Used the Alexa Log-C LUT, and dialed down the gain since I shot without a viewing LUT, and was overexposed by S-Log standards. Of course nothing was clipping anyway, but I had to adjust that exposure.

Skintones and overall look are prettier than I can achieve without a LUT in FCP:



Farmers Insurance/ Marvel's The Avengers -- Suit Up -- Behind the scenes: University of Farmers - YouTube

Used the Alexa Log-C LUT, and dialed down the gain since I shot without a viewing LUT, and was overexposed by S-Log standards. Of course nothing was clipping anyway, but I had to adjust that exposure.

Skintones and overall look are prettier than I can achieve without a LUT in FCP:



Farmers Insurance/ Marvel's The Avengers -- Suit Up -- Behind the scenes: University of Farmers - YouTube (http://www.youtube.com/watch?v=Nm3pcW6dugg)

So you shot the behind the scene with an F3 with S-LOG?

So you shot the behind the scene with an F3 with S-LOG?

Yes. To XDCAM.

The spot's being shot with Alexas and you're shooting BTS with an F3 with S Log? Interesting to compare footage side by side. Anyway, it looks like fun kooky shoot. Those Coppolas have great genes.

Sorry to be naive, but is Alexa Log C LUT installed in F3 picture profiles? So you shoot to SXS cards using this profile? Then it was graded in Resolve?

All handheld shooting with what kind of rig? Shooting with zoom lenses?

Sorry to be naive, but is Alexa Log C LUT installed in F3 picture profiles? So you shoot to SXS cards using this profile? Then it was graded in Resolve?

Sorry, no, the Alexa LUT is used to "decode" in Resolve. There are no easily obtainable S-Log LUTs avail for Resolve, so I used the built in ones for Alexa. Looks fantastic.

I shot without a LUT, monitoring and exposing with the flat image. I goofed a bit, and exposed it hotter than it's meant to be. Still tons of wiggle room to fix, as you can see in the video. When I talked about "gain" above, meant image gain in Resolve, not in camera.



All handheld shooting with what kind of rig? Shooting with zoom lenses?

Mostly handheld. Element Technica baseplate + CAS Spidergrips. Red 18-50 & 50-150 zooms.

You can save the F3's internal LUT's to an SxS card (in the "others" menu) and you should then be able to load those LUT's into resolve. Not sure what LUT's resolve supports but the .ce2 files the F3 produces are pretty standard. As they are text files they are easy enough to copy into the appropriate wrapper.

I'd been planning to buy the S Log for my F3 since I shoot a lot of documentary work where you can't control the lighting (there's also the killer outdoor Australian light, so unforgiving, much like southern Cal) but was trying to decide whether to shoot to the SxS cards to get the extra stop or invest in a separate recorder.

Your work with the F3 is the best and most imaginative I've seen so far, judging from the clips on your website. Or are some shot with other cameras? And you grade with Resolve mostly?

Michael

You can save the F3's internal LUT's to an SxS card (in the "others" menu) and you should then be able to load those LUT's into resolve. Not sure what LUT's resolve supports but the .ce2 files the F3 produces are pretty standard. As they are text files they are easy enough to copy into the appropriate wrapper.

Allister,

The ce2 files are a group of 5 LUTs packaged together for the benefit of the CVP editor. Proprietary, from what I can tell.

The individual .lut files the CVP editor and Sony cameras use are not directly usable in Resolve, or at the very least, I can't get them to recognize and I've had success with other format LUTs. I'm sure they can be converted for use, as you're right, they're very simple 1D LUTs, but I haven't found the method yet in my maybe 2 hours of playing.

Regardless, if you shoot and expose to the Sony in-camera LUTs, the Alexa LUT more or less keeps the same exposure, and along the way adds a very refined s-curve contrast to the image along with nice saturation and blowouts, in my opinion.

Anyone know if you can easily load the Alexa LUT into the HDLink?

Anyone tried this: Mac App Store - LUT Translator (http://itunes.apple.com/us/app/lut-translator/id454961834?mt=12)

Say's it supports Sony SRW LUT's, which should be .ce2 LUT's.

All we need initially is for someone to convert the 5 F3 LUT's to something a bit more common, then you could use LUT Buddy (free) to convert to other standards.

I'm curious, do you think this really would have looked a whole lot different if you had shot it without sLog?
Any easier to shoot or edit?
I'm guessing that you were the editor also and thus didn't have to convince someone to shoot in SLog and take the time to grade.
I'm trying to figure out where I can suggest to clients that they shoot with sLog and generally what I hear is - "If I have the time to do all that grading I can afford to shoot with an Alexa". I suspect on a shoot like this my clients would choose the marginal quality drop of cine gamma or 709 over the time added in grading.

Its not a criticism , I just see a lot of example of sLog on the boards that don't look much different to what I can get without it and without the added hassle.

So mush has been said about the ability of S LOG handling highlight that the real used has being ignore.
Having too mush light has never been a problem, close the lens or stick an ND filter and you are set. The problem is latitude from highs to lows and that is where the SLOG excels compare to non SLOG.
It is hard to tell if you don't have two exactly identical clips one with and one without SLOG.
I usually look for the transition of shades in the lows to tell the difference.

Grading S-Log is SOOO simple and easy that any Pro NLE can handle it - you don't need Lustre or Resolve to do it. I don't understand the 'hassle' that people talk about. Aside from Doug, doesn't everyone else normally apply some sort of finishing touches to their footage when editing? If going to broadcast or DVD, you absolutely must get everything in check, which means applying an effect or two.

Maybe tell clients who expect a picture perfect image on their monitor during production that they need to include room in the budget for a DIT.

Then again, isn't it the DP's role to decide when and when not to shoot in S-Log? If you have a low-con scene, then S-Log won't add much.

I don't know about you but in my world I can't simple tell a client he has to use sLog because I think it would be better. I agree that everything should be graded to some extent but many people like to do as little as possible. I don't entirely get it to be honest as I love to grade my own stuff and can't imagine not correcting everything 709 nor not.

I don't entirely get it to be honest as I love to grade my own stuff and can't imagine not correcting everything 709 nor not.

I agree 100%.

I think the problem is that most of these people have been in the industry for years and still think of 'grading' as something that costs <$1000/hr on a Resolve, Scratch, Lustre, etc. It is so simple and easy to do now with inexpensive computers and a $5k Flanders Grade 1 monitor or $3k Sony OLED.

If a client doesn't want to grade, then why bother even bringing it up? Its not our job to teach these people about the benefits of one camera's tech. Also, you can't expect to send a 14 stop image to broadcast either so to utilize the full benefits of S-Log mean it needs to be graded.

If it's not our job to guide those that don't understand then whose job is it?

Education, it's all about education.

I'm not just talking about students and newbies. It's the 20 years in the industry camera operators, producers, directors etc that need educating. Most of those reading this are here to learn and I applaud that. But there are many that have been in the industry for 10 years or more that have "seen it, done it" and think there is nothing new to learn.

In the last couple of years there have been some huge changes and additions to the tools available to the film maker. In particular an incredible set of tools now available to low/no budget productions that were previously reserved for the big boys. Many traditional documentary, news or current affairs people will have no idea about what S-Log really is and how it can be used. In some respects the internet is not helping as there is a lot of miss-information and technical mumbo jumbo that makes some of this stuff appear to be rocket science, when it really isn't.

I'm curious, do you think this really would have looked a whole lot different if you had shot it without sLog?

To me, yes. I can't handle the traits of the F3 without S-Log anymore. It's not a look I like.

Any easier to shoot or edit?

Easier to shoot? Yes. I have much more wiggle room on exposure, things I can fix in the color correction easily.

Edit? Edit's not more difficult, other than I have to do a color-correction pass, which I do anyway.

I'm guessing that you were the editor also and thus didn't have to convince someone to shoot in SLog and take the time to grade.

Either color correction is in the budget or it isn't. In Los Angeles, I rarely find any job that won't do at least SOMETHING with the color, even if it's just the editor having a shot at it in FCP or Avid.

I'm trying to figure out where I can suggest to clients that they shoot with sLog and generally what I hear is - "If I have the time to do all that grading I can afford to shoot with an Alexa". I suspect on a shoot like this my clients would choose the marginal quality drop of cine gamma or 709 over the time added in grading.

It's about taking money to craft a look. It doesn't have to be a lot of money. It took me 1.5 hours to color the piece above. It comes out of the pool of hours budgeted for creative edit. It looks better than it did before. Gets me more work.

Its not a criticism , I just see a lot of example of sLog on the boards that don't look much different to what I can get without it and without the added hassle.

Well, if you don't see it, you don't see it. Not much I can do to convince you.


I think the problem is that most of these people have been in the industry for years and still think of 'grading' as something that costs <$1000/hr on a Resolve, Scratch, Lustre, etc. It is so simple and easy to do now with inexpensive computers and a $5k Flanders Grade 1 monitor or $3k Sony OLED.

I hate to throw out this "out here in La-La Land we do this and that and this", but this is the way things are going. Editors are learning Resolve, buying $1500 control surfaces, and going to town. At the very least they are slapping Magic Bullet on everything, and as much as I hate it, getting pretty good results. I know some color correction facilities that are having a hard time. The sisters are doing it for themselves.

If a client doesn't want to grade, then why bother even bringing it up? Its not our job to teach these people about the benefits of one camera's tech. Also, you can't expect to send a 14 stop image to broadcast either so to utilize the full benefits of S-Log mean it needs to be graded.

To push for better images. I've never shot a frame that couldn't be made better by working the color in post. The better my work looks, the more I'm able to charge.

If a client wants to be ignorant about how to make their job look better, I guess I'm not going to argue, but I'll sure as heck try to steer them in the right direction.

[QUOTE=Steve Kalle;1729762]Grading S-Log is SOOO simple .... I don't understand the 'hassle' that people talk about. Aside from Doug, doesn't everyone else normally apply some sort of finishing touches to their footage when editing? If going to broadcast or DVD, you absolutely must get everything in check, which means applying an effect or two.

Maybe tell clients who expect a picture perfect image on their monitor during production that they need to include room in the budget for a DIT.

For corporate and industrial work, the thought of the added out-board recorder, and yes some additional time in the edit suite to correct EVERY shot is simply not in the budget of time and money. And for what gain, some highlights held, that are probably no concern of anyone? Let's be real, it's the face and mid tones that truely count. A good picture profile on the F-3 is far more important than ANYTHING ELSE next to good glass. Sorry but RED lenses don't have good mid tone contrast to my eye, and they aren't sharp. Good glass and a good picture profile beats anything I've seen so far from S-log. My opinion, my eyes...everyone has a different set of both. FWIW, my clients appreciate the difference I am able to provide, without the jump in expense to RED or Alexa.

Hi Richard and welcome to DVInfo!

I understand where you are coming from in that many videos with S-Log don't look much better, if any, than videos with cinegammas. This is due to quite a few people not understanding S-Log and not knowing how to grade and/or handle S-Log in post. While I say that its very easy to just apply a S-shaped Curves effect and add some saturation, there is so much more that can and should be done to enhance the final image.

I have watched 100's of hours of online training from Lynda.com to FXPHD and others covering editing, vfx (AE, Nuke, Smoke), 3D modelling (C4D), DoP, Directing, script writing, etc. There is a huge difference between Lynda & others from FXPHD, which has had several courses on grading, color theory and Resolve. If I hadn't watched any of those FXPHD courses and relied on the other websites, I wouldn't have a good enough knowledge of grading and how to deal with S-Log properly. So, what I am trying to say is that there is not much info & training on the web for most people to teach themselves how to grade S-Log, which results in decent looking images.

With a decent colorist, S-Log easily looks noticeably better than cinegamma videos (when exposed correctly and recorded in a high quality 10bit codec like PR HQ).

I am sorry but I totally disagree that there isn't anything else to S-Log other than extra headroom in highlights. Unless you have spent a fair amount of time shooting and grading S-Log footage, then its difficult to understand and see the added benefits of S-Log. Just looking at other people's poorly graded S-Log videos won't provide anyone with an understanding of its benefits. One needs to test cinegammas and S-Log in the field/studio with a proper monitor (ie, 17" Panasonic 1700 series or better) to see where S-Log increases the quality of the image. And then take that footage into a NLE, After Effects or Resolve and begin pushing the image to see where the added Dynamic Range (2-2.5 stops over cinegammas) helps. For example, the shadows actually have detail and additional latitude can be extrapolated from it - this is especially helpful in dark scenes. In bright scenes like someone shot on the Vegas strip at night, the vast array of lights in and around signs can be seen and recorded in S-Log whereas the cinegammas would have had mostly blown out lights.

As Nate Weaver and I have learned from our own testing, one can get away with shooting S-Log to SxS, but you must know what you are doing such as knowing when a scene has elements that won't work with 8bits very well, which could end up as banding or posterization. There also isn't any much wiggle room in getting the exposure spot on when recording to SxS whereas 10bit Pro Res provides a fair amount.

Thanks Steve. I am open to getting a better product from the F-3. But as you say, it's not shown online as yet. Will take a look at the training sites you mentioned. A big issue for me is that I would have to be the colorist in the equasion as there are no local resources for me in my immediate area. And certainly, a 10 bit recorder would required to make the noticible improvements the S log could be capable of.

A few more S-Log via Alexa LUT images:

it's my opinion that there is a night and day difference between a F3 without S-Log and an F3 with S-Log. For me one of the key things is the way highlight and in particular highlight saturation is handled. It is so much better with S-Log. You can get close with the cinegammas but S-Log takes the F3 to another level. I find S-log quick and easy to grade, in part because you have a consistent image from shot to shot, assuming you exposed correctly during the shoot.

I really appreciate all the feedback here and hope my questioning some sLog footage is taken too negatively. I do try educate and lead my clients, but so far this looks like a harder sell than I expected. Perhaps a lot of you are working on higher budgets than I usually am.

I'm trying to justify the cost of a Samurai (I want it quite a bit) but am running into a lot of feedback in San Francisco that generally says " If people have the time and budget to do all that color correction, they can also afford to shoot on the Alexa instead." So just how much time is involved with correcting SLog is something I need to know and be able to convincingly explain. Most people I work with are still grading only in Final Cut Pro which it sounds like is not ideal for grading sLog because it doesn't have curves. Is that correct? I am beginning to play with some tests I've shot just using the 3 way color corrector and adding a "shadow highlight" plug in from TMTS that is great for adding lots of knee and toe compression.

I hope to do some Slog vs other gamma tests this week and then grade them.

There can be a quite big cost difference between shooting on an Alexa or a very small one depending on how you work.

On the shoot side: An F3 with a few DSLR lenses and a Samurai is a much cheaper option than an Alexa with PL glass. The F3's media costs will be lower (an SSD) and an owner/operator probably won't need a DIT or assistant. On the other hand a fully loaded F3 with SR-R1 recorder and PL lenses costs only a little less than an Alexa to rent. When working with SR-Memory the high media costs will mean you may want a DIT or loader to manage your rushes and provide backups while you shoot, so in this scenario there is probably only minimal cost difference between Alexa and F3.

It's the same in post. An F3 owner/operator could use the free version of resolve or FCP with a low cost plugin like Natress Curves to grade the material. The soon to be release Adobe CS6 Cloud might be an interesting option as it includes Speed Grade. Or you could take your F3 material to a dedicated colourist that will cost you the same whether the material is from an F3 or an Alexa.

In terms of time, you can spend a short amount of time, creating a single look and applying that to the entire shoot or spend a lot of time carefully grading each shot. I normally end up with an overall look that then gets tweaked form scene to scene. I don't feel the extra time is excessive considering the improvement to the end result. There is a learning curve as you figure out your optimum workflow and work out how much time you want to spend on individual shots, but once you get into the groove it's not so bad. What I would add is that as we start to move more and more towards workflows that involve shooting RAW, a good sound knowledge of grading techniques and methods will help smooth the transition to RAW if that's the way you end up going.

On a recent fly away shoot we had one crew working with an Alexa, one with the F3. The Alexa crew (operator + loader) had close to 100kg of equipment, the F3 crew around 30kg. The Alexa was on an O'Conner 2675 tripod so needed both members of the crew to reposition, one carrying the camera, one the legs. The F3 crew operator was using a Vinten 5AS so could pickup the entire rig and move it by himself. The F3 operator shot twice as much as the Alexa crew. In the finished programme it is extremely hard to tell from the images which was shot with the F3 and what with the Alexa. The cost to the production of the Alexa was 3 times that of the F3, yet there is a lot more F3 material in the finished show than Alexa.

Nate, I think that's an outstanding use of Alexa LUT's for S-Log footage, I wasn't aware that could be done. I will recommend that to certain clients who use DaVinci regularly.

I send a ton of F3 S-Log Samurai recorded Prores HQ footage to a couple of other clients who only use FCP and Avid for editing and their reports back are that there are no real issues with using those basic systems to grade as, as Alister has pointed out, the S-Log is consistent throughout if exposure levels are correct and accurate. Granted it would be better to use a package like DaVinci, but as Leonard points out some clients are not in that game.

I'm just waiting for Steve Shaw at Light Illusions or someone else to publish some downloadable new LUT's for F3 so we can start to do the obvious for clients who don't want or can't grade which is to use and record the S-Log for it's strengths and simultaneously record out to a good LUT representation for immediate edit or dailies. I do that now for some clients but the REC709 out of the F3 is not so instantly usable as has been discussed on several threads here.

So far I've been having trouble getting a decent grade using the standard Final Cut tools. Flesh tones have just looked crappy.
However on Alister's suggestion I just downloaded a demo of the newer version of Natress Curves and Levels from FXFactory. it's only $49 and so far it seems to help quite a bit. I've only played a little bit and was actually using it wrong but it already gave me a much more natural looking grade. I was also adding the TMTS and Lyric versions of shadow highlight filters (both free and worth every dime) to get some extra control at the toe and knee.
I tried the Pomfort Log correction plug in and it was way too aggressive and not adjustable at all.

if I can figure out a simple and fast way for grading this stuff then I will feel comfortable educating my clients.

Most people I work with are still grading only in Final Cut Pro which it sounds like is not ideal for grading sLog because it doesn't have curves. Is that correct?

Not really. Not "ideal" because it's not real time and FCP7 is a little bit of a pain to color in, but the tools are available. If this is what's holding them back, it's a pretty small reason.

I think a good combo of plugins for working in FCP7 would be (and stacked in this order):

-Red Giant Colorista

-Red Giant LUTBuddy, with Alexa Log-C LUT loaded, like I've been doing in Resolve. LUTBuddy is free.

However on Alister's suggestion I just downloaded a demo of the newer version of Natress Curves and Levels from FXFactory. it's only $49 and so far it seems to help quite a bit. I've only played a little bit and was actually using it wrong but it already gave me a much more natural looking grade.

I got pretty good results with that too...before I figured out the Alexa LUT. Almost bought it.

Adding a very careful s-curve to the image seems key to getting a good image. But it takes finesse. Secondary to that seems (again, my eye) to be the actual de-logging of the gamma. An s-curve alone will ALMOST make it look like you've de-logged and put gamma where it belongs. Regardless,

I tried the Pomfort Log correction plug in and it was way too aggressive and not adjustable at all.

Agreed. I tried it too.

It was that particular plug that made me realize it's important where the de-logging happens in a CC filter chain. In tools not designed specifically for color-correction, you want the de-logging (or LUT application) to happen last, as then you can adjust exposure BEFORE the de-logging and highlights are thrown away in the pipeline, so to speak.

Interestingly enough, I had manage the order of things in Resolve too, and have that LUT applied towards the end of the pipeline. Luckily Resolve gives you about 4 different way/places to apply a LUT, for those very reasons.



if I can figure out a simple and fast way for grading this stuff then I will feel comfortable educating my clients.

Sure, makes sense. If I'm having a hard time being readable, we should get Stu from Red Giant in here. He's responsible for probably the best tools to make this happen in FCP7.

One FCP 7 issue is that any 3rd party effects render previews are done in 8 bit which doesn't help. There are only a handful of effects and transitions that render in 10 bits.

OK I want to try the LUTBuddy / Alexa Log-C LUT combo on FCP as an alternative to Natress before I buy anything.

I installed LUTBuddy but how do I get the Alexa Log-C LUT installed in it?
Do i need Colorista, and if so can the Free version suffice?

I did go to the Arri site and downloaded what i thought were a bunch of LUT's, but LUTBuddy didn't recognise them.

(Unfortunately Resolve Lite won't work on my system)

Thanks again for continuing support for this blind man.

There's a lot of unknowns here, but I'll try


I installed LUTBuddy but how do I get the Alexa Log-C LUT installed in it?

LUTBuddy is pretty short on documentation, especially where it comes to LUT formats it accepts. The Arri LUT generator, as a last option, allows you to pick a file format.

I'd start with a LUT for Apple Color (.mga), and then work my way through the other LUT formats (with a concentration on non-high-end color correction programs)

I assume once LUTBuddy is installed as a plugin, it's straightforward to get it to recognize a LUT file? As in, a README file tells you where to put the LUTs, etc etc?



Do i need Colorista, and if so can the Free version suffice?

It HAS to be better than the FCP 3-Way.


I did go to the Arri site and downloaded what i thought were a bunch of LUT's, but LUTBuddy didn't recognise them.

Lotta options on that generator site. I've made a screen grab of the options I recommend. Take special note on that last pulldown menu in lower right. You're gonna have to try a bunch of different file formats until you happen upon one LUTBuddy likes.

Thanks Nate,
That helps. Good to know that I'm on the right track with the Arri site & just need to experiment with file formats. I found some pretty good documentation on LUT Buddy and a tutorial that shows you how to build a preset LUT using colorista and Curves in AE then you can import that preset to FCP. Actually I very quickly built a LUT that was pretty reasonable.

The Natress FxFactory "Curves & Levels" plug in also looks promising so its all starting to look like I night be able to give clients an easy roadmap to slog grading so they don't freak-out. (I found a glitch that Graeme is working on though.)

Why do you prefer Colorista Free to the FCP 3 way? On quick glance they look pretty similar tho Colorista might be a little easier & faster to use.

Can you make that Arri screen grab available or send it to me @ <NSLL@pacbell.net>?

lenny

Slightly off subject but since Colorista came up--I have to say that the secondary key and pop adjustment is the quickest and most effective way to apply "digital makeup" that I've seen (it's in the full version, not the free one). I use it all the time to make the ladies purtier. Colorista is pretty great.

The F3's MLUT's converted to standard .lut files are available here for you to download:
XDCAM-USER.COM &bull; Login (http://www.xdcam-user.com/forum3/viewtopic.php?f=42&t=1010)

These work in LUT buddy and most other grading applications. Let me know how you get on with them.

Alister,

Thank you so much.

H.

Alister,
Thanks so much for the LUT's. At first glance they look more useful than the others I've tried. However I am having a problem with them.

The 8 bit LUT's seem fine but with the 10 bit LUT's I'm getting some kind of weird reverse color that looks like its solarized or something very bizarre. I'm using Red Giant LUT Buddy in FCP 7.03 on a sequence that is Pro Res 422 on shots recorded in a PIX in 10 bit . The sequence is set either in render all 10 bit in high precision YUV or render all YUV in high precision . I tried it with both.

I had the same thing happen with Natress Curves when I tried to use its option "S-curve".

By the way do you know what the other settings in LUT buddy should be .I've played with the settings on the import tab and on the plug in but they don't seem to change anything

FCP only renders effects previews in 8 bits. This may be part of the problem, but I think it might be LUT buddy.

Great Final Cut Pro is crashing when i try to render it in either LUT. Might be LUT Buddy.
Why is this so damn hard!!!!!!!

I never had any luck with LUT Buddy. Tried using the Cinestyle LUT when Technicolor first released it, and it crashed FCP 7 every time.

Trying to figure out now how to adapt these LUTs for Resolve.

My experience with LUT Buddy is that Alister's LUT's which are .lut files all crash FCP, however if you make .mga LUT's from the Arri C-log LUT software on-line , those will work. Also a .cube LUT made by LUT Buddy in AE also doesn't crash FCP.

Alister, Is it possible to transform your LUT's into another format? ( I tried just changing the file suffix top .mga and .cube as a long shot but it didn't work.)

.cube works?

Leonard, emailing you the .cube Alexa Log-C LUT out of Resolve

Here is a .cube version of the Sony 709(800) F3 Lut.
XDCAM-USER.COM &bull; Login (http://www.xdcam-user.com/forum3/viewtopic.php?f=42&t=1010&p=1332#p1332)

Couldn't attach it here as the file is too big. While it is a 3D Lut, the original LUT was 1D so there is no colour change.

That's great Alister.
It worked fine. Was that a 10 bit or an 8 bit LUT?
Hope it was the 10 bit because it was fine in preview as well.

On on my to work, but just checking briefly it looks more natural than some of the other curves I've been trying.

Will you make cube versions of the other Sony LUT's also?

I've converted all 4 to .cube

XDCAM-USER.COM &bull; Login (http://www.xdcam-user.com/forum3/viewtopic.php?f=42&t=1010&p=1335#p1335)

The .cube luts are 32 bit floating point 3D LUT's with 128 samples. As the original F3 LUT's are 1D these only perform a 1D transform.

So let me get this straight-- the .cube will work in both LUT buddy and Resolve?

XDCAM-USER.COM &bull; Login (http://www.xdcam-user.com/forum3/viewtopic.php?f=42&t=1010&p=1335#p1335)

The .cube luts are 32 bit floating point 3D LUT's with 128 samples. As the original F3 LUT's are 1D these only perform a 1D transform.

Well.. At risk of exposing my technical inadequacies I have to ask again if that means they're 10 bit. I think 32 bit floating point implies 10 bit doesn't it? but what about 128 samples, is that enough? Do I have any idea what I'm talking about?

The original 1D sony LUT's give a single in and out value for each bit of RGB data. So for an 8bit file or 8bit environment you need an 8 bit LUT, and 10 bit LUT for a 10 bit file. Taking 10 bit as there are 1023 values for each of R, G and B channels then there a total of 1023 x 3 values in the table = 3069. That's not a big file.

A 3D LUT works differently. As a 3D LUT transforms not only the RGB level values but also the saturation and phase values there are many more values in the table. In addition on the input side it works on RGB triplets, so it' not just looking at say the red input value, but the combined red, green and blue value. So a full 10bit 3D lot would have 1023x1023x1023 input values each input value could give any one of 1023x1023x1023 output values, so the table would be impossibly large.

As a result 3D LUTs only have a much smaller number of samples, in the case of a .cube LUT, there are only 128x128x128 input and output samples. As there are fewer samples than there are bits of data the table no longer refers directly to data bits and instead works on % values. For example when the input value = 2% the output is transformed to 4%. As a result it does not matter whether the material is 10 bit or 8 bit. 32 bit floating point is just a measure of the accuracy of the transformation in terms of the number of decimal places used in the multiplier values in the table.

So a .cube LUT does not care whether the material is 8, 10 12 or even 16 bit. It should work in LUT Buddy and resolve.

Thanks again Alister, I think I understood that.

With the help of everyone here I've been able to progress a lot further in learning how to grade SLog in Final Cut Pro effectively. The LUT's look way better than what I was able to do with the 3 way. Again, for the time being I want to stay in FCP because I know that's what many of my clients use and I want to be able to give them a clear and easy path to grading SLog.

A number of questions remain for me though. So I'll summarize what I've figured out so far & then ask a couple of questions if anyone is still awake or interested.

Now I'm finding an embarrassment of riches in the choice of LUT's to use.
So far Using LUT Buddy free from Red Giant :
- Alister has provided 4 that are the Sony 1D LUT's ,
- you can download Alexa LUT's also and configure them in few different ways with more or less highlight and shadow roll off,
- There is a technicolor LUT designed for the Canon's that works with LUT Buddy ( seems very dark though)
- and you can make your own using LUT Buddy and Colorista free in AE then import the LUT into FCP.

Additionally you can download Natress "Curves and Levels" for $50 and make your own though it only allows you to change the curve at 5 points 0 , 25%, 50%, 75% and 100% on the X axis of exposure.

Some of them (I think) are 3D LUT's that seem to add back some Chroma ( I think the Alexa and the Technicolor) and some like Alister's are 1D and don't, but even the 3D LUT's seem to me to still need a little chroma boost or manipulation.

None of these LUT's are perfect out of the box for every shot of course and because FCP doesn't provide a curves tool of its own, they all seem to need the help of additional filters, especially additional highlight compression and shadow control to get the most from SLog. So I've been experimenting with 2 free plug ins each called Shadow-Highlight from Lyric and Too Much Too Soon that are very useful. To that i add the FCP 3 way for saturation and color control.

I've started trying to compare the LUT's but its pretty time consuming and so far it looks like at least a few of them can be manipulated back to a similar place pretty easily.

Questions -
- Is there any reason to prefer a 3D LUT like the Alexa 's to the 1D LUT's from Alister if you are going to add saturation back anyway? I know a LUT you actually designed for a specific shot would be preferable but is there any reason to think that say the Alexa LUT's would offer an advantage (like perhaps correcting for too much chroma in the shadows or highlights or something else?)

- How do you correct for exposure differences? If you over or under expose the original Slog wouldn't that make you want to adjust your curve to compensate?
Would you:
- Just de-Log first with the LUT and then use the ordinary 3 way controls to compensate?
- Lift or drop your gamma in the 3 way before applying the LUT?
- actually make separate LUTs for different ISO's ( I have seen those somewhere I think for the Alexa)?
- Decide to use Natress instead of the pre made LUT's because you can easily adjust those curves and raise or lower the mid points to adjust for exposure?

- Any other suggestions for other additional filters to use with LUT Buddy or Natress to affect the highlights or shadows. I'd like to find an easy inexpensive tool to change the saturation in the Gains, Gamma's and Darks.
Anybody use Tonalizer/VFX PRO from Irudis?

Thanks again for making this process begin to work for me. (I know a lot of other people have the same questions within FCP.)

lenny levy

Some of them (I think) are 3D LUT's that seem to add back some Chroma ( I think the Alexa and the Technicolor) and some like Alister's are 1D and don't, but even the 3D LUT's seem to me to still need a little chroma boost or manipulation.

Agreed. on the 3D LUTs add chroma, disagree on they don't add enough. Think it depends on the shot, really.


- Is there any reason to prefer a 3D LUT like the Alexa 's to the 1D LUT's from Alister if you are going to add saturation back anyway? [...] is there any reason to think that say the Alexa LUT's would offer an advantage (like perhaps correcting for too much chroma in the shadows or highlights or something else?)

I can only go by my eye here. I downloaded Alister's Sony-derived .cube LUTs and made some stills in Resolve. I GREATLY prefer the Alexa LUT, but opinions, armpits, etc etc.

[crud. I uploaded all these stills with descriptive filenames so you could all see what's what, but the filenames are stripped off in posting. Make some guesses, and I'll repost a legend to the stills when I get back. Have to run!]

A LUT is not meant to replace grading. The primary purpose of a LUT is to allow you to view your 12+ stop footage on a conventional 6 stop monitor without it looking like crud. A secondary benefit is that you can create a LUT that will be a close approximation of what your footage might look like after grading. But the LUT is not meant to be a substitute for grading. Any grading should be done before the LUT is applied so that you grade in the widest possible bit/color/dynamic range. After applying a LUT your dynamic range etc is reduced, so grading after the application of a LUTvwill not give the best results.

A real eye opener for me this week has been doing a lot of work with 16 bit linear footage from an F65. You have to have a LUT to even see the material. The default camera LUT is S-Log2 (regular S-log does not have enough DR). Without a LUT the image is almost entirely black.