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Issue: Noise in the A6500 :(
  • Yesterday I made cinematography in a short film in which I used this camera accompanied by a Meike 25mm f1.8 and a Rokkor 58mm 1.2 with the profile PP5 and the Gamma S-Log3 I did not touch anything of the rest of the configuration, 1,50 ISO 1,600 only for a shot and in the rest at ISO 800, and 1/50 with a WB at 2600K because the director asked for a cold atmosphere between blue and gray.

    I was surprised cause that it produced noise in both circumstances, we had illuminated using two points of light and to try although I did not use other profiles, I changed momentarily only for to see the scene behavior of the noise and in the other modes there was noise. I get a lot of attention because this camera handles sensitivity well and I made a short time inside a bus with very low light, in fact we only used a light that came from the roof of the same bus and a small LED that I used for filling using more quirky ISO's around 4,000 and the noise was minimal.

    Is there any reason for it? I let a clip of the short with a gradding.

    Thanks in advance.

  • 10 Replies sorted by
  • @Manu4Vendetta

    Issue can be combination of blue and log used.
    Guys who are more into film stuff and/or used 6500 will tell you more, I guess.

    And don't be obsessed with noise.

  • I haven't used the A6500, but on the A7s II and the A7rIII, I usually overexpose slog3 by a little bit because the shadows tend to be pretty noisy. Was your histogram pushed over toward the right a bit or was this around the middle?

    Also, why are you using cine1 with slog vs just using the default s-gamut with slog?

  • @Vitaliy_Kiselev, may be.

    @eatstoomuchjam, Really I I dont know well the video features of the A6500. I had asked in the corresponding thread without success. On YouTube I saw some video about the benefits of Slog-3 and the logical thing is to be a profile that provides a flat image that keeps the entire dynamic range of the camera to work on post-production. Evidently isnt like that.

    The one that I used some time ago that was inside the PP7/cine3/Cinema mode in conditions of extreme darkness, with high ISOS and gave me better results.

    I do not understand one thing: if you overexpose you should make more noise, because you are raising information from the dark areas, so I do not understand how it would be indicated.

    Thanks to both.

  • @Manu4Vendetta Overexpose wasn't really the right term - exposing to the right would be more technically correct. If you have to expose more to the right by increasing gain/iso, you might end up increasing noise all through the image. At some point, you're just at a point below where your lens and sensor can produce a sufficiently clean image.
    Since you were at ISO 800, I'd think you'd have some space to boost ISO without introducing unreasonable noise. In general, most sensors are noisiest closer to the exposure floor which is why a lot of people expose them with the histogram pushed as far to the right as possible without blowing out the highlights.

    Slog3 is indeed a very flat picture profile which keeps increased dynamic range for post-processing at the expense of some fidelity in the middle of the exposure range. It's usually combined with s-gamut color space, though, and not whatever is associated with the cine profiles. I haven't really met a lot of people who mix them in that way. I don't think that would be why you got a bunch of extra noise, but it seems like you're making your own life harder when doing correction later (have to do it all by hand vs starting by just applying one of Sony's input luts).

  • I do not understand one thing: if you overexpose you should make more noise, because you are raising information from the dark areas, so I do not understand how it would be indicated.

    that's in postproduction. You mixed that up. If you overexpose without clipping and bring it down in post you get a cleaner image.

  • Most professionals, expert with Sony cameras, recommend not to use Slog3, but to use Slog2. And ETTR is the best way to minimize noise. Selecting WB manually is also important.

    http://www.alisterchapman.com/2014/08/19/exposing-and-using-slog2-on-the-sony-a7s-part-one-gamma-and-exposure/

  • I've always been pretty happy with slog3, but I'm neither a professional nor would I call myself an expert (and I've definitely pushed grades with both slog2 and 3 to the point where they broke). :)

  • most professionals recommend to use not sLog neither slog3 nor sLog2 with 8bit internal recording at all.

  • Professionals recommend this

    image

    sa5474.jpg
    403 x 606 - 32K
  • The scene has low contrast. No need to use any slog profile to easily capture the dynamic range and do expose to the right or go for a well lit scene and darken it in post to create the night effect,