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Raven does not support LUTs - How to expose?

J

Jeffrey Walther

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Hi!

I wonder how to expose difficult conditions (bright day, snow etc) if the Raven has no LUT support.
Any ideas?

Jeff
 
Last edited:
Jeffrey Walther said:
Hi!

I wonder how to expose difficult conditions (bright day, snow etc) if the Raven has no LUT support.
Any ideas?
Click to expand...

LUT or not, it's imperative to get familiar with the In Camera Exposure Tools to ensure a desired exposure. The tools clearly tell you if you are clipping or crushing as well as where your general values fall.
 
Jeffrey Walther said:
Another option would be replacing the 4.7" monitor by another one that supports LUT. Or even that new Atomos Flame series may be nice.
Click to expand...

Sorry, I did not understand the intent of your question.

In my experience, look up tables are not a replacement for learning how light behaves with a sensor.
 
Phil Holland said:
LUT or not, it's imperative to get familiar with the In Camera Exposure Tools to ensure a desired exposure. The tools clearly tell you if you are clipping or crushing as well as where your general values fall.
Click to expand...

As mentioned above, I was talking about difficult situations where you have to compromise.
Sometimes, clipping can be acceptable and also wanted (for whatever reason). So having the option to directly see the output in its entire range as close as possible is helpful.
 
You may be confused. Raven does not have the ability to store 3D luts. All the 1D Red luts work as normal in any red cam, including raven
 
I mean, I'm not trying to sound like a jerk...but just read your histogram/waveform? I never rely on LUTS for exposure.
 
Joe Karably said:
I mean, I'm not trying to sound like a jerk...but just read your histogram/waveform? I never rely on LUTS for exposure.
Click to expand...

You did not get the point.

The histogram/waveform tells you which parts get clipped. No doubt.
But this was not my question.


Sometimes you have to decide on set (while having an extrem wide dynamic range):
do you crush the blacks, or do you clip the highlights. It's a question of personal taste which cannot be answered by a histogram/waveform.

But how to decide if you cannot see on screen which information you really will lose (in shadows or in highlights) while setting the exposure.
The announced Atomos Shogun Flame is such a tool for those cases.

But back to Raven: a 3D LUT would give an idea how the scene could look like in post while discussing with director and customer.
They need to see that on set. They cannot read/interpret histogram/waveform.

But I think that the Flame will be used instead of the 4.7". So I'll have all my options for my director and customer.
 
Sometimes you have to decide on set (while having an extrem wide dynamic range):
do you crush the blacks, or do you clip the highlights. It's a question of personal taste which cannot be answered by a histogram/waveform.

But how to decide if you cannot see on screen which information you really will lose (in shadows or in highlights) while setting the exposure.
Click to expand...

Don't quite understand what's preventing you from seeing what you're clipping or crushing without 3D LUTs.
3D LUTs are really not exposure tools.
 
Listen to me: there are 1d luts in camera for exactly what you want to do
:)
 
A 3dlut is locked, the color tools in camera and whats available in RCXP is not so preferably you get close to what you want with those tools. Thats how people have been shooting until weapon was released. And if 3d luts was a must have I think it would have been implemented around the release of red one...

To me shooting trough a lut actually makes it even more difficult to expose right. It might look pretty on the screen but in fact you could be clipping for no reason just because that setting makes a good looking image trough that lut. So exposing to get good material to grade later is something very different from exposing to make it so the result looks pretty when pulled trough a lut. So I think when this lut features starts to be more commonly used I also think we will see a wave of ill exposure, simply because people try to make a good looking image on set instead of getting a rich capture...
 
Exposing while trusting a lut, is extremely dangerous. Specially when looking at a 7" or 4.7". You need to trust the exposure tools the camera gives you, trust your knowledge and instincts. I have seen footage where people trusted what they saw, and when it came time for post, the footage was incredibly under exposed and incredibly noisy. That's just one example.
You need to fully understand how the camera works, what really changes the amount of light that hits the sensor, and how much of that light it can take or how much it needs. LUTs are really, IMHO, to give clients a closer idea of how the footage will look after color work.
Another point is that, what if you expose to a certain look that you like, and then in post, the client changes their mind and feel like a different look? Now the footage might be under/over exposed, and your phone might not be ringing again...
 
Are you assuming the camera can only display in LOG while shooting? The tools available in the camera are very intuitive for exposure. Plus the look is all meta data. Put whatever curve you want on while shooting because it can be all zeroed out after. The RED gamma curves are pretty much Rec709 which is what you should be exposing for anyway. Just my 2 cents.
 
I was interested in how to show content to unexperiened viewers.

Again, the camera tools are used for a well balanced exposure. This is my job as a DoP.
But there are cases where you have to crush or to clip because the dynamic range is too large
and cannot be captured at all.

Question is: do I rather keep the shadows, or do I keep the highlights. What's important to the dir/customer and his story.

Well, since I am not able to explain my issue properly I'll cancel my question.
Thank you for your answers so far.


Listen to me: there are 1d luts in camera for exactly what you want to do
:)
Click to expand...

No information on this in the specs.
 
Agree to disagree I guess. I've shot in both environments you've described, on both Red and Sony. Waveform has never let me down. Luts are not reliable in my opinion. When clients request to see a balanced image, I give them a 709 output and all is well.
 
I don't think you've used a red before. There ARE luts in Raven. They are made by Red and are called Redgamma. They will change the raw/log signal into a normal looking image on your monitor and on the client monitor. You can then expose by eye, just like you want, and then check the raw signal with your exposure tools. So you have no problem. 3d luts are a new thing in the weapon bodies, but 1D luts have been in every cam red ever made.
 
Jeffrey is clearly confused because he seems to be assuming that the only display option and video output on the Raven is Redlogfilm. This is obviously not the case. He can read the manual for any Red camera or read their educational documents online to discover this. Clearly just using the supplied default curves will give him exactly what he is looking for. And you can output those curves to client monitors as well. As for me, I plan to eventually invest in an OMOD so I can apply custom LUTS for heavy grades when projects come around that calls for it. But ultimately the histogram and false color tell you everything you need to know about exposure for any shoot if you know how to use them.
 
Björn Benckert said:
To me shooting trough a lut actually makes it even more difficult to expose right. It might look pretty on the screen but in fact you could be clipping for no reason just because that setting makes a good looking image trough that lut. So exposing to get good material to grade later is something very different from exposing to make it so the result looks pretty when pulled trough a lut. So I think when this lut features starts to be more commonly used I also think we will see a wave of ill exposure, simply because people try to make a good looking image on set instead of getting a rich capture...
Click to expand...

If it is a properly designed LUT, made for a specific camera it can help.
Good looking image is made on set, and with a proper transform it can also be seen on the set.

LUT is adding contrast to an image, and if it is not "a LUT" from somewhere doing something but made by someone who actually knows what he's doing, good looking image comes from a proper signal.

So, if you are shooting raw and just viewing through that LUT you are unlikely to under or over expose based on it, unless you are pointing the camera at one direction with head turned towards another.

It can also help to deliberately choose sacrificing highlights by seeing how the falloff to white looks and how properly exposed face looks and needs to look after proper gamma transform.
So, not only is it helpful for the clients and experienced shooters but for the inexperienced as well, where it is not uncommon to dramatize for keeping all the highlights in (just because) while bringing to post face 3 stops under.

People have been exposing based on how it looks for quite a while on much worse monitoring tools than today exist and many still expose based on the image today for broadcast work. Zebras and false color are distracting for continuous usage, after a while also redundant and simple histogram can be enough to know where the signal is. No time for light meters and grey cards and no second chances in Take #2 or in a grading suite and one learns how its tool of choice works and doesn't need to measure everything every single time.
 
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