FORUMS: list search recent posts

Question about "log" switch

COW Forums : Autodesk Smoke

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jeremy Garchow
Question about "log" switch
on Jun 30, 2012 at 4:11:22 am

Love the log switch, but what footage is that appropriate for, or I it just AE general and quick linear conversion?

I see the LUT prefs, does the log switch allow a specific LUT?


Return to posts index

Grant Kay
Re: Question about "log" switch
on Jul 2, 2012 at 9:02:10 am

Hi Jeremy,

All the log switches and LUT options are allowing to work with any material created in a Logarithmic colour space.

If you are simply editing the material together and not apply major effects than it is not necessary to go through the whole process of linearising the material as you can use LUTs to correctly adjust your viewers t o view the colours correctly.

If you intend on doing pixel manipulation, compositing with other linear elements and colour correction (although I know some who grade in log), then working in linear is the best way to proceed.

The big question at the end is what colour space are you delivering on ? Linear or Log. That will also determine how you treat your material.

Unfortunately for the 1st Pre-Release of Smoke 2013, these options are not enabled but they should be back soon.

Regards
Grant

Check out my Smoke blog at http://area.autodesk.com/blogs/discreetuk
Subscribe to my YouTube Channel - SMOKEHOWTOS
Follow me on Twitter - http://www.twitter.com/discreetuk


Return to posts index

Jeremy Garchow
Re: Question about "log" switch
on Jul 2, 2012 at 1:37:10 pm

[Grant Kay] "The big question at the end is what colour space are you delivering on ? Linear or Log. That will also determine how you treat your material."

I deliver linear 100% of the time.

We shoot with a mixture of footage, and sometimes different log formulas.

There's LogC from Alexa, RedLogFilm, Technicolor "Cinestyle" Log from DSLR, and of course we sometimes mix these in one shoot/project along with regular linear material.

I guess I'm just trying to find the best way to go about all of this. In other NLEs, I could add the appropriate color transform on a filter until it became time to do the actual grading.

What's the best way to do this in Smoke?


Return to posts index


Grant Kay
Re: Question about "log" switch
on Jul 2, 2012 at 2:15:35 pm

If you are delivering Linear all the time than at some point you will have to linearise the footage.

In Smoke you could either do this on import or you could do it to each shot as you apply effects to them.

As the old saying goes, "the choice is yours" :)

As I said, you are able to put a LUT on your viewer for correct displaying purposes however if you are mixing a wide variety of log spaces, I don't think there is a global LUT that would correct display off the mixed data. Best guess in this case would be to convert to linear.

I did check but currently in the Pre-Release 1 version of Smoke 2013, you can't use LUTs on import however you can apply LUTs to shots using the ConnectFX in each segment.

Hope this helps.

Regards
Grant

Check out my Smoke blog at http://area.autodesk.com/blogs/discreetuk
Subscribe to my YouTube Channel - SMOKEHOWTOS
Follow me on Twitter - http://www.twitter.com/discreetuk


Return to posts index

Jeremy Garchow
Re: Question about "log" switch
on Jul 2, 2012 at 6:22:43 pm

[Grant Kay] "I did check but currently in the Pre-Release 1 version of Smoke 2013, you can't use LUTs on import however you can apply LUTs to shots using the ConnectFX in each segment.

Hope this helps."


Thanks, Grant.

If choosing to do this on import (and not ConnectFX), how is that assigned? Does it come up through a "filter" or is baked in to a transcode of the media?

Jeremy


Return to posts index

robert coulin
Re: Question about "log" switch
on Jul 2, 2012 at 8:10:24 pm

hi,

choosing a lut on import (which isnt available currently, as Grant pointed out) would result in new clips - choosing a lut at the beginning of the cfx-pipeline leaves it open.

robert

robert coulin
http://www.dreamwalks.com


Return to posts index


Jeremy Garchow
Re: Question about "log" switch
on Jul 2, 2012 at 8:19:42 pm

[robert coulin] "choosing a lut on import (which isnt available currently, as Grant pointed out) would result in new clips - choosing a lut at the beginning of the cfx-pipeline leaves it open."

Thanks.

So bringing it back around, the "log" space that's in the monitoring pipeline now, what log space is that calibrated for?

What I am envisioning is real time layoffs with this option on.

Jeremy


Return to posts index

robert coulin
Re: Question about "log" switch
on Jul 3, 2012 at 7:56:58 am

hi,
im not a scientist, but as far as i understand (i hope this isnt completely wrong, theres tons of literature with serious numbers about this ...)

basically "log" (vs lin) doesnt refer to a specific colorspace, but just means a not linear distribution of brightness values over the entire luminance range (like a gamma curve)-
e.g. the "visual" difference between 2 values in the shadows (050 > 051) is "smaller" than in the lights (200 > 201)

"linear" means, that "mathematically" all steps from one value to the next are "equal" (this is the reason, why 3D & comping more&more is done in "true linear" space, because the tools are easier to manipulate),
but in flame/smoke (& NLEs etc) work is beeing done in "(video)linear", which means "equal steps" of the tools BUT with a final gamma correction on top to "make it look right on a video monitor" (this is, where apple QT has a slightly different opinion, than the rest of the market...)
current "log" camera-formats of ARRI, RED etc are in addition (to pure "log" characteristics) referring to a specific colorspace, which may/will also have different treatment of RGB channels, to create a specific look on top of the luminance corrections.
So for your workflow you would ideally have LUTs, which adjust the appearence of the images to "look right" ...

if you want to work with the monitor "log" option, you would need a second adjustment, as this will only give you a basic "visual correction" of the images, but not the "final look" yet.
also be careful, because the parameters in the tools (CC/CW/Keyer) are behaving "linear", so adjusting log images with just a monitor LUT will behave "strange" (different in Shadows & Lights)

i hope this makes sense ...
robert

robert coulin
http://www.dreamwalks.com


Return to posts index

Grant Kay
Re: Question about "log" switch
on Jul 3, 2012 at 10:49:02 am

Pretty much what Robert said :)

Regards
Grant

Check out my Smoke blog at http://area.autodesk.com/blogs/discreetuk
Subscribe to my YouTube Channel - SMOKEHOWTOS
Follow me on Twitter - http://www.twitter.com/discreetuk


Return to posts index


robert coulin
Re: Question about "log" switch
on Jul 3, 2012 at 11:55:19 am

hi Grant,

thanks for confirmation ;-)

robert

robert coulin
http://www.dreamwalks.com


Return to posts index

Jeremy Garchow
Re: Question about "log" switch
on Jul 3, 2012 at 2:24:26 pm

Yes, it makes sense, Robert. Thanks.

I understand the differences, but perhaps I'm asking the question incorrectly.

What I like about the "log" switch is that there's no rendering and I still get real time playback.

In the early stages of a content edit, this could be a huge time saver if I don't have to render evry single frame of the sequence.

So, while it might not be as accurate as a true LUT, I am attracted to the real time of it. If there were options of, say, a LogC option, that would be down right sexy.

Again, this is not for the final look, but rather for a "one light". It's the most real time I've seen coming straight out of a baseband device with no rendering. Since it seems to work really well, I would like more control of it, or st least know how it's setup.

LogC material looks decent when viewed in "Log". Decent enough for simple content reviews anyway.

Obviously, if there were mixed log spaces, I'd have to adjust each clip via LUT or color correction.

In all other NLEs, I have to render every frame, even for content cuts. I am looking for efficiencies is all.

Jeremy


Return to posts index

robert coulin
Re: Question about "log" switch
on Jul 3, 2012 at 2:33:24 pm

hi Jeremy,

thanks for clarification - of course this makes perfect sense!
unfortunately there is only this "3level" setting for the views. (lin/video/log)
you can apply a viewing lut (on top or instead of changing the view setting) - not sure, but with a 3D lut you might loose realtime then...
as a different approach you could use a monitor, which can load LUTs itself - or an external box, like davio from cinetal - depending on the amount of related work it might be worth the investment ...

still i would start with a viewing lut (1DLUTs beeing less performance intense than 3D) & see, what it gives ...

robert

robert coulin
http://www.dreamwalks.com


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]