The PMW-F5 and F55. Expose as you would film when using raw.

advertise-here-275 The PMW-F5 and F55. Expose as you would film when using raw.

I have to say that the more I use my F5 the more I’m coming to love the images it produces. However it has taken a little while to really find the best way to expose it when shooting raw.
In order to record raw the camera has to be in the Cine EI mode which means that the internal recordings use S-Log2. S-Log2 uses lower black values than S-log and as a result looks less flat, even though it has greater dynamic range, so judging exposure is a little easier but still tricky, especially if your not used to the way log looks.
One issue at the moment is the lack of any built in waveform, histogram or spot meter, these should come with a later firmware update. In the mean time there are several things you can do. You can use an external monitor with a waveform display (I use the Alphatron EVF which now has a waveform display). You can use a light meter or you can use one of the built in LUT’s and then use zebras as you would normally. If using the LUT’s please remember that at the moment when the LUT’s are ON not only is the LUT applied to the HDSDI and HDMI outputs, but it is also applied to the internal recordings, so you are no longer recording S-Log2. Sony define Middle grey for s-Log2 as 32% and when exposed like this the images do look quite under exposed but do grade very well. The issue is that while this is great for Log where you do need to try to keep skin tones and the mid ranges in the lower more linear part of the gamma curve it’s not ideal for raw. This is because the raw is linear raw. There is no highlight or mid range compression as with standard gammas or log, so where you put middle grey is much less important as skin tones and mid tones will grade equally well even if exposed very high.
By deliberately over exposing the raw you can minimise noise and the F5/F55 raw is incredibly tolerant of over exposure. So the camera behaves much like a film camera when shooting raw and IMHO often benefits from exposing brighter with raw than the S-Log optimum. So a waveform display that allows you to see where your highlights are helps judging raw exposure much better than just sticking mid grey at 32%. When you shoot with the majority of video cameras you are always conscious of protecting your highlights because over exposure looks really bad and makes grading a nightmare. With most cameras the limited dynamic range and the way traditional gamma curves compress the highlights means that many of us camera operators and DP’s will deliberately slightly under expose when shooting video.
But when you shoot linear raw and have 14 stops of dynamic range to play with it really is very different. There is so much over exposure headroom that you are hard pushed to over expose the camera anyway. Because each stop contains the full amount of data it really doesn’t matter where you place your exposure range. Provided the brightest parts of your scene are not actually clipping you can afford to push your exposure levels up. There really is no need to underexpose. Exposing brighter brings an added benefit and that is that after grading you will end up with less noise than a scene exposed darker. So for the F5 and F55 when shooting raw (just as with the F65) I favour exposing on the brighter side and this is how you would work with a film camera. Film doesn’t like under exposure, under expose film and it gets noisy and grainy, just like underexposing raw with an F5/F55.
When shooting raw I prefer not to use a LUT and use a waveform display to keep an eye on my highlights. I will typically expose S-Log2 so that my highlights sit just below 100%. Very often the log will look a little over exposed (but the raw will be fine). If use a grey card and set middle grey to the recommended 32%, very often this will result in a darker exposure than I will actually use for shooting raw. This does mean that the S-Log2 footage may not grade as well as it should being a bit over exposed, but the raw looks fantastic and I can minimise noise levels by shooting this way.

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