A7S recording to Ninja Blade or O7Q Prores contrast issue

R

roro20

Well-known member
Hope somebody can help me out here? We have tested recording on the A7S to our Ninja Blade, as well as to our Odyssey 7Q and are noticing something on both that makes me think there is a setting somewhere in the A7S that we are missing. We are recording in SLOG2 (PP7)- straight to SD card in XAVC the recorded image looks as we would expect from SLOG and seems to match up very nicely with our FS700. However, when we record Prores HQ to the Blade or to the O7Q the image seems to have a contrast boost from what the recorded SD card footage is. Am I missing a setting that would allow the Prores image to look more "log-like" like the SD card footage (less contrast, more DR).

We have also tested this through a 4K-2K scaler and the resulting Blade or 7Q Prores image is more contrast-y.

Any help would be greatly appreciated. Thanks! Ronnie
 
Prores is a limited range codec, therefore when watching the footage in the computer it will only show the limited range data. Open the file inDavinci resolve, and check DATA levels on the clip properties. It should match the mp4 files and show the full range without clipping highlights.
 
macgregor said:
Prores is a limited range codec, therefore when watching the footage in the computer it will only show the limited range data. Open the file inDavinci resolve, and check DATA levels on the clip properties. It should match the mp4 files and show the full range without clipping highlights.
Click to expand...

+1
 
Thanks for your response. I understand that. The reason why I still think it is something that I am missing (or a limitation of) the A7S is because I dont see this issue when we record Prores via HDMI from the FS700, only when we use the A7S.
 
Little off topic from your question, but aside from the contrast issue, how much nicer are the A7s files you are getting with your 7Q working out for you? I have not gotten to try this yet because I still need to get an SDI to HDMI converter for my 7Q before my next shoot assuming it seems to be worth it....? Thanks in advance for the info!
 
roro20

I did some HDMI capture tests with the A7s going into a Blackmagic Intensity board. I captured both lossless and MJPEG. I see no significant difference in contrast between the HDMI captures and the in-camera recording. I tested both S-Log2 and a few other gammas. The HDMI picture has an ever so slight shift toward the green, but that's the only difference.

I'm still interested in what scaler you used.
 
But I dont think its the scaler because I see the same issue recording 1080P straight out of A7S to the Blade, as well.
 
That's good to hear. I'm wondering if it could possibly the micro hdmi cable that I am using. I have tried 2 of them, both of which were cheap $5-$7 ones I found. Any suggestion on which micro HDMI cable to try?

Thanks.
 
Bad HDMI cables. Used a different one and now I am seeing the same information. Thanks for your help.
 
Ralph- yes the scaled down 4K image is noticeably sharper than the 1080 image. We will use this until the Shogun is available or until CD adds A7S support for our 7Q.
 
Thanks, that's helpful. But, which adapter tips do you need? Sorry to keep asking questions, but I'm trying to put together a complete parts list.
 
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