ABSTRACT
I check the speed of a Panavized F900 in exactly the way I would when testing a film stock’s ASA or EI rating. Note that the numbers will be the same.
When checking a film stock’s ASA speed, I set the camera up facing an 18 per cent reflectance grey
card and make a range of exposures, noting the setting on my meter for each one. Then I ask the laboratory to make me a middle of the range one light print. Whichever exposure most exactly matches the tonality of the original grey card I deem to be the correct rating for that particular
film stock. With any HD camera my approach is the same but the technique a little different. I set the 18 per
cent grey card up as before and, close by, set up a carefully lined up 24-inch monitor. Making sure that the card is evenly lit, I adjust the exposure until the grey on the monitor exactly matches the grey of
the card. Now I take a reading of the card with my Pentax digital spotmeter and set the reading in the viewfinder on its scale, then I adjust the ASA setting on the meter until the aperture shown is the same as that on the lens. The ASA setting on the meter is now showing the equivalent ASA speed of the
camera. Every time I do this with any version of the Sony HDW F900, I arrive at an equivalent ASA of 320.
