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2K BlackMagic Pocket Cinema Camera, active m43, $995
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  • Yes, LUTs are for grading. What else are they for? I think you might be getting color correction and grading mixed up here. The only reason LUTS exist are for grading.

  • LUTs actually were not originally intended for grading or looks, they were created to sort of "unify" display devices/sources, so people could see their final results for a specific distribution channel.

    They're not being used for such within this sort of community because it isn't as important, although a lot of us could benefit from learning how our choices are reflected across a wide gamut of computer screens and why having a proper sRGB workflow could make your finished product stronger.

    The only time I've seen a full on Colorist use a LUT's been for a quick job that can't afford the time. Most Ive come into contact with have their own powergrades for specific cameras and prefer to avoid the inherently destructive nature (as Peter from BMD put it) of a LUT. As, it is a destructive process.

    Edit: Strangely enough, the more I've gone into color, the more I realize that I do not like LUTs, and once I put them away I learned more about each camera that I've worked with in post than before.

    I've got powergrades stored away from Canon DSLRs, Alexa, and all of BMDs cameras at this moment ... and I'm constantly refining them the more footage that I get. Converting any of these into a LUT that gets within 95% of the powergrade, even with R10s 32 Point (I think it's 32 Point) capability, hasn't been successful.

  • @kholi I know you're a busy guy, but I'd be very interested in having a peek at some of your power grades that you've developed for the BM cams. Any chance you'd be willing to share one or two?

  • @JuMo

    I wish I were busy! It's the end of the year and I'm in Georgia... ssllooowwww state.

    They aren't really much of anything, the PGs, it's just to pull everything that I don't like out of an image, and to balance it/neutralize it for a very "pure" base. Then there are variations of that "neutralized" look to account for IR pollution, Tiffen IR NDs, and Schneider IR NDs.

    All really boring, I believe Hook's LUT is more of a look than what I'm doing. Most of the timeI just want to separate colors, stretch DR, tame red/blue, remove color casts (depending on lens combinations with BMD Cameras), and identify a black point which seems to be a really hard thing to do with BMD cameras? Never really understood why but you have to go and put work in or you end up crushing the lower fifth of your scale if you don't fine tune.

    I imagine that's why you see a lot of washed out footage from the existing cameras.

  • LUTs are also used for bulk transcoding rushes. The series I'm currently on now shoots 2-4 hours per day every day. So it's a quick way to get a "dailies" grade without having to sit there and grade every shot. It's common in pre-production to also develop a "look" or different treatments so editorial have a BETTER idea of your intention as a DOP. You might have flashbacks that you want a certain look for example. Pop a note on the slate and the dailies will come back with that "flashback" LUT you've come up with in pre so in the edit they don't have to GUESS what it will look like beofre you actually get to the grade.

    LUT's are a temp grade that give the idea or notion of a look. They aren't THE LOOK though.

    JB

  • ^ That's also true. Say Alexa > REC709 works really well with 2.5K footage for Rushes, or I like to use ACES > CAM 2020 > REC709 to rush Pocket or 2.5K footage for someone to edit.

    It still looks LOGish which, for WHATEVER reason producers feel safe with (don't even ask me... I think it's a mental thing, like safe zone) but you can see what's there as an editor.

    However, it's definitely not THE LOOK, like JB said.

    I've sat in on a decently budgeted feature as part of the post chain and they start to develop a look in camera tests. Colorist saves powergrades, as footage rolls in he may ask for a few clips to test out looks in various situations, fine tune, and save that.

  • Also for previewing THE LOOK on set. You can load LUT's into monitors and cameras for example....

    Again, for previewing footage and in a non-distructive non-commital way.

    jb

  • Flanders is great for skipping the LUT box (whichever you go with), but they're also using a LUT to convert the LOG.

    I'm pretty sure you can do this with the thunderbolt port on the camera, a Macbook Retina, and a Thunderbolt Mini monitor out to an HDMI or HD-SDI source.

  • Speaking as a programmer, a LUT (Look Up Table) can be (and is) used for any kind of colour conversion, including just converting between different colour spaces. In fact you can encode any number of colour space conversions, curves and/or grading all into a single LUT if you want, as long as only colours are changed (ie. stuff like sharpening, blurring or any other kind of inter-pixel operation cannot be encoded into a LUT).

    Programs often have built-in LUTs for changing from linear to rec709 for example, or LOG etc. You don't necessarily see those because they may be hidden behind the GUI, but look at the LUTs included with Creative Suite for example (here from SpeedGrade CS6):

    SpeedGrade LUTs.gif
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  • LUTs don't have to be destructive, shaper LUTs or input LUTs can remap 'out of bounds' data to work between 0-1 so there's no clipping - the BMDFilm to 709 works with a shaper LUT. Also if you 'prepare' the image before the LUT there doesn't need to be clipping either. LUTs do interpolate data, but i think calling them 'destructive' is a simplification that doesn't really help. 3D animation is interpolation, Vector based images are interpolation, etc etc - i would never call these things destructive. I mean people are using calibration LUTs in their grading monitors etc every day. And that's the thing, there's 'technical' LUTs and 'creative' LUTs. The technical ones usual involve measurement devices and probes etc, and are generally about accuracy and reproduction.

    Powergrades are great for flexibility and continual refinement and adjustment, but i've seen a few of the best colourists in this country work and they use LUTs often as well. The main thing is neither one should be used in exchange for working an image in context to best tell the story. LUTs or powergrades can assist though. Originally i decided to share what i was often doing with BMCC footage as a LUT because the powergrade was too complex and honestly most people wouldn't get realtime playback with it, plus i did want to protect a little bit of the work i put into it. :D I did check the accuracy of the LUT and it was definitely 95%+ of what i was seeing otherwise, i've tried to talk Kholi into sending me a Powergrade before to see why it wasn't converting into a LUT to his satisfaction as it makes me curious. Resolve generates 33^3 cubes for reference. :)

  • @_gl

    I think Resolve actually keeps sharpening in a LUT conversion, I've tested it and either it's holding the Sharpness or the LUT generator sees sharpening as something else and it translates. It's really weird, but you can try it out and the sharpness difference is apparent.

    Don't ask me though!

    @CaptainHook

    Thanks for clarification on what R10 generates. I do think you're right, as far as a matter of how people want to work. It's a reminder of art school and those that refused to prime a canvas before painting, those that refused to buy pre-made canvas altogether and stretch it themselves.

    Or, with mixing your own colors versus buying tubes of premade hues.

    Subjectivity's still all there, and it's a matter of how people want to work in general.

  • @kholi, I haven't used Resolve, but a simple 3D LUT (3D = 1 per pixel channel) cannot encode sharpening. It's possible they add extra sharpening information in their files, if so they're more than just a LUT.

  • Oh and @CaptainHook re- PG vs LUT sharing: it's also a bit confusing when you look at a PowerGrade, and having to explain to someone that you need to adjust this or that on certain nodes to get the best results is overcomplicating things.

    In the end, a LUT (IMO) is the better way to share that... =P And it's a good way to sort of hold your own mark over the creation of it. You put in a lot of time dissecting hours upon hours of footage, too much!

  • I agree with @Aria that there isn't a 'correct' grade. But I agree with everyone else that there are good and bad grades. Good is anything that looks right for the feel you're trying to create and suits the footage in some way. There are no rules, but like with all art, we know when it works 'cause it feels right.

    It's like camera shaking. Is it always bad? No, it can be perfect if it's used in an artistic way (to create tension for example). But often it's just 'somebody shoulda used a tripod' (especially with Pocket sample footage : ).

  • @Kholi - i agree. Also, i made my own rather than use someone elses as i want to mix my own paint. :D But i could see it being useful for others (especially not used to 'grading' their images) so i shared it.

    Are you sure about the sharpening thing? I just tested right now by attempting to create a LUT that adds only sharpening and the LUT makes no perceivable change (not on scopes either). How were you doing the sharpening?

  • @CaptainHook

    Usually in on a Layer I think. When I first started trying the LUT thing I had sharpening in a node and couldn't figure out why things looked oversharpened. Took it off and re-generated the LUT and it helped.

    There's a chance that I'm seeing something else though because I know it's not supposed to hold Sharpening at all.

    Edit: I'll check tonight with the LUT that I had. I'm PRETTY sure that's what I was seeing but it was also like months ago and I haven't messed with it since.

  • I want to STRONGLY repeat that to discuss grading and LUTs we have proper topics and section.

  • Heeey guys, abit of a silly question, but does anyone know what is the true image sensor resolution of the Blackmagic Pocket Cinema Camera??? :)

  • @JuMo A few days late, but I had wanted to say:

    A few pages back, you had mentioned taking stills during a shoot to use as references later when grading. Thank you for this!

    As a beginner to all of this myself, I had never considered this, and this would certainly have saved me some time. I have a hard enough time trying to remember to bring an index card to flash in front of the camera, just to have a white point when grading later. Taking a picture or two wouldn't take very long, and would be useful on a number of fronts.

    • Also, as this is my first post here on PV; Just wanted to say thank you to all of you for your posts and insight. It has certainly been helpful while I've been trying to learn my way around this camera and color grading in general. Cheers!
  • @Aaron_DeBerry No problem, I'm glad I could share something helpful! I can't remember where I first heard about that approach, but it's a great time saver. I appreciate that PV'ers like to share what we have learned with each other, especially when we're exploring relatively new technology (there no sense in each of us reinventing the wheel). This forum is chalk-full of great tips from some very talented people, as I'm sure you're discovering. Welcome to PV and enjoy your amazing adventure with this amazing little camera!

  • I think my new BMCC Pocket has problems with sensor. I found some artifacts after grading with aggressive vignette at some shots, it looks like vertical half translucent bar near left end of frame. After that I found the same problem with ungraded footage. All shots have it... I see it also at camera LCD screen, and more clear with Zacuto EVF-HDMI with all lenses. I need send the camera to Australia to service center. :(

  • @hook I was mentioning destructive from a workflow point of view. When you apply a lut to transcoded rushes SAY AVD DNX transcodes of LOG footage from an Alexa and BMCC, editorial get to look at pre graded footage but once the conform happens after the edit you can go back and grade from the untouched camera orginals and no grade has been applied...thus non destructive grading.

    jb

  • On a more serious note, my red dot on my record button fell off today. I can't record anymore without it. damn! I wonder if thats covered under warranty? lol