Canon XC10 4K camcorder

[Lintelfilm]

ARRRGH! More XC10 issues!

I've been using 100% zebras to help meter and of course guard against over exposure for a while now and it's been working great. However all of a sudden it seems to have stopped. Now, if I expose the sky in a landscape shot so that the zebras are a notch under 100% (i.e. no zebras showing but a slight tweak to up the exposure and they start showing), the sky gets completely blown - and I mean completely. No information at all! I've now tested this several times and the 100% zebras are clearly not accurate. Add on top of this there are supposed to be superwhites and I'm very concerned my unit has become defective. It's possible it was always like this but I'm pretty confident it wasn't as I've been exposing like this for a while now.

Can anyone contribute? How do your cameras respond to using 100% zeberas to expose to the right (just before clipping)?

Arghhh!

[kidzrevil]

On 11/12/2016 at 3:50 AM, hyalinejim said:

Looks great! You've been having some nice weather in NY. I'm heading to Belfast today and will try to get some shots there.

Why do you prefer CLog and Cinema EOS Standard to the others? I'd be interested in your thoughts on this as I'm slowly working my way through the various picture styles. I agree that CLog is best for recovering highlight and shadow detail, but I found a lot of banding compared to WideDR. But it does have compatibility with a huge selection of luts. 

WideDR looks similar to CLog but as sharper roll off into highlights and shadows and the colours are slightly different.

With Cinema EOS Standard and Standard you can drop the ISO to 160 - although I suspect the white clipping point is the same as CLog and WideDR at 500 and shadow noise looks around the same. But people say ghosting is decreased. However, both these profiles have a video-ish saturation burnout in the highlights compared to CLog and WideDR. This can be fixed, a bit, in post by gently desaturating highlights.

Now, they also differ greatly from each other in colour reproduction. Standard seems to me closer to WideDR and CLog. I'm not sure yet what to make of the colours in Cinema EOS Standard.

Basically, all four of those picture styles offer the same clipping points, but they differ in how usable different parts of the dynamic range are: CLog is best for shadows and highlights but suffers from banding if you push it too far. They all give (sometimes dramatically) different colour reproduction. And ghosting is worst on CLog, followed by WideDR, and better on the standard profiles.

Will continue testing!

PS: For sharpness, the EBU paper says 3 is the max before aliasing begins to hit IIRC

Cinema EOS standard seems to push red and yellow closer together to optimize skin tones sort of like the Skin Squeeze feature in magic bullet or how the m31 LUT handles skin. The shadow's seem to be raised slightly to record low light detail and the midtones are raised high enough to create a better roll off into the highlights than the other profiles. I also like the fact that the profile isn't heavily saturated which should help with color clipping and I am considering raising the saturation in camera to come closer to the standard profile. Last but not least I am seeing that the in camera sharpening is vital because C-LOG can turn your footage into mush even though it has fantastic DR. I am going to use a diffusion filter to cut down on edge sharpness. All the picture profiles give the same DR but it's just distributed differently and I feel like Cinema EOS is a good middle ground between them all

[mercer]

1 hour ago, Lintelfilm said:

ARRRGH! More XC10 issues!

I've been using 100% zebras to help meter and of course guard against over exposure for a while now and it's been working great. However all of a sudden it seems to have stopped. Now, if I expose the sky in a landscape shot so that the zebras are a notch under 100% (i.e. no zebras showing but a slight tweak to up the exposure and they start showing), the sky gets completely blown - and I mean completely. No information at all! I've now tested this several times and the 100% zebras are clearly not accurate. Add on top of this there are supposed to be superwhites and I'm very concerned my unit has become defective. It's possible it was always like this but I'm pretty confident it wasn't as I've been exposing like this for a while now.

Can anyone contribute? How do your cameras respond to using 100% zeberas to expose to the right (just before clipping)?

Arghhh!

This is why I stopped using 100% zebras and started using 70%. At 100% I could not save any of the highlights, they were gone. But I actually have had two cameras. BH accidentally sent me a return, but I tried it out and had those results. After speaking with a few people on this site, I was told to use 70% because of the whole 18% grey card exposure rule for C-Log. I was told, if you don't use a grey card to expose (I never have) than the simplest, safest way was to use 70% zebras. When I received my new camera. I went right into using 70% and it seemed to work fine. Since then I was told to use 100% but I haven't had the camera out in a while, to give it another test. 

[UHDjohn]

1 hour ago, Lintelfilm said:

ARRRGH! More XC10 issues!

I've been using 100% zebras to help meter and of course guard against over exposure for a while now and it's been working great. However all of a sudden it seems to have stopped. Now, if I expose the sky in a landscape shot so that the zebras are a notch under 100% (i.e. no zebras showing but a slight tweak to up the exposure and they start showing), the sky gets completely blown - and I mean completely. No information at all! I've now tested this several times and the 100% zebras are clearly not accurate. Add on top of this there are supposed to be superwhites and I'm very concerned my unit has become defective. It's possible it was always like this but I'm pretty confident it wasn't as I've been exposing like this for a while now.

Can anyone contribute? How do your cameras respond to using 100% zeberas to expose to the right (just before clipping)?

Arghhh!

The Zebras work on the green channel so with blue sky you can be not showing any clipping but be very overexposed. ETTR is not a good idea with any in-camera profile as it's an exposure strategy for shooting RAW. With RAW you get as much info onto the sensor before clipping to maximise DR and keep out of the noise and then apply a tone curve in post production. With non RAW capture the tone curve is 'baked in' to the data so if it's a low contrast scene you will overexpose if you ETTR and you have to pull down the values in post but you are moving values to a different part of the tone curve where with 8bit they can get stretched out and cause banding. Like I said this camera needs scopes ( as they decided to do with the XC15) but more importantly an RGB parade so you can see the individual channels ( not sure if they have done this with the XC15) - or use an external monitor / recorder but this kind of defeats the ergonomics. 

[Lintelfilm]

2 minutes ago, UHDjohn said:

The Zebras work on the green channel so with blue sky you can be not showing any clipping but be very overexposed. ETTR is not a good idea with any in-camera profile as it's an exposure strategy for shooting RAW. With RAW you get as much info onto the sensor before clipping to maximise DR and keep out of the noise and then apply a tone curve in post production. With non RAW capture the tone curve is 'baked in' to the data so if it's a low contrast scene you will overexpose if you ETTR and you have to pull down the values in post but you are moving values to a different part of the tone curve where with 8bit they can get stretched out and cause banding. Like I said this camera needs scopes ( as they decided to do with the XC15) but more importantly an RGB parade so you can see the individual channels ( not sure if they have done this with the XC15) - or use an external monitor / recorder but this kind of defeats the ergonomics. 

Thanks good to know. But in my tests it was actually the red channel that got exposed correctly and the green and blue that got blown. The zebra said the green (if it is the green it's reading) was fine. I wasn't really exposing to the right I was just trying to get as much latitude as possible as it was a very high contrast scene with dark shadows under trees and bright skies so I needed to use as much of the right and left as possible.

[UHDjohn]

1 hour ago, kidzrevil said:

Last but not least I am seeing that the in camera sharpening is vital because C-LOG can turn your footage into mush even though it has fantastic DR. I am going to use a diffusion filter to cut down on edge sharpness. All the picture profiles give the same DR but it's just distributed differently and I feel like Cinema EOS is a good middle ground between them all

The XC10 profiles do not all have the same DR - hook up a monitor with some scopes and then point it at a highish contrast scene that can just be captured in C-LOG and then see the data go off the top and bottom when you switch to other profiles. C-LOG doesn't have any sharpening applied and it's designed that way so you can add much better sharpening in post. production where you can do it with more control and sophistication. I just with they did the same for NR and disabled it for the user to apply in post.

[Lintelfilm]

57 minutes ago, mercer said:

This is why I stopped using 100% zebras and started using 70%. At 100% I could not save any of the highlights, they were gone. But I actually have had two cameras. BH accidentally sent me a return, but I tried it out and had those results. After speaking with a few people on this site, I was told to use 70% because of the whole 18% grey card exposure rule for C-Log. I was told, if you don't use a grey card to expose (I never have) than the simplest, safest way was to use 70% zebras. When I received my new camera. I went right into using 70% and it seemed to work fine. Since then I was told to use 100% but I haven't had the camera out in a while, to give it another test. 

Thanks yes this is what I've done. However the 70% zebras are really for exposing isolated subjects (usually people/skin) properly and not for protecting highlights (hence they disappear again after about 85% which is annoying if you're thinking about highlights.)

[UHDjohn]

2 minutes ago, Lintelfilm said:

Thanks good to know. But in my tests it was actually the red channel that got exposed correctly and the green and blue that got blown. The zebra said the green (if it is the green it's reading) was fine. I wasn't really exposing to the right I was just trying to get as much latitude as possible as it was a very high contrast scene with dark shadows under trees and bright skies so I needed to use as much of the right and left as possible.

I could be wrong and it could be the LUMA channel but I'm assuming it's like their DSLR's which all show the clipping in the green channel only but I'm pretty sure when I had the RGB parade up and was pointing at a 24 patch colour checker I saw how it reacted. In the situation you describe, which is going to be a tough test for any camera, your best approach is to use an external monitor with scopes and make sure you get a custom WB. 

[Lintelfilm]

Quick tip: I think there are a few XC10 users here using FCPX? Alex4D's free Unsharp Mask plugin works great. It's default sharpness is far too strong but if yopu apply it and then bring the radius down to about 1.9 and crank the "amount" slider up it really brings the detail out in a nice organic way. If you're using grain remember to stack it under (i.e. apply it before/top of the inspector) so it doesnt sharpen the grain too. This technique with a fine 4K grain (e.g. Film Convert's 35mm) on top of a low-radius unsharp mask gets fantastic results, great with 4K but even with HD footage too.

For best HD results: upscale HD to 4K > add subtle unsharp mask > add a contrasty curve > add 4K grain = HD that looks very much like 4K!

1 minute ago, UHDjohn said:

I could be wrong and it could be the LUMA channel but I'm assuming it's like their DSLR's which all show the clipping in the green channel only but I'm pretty sure when I had the RGB parade up and was pointing at a 24 patch colour checker I saw how it reacted. In the situation you describe, which is going to be a tough test for any camera, your best approach is to use an external monitor with scopes and make sure you get a custom WB. 

Yeah I really miss not having a waveform on the XC10. I really hope Canon add it with a firmware update.

[hyalinejim]

29 minutes ago, UHDjohn said:

The XC10 profiles do not all have the same DR - hook up a monitor with some scopes...

Yes, but is your monitor showing what's in 100 to 109 IRE?

Quote

For  comparison,  the  same  test  was  done  using  Look5  and  ISO500  (10.5dB)  which  was  expected  to have  a  much  wider  range.  The  exposure  difference  was  again  80:1,  again  making  a  total  dynamic  range  of  about  2, 3 00:1. This is a surprise, since it implies that the  only advantage in using the Looks is in the distribution of  this,  apparently  fixed ,  dynamic  range.

Source: page 11 of Alan Roberts' EBU paper

https://tech.ebu.ch/docs/tech/tech3335_s17.pdf

2 hours ago, Lintelfilm said:

How do your cameras respond to using 100% zebras to expose to the right (just before clipping)?

On mine, all of the info is there sitting under 100 IRE on the waveform monitor as would be expected. Is your software somehow interpreting the footage as 16-235 levels? Can you upload a clip for us to check out?

[UHDjohn]

The scopes on my PIX-E and Shogun don't show super whites but I can see them in Resolve by switching between Data and Video. The EBU paper didn't test the DR in C-LOG and I was comparing C-LOG to the other profiles for DR but I'm prepared to believe all the other non LOG profiles have similar DR. 

[kidzrevil]

3 hours ago, UHDjohn said:

The XC10 profiles do not all have the same DR - hook up a monitor with some scopes and then point it at a highish contrast scene that can just be captured in C-LOG and then see the data go off the top and bottom when you switch to other profiles. C-LOG doesn't have any sharpening applied and it's designed that way so you can add much better sharpening in post. production where you can do it with more control and sophistication. I just with they did the same for NR and disabled it for the user to apply in post.

They definitely do they are just mapped differently. For instance there are profiles that have superwhites like the cinema eos standard with a raised black then you have the standard profile that lowers shadows and highlights. Alll give 11-12 stops they are just distributed differently. EBU documentation proved this

[hyalinejim]

2 hours ago, UHDjohn said:

The EBU paper didn't test the DR in C-LOG

On page 11 there's a comparison of DR between Standard and C-Log:

I don't fully understand the DR test, but I interpret this graph as showing that the clipping point at 100 IRE is earlier for Standard than it is for, but that the final maxed out clipping point at 109 is roughly the same for both. So if you're shooting standard with 100% zebras and you're seeing clipping, there could be quite a bit of info still in those superwhites. It just appears that Standard has less DR when you switch back and forth between it and C-Log because the area under the zebras increases.

4 minutes ago, kidzrevil said:

They definitely do they are just mapped differently. For instance there are profiles that have superwhites like the cinema eos standard with a raised black then you have the standard profile that lowers shadows and highlights. Alll give 11-12 stops they are just distributed differently. EBU documentation proved this

I think so too, from reading the EBU paper and from my own experience of tinkering with the files.

I shot a lot of 4K C-Log yesterday at 205mbps and noticed a bit of chroma artifacting going on with FilmConvert. So I went back to the old fashioned way of grading and came up with a curve for C-Log that I really like and that doesn't seem to cause as much breaking up of the footage. Here it is if you wanna check it out:

https://drive.google.com/file/d/0B1exEpCRAfgFVzlUaVByczNDR1U/view?usp=sharing

I like this because it's quite contrasty but doesn't really crush shadows at all. Just set your white point and black point with curves or levels before this lut.

5 hours ago, kidzrevil said:

 Last but not least I am seeing that the in camera sharpening is vital because C-LOG can turn your footage into mush even though it has fantastic DR.

I am seeing this as well with C-Log... must do some comparison with other styles with sharpening whacked up.

[Lamplighter55]

5 hours ago, Lintelfilm said:

ARRRGH! More XC10 issues!

I've been using 100% zebras to help meter and of course guard against over exposure for a while now and it's been working great. However all of a sudden it seems to have stopped. Now, if I expose the sky in a landscape shot so that the zebras are a notch under 100% (i.e. no zebras showing but a slight tweak to up the exposure and they start showing), the sky gets completely blown - and I mean completely. No information at all! I've now tested this several times and the 100% zebras are clearly not accurate. Add on top of this there are supposed to be superwhites and I'm very concerned my unit has become defective. It's possible it was always like this but I'm pretty confident it wasn't as I've been exposing like this for a while now.

Can anyone contribute? How do your cameras respond to using 100% zeberas to expose to the right (just before clipping)?

Arghhh!

Humm could it be that the luminance gradient from the zebra cross-over values are much brighter than in previous shoots? Light being logarithmic the values could easily rise to a 'burn-out' level if you are shooting on a bright sunny day - for example any direct specular sunlight reflections will be orders of magnitude above 'correct exposure'. 

[UHDjohn]

17 minutes ago, hyalinejim said:

On page 11 there's a comparison of DR between Standard and C-Log:

I don't fully understand the DR test, but I interpret this graph as showing that the clipping point at 100 IRE is earlier for Standard than it is for, but that the final maxed out clipping point at 109 is roughly the same for both. So if you're shooting standard with 100% zebras and you're seeing clipping, there could be quite a bit of info still in those superwhites. It just appears that Standard has less DR when you switch back and forth between it and C-Log because the area under the zebras increases.

I think so too, from reading the EBU paper and from my own experience of tinkering with the files.

I shot a lot of 4K C-Log yesterday at 205mbps and noticed a bit of chroma artifacting going on with FilmConvert. So I went back to the old fashioned way of grading and came up with a curve for C-Log that I really like and that doesn't seem to cause as much breaking up of the footage. Here it is if you wanna check it out:

https://drive.google.com/file/d/0B1exEpCRAfgFVzlUaVByczNDR1U/view?usp=sharing

I like this because it's quite contrasty but doesn't really crush shadows at all. Just set your white point and black point with curves or levels before this lut.

I am seeing this as well with C-Log... must do some comparison with other styles with sharpening whacked up.

There is no comparison with C-LOG in at paper.

[hyalinejim]

What is Look 5?

[Lintelfilm]

3 hours ago, hyalinejim said:

On mine, all of the info is there sitting under 100 IRE on the waveform monitor as would be expected. Is your software somehow interpreting the footage as 16-235 levels? Can you upload a clip for us to check out?

I've just been wondering the same thing. I've only noticed the blown areas since updating to FCP 10.3. Perhaps I need to see if I can tweak the interpretation levels somehow. 

I'll also look at the footage in resolve to see if that changes anything. 

Thanks!

[kidzrevil]

37 minutes ago, hyalinejim said:

What is Look 5?

look 5 is C-LOG but according to @UHDjohn there has been no comparison lmao

Anyway @hyalinejim I can't wait to see your tests

[Lintelfilm]

4 hours ago, hyalinejim said:

On mine, all of the info is there sitting under 100 IRE on the waveform monitor as would be expected. Is your software somehow interpreting the footage as 16-235 levels? Can you upload a clip for us to check out?

FFS!!! I was right!!! Thanks for making me look at this further. It's not the levels though.

The new FCP 10.3 now has built in Log Processing that appears to be getting applied automatically! It was detecting CLog (somehow?) and applying it's own F-ing LUT to the footage in my browser! Unfortunately this LUT is just blowing the crap out of my levels. 

For anyone else who runs into this issue, you need to go into the "i" tab of the inspector, select "settings" view from the small dropdown menu at the bottom and then change log processing to "none". Yes, it really is that hidden away and complex. FFS!

So the good news is that the two days of shooting I did last week for a job that is getting far too close to deadline were not entirely wasted. The footage is actually absolutely fine now I've taken this new auto-LUT off it! It also means I'm not going insane and can go back to my original method of exposing using the 100% zebras as a safety net. I also don't feel like a complete f-ing amateur getting home with almost entirely unusable dalies!

Jees Apple. It's a nice feature to have but maybe don't set it to on as default and then bury it in the back of beyond.

Phew. Thanks guys. I might start a thread just to warn others.

[UHDjohn]

Sorry yes it's ' look 5' - was looking for C-Log. I got more DR out of it than the other profiles in my tests so will continue to use it. If I get time I'll post some tests.