New to log - Inferno Monitor Mode question at DVinfo.net

Nick Mirro · October 18th, 2020, 09:29 PM

Hi and thank you for any help. I have a new XC15 as a second camera to an XF400, both shooting in WDR. I didn't buy the XC for the log capability but really want to learn about that feature.

I put 3D LUTs on the recorder and see how to display and record the different looks.

What about Log to Video? The options for Canon are: Log, Log2 and Log3. Which applies to the XC15?

Setting gamut to Rec709, Log(1) looks best. If I set gamut to Cinema, then Log and Log3 are vivid and saturated. Which are/are not intended for this model?

Christopher Young · October 19th, 2020, 01:29 AM

Nick. If you are delivering in Rec 709. Which is the standard for most TVs, DVD and BD delivery then 709 is what those bits of hardware are expecting to see as they are all 709 calibrated devices.

For shooting, the XC-15 doesn't offer you the option of Canon Log 2 or Log 3. If shooting the XC-15 using its LOG setting then the correct monitor LUT to view with would be the Rec 709 one. Afterwards in post you can then apply a Transform or 709 LUT to to your LOG footage to suit. Then generally grade for Lift, Gamma and Gain PRIOR to the LUT if using LUTs.

Chris Young

Nick Mirro · October 19th, 2020, 08:46 PM

That really helps, thanks! I woke up this morning completely confused :)

Footage with the XF400 is shot in Wide DR. Since the XC has that look and can also shoot in log, does it make sense to shoot log with the XC? ...since the transform or RCM (I'm using Davinci) can bring the log back to rec 709.

Do you think the XF images will end up matching the (mostly scenic) b-roll shot with XC. I am wondering if I can improve lows and highs with log footage, and (without too much work) produce a reasonable match for the XF.

Christopher Young · October 21st, 2020, 10:13 PM

Nick. Where the benefit of LOG comes to the fore is when you have very wide dynamic range scenes. Extremes of light and shadow. LOG captures the most of the sensors' dynamic range so will help in grading an image to capture most of that range into your 709 delivery file. If your scene is an indoor interview or an average indoor scene with around four to six stops of range then in most cases a well exposed 709 scene file will deliver a good image with a lot less post work than LOG. LOG in real low light narrow dynamic range shooting can be detrimental to your image.

Why waste a 10-14 stop dynamic range, depending on camera, with all its data values when you are better off to use a scene file with all those data values distributed across a six stop range like 709 if the scene you are shooting only has a six stops or less dynamic range. Makes far more sense. If I'm shooting indoors and lighting the scene I will set the base exposure I want to work with and then light accordingly. Not too much light to over expose key parts of the scene and enough light into the darker shadow areas so that they don't drop into the mud.

Apart from HDR delivery nearly every display we look at is calibrated to display the Rec 709 six stop range. Therefore try to use all the data values your sensor can capture and fit that into the display range. Sure a bright outdoor sunlight and deep shadow image will well exceed six stops. That's where your LOG can come into play to capture that wider range. Then in post grade and 'compress' that wider range into the 709 delivery color space. Tailor the camera's capture mode to suit the dynamic range you have to capture. All the capture modes have their pluses and minuses and all work best when matched to the scene's dynamic range that you need to capture.

Chris Young.

Nick Mirro · October 22nd, 2020, 09:20 PM

Well that is hugely informative! Thank you! I am shooting on a river. My first run was a nightmare because we were in a moving kayak (on-kayak interview) on a partly cloudy day. I spent most of my time adjusting NDFs and exposure as the scene constantly changed. We're going back this weekend having since learned a lot.

Thanks for taking time for me here. Your explanations have really gotten me up to speed on this. :)

October 18th, 2020, 09:29 PM	#1
Nick Mirro Regular Crew Join Date: Jun 2008 Location: Dallas, Texas Posts: 119	New to log - Inferno Monitor Mode question Hi and thank you for any help. I have a new XC15 as a second camera to an XF400, both shooting in WDR. I didn't buy the XC for the log capability but really want to learn about that feature. I put 3D LUTs on the recorder and see how to display and record the different looks. What about Log to Video? The options for Canon are: Log, Log2 and Log3. Which applies to the XC15? Setting gamut to Rec709, Log(1) looks best. If I set gamut to Cinema, then Log and Log3 are vivid and saturated. Which are/are not intended for this model?

October 19th, 2020, 01:29 AM	#2
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,567	Re: New to log - Inferno Monitor Mode question Nick. If you are delivering in Rec 709. Which is the standard for most TVs, DVD and BD delivery then 709 is what those bits of hardware are expecting to see as they are all 709 calibrated devices. For shooting, the XC-15 doesn't offer you the option of Canon Log 2 or Log 3. If shooting the XC-15 using its LOG setting then the correct monitor LUT to view with would be the Rec 709 one. Afterwards in post you can then apply a Transform or 709 LUT to to your LOG footage to suit. Then generally grade for Lift, Gamma and Gain PRIOR to the LUT if using LUTs. Chris Young Attached Thumbnails

October 19th, 2020, 08:46 PM	#3
Nick Mirro Regular Crew Join Date: Jun 2008 Location: Dallas, Texas Posts: 119	Re: New to log - Inferno Monitor Mode question That really helps, thanks! I woke up this morning completely confused :) Footage with the XF400 is shot in Wide DR. Since the XC has that look and can also shoot in log, does it make sense to shoot log with the XC? ...since the transform or RCM (I'm using Davinci) can bring the log back to rec 709. Do you think the XF images will end up matching the (mostly scenic) b-roll shot with XC. I am wondering if I can improve lows and highs with log footage, and (without too much work) produce a reasonable match for the XF.

October 21st, 2020, 10:13 PM	#4
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,567	Re: New to log - Inferno Monitor Mode question Nick. Where the benefit of LOG comes to the fore is when you have very wide dynamic range scenes. Extremes of light and shadow. LOG captures the most of the sensors' dynamic range so will help in grading an image to capture most of that range into your 709 delivery file. If your scene is an indoor interview or an average indoor scene with around four to six stops of range then in most cases a well exposed 709 scene file will deliver a good image with a lot less post work than LOG. LOG in real low light narrow dynamic range shooting can be detrimental to your image. Why waste a 10-14 stop dynamic range, depending on camera, with all its data values when you are better off to use a scene file with all those data values distributed across a six stop range like 709 if the scene you are shooting only has a six stops or less dynamic range. Makes far more sense. If I'm shooting indoors and lighting the scene I will set the base exposure I want to work with and then light accordingly. Not too much light to over expose key parts of the scene and enough light into the darker shadow areas so that they don't drop into the mud. Apart from HDR delivery nearly every display we look at is calibrated to display the Rec 709 six stop range. Therefore try to use all the data values your sensor can capture and fit that into the display range. Sure a bright outdoor sunlight and deep shadow image will well exceed six stops. That's where your LOG can come into play to capture that wider range. Then in post grade and 'compress' that wider range into the 709 delivery color space. Tailor the camera's capture mode to suit the dynamic range you have to capture. All the capture modes have their pluses and minuses and all work best when matched to the scene's dynamic range that you need to capture. Chris Young.

October 22nd, 2020, 09:20 PM	#5
Nick Mirro Regular Crew Join Date: Jun 2008 Location: Dallas, Texas Posts: 119	Re: New to log - Inferno Monitor Mode question Well that is hugely informative! Thank you! I am shooting on a river. My first run was a nightmare because we were in a moving kayak (on-kayak interview) on a partly cloudy day. I spent most of my time adjusting NDFs and exposure as the scene constantly changed. We're going back this weekend having since learned a lot. Thanks for taking time for me here. Your explanations have really gotten me up to speed on this. :)