DVX ASA rating

Grabthar73

Grabthar73

New member
I'm an EFP/EFP DP for a cable TV network who used to shoot a lot of film in the 90's. Sadly, the fast paced, low manpower nature of EFP/ENG shooting makes using a light meter impractical. However, there are times (few and far between) when the opportunity arises where I can play with the lighting and image control in more depth. In addition, I'm trying to take on more short film work in the effort to do some feature length projects. And finally, my quandry: even though your standard Sony BetaSP and DVCAM cameras are typically rated 320, I'm wondering if the same goes with the DVX100A. Would you guys rate it at 320, set it at 24P and choose your T stops from there? How about pushing it to 400 or 500? Any advice would be awesome. Thanks.

Mike Dunn
Creative Film & TV
michaelb.dunn@gmail.com
 
Thanks Barry. Do you happen to have any suggestions as to what brands/types of light meters people are using these days? Geez, has it been that long?
 
Using a lightmeter with video is kind of backwards. The camera is inherently a light meter in and of itself; the proper tool to use for exposure is a waveform monitor (and a properly-calibrated production monitor).

A lightmeter can help with vague reference, but is not ideal for use with video. Good for scouting, or for previsualization and setting ratios, but not ideal for exposure; you'd do much better with a waveform monitor.

That said, I've got a Sekonic L508C, combo incident/spotmeter with cine settings, works rather nicely.
 
I would recommend getting a footcandle meter instead. Sekonic makes an analog incident footcandle meter for under $200. The good ones are made by Spectra, but cost more. Video's exposure response is not linear, so, in my opinion, traditional exposure meters aren't that valuable to me in video production. Footcandle meters measure absolute values, which I find very useful in video. And since, footcandle meters measure light in linear units, calculating lighting ratios is easy as pie.
 
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People always say it is pointless to use a light meter with video, but it is useful.

A monitor is a great way to meter your light and see exactly what you are getting. in a big scene with a lot of key lights, it is not practical to keep looking at it everytime you set a light. I usually know what I want my exposure to be at and balance all my keys with a light meter. Then I refer to the monitor when setting my fills, backlights, and ambience.

But, everyone does things differently, and I feel everyone should work the way that best fits their style.
 
It is an ongoing debate, to be sure. In shooting single camera short films, I find myself using a field monitor and the DVX's LCD to balance the lighting and get the look I'm going for. I've been doing it for so long now that whenever I work with an LD in the studio (who is used to lighting for multiple cameras), I find myself having to reach back and get my frame of reference for using the meters. It begs the question then, what do the DP's lighting such shows as 24 (shot with Panavision's Genesis) and Superman (also Genesis) do? I would think they still use their meters like a film project in conjunction with the HD monitors and waveforms, yeah?
 
I have heard of DP's in Hollywood sitting in the tent and only looking at the monitor while telling their crew where to put the lights. I have also heard DP's that only use the monitor to get framing right and do all the lighting the film way.
 
hmm i have looked a lot around these forums and inside the dvx book and I thought Barry always said the DVX100 rating could change depending on the situation and cant be acurate all the timw with one setting. Am I mistaken and you should use 640? or is 640 just the best estimate to use but it can be changing?

thanks
 
I have a P-251 lightmeter from spectra that indicates footcandles. But it still needs to sets the ASA before having any kind of mesure.

If the ASA isn't consistent, how can I get a proper footcandle mesure through my meter?

Thanks.
 
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footcandles are a ratio unit of measurement of lumens per square foot. 1 lumen per square foot = 1 foot candle (I think... been a while). Anyway, point is, you can use footcandles to guage the amount of light in an area, that has nothing to do with response of your camera or capture device, nothing to do with the ASA or F/Stop.

One of the best uses would be for ratios. If one side of the face is 100 lumens and the other side of the face is 300 lumens, then you have a 3:1 ratio.

You still have to determine what amount of light is an appropriate key for your camera.
 
I see what you mean.:)

Yet, if I get some 100watts flood bulbs (same for your home), when I'm preparing the shoot by gauging the light I will need (let's say I know how a 100w illuminates, and it happens that's what I need), I would need a reference in footcandle.

A 100 watts bulb is around 1690 lumens. BUT my lightmeter is in footcandle, and according to what ASA I'll set my meter, the values will differs.

If I want to use footcandles as a reference during preparation, and use that same reference on set, am I suppose de set the ASA at a level which the amount of light falling on a surface (the footcandle) will be close to the appreciation the human eye mesures the illumination of a 100w bulb? If so what would it be? (since all the mesure of my meter is influenced by the ASA I set), OR the meter shouldnt be set to any ASA (which would let the light going to light cell straight...

If not, does it mean whatever the ASA of my lightmeter, as long I keep as a reference from preparation to the shoot? (then, foot-candles would not have a standard reference, the world would end, and earth would collapse :kali: euhmm sorry

Now, I don't know if this is in the good topic anymore.... :furious3: but if anyone understood what I did'nt....

Thanks for reading (or trying to) anyway ;)
 
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