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Ishak Sahertian

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    Ishak Sahertian reacted to Sage in Pocket 4K to Alexa Conversion   
    "Pocket 4K footage is precisely transformed to match the color science of the Arri Alexa, without compromise. This is achieved without artifacts, while introducing a smooth, organic rolloff."

    For the better part of the last year, I've been working to map the color of P4K BMDFilm to match my Alexa's LogC, as measured under sunlight and halogen. To do this, I wrote an interpolation program in C++ that can accept an enormous amount of data (~40k samples per camera), and interpolate smooth internal contours, or 'waves' between them. Exposure compensation conversions were made with the same interpolation engine (transforms replicating sensor color response with variant exposure).

    Another significant element of the project was to recreate Arri's Rec709 to maintain the entirety of recorded LogC gamut, in a film-derived envelope (for the display variations). This was particularly difficult, as the correct RGB primary behavior needed to be exactly replicated within contiguous 709, but smoothly diverge to HDR-like handling of far gamut (where Arri's Rec709 ends). This new envelope (EC Gen.4) is particularly impressive, and I may release it for the Arri, as it is significantly preferable to normal Arri Rec709.
    P4Ka PDF
    Emotive Color

  2. Like
    Ishak Sahertian reacted to Sebastien Farges in AIVASCOPE 1.5x anamorphic on Helios on Lumix S1H   
    AIVASCOPE 1.5x on Helios 44-m 58mm f2 @ full aperture on Lumix S1H
    I had a two hours time having in my hands the Lumix S1H in a workshop organized by Panajou Photograph shop in Bordeaux.
    This was shot in full frame 4k 24p 8bits then 10 bits 150 mpbs (after the desolve @3'48'') -my sd card didn't want the 400mbps-
    Unfortunately my old Premiere didn't liked the 10bits, I had to transcode it.
    Panasonic Lumix S1H
    Sigma adapter
    L mount to M42 adapter
    Helios 44-m 58mm f2 @ full aperture f2
    Aivascope anamorphic lens
    variable ND filter
    +3 macro filter
    full frame 4k 24p
    Few CC Lumetri Cinespace 25
    Thanks to Aivascope
    Thanks to Panajou Photograph shop
    Thanks to Bernard Bertrand for his precious help
    Music : 
    L'impératrice "Le départ"
    Gyoergy Ligeti "Musica Ricercata N°7"
  3. Like
    Ishak Sahertian reacted to liork in Aren't you waiting for the Panasonic S1?   
    It is 72 in HEVC so more like 140Mbps in H.264.
  4. Like
    Ishak Sahertian reacted to Oliver Daniel in “The Middle Path”: A Lumix GH5s Short   
    The forehead is most in focus, which means, erm.....
    ....the tonal shifts seem deeper and smoother than regular GH5, but who knows, that could just be better grading. 
    Dual ISO seems the most likely, with RAW a big stretch but fun to consider! 
    I do think it’s a new camera AND a firmware upgrade, with the “new” camera probably receiving something a little extra, like the GH4R did. 
  5. Like
    Ishak Sahertian got a reaction from webrunner5 in Lumix GH5 Downloadable Footage   
    remember right now the current alpha series cameras still don't output 10bit throught the HDMI only 8bit.. but that may change in the future if they decide not to pull a "canon"(by protecting their cinemaline)
  6. Like
    Ishak Sahertian reacted to wildrym in Lumix GH5 Downloadable Footage   
    Yes I get it, but what I mean is that instead of using almost 1024 values, it is limited to only 600ish. In 10 bit files, it is ok i guess (even though non optimal), but in 8 bit files it becomes only 160ish values. So using Vlog in 4k 60p may lead to severe banding.
    In comparison here are two waveforms from a7s 4k slog2 footage. The second is the same as the first one with superwhite pulled down. Third is GH5.
    As you can see, sony files use roughly IRE from 10 to 109, so approximately 230ish values in 8 bit. It 10 bit it would be 950ish values which would give better tonality than GH5 Vlog files.
    That is why I find it quite disapointing (tell me if I'm wrong with my reasoning!)

  7. Like
    Ishak Sahertian got a reaction from webrunner5 in Lumix GH5 Downloadable Footage   
    I don't think V-log records less "shades" than the other profiles, probably more like that everything(what the sensor is able to capture) is being compressed between 20 and 80IRE
  8. Like
    Ishak Sahertian got a reaction from BrorSvensson in All Canon cameras gets Custom C-Log Profile   
    Log footage has compressed colorspace where the information is still intact from what I understand , s-curve is baked in
  9. Like
    Ishak Sahertian reacted to The Chris in What would you like to see Nikon, Olympus, Fuji do to improve video?   
    The Nikon 1 series has some pretty amazing PADF capabilities, and had it before Canon or Sony, they can do mirrorless AF.
    They're in a tough spot to do large sensor mirrorless because of their commitment to the F-mount, Sony isn't exactly lighting the world on fire with the kludgy LAEA adapters that mate A-mount glass to E-mount bodies, reception to and adapter will probably be equally cold. 
  10. Like
    Ishak Sahertian reacted to varjohukka in Rectimascop 48 2x focusing problems / adjusting?   
    Thank you, guys! That totally did the trick. Now it's sharp even with the 50mm @ f1.2  (well as sharp as it gets at this aperture). I'm excited
  11. Like
    Ishak Sahertian got a reaction from varjohukka in Rectimascop 48 2x focusing problems / adjusting?   
    On my Rectimascop it's the backglass you can rotate, for me it took a nudge. You don't have to unscrew the backlens, just loosen the screws and give the backlens a nudge clockwise or counterclockwise. And fasten the screws when you get a sharp image via Vladimir's method
  12. Like
    Ishak Sahertian got a reaction from varjohukka in Rectimascop 48 2x focusing problems / adjusting?   
    I think this is your problem, had the same issue when I first received my Rectimascop. Now i can shoot wide open and still get sharp images, after getting it alligned 
  13. Like
    Ishak Sahertian reacted to sanveer in Panasonic GX80 - 5 Axis IBIS works on video!   
    I saw that one last night. Nice review. And, so many hidden features. I can imagine 5k Photo Modes (pre-burst, post focus etc) easily covering most photography needs. 
  14. Like
    Ishak Sahertian reacted to Andrew Reid in Did we get hacked? (No)   
    Not a hack, just a normal spam attack from about 7 robot controlled members.
    I'm clearing it up in the admin panel as we speak.
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