Dynamic Range z8/9 video curiosity

[owenleve]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

 

[ClintGryke]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

You are bringing up a few issues here and I don't think there is much if any official info on this at all. Horshack has looked at the log v SDR issue but I'm not sure exactly what he concluded in his deep dive. I would need to have another read through a very long thread which I guess you are familiar with.

Anyway that was before my time on here and I did some testing myself before I came across Horshack's excellent work. I would have to dig out the tests and remind myself of exactly what I found but I recall some conclusions which might shed some light on your question.

In relation to the log v SDR comparisons, I found that there was little difference in dynamic range when working in raw (NRAW or ProRes Raw) once corrected for the ISO differences. In other words, there is no significant difference between Log and SDR in terms of highlight or shadow detail or in terms of noise. I think the SDR raws can develop a greenish colour cast in the shadows if pulled too far but otherwise there is little to choose. I chose to keep working in Log in any case.

However, there is a significant difference when working in non-raw formats (H.265 and ProRes) in terms of shadow detail. In SDR the shadow detail can go to complete mush whereas somewhat better deep shadow detail can be recovered with Log. I came to the conclusion that Log is the only way to go if working in either ProRes or H.265.

In relation to the Lo ISOs, it is very easy to check what is happening if you look at a waveform in camera or in post. If the highlights are clipping at ISO 800 as indicated by a flat top in the waveform, going to lower ISO has no effect on highlight recovery so there is no gain in dynamic range. I quickly came to the conclusion that these so-called false ISOs are of little use to the way I shoot video (essentially ETTR with the waveform) as there no benefit in terms of highlight recovery. Others may find these false ISOs benefical. I don't.

Incidentally the Z6III has the same Lo ISOs and I've just checked that they do exactly the same as the Z8 and Z9.

 

[owenleve]

Thanks for the reply. For sure LOG is going to provide the best latitude for editing-with a little more work.

The reports I've seen all relate to N-raw and I couldn't find any direct info on h.265 log v.s. standard. Again, pure interest only as it is what it is and shooting log is for sure going to provide better results/more room to adjust in post.

 

[ClintGryke]

Thanks for the reply. For sure LOG is going to provide the best latitude for editing-with a little more work.

The reports I've seen all relate to N-raw and I couldn't find any direct info on h.265 log v.s. standard. Again, pure interest only as it is what it is and shooting log is for sure going to provide better results/more room to adjust in post.

Yes there is a dearth of official info which is why I did my own testing. It's the best way as it iformed how I work so it wasn't just academic.

I don't think it is a lot of extra work over SDR. as Resolve handles NLOG really well automatically and you end up with a good starting point for grading. The biggest issue is in camera trying to see what you are shooting.

 

[Horshack]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

On the Z8/Z9, N-Log ISO 800 corresponds to sensor ISO 64/100, so using an N-Log ISO below 800 (which was enabled starting in Z9 FW 4.0) uses one of the fake "Lo" ISOs, equivalent to the stills mode use of "Lo" ISOs. You can read more about it here:

https://www.dpreview.com/forums/post/67101273

 

[primeshooter]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

I am not a huge video guy, however I just shoot in H.265 10-Bit and importantly use a flat picture profile to capture the most dynamic range possible, shooting at base ISO of 64 most of the time. Obviously in Pro Res, 12 bit mode you will eek out more, but the processing is more "painful" and so far I don't care enough about video to bother. This is why I stick to H.265 and a flat profile.

 

[owenleve]

Do you have view assist turned on? This uses a LUT so you are not seeing the flat log when shooting. Works on playback too, once you hit play.

 

[ClintGryke]

Do you have view assist turned on? This uses a LUT so you are not seeing the flat log when shooting. Works on playback too, once you hit play.

I've tried it but I don't find it useful for outdoor use as it is too bright. I've gotten used to gauging outdoor scenes in log, using the waveform for exposure to ensure I don't clip highlights. It's probably more useful to me for low light situations. I will take another look. though.

 

[Thom Hogan]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

As Horshack has explained, N-Log uses a base ISO of 800, and if you use a lower value you're essentially doing the same thing as when you set Lo ISO values: the base ISO is still used, but the scene is likely now overexposed. This means you'll potentially lose highlight information.

 

[ClintGryke]

As Horshack has explained, N-Log uses a base ISO of 800, and if you use a lower value you're essentially doing the same thing as when you set Lo ISO values: the base ISO is still used, but the scene is likely now overexposed. This means you'll potentially lose highlight information.

I had to re-read that and try it out to understand what you mean. Yes indeed you will overexpose if you are metering for a midtone so you will need to open up a stop if you go from ISO800 to a Lo 1 ISO value to get the same middle gray value, for example, which may cause loss of detail in the highlights.

An alternative scenario occurs if you are metering for the highlights (essentially ETTR) ensuring that there is no highlight clipping. This has the advantage of reducting noise and works well if you know you are going to be grading the footage. So you might have a scene where the highlights are just clipping and you want to decrease the exposure by a stop to retain highlight detail.

In this case, changing the ISO from 800 to Lo 1 does not result in a gain in highlight detail as would be the case if this was a true ISO. It just moves the entire waveform down by 1 stop with no gain in highlght detail. If the waveform is showing a flat bar due to slight overexposure at ISO800, it will still have the flat bar at Lo1 and show highlight clipping, although it will appear be at an unclipped level on a waveform. The rest will be darker and even potentially underexposed. When Nikon introduced these in FW4, I thought great until I tried them and realised they did nothing for me in the way I meter. The only way to retain highlight detail in this scenario is to reduce the exposure by some other means (e.g ND Fiilter, aperture or shutter speed).

So I have to wonder what is the purpose of these so-called fake ISOs?

 

[owenleve]

Looks the same as not using log.

 

[A Owens]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

You are bringing up a few issues here and I don't think there is much if any official info on this at all. Horshack has looked at the log v SDR issue but I'm not sure exactly what he concluded in his deep dive. I would need to have another read through a very long thread which I guess you are familiar with.

Anyway that was before my time on here and I did some testing myself before I came across Horshack's excellent work. I would have to dig out the tests and remind myself of exactly what I found but I recall some conclusions which might shed some light on your question.

In relation to the log v SDR comparisons, I found that there was little difference in dynamic range when working in raw (NRAW or ProRes Raw) once corrected for the ISO differences. In other words, there is no significant difference between Log and SDR in terms of highlight or shadow detail or in terms of noise. I think the SDR raws can develop a greenish colour cast in the shadows if pulled too far but otherwise there is little to choose. I chose to keep working in Log in any case.

However, there is a significant difference when working in non-raw formats (H.265 and ProRes) in terms of shadow detail. In SDR the shadow detail can go to complete mush whereas somewhat better deep shadow detail can be recovered with Log. I came to the conclusion that Log is the only way to go if working in either ProRes or H.265.

In relation to the Lo ISOs, it is very easy to check what is happening if you look at a waveform in camera or in post. If the highlights are clipping at ISO 800 as indicated by a flat top in the waveform, going to lower ISO has no effect on highlight recovery so there is no gain in dynamic range. I quickly came to the conclusion that these so-called false ISOs are of little use to the way I shoot video (essentially ETTR with the waveform) as there no benefit in terms of highlight recovery. Others may find these false ISOs benefical. I don't.

Incidentally the Z6III has the same Lo ISOs and I've just checked that they do exactly the same as the Z8 and Z9.

Out of interest, what is your method to bring exposure back down in post? Do you use DVR and if so will you simply use offset?

 

[ClintGryke]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

You are bringing up a few issues here and I don't think there is much if any official info on this at all. Horshack has looked at the log v SDR issue but I'm not sure exactly what he concluded in his deep dive. I would need to have another read through a very long thread which I guess you are familiar with.

Anyway that was before my time on here and I did some testing myself before I came across Horshack's excellent work. I would have to dig out the tests and remind myself of exactly what I found but I recall some conclusions which might shed some light on your question.

In relation to the log v SDR comparisons, I found that there was little difference in dynamic range when working in raw (NRAW or ProRes Raw) once corrected for the ISO differences. In other words, there is no significant difference between Log and SDR in terms of highlight or shadow detail or in terms of noise. I think the SDR raws can develop a greenish colour cast in the shadows if pulled too far but otherwise there is little to choose. I chose to keep working in Log in any case.

However, there is a significant difference when working in non-raw formats (H.265 and ProRes) in terms of shadow detail. In SDR the shadow detail can go to complete mush whereas somewhat better deep shadow detail can be recovered with Log. I came to the conclusion that Log is the only way to go if working in either ProRes or H.265.

In relation to the Lo ISOs, it is very easy to check what is happening if you look at a waveform in camera or in post. If the highlights are clipping at ISO 800 as indicated by a flat top in the waveform, going to lower ISO has no effect on highlight recovery so there is no gain in dynamic range. I quickly came to the conclusion that these so-called false ISOs are of little use to the way I shoot video (essentially ETTR with the waveform) as there no benefit in terms of highlight recovery. Others may find these false ISOs benefical. I don't.

Incidentally the Z6III has the same Lo ISOs and I've just checked that they do exactly the same as the Z8 and Z9.

Out of interest, what is your method to bring exposure back down in post? Do you use DVR and if so will you simply use offset?

I use Resolve (DVR) for grading unless I've shot ProRes Raw (FCP in that case but rarely now as NRAW is as good and file sizes are much smaller). With NRAW I would use the raw tab as the exposure slider is linear (i.e. one unit corresponds to one stop exposure) and with H.265 I would use the HDR tools tab and Global. It doesn't have to be HDR to use these tools.

However, if I have somehow managed to truly clip the highlights, which I rarely do as I have learnt to be very careful exposing with the waveform, there is no way to recover them. The only way is to make sure not to clip highlights when shooting. Blue skies can be tricky. They may not show as clipping in-camera as the waveform seems to average over the the three channels so I'm extra careful with skies.

 

[A Owens]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

You are bringing up a few issues here and I don't think there is much if any official info on this at all. Horshack has looked at the log v SDR issue but I'm not sure exactly what he concluded in his deep dive. I would need to have another read through a very long thread which I guess you are familiar with.

Anyway that was before my time on here and I did some testing myself before I came across Horshack's excellent work. I would have to dig out the tests and remind myself of exactly what I found but I recall some conclusions which might shed some light on your question.

In relation to the log v SDR comparisons, I found that there was little difference in dynamic range when working in raw (NRAW or ProRes Raw) once corrected for the ISO differences. In other words, there is no significant difference between Log and SDR in terms of highlight or shadow detail or in terms of noise. I think the SDR raws can develop a greenish colour cast in the shadows if pulled too far but otherwise there is little to choose. I chose to keep working in Log in any case.

However, there is a significant difference when working in non-raw formats (H.265 and ProRes) in terms of shadow detail. In SDR the shadow detail can go to complete mush whereas somewhat better deep shadow detail can be recovered with Log. I came to the conclusion that Log is the only way to go if working in either ProRes or H.265.

In relation to the Lo ISOs, it is very easy to check what is happening if you look at a waveform in camera or in post. If the highlights are clipping at ISO 800 as indicated by a flat top in the waveform, going to lower ISO has no effect on highlight recovery so there is no gain in dynamic range. I quickly came to the conclusion that these so-called false ISOs are of little use to the way I shoot video (essentially ETTR with the waveform) as there no benefit in terms of highlight recovery. Others may find these false ISOs benefical. I don't.

Incidentally the Z6III has the same Lo ISOs and I've just checked that they do exactly the same as the Z8 and Z9.

Out of interest, what is your method to bring exposure back down in post? Do you use DVR and if so will you simply use offset?

I use Resolve (DVR) for grading unless I've shot ProRes Raw (FCP in that case but rarely now as NRAW is as good and file sizes are much smaller). With NRAW I would use the raw tab as the exposure slider is linear (i.e. one unit corresponds to one stop exposure) and with H.265 I would use the HDR tools tab and Global. It doesn't have to be HDR to use these tools.

However, if I have somehow managed to truly clip the highlights, which I rarely do as I have learnt to be very careful exposing with the waveform, there is no way to recover them. The only way is to make sure not to clip highlights when shooting. Blue skies can be tricky. They may not show as clipping in-camera as the waveform seems to average over the the three channels so I'm extra careful with skies.

Thanks very much, most helpful.

 

[ClintGryke]

Hello. I am unable to find this info anywhere. Question about h.265 N-log vs standard and dynamic range. According to Nikon, Log delivers 12 stops dr (this may only be n-raw?).

However, according to Nikon DR drops when using iso lower than 800. The 8/9 series have low settings that are 200/400/640.

What I’m curious about is in the lower settings, am I getting less or equal DR to standard h.65? Curious if anyone has seen info on this. Even with a decrease the benefits of log are still beneficial for color grading and mixing standard and log footage is far from ideal.

It's odd that Nikon (to my knowledge) doesn't provide this information in any meaningful manner.

It's more a matter of pure interest and nerding out.

You are bringing up a few issues here and I don't think there is much if any official info on this at all. Horshack has looked at the log v SDR issue but I'm not sure exactly what he concluded in his deep dive. I would need to have another read through a very long thread which I guess you are familiar with.

Anyway that was before my time on here and I did some testing myself before I came across Horshack's excellent work. I would have to dig out the tests and remind myself of exactly what I found but I recall some conclusions which might shed some light on your question.

In relation to the log v SDR comparisons, I found that there was little difference in dynamic range when working in raw (NRAW or ProRes Raw) once corrected for the ISO differences. In other words, there is no significant difference between Log and SDR in terms of highlight or shadow detail or in terms of noise. I think the SDR raws can develop a greenish colour cast in the shadows if pulled too far but otherwise there is little to choose. I chose to keep working in Log in any case.

However, there is a significant difference when working in non-raw formats (H.265 and ProRes) in terms of shadow detail. In SDR the shadow detail can go to complete mush whereas somewhat better deep shadow detail can be recovered with Log. I came to the conclusion that Log is the only way to go if working in either ProRes or H.265.

In relation to the Lo ISOs, it is very easy to check what is happening if you look at a waveform in camera or in post. If the highlights are clipping at ISO 800 as indicated by a flat top in the waveform, going to lower ISO has no effect on highlight recovery so there is no gain in dynamic range. I quickly came to the conclusion that these so-called false ISOs are of little use to the way I shoot video (essentially ETTR with the waveform) as there no benefit in terms of highlight recovery. Others may find these false ISOs benefical. I don't.

Incidentally the Z6III has the same Lo ISOs and I've just checked that they do exactly the same as the Z8 and Z9.

Out of interest, what is your method to bring exposure back down in post? Do you use DVR and if so will you simply use offset?

I use Resolve (DVR) for grading unless I've shot ProRes Raw (FCP in that case but rarely now as NRAW is as good and file sizes are much smaller). With NRAW I would use the raw tab as the exposure slider is linear (i.e. one unit corresponds to one stop exposure) and with H.265 I would use the HDR tools tab and Global. It doesn't have to be HDR to use these tools.

However, if I have somehow managed to truly clip the highlights, which I rarely do as I have learnt to be very careful exposing with the waveform, there is no way to recover them. The only way is to make sure not to clip highlights when shooting. Blue skies can be tricky. They may not show as clipping in-camera as the waveform seems to average over the the three channels so I'm extra careful with skies.

Thanks very much, most helpful.

Don't mention it. Glad it helps. I've been challenged here about using what is effectively ETTR for shooting video but I find it really works in practice as long as I stick to the mantra of "Don't clip the highlights".