhaps it's just my inexperience, expecting the exposure to be right if the light meter shows it's good?

[Tim]

Hello PHoward188,

You have images there of the waveform monitor and the vectorscope, neither of which is exactly a light meter.  And if you're using the vectorscope as a light meter specifically, that especially won't work because the vectorscope is measuring chrominance (color), not exposure. 

There's a DSLR style light meter in the viewfinder, I suggest adding more light to the scene because the waveform monitor you sent a photo of suggests an underexposed image, not a properly exposed one.   

[PHoward188]

Hi Tim

Thanks for that. But that is the whole point of my post. I used the light meter in the viewfinder and it was spot on the centre mark. This is why I was surprised that the footage was underexposed.

[Waddizzle]

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@PHoward188 wrote:
Hi Tim

Thanks for that. But that is the whole point of my post. I used the light meter in the viewfinder and it was spot on the centre mark. This is why I was surprised that the footage was underexposed.

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It appears you used ambient, artificial lighting.  You could be encountering an issue with light flicker.  Do you have the light flicker compensation enabled?

[PHoward188]

No I didn’t even know there was such a thing?