Z-LOG and LUT advice

[lumbowski]

I purchased the Z-LOG profile and I'm looking for some advice on how to use it properly. Using a Z6 and the Cinematic profile. Once I drop the footage into Resolve, it looks suitably low contrast, as you'd expect, but once I apply the Cinematic LUT, it just seems to make it really contrasty and dark. Is this right? 

Here's an ungraded still before adding LUT: https://ibb.co/t8wv5nX

And here's it with the Cinematic LUT: https://ibb.co/42WYcjn

I can pretty much replicate the effect of the LUT by upping the contrast. 

What am I missing? 

Thanks. 

[Andrew Reid]

[Alexis Fontana]

So - there’s a few things going on here. 
 

I suggest you try to google “what is a 3dlut” and watch some of many good videos that explains the concept. 
 

Always try to avoid thin pinstripes in talents clothes, as they will often create moire as in your shot. 
 

Also - try to point the microphone towards the talents mouth instead of pointing down. 

[lumbowski]

@Andrew Reid Thanks for that. Very helpful. It was an honest question, explaining that I know I'm missing something, in the hope of a little guidance. Maybe you've heard this question a million times, but I couldn't find much in the forum to help. 

@Alexis Fontana I have read around the subject, I understand what LUTs do - why would I have bought this if I didn't think it would be of benefit? I guess I'm asking what I should expect from the EOSHD LUT. To your comments on the setup, which aren't related to the question I asked in any way, I had no control over what people wear and I point the mic down to counter plosives. 

[TomTheDP]

@lumbowski
What were the conditions you shot the video in? I am seeing a possibility of some harder light sources. 

Luts can't really be one size fits all so you have to adjust based on how your video was lit and exposed. 

In terms of a cinematic look there are many different kinds both lower and higher contrast looks. The final image with the lut looks relatively normal to me. It's definitely on the higher contrast side but also normal looking. 

Yes the image with the lut is more contrasty. Upping the contrast on the original image might take you closer to the look of the LUT but it won't be the same. There are usually subtleties going on in regards to color and roll off with luts that can't be replicated by simply adjusting the contrast slider. 

[seanzzxx]

21 hours ago, Alexis Fontana said:

So - there’s a few things going on here. 
 

I suggest you try to google “what is a 3dlut” and watch some of many good videos that explains the concept. 
 

Always try to avoid thin pinstripes in talents clothes, as they will often create moire as in your shot. 
 

Also - try to point the microphone towards the talents mouth instead of pointing down. 

Those mics are omnidirectional so what are you on about. Pointing the mic down is a common technique to avoid popping sounds from the person speaking, as pointed out by OP.

[Alexis Fontana]

11 hours ago, lumbowski said:

@Andrew Reid Thanks for that. Very helpful. It was an honest question, explaining that I know I'm missing something, in the hope of a little guidance. Maybe you've heard this question a million times, but I couldn't find much in the forum to help. 

@Alexis Fontana I have read around the subject, I understand what LUTs do - why would I have bought this if I didn't think it would be of benefit? I guess I'm asking what I should expect from the EOSHD LUT. To your comments on the setup, which aren't related to the question I asked in any way, I had no control over what people wear and I point the mic down to counter plosives. 

Ok. My bad on the mics - the ones I use are directional.

 

Still, you may have read about Luts but you clearly don’t understand them. Also Luts are modern day snake oil so there’s that to consider. 

[lumbowski]

Do you do this on other questions/forums? Just pointlessly comment without offering any help at all? Seems a strange way to pass the time. 

[lumbowski]

@TomTheDP Thanks - it was my usual setup of one key and one backlight. I'm happy with the footage, I'm just trying to get my head around using the Z-LOG profile and LUT. Good to know it looks OK to you. I've now graded the footage and blended the LUT more subtly so the final result looks good to me. 

The profile is set in the camera, I put the footage into Resolve and apply the LUT. My (basic) understanding is that the LUT maps the existing image info to different info and so changes the look of the image. I've applied a load of LUTs in Resolve and can see the difference so I'm not sure why the first two replies were so dismissive and unhelpful.

I know they can be used on input/output for an entire project and to balance different cameras and all that, but is there anything wrong using them this way? 

[TomTheDP]

9 hours ago, lumbowski said:

@TomTheDP Thanks - it was my usual setup of one key and one backlight. I'm happy with the footage, I'm just trying to get my head around using the Z-LOG profile and LUT. Good to know it looks OK to you. I've now graded the footage and blended the LUT more subtly so the final result looks good to me. 

The profile is set in the camera, I put the footage into Resolve and apply the LUT. My (basic) understanding is that the LUT maps the existing image info to different info and so changes the look of the image. I've applied a load of LUTs in Resolve and can see the difference so I'm not sure why the first two replies were so dismissive and unhelpful.

I know they can be used on input/output for an entire project and to balance different cameras and all that, but is there anything wrong using them this way? 

I mean the usual use for a LUT is converting LOG into a REC709 colorspace. What LUT were you using? Was it designed for the type of LOG profile you used?

ZLOG comes with two versions of LOG, Zlog and Zlog-L.

Zlog is designed to mimic a less flat log curve like C-log. So if you are using LUTS they should be ones designed for CLOG. 

If you are using Zlog-L you should use LUTS designed for Slog2, Vlog, or Flog. 

Some LUTs are better than other as its completely dependent on whoever made them.