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Z-Cam E1 ZLog - how to use??!?
  • Does anybody know how correctly shoot in zLog mode? I never had any experience with any log profiles. There are many Z-Cam E1 LUTs to different color spaces. But when I convert zLog footage to sRGB, for example, I see VERY HUGE difference. Please, explain me how it works.

  • 21 Replies sorted by
  • @Vitaliy_Kiselev, I know about it. Do you mean that I need to make my own LUT with Color Checker? Why zLog has 2 versions (zLog and zLog2)? And why colors are wrong?

  • @storyboardcreativity

    If you value your time, yep. Faster to make something working.

  • @Vitaliy_Kiselev, my aim is not to do smth as fast as I can. I want to know how everything works (I ask not because I have a project with deadline or smth else). Maybe somebody has same problems too. And zLog plugin for Premiere crashes for some reason too.

  • And zLog plugin for Premiere crashes for some reason too.

    Software side is not strong point of Z-CAM :-)

    To understand how something works, make multiple shots of exact same studio scene (from dark shadows to bright lamp) and also with different colors (lot of pencils and such), color chart will just help save time a little. And shot it in usual sRGB and after this in zLog modes. Use 3D LUT Creator to make LUT or understand difference using all its tools.

  • @Vitaliy_Kiselev,

    Software side is not strong point of Z-CAM :-)

    Yes, their camera has a lot of bugs. I really can't understand how can they release raw draft products to the market. But it's funny :D

  • I really can't understand how can they release raw draft products to the market. But it's funny :D

    They have tiny team that is managed by hardware guys. Very few firms have good software as none of them can compete for good developers with leaders.

  • I am confused. I posted three videos shot using Zlog 2 in the thread devoted to the hack, which the OP viewed. Did you see a problem with color? In one I used the Z Cam Zlog2 to REC709 LUT. In the others I simply upped saturation and played with curves.

    As for bugs, many that are reported are by users who do not understand how to use the camera.

  • come on....you're being unfair.Most people bought this camera for $200 ! And zcam has released fw upgrades, not unlike many camera companies do....mentioning blackmagic for example. @storyboard just made this camera far more utilitarian than the 200bucks it cost. One easy way to play with the log is in photoshop. CS6 and beyond work with video the same manner as photos. Does anyone know if the log file actually has more dr than the rgb? ..maybe 1/2stop?

  • @markr041, I now think, that the problem is in exposure. I shot a footage and it was too bright in zLog => almost no black colors => tiny dynamic range. When I use zLog lut, colors seem very unstable and bright. Footage after LUT really blinds me :D

    And, sure, 8-bit H.264 footage is NOT GOOD to use logarithmic color.

    As I understand, logarithmic footage has linear colors (like RAW, for example) => I can use "brightness" filter with "Legacy" option to make it not so bright BEFORE I attach LUT. Do you think it's right? When I do it (brightness -50), I see colors, that not very far from original REC709 footage. Maybe this is my problem.

    And I still don't know, why in Z-Camera LUT archive there are different LUTS: zFlat, zLog1 and zLog2? What is the difference???

  • @storyboardcreativity

    it is called LOG for a reason, so it is not linear :-)

  • @Vitaliy_Kiselev, oh, ok. Well, it means that I need to apply LUT first and then adjust image brightness and contrast.

  • zFlat is with a standard color gamut, IIRC
    zLog1 is their older log format (expose more to the right)
    zLog2 is their newer log format (expose more to the center)

  • @eatstoomuchjam

    zFlat is with a standard color gamut, IIRC

    Please, explain. What is IIRC? And "standard color gamut"?

  • I installed the Premiere Lut app but have no idea where to find it in Premiere. Any help would be highly appreciated. Cheers.

  • IIRC is "If I recall correctly."

    And sorry, "standard color gamut" was just plain wrong. Here's a post from Jason Z from Z-Cam explaining it - it's like a log profile, but with the colors already baked in so you should only need to adjust saturation/contrast.

    https://www.facebook.com/groups/zcame2/permalink/334812817249670/

  • @eatstoomuchjam, I can't open this page because I don't have facebook. Can you copy this page for me?

  • There is no "Flat" mode (Zflat) on the E1. I have no idea what you guys are talking about. There is Standard and Zlog2 on the E1. That's it. Btw, the LUT for Zlog2 supplied by Z Cam for the E1 has problems.

  • There is no "Flat" mode (Zflat) on the E1. I have no idea what you guys are talking about. There is Standard and Zlog2 on the E1.

    @markr041, yes, that info I was needed! Thanks!

    That's it. Btw, the LUT for Zlog2 supplied by Z Cam for the E1 has problems.

    Yes! I started this topic because I get strange result using their LUTs.

  • I'm not surprised that flat mode is only available on the E2. Here's the post that I linked above, just because you asked...

    How about the FLAT mode's dynamic range? https://drive.google.com/open

    FLAT mode has color matrix builtin but still with Zlog2 curve. It is designed for those who do long term recording and there's not enough budget for color grading. Basically you just need to adjust saturation and contrast to get basic color right. Easy and quick option.

    The flexibility you lost here is that it already has certain saturation level baked in so for over saturated lights it may has less performance than log.

    Since we considered the way people grade the footage you can get very good noise performance comparing to previous zlog.