ImpulZ Film Emulation 3D LUTs with the GH4?

[jcs]

@jcs but... Sherif says if clips aren't denoised before applying LUT, you can get macroblocking and colored noise (actually, I've been shooting with NR at lowest setting and not bothering with Neat Video, and I never noticed these defects when using LUTs- not to say they weren't there), but it's the banding that annoys me. So - add noise first - how? Or are you pulling my leg?

Noise/grain can help reduce banding. It's best applied before the operation which causes banding.

[jonpais]

Thanks, even though I'm getting more and more confused.

[jonpais]

Noise/grain can help reduce banding. It's best applied before the operation which causes banding.

Thanks, jcs and sudopera. 

@jcs but, but, but what about macroblocking and colored noise? and how do I ADD noise? are there actually products on the market for adding noise? It sounds absurd really - I don't think I could watch my clips if they were any noisier than they already are!

[sunyata]

Are these tools meant to be used for general color grading? Because NoFilmSchool says really LUTs are supposed to be used at the final stage to make up a difference between monitor colour and film print

 

You're right about this but now LUT's are used for simulating film stocks or looks.. it used to be for matching film and a labs process when you worked and then you would take it off when you rendered. Just keep in mind that in order for the LUT to show an accurate film stock profile etc, you need to make sure your scene-referred gamut is correctly matched (what is coming from the camera). 

[sudopera]

Thanks, jcs and sudopera. 

@jcs but, but, but what about macroblocking and colored noise? and how do I ADD noise? are there actually products on the market for adding noise? It sounds absurd really - I don't think I could watch my clips if they were any noisier than they already are!

On top of the page you have free film grain for download, here is the link:

http://www.vision-color.com/free-stuff/

Put the clip with grain on top of your main clip, set the blend mode to overlay and adjust opacity to your liking

[utsira]

Okay, but whether I add grain before or after the LUT, how do I know what FCPX is doing, since there are no nodes, I don't know what it's prioritizing :( And is there a difference between applying the LUT to an adjustment layer rather than directly over the clip? I thought adjustment layers were just for convenience - you know, to apply the same look to a bunch of clips at one time rather than individually.

My understanding of the FCPX order of operations is that it basically goes from the top of the video inspector panel to the bottom; ie the first effect to be applied is at the top of the effects section, then the colour board after all of the effects. It then moves up the timeline (I guess that's a confusing switch of direction), adding overlays and adjustment layers.

So the vision color recommended order, on their digital negative page, is denoise, then primary colour correction, then film grain (an overlay, or I made it into a motion effect. Grain is basically adding a kind of noise), then LUT (using the adjustment layer, so that the LUT is applied after the primary correction on the colour board), then, if necessary, a second colour board correction in the adjustment layer, which would be applied after the LUT.

I agree with you though, that I'm not sure whether the "always denoise the chroma" (ie even broad daylight at iso 100), followed by add grain is necessary. I guess the theory is that one noise is ugly, the other is beautiful? And I wonder whether Sherif is overdoing the denoise? i.e. the woman's face looks, as he puts it, plastic, all the texture has gone. Perhaps he forgot to dial down the luma denoise? Ie vision color recommend denoising the chroma channel only, unless there is, you know, actual visible noise.

[jonpais]

Hmmm... I just read this article by Oliver Peters, where he says

 

 

Likewise, actual effects filters are always added after color correction in the Color Board. There are two workarounds for this. The first is to work with Compound Clips – the new term for a “nestâ€. If you want to add a correction after the application of a filter or apply an additional overall correction to series of clips, select the clip(s) and click Option-G for a new compound clip. Now apply the new effect or correction.

:(

But looking at your 'order of operations', it makes sense to me now. I think. :)

[Inazuma]

When you DirectLink form Premiere Pro to Speedgrade and then bring it back, there is no extra effect added to the layer that represents the Speedgrade edits. So does that mean that if I add a denoise effect on the same layer, then the denoise will be happening after the LUT application from Speedgrade?

[utsira]

Hmmm... I just read this article by Oliver Peters, where he says

:(
But looking at your 'order of operations', it makes sense to me now. I think. :)

Peters is wrong, it definitely goes from top to bottom in the inspector window, ie all effects first, then colour board.
http://www.fcp.co/forum/4-final-cut-pro-x-fcpx/3882-effects-before-color-correction

http://www.larryjordan.biz/fcp-x-stacking-multiple-effects/

[sunyata]

Thanks, jcs and sudopera. 

@jcs but, but, but what about macroblocking and colored noise? and how do I ADD noise? are there actually products on the market for adding noise? It sounds absurd really - I don't think I could watch my clips if they were any noisier than they already are!

 

yea, the whole add noise as part of a remove banding workflow is not something i would recommend, and i've used it in the past. the problem is that banding can be consistent across motion, where noise is always dancing around, so your eye will see the telltale pattern of banding when it moves, but the noise appears invisible. the technique of course also adds a lot of additional noise to footage that is probably already too noisy! the unfortunate answer is to avoid the introduction of banding. that's another topic.

 

but you shouldn't need a product to do it, most programs have a grain filter or noise filter. 

 

i'm also very leery of de-noise as part of any standard workflow. de-noise is an imperfect science and usually creates an unsharp mask effect. 

[jonpais]

You neglected to add, "and denoising takes all night to render". :)

[Nikkor]

And remember to be in 32bits or at least 16bit colorspace,if you work in 8bit banding will occur with any adjustment. I know you know it but someone might forget.

[jonpais]

Yep. I'm experiencing banding, and I hardly ever lift shadows or shoot huge expanses of sky, and it happens even without the help of LUTs, though they tend to exaggerate the effect.  So, you're saying even 10bits isn't sufficient? I thought that was the holy grail...

[sunyata]

ru asking me that? 16bit kills banding for CG and 10bit is good enough for film/video. largely because of, you guessed it, grain.

[jonpais]

And remember to be in 32bits or at least 16bit colorspace,if you work in 8bit banding will occur with any adjustment. I know you know it but someone might forget.

I know 8bit doesn't cut it, at least not for me, but why do you say 10 bit isn't good enough? 

[sunyata]

ah, i think he was saying "working space", i don't know of any apps that have a 10bit working space except the older versions of flame and shake's "bytes" node. but 8, 16, or 32 are usually your options for working space depths.

 

actually, i take that back, shake also only had 8, 16 or 32.

[Nikkor]

I know 8bit doesn't cut it, at least not for me, but why do you say 10 bit isn't good enough? 

I meant the workspace, 8bit footage in a 16/32bit workspace. If you work with 8bit in 8bit workspace it's banding parade. Someone might not know it, I also find that luts don't seem to work that good in 8bit (why bother with 8bit workspace anyway)

[jonpais]

I meant the workspace, 8bit footage in a 16/32bit workspace. If you work with 8bit in 8bit workspace it's banding parade. Someone might not know it, I also find that luts don't seem to work that good in 8bit (why bother with 8bit workspace anyway)

duh... maybe because there aren't any cameras in my price range that offer 10bit (at least, none with a workflow I'm willing to endure). Right now, it's banding and moire (GH3). I'll upgrade and it'll be something else altogether. It never ends...

 

/edit/someone here in one or another thread rightfully said, nobody ever complained about the resolution of a movie they'd seen at the theater, or something to that effect. Which might be true, but what matters to me isn't what other people notice, it's what I care about that counts. And even though nobody's ever said, 'Jon, your pictures are unwatchable - too much aliasing!', I know it's there.

[sunyata]

yep, you'll upgrade right when 4D 16k comes out.

 

a lot of people are familiar with moore's law but my favorite is blinn's law, which states, no matter how much faster computers get, the time it takes to render really stays the same, because the client always wants more (or in the case of editing, no matter how much faster your drives get, they always will be too slow for the newest format).

[jonpais]

:)

I've only owned my iMac a month or so, and already buyer's remorse. I expect the same will happen with the GH4. As for LUTs, I've got too many LUTs, not enough footage to grade!