Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.

A very useful feature not well documented on the FS7, F5 and F55 cameras (and the F65 too) is the High/Low Key feature.

The High/Low Key function works by changing the brightness range of the image displayed in the viewfinder, this is very useful when shooting in the Cine-EI Mode and using a LUT to help judge your exposure.

My preferred LUT for exposure assessment is the 709(800) LUT. As this LUT is compatible with the gamma curve used in most TV’s and monitors it provides a nice contrasty image with what I would call “normal” brightness levels (middle grey at 42%, white at 90%, skin tones around 60-70%). So if you expose via the 709(800) LUT so that the pictures look right on the screen or in the viewfinder then your S-Log recordings will also be correctly exposed.

But the 709(800) LUT, like most LUT’s cannot show the full 14 stop capture range of the the S-Log recordings. So sometimes you might see an image via the LUT that looks correctly exposed but the highlights might look clipped or blown out as they are beyond the range of what the LUT can show as in the image below where the sky looks blown out. This is where the High/Low Key function comes in to play.

normal-key-1024x576 Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.
Normal range 709(800) as seen in the viewfinder. Is the sky over exposed or not in the Slog recording? It’s hard to tell.

To access the function you have to assign High/Low Key to one of the cameras assignable buttons. Once assigned to a button on the first press of the button the viewfinder or monitor image will show the High Key parts of the shot. To do this the VF or monitor picture is made darker so that you can “see” into the full highlight capture range.  “High Key” will be displayed in the top left hand corner of the viewfinder. As you can see in the image below we can now see that the sky is not blown out, so we know the S-log recording will be OK.

high-key-1024x576 Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.
The High Key function darkens the LUT image so we can view the High Key range of the Slog recordings . We can see that the sky is not over exposed so the Slog recording will be not be clipped or over exposed.

The second press of the button shows the Low Key (darker) parts of the scene. This is done by making the image much brighter so you can “see” into the shadows better and the entire under exposure range of what is being recorded is shown. “Low Key” is displayed in the top left of the viewfinder screen.

low-key-1024x576 Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.
The Low Key function brightens the LUT image so we can see whats going on in the deepest shadows and dark areas (Low Key areas) of the Slog capture range.


The third press of the button returns the image to the normal range that the LUT can show.

So by using the High / Low Key function you can see the entire range that the camera is capturing, check for over exposure or under exposure issues without having to turn the LUT on or off. This is a really useful function that I recommend you take advantage of when shooting with CineEI and LUT’s. However do remember to make sure you are back to the standard view range when setting your exposure level.

460x150_xdcam_150dpi Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.

6 thoughts on “Using the High/Low key function on the PXW-FS7, PMW-F55 and PMW-F5.”

  1. Hello Alister

    Thanks for all the content you put out there, I’ve learned a lot about the FS7 and exposure in general.

    Do High and Low Key always show you the highlights and shadows of the recorded signal, irrespective of whether you’ve rated the camera at 2000EI, 1000EI or 500EI? Or does exposure indexing affect the displayed highlights and shadows as well as the midtones?

    As I understand it, if I’ve rated the camera at 500EI, by using the High Key function I can view the highlights/shadows of the recorded signal, as if I was viewing the LUT still rated at 2000EI – the exposure indexing is effectively suspended for use of High & Low Key….have I got that right?


    1. Yes, Hi and Low key will always show the extreme ends of your exposure range regardless of EI.

  2. I started using your Venice look for Sony EI Cameras in my FS7 Mkii two days ago. I don’t know how I missed you making this LUT for this long. It is now one of my favorite LUT’s created by anyone for the FS7 to date IMHO.

    Using the waveform I certainly get a perfect exposure, however I also tried using the High/Low key to check my exposure visually. I can see the High/Low text cycling through these settings in my viewfinder, but see no difference in picture. Is this correct for this MLUT? Does the High/Low function only work when using a REC709 MLUT for the viewfinder?

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