EOS C70 output problem

electric_sun — Wed, 13 Jul 2022 08:12:56 GMT

I have a problem with the output signal via HDMI and the stored data only at C-log2 and C-log3.

Prerequisites: All devices and programs are on the current firmware. If the LUT were measured, the WFM would look different!

When I connect my smallHD to the C70, I see a complete difference in the WFM: In the highlights and shadows, the WFM is cut off at various points.

r/cinematography - To all Canon EOS C70 owners and users Fig. 1 (WFM white samllHD, WFM green C70 on samllHD)Fig. 1 (WFM white samllHD, WFM green C70 on samllHD)

When I open the associated file in Davinci, the WFM looks like this:

Fig. 2 Davinci

Summary overexposure

WFM samllHD	WFM Davinci	WFM C70
85IRE	85IRE	approx. 92IRE

And in the shadows there is also a clear difference. The picture is unfortunately not quite clear, but I hope for you meaningful enough.

Fig. 3 (WFM white samllHD, WFM green C70 on samllHD)

Fig. 4 Davinci

Summary underexposure

WFM samllHD	WFM Davinci	WFM C70
approx. 9IRE	approx. 9IRE	approx. 3IRE

Then there is also the fact that the mids are not identical. Please compare in figure 3 the brightest part of the picture around the 60IRE. There is also a shift. When I turn on False Color on the C70 and on the smallHD, the mids are clearly not in the same place.

Can someone please check this on their C70 to see if it's the same there?

I also did the test with an Atomos Ninja. It is not meaningful for me as a reference monitor, because it displays the same as the C70. So it's best to compare the WFM from the C70 with the one from Davinci!

I trust Davinci more than I trust the C70.

I would be very happy if someone can help me. I am a bit at a loss.

Re: EOS C70 output problem

shadowsports — Wed, 13 Jul 2022 14:37:41 GMT

Have forwarded this thread to rs-eos (ricky) to see if he has anything to add.

Re: EOS C70 output problem

electric_sun — Wed, 13 Jul 2022 15:02:12 GMT

Thank you!

Re: EOS C70 output problem

rs-eos — Wed, 13 Jul 2022 17:43:21 GMT

I saw this thread, but I don't use any external recorders. Thus have not used the HDMI output.

Having said that, no that I looked again, I believe CLog2 vs CLog3 does have different values to where it wants 50% gray to be. I only use CLog2, so on the internal waveform, I try to get as close to that as possible. Or, to use false color.

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EOS C70 output problem

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Re: EOS C70 output problem