monitoring & color correction w/sLog

L

Lenilenapi

Carbonite Member
I screwed around with my Flanders monitor & slog today for just a few minutes so these are extremely preliminary findings. I may report back NOT to do this but so far:

My first experiences using the user LUT's in the F3 were that they suck and just don't look very good - mine are very desaturated.
So today I created a preset turning the Chroma way up on my FLanders 1760 (+60) switching the gamma to 2.8 and dropping the brightness a bit. At least on a picture of my daughter in my living room it looked pretty good and certainly gave me a fair idea of what the final picture could look like. I still need to test it in different lighting and exposure situations. Color wise it looked similar to 709 on a properly adjusted monitor.

Secondly played around with the S-log color shift controls and roughly it seemed like dropping Blue and raising Red equal amounts had a similar affect to warming the color balance and vise versa. I'm sure it would also work to raise red and blue to add magenta to balance out green. I will later try to work out numbers for 1/8 , 1/4 , 1/2 shifts etc by matching to gels.

So it looked to me that for monitoring purposes on the set it might be possible to pretty quickly give the director a decent idea of what the final picture color would be. I'm hoping it would also be useful for lighting and color decisions on the set.

I need to test more to figure out how much of the contrast range it will capture. Probably not all of sLog and it may be that you need to adjust the monitors contrast & brightness for different kinds of shots which might be a little dicey. But on first glance it looked much nicer to me than any of the built in LUT's on the camera.

I encourage others to try it out and send feedback.

I realize some will tell me I'm barking up the wrong tree and should just treat it like film (Timur?). Maybe they're right but there are many things I like about shooting video with a monitor. This won't be the same but if it can help I'll be pleased.

Hope to try more tonight and tomorrow.

Lenny Levy
 
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I'm afraid you answered your own question...Slog log is a different mindset. Your client will be fine with just the chroma turned up on the monitor, if he understands the concept. It is like just shooting film and transferring. You should have seen the images we used to have for the video tap on a film camera. Complete crap. But you just have to get past it, because you a DP knows what the end result will look like. So just get it close and for get about it. Your shooting a video negative, all will be corrected later. Your concern should be on exposing, composition and lighting and about a hundred other things. Not the monitor looking like a corrected image.
I as will thought the LUT's were bad, adjusting the monitor was totally fine and doable.
 
DIT should be handling LUTs.

If you cant have a DIT, have one build you a few custom luts. you can import them in to the camera.
 
In San Francisco budget unfortunately often dictates I don't have a DIT. I'm often the most knowledgeable tech on my own jobs. There are plenty of good RED techs, but at this point I might be the second person in town to even have sLog for the F3. So its more an issue of me being eager to offer sLog but needing to make it easy for my clients. It is possible at some point I can get together with a DIT and play with making LUT's but it won't happen real soon. I looked briefly at the Sony CVP LUT editor and didn't see any adjustments for saturation. Are they there?

Timur, Do you have any camera LUT's you can make available, or know of any place you can download them? That would be great. I don't really care a great deal about the contrast issues as getting the color close. I've played a bit with the Red and Blue offsets and am surprised at how well they seem to mimic the Red and Blue pots on a typical paint box. Don't see any reason to be limited to 3200 and 5600 only.

JD, I grew up shooting film and understand the mindset, but especially in the last few years find my director or client being very involved in setting and approving the shot. Oddly more on interviews than anything else. But I know they will be uncomfortable giving that up, especially when they can do it with a Red. It will be a disincentive to use the F3 and sLog. Are Alexa viewing LUT's better?
 
Lenilenapi said:
JD, I grew up shooting film and understand the mindset, but especially in the last few years find my director or client being very involved in setting and approving the shot. Oddly more on interviews than anything else. But I know they will be uncomfortable giving that up, especially when they can do it with a Red. It will be a disincentive to use the F3 and sLog. Are Alexa viewing LUT's better?
Click to expand...

I think you should make an effort to educate the client. I know it's tough, I've been there with above the line folks who start getting riled up about image details they should shut up and let the DP do his job. Incidentally I spend time on some pretty big budget sets (day playing as operator) where they're shooting Alexa or 35mm. Both agency & end client understand that a film tap image is not the last word, and neither is the image from some digital cameras (Alexa). I find the higher end the agency and client, the more they understand this (experience).

In addition, on those biggest sets, only the DIT cart has an image with a LUT of it, for the DP to look at occasionally (usually they ignore it). Video village gets whatever comes out of the camera easy. I haven't seen anybody using in-camera LUTs on an Alexa shoot yet.

[edit: the more I think about this, the more I feel the client just has to be shown the way, kindly, respectfully, firmly. Or tell them they can throw down for a DIT and a Davio box and they can twiddle knobs on-set all they like and leave you to shoot their damn job :-))
 
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please forgive a stream-of-conciousness post...

Lenny, I'd sit down with a *good* colorist and some 10-bit s-log stuff you so KNOW what you can get away with. And have conviction when you tell these folks to trust you. For some reason, I've never had that issue when I have to tell somebody "trust me, it will look great" when they're looking at a flat, broken image. I say it once nicely, and they stop. It's either my game face or it's my reel. I dunno.

I'm no expert colorist, but I know my way around Resolve and my shooting is magnitudes greater because I know what can and can't be done in the box. With Red, with Alexa, with s-log. It's invaluable.
 
I appreciate and respect the advice and experience, and am interested in how other people are working with sLog on the set. But - I have been around the block, began in film many years ago and have a good idea of my clients and how to deal with them. I am of course shooting tests and figuring out what i can do in post and sometimes work as a colorist myself. However I work in a world where monitors are very important and frankly I like them myself.

What I've been trying to talk about here is strictly technical - how good an image I can get on a monitor and how to get it.

Its a perfectly legitimate question and to my mind there is no reason to settle for something with no chroma and a poor color balance if its not necessary. I'll adjust my working methods to whatever those limitations are, but for now I'd prefer to keep the conversation to the technical issue.

(Its funny- I asked the same questions on DVInfo.net and got the opposite reaction from a number of posts - "Why do you need Slog anyway , its not worth the hassle")
 
Hey Lenny...sorry for the goofy advice. I guess I was just in a spicy mood last night. I guess my personal deal these days is I'm being less of a "yes man" to my clients and it's novel and working out for me :-)

I just opened the Mac CVP editor for first time, and under MLUTs I'm seeing a saturation slider. Also seeing specific documentation saying the F3 supports MLUTs. ("Monitor LUTS".

I'll see if I can't figure out how to make one and load it in the camera. My only fear right now is that one would be best off using one of the LUTs in the camera as a starting point, and not sure if I can get one from camera to computer?
 
ok, so after an hour of playing around with CVP Editor and my camera...

You can indeed make LUTs for the cam with CVP editor. The short story is as soon as you get into the juicy modifications in the ASC CDL section, where you get individual control over the curves in the RGB channels, the camera stops loading the MLUTs correctly from the card, erroring out with "Recall NG"

If all you do is load a new gamma curve into the MLUT you construct in the FIRST panel of the CVP Editor, the MLUT will then work in the camera.

My guess is that the deeper RGB control (including a saturation slider) in the "ASC CDL" (ASC Color Decision List, if you want to Google) is only supported by the F23/9000/F35/F65 cameras.

I'd love to find out more from Sony on this, but my experience so far with ultra-deep stuff like this has been less than satisfying.

I think the easiest way to solve this is going to be an an BM HDlink with a LUT loaded up velcroed to the back of your monitor. $470.
 
Nate,
Thanks for all your leg work.
I will look into that as well when I get more time next week. It would be nice to hear from Sony directly about this.
I have some contacts there and will try to see if I get anywhere.

Just to make sure I'm reading you correctly, are you saying only that you can't modify the 4 preloaded LUT's to add Saturation, or that you can't do it even to ones that you create from scratch? It sounds like you're saying the latter

I find the whole business of these LUT's kind of confusing. Why would Sony bother to give you LUTs at all and tout them as ways to monitor traditionally if they are so desaturated? How come Andy Shipsides at Abel Cine doesn't mention this whle lauding the LUT's and even suggested recording directly to the SxS card with the 800% LUT and says it looks good on a monitor? Why am I the first guy I've seen complain about these on the boards? Its made me wonder if something was wrong with my camera.

Does anyone actually use these LUT's?

I have thought about HD Link though I'm very tired of spending money on more accessories for this guy.

Lenny
 
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I use a LUT all the time with S-Log on my last two features and one TV show. It seems to me that the LUT is slightly inconsistent. The results seem dependent on the amount and quality of light available. (All my lights are daylight balanced now, but spill from a window, bounced light, etc makes a big difference.) The color corrections aren't the same from scene to scene.

However, I haven't had any problems with a director or producer not liking what they see on the monitor. What I do is show the before and after of a still image from a prior shoot before we even start.
 
Duke,
Thanks for bringing your experience to the discussion. I'm not surprised that the LUT was inconsistent especially if you were exposing to s-Log (i.e. a grey card etc) rather than specifically to the LUT. After all if you shoot Std5 709 you usually paint every shot if you have the time.

Did you use one of the Pre-loaded LUT's (which one) or make your own? And did you find the LUT desaturated on a normal monitor set-up? If so did you just live with that or crank the monitor Chroma to compensate.

If a custom LUT, how did you make it?

Thanks,

Lenny
 
Bill ,
To me that's a pretty desaturated image. Its not terrible but I don't get why I can't get an image with full saturation. For me (maybe I'm just lame) there are subtle decisions that can't be made with that image. What color is the wall for example,. If you add a light to that wall will it make a difference if it's 1/8, 1/4, or 1/2 CTO. Is the green of the plant reading, If there are windows are we getting any unexpected blue fill on the face, If there is a computer or a small floro lamp in the shot are we getting green from it. These are things that are of ten hard to see.

I imagine Some will say I have become too tied to the monitor, and maybe they're right, but i like it and so do my clients. Doesn't seem too much to try for a full quality image. maybe just raising the Sat on the monitor will do it, but I would prefer to do it with the LUT itself. maybe there's a reason it isn't offered. Am i the only guy who is bothered by this. My friends - long time pros - share my concern.

I don't know a lot about adding saturation in post but off hand it seems to me that in starting with an 8 bit picture you would want something as close to the final image as possible,not something you need to add a lot of chroma to.
Just my thoughts, no answers.

Lenny
 
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CinemaElectronika said:
Nate,

Would you please post the link to download this Mac CVP Editor?

Thanks.
Click to expand...

I found it here; http://www.bandpro.com/manuals/Sony/CVP File Editor/ My Laptop runs Windows 7 64bit and CVP editor would not run on this OS. I downloaded and installed Windows Virtual PC and Windows XP Mode software. This setup runs Windows XP on top of Windows 7 sort of like when Microsoft first started running windows on top of DOS, molten magma riding on top of tectonic plates. From what I can see the program opens and works in this configuration.
 
Stephen,
Thanks for the link to the Alexa LUT info . Its very informative.
Just saw this reply to my questioning Andy Shipsides at Abel Cine after he talked about how good the LUT's were on his tutorial

Leonard, I agree that the built in LUTs are too desaturated, because they are 1D LUTs there isn't much that can be done about that. In my next blog I'll go over using CVP File Editor to create the in-camera LUTs, but they will always be relatively desaturated. So I'm also going to show creating LUTs with an external box, the HD Link Pro. The CVP File Editor has many different functions that work with the higher end F23/F35/9000 which are locked out, but it can still be used with the F3 in a simple way.

So I'm glad to see it wasn't just me complaining about this. It would be nice if Sony would open up their software to make a better LUT possible. Until then the only solutions I see are:

1- Live with desaturated LUT's if you want to bother with them at all.

2 - Go with an HDLink and software for $1K + or another similar system as described on the link Stephen Coklin posted
http://www.negativespaces.com/blog/2...w-options.html

3. Try the poor man's solution and adjust your monitor to either an existing LUT or sLog itself.

4. To give post an idea of what you were aiming for the only thing I can see is shooting a few moments of each set-up with standard PP settings , then switch back to sLog. In the field it would be a bit cumbersome but maybe no worse than screwing around with the monitor.

I'll experiment more with #3 for the time being as i'm broke. Samurai comes first in the spending order.
I also hope to come up with some R & B color shift settings that are equiv to CC filters.

Anyone else adjusting their monitor?

Sony can you open up your software to help us out here?

Lenny Levy
 
Thanks Lenny for the update, I was hoping to see that reply from Andy, AbelCine says on their website: "User-defined LUT (created by CVP file editor)" Can the F3 software be upgraded to 3D LUTs? I hate to spend the $1000.00 for the Black Magic box and Link Color software only to have Sony come out with an updated Software and Camera LUT package:).

The Arri LUT generator can pass on the LUT data to the editor so that the look that the DP wanted can be implemented in post. I would think you would need to be using 3D LUTs for this process, still it would be a nice upgrade for the F3. As the Arri workflow post said in the future being able to store and recall LUTs or Looks for future shoots would be a tremendous asset and time saver.

Canon is offering software for their C 300 C-Log to implement their LUTs with Avid software. http://www.usa.canon.com/cusa/profe...inema_eos_cameras/eos_c300#DriversAndSoftware

I forgot to add in the Canon software link you need to select download software and then select your OS to see all of the software offered.
 
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