Light Strenght

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  • #215260

      I just don’t get this simple thing, please help! I work by eye and do not use a lightmeter. Let’s say i have a Keylight and a Backlight LED Tube which can be go up to 100%, how do i know how bright i shout turn it? using my eyes?

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    • #215270

        If you are shooting digitally, you could try setting your camera to the ISO/shutter speed/f-stop you’d like to shoot at, turn on the LED lights at full, then by looking at an accurate monitor or your viewfinder if it has some exposure tools (zebras or false colors), start dimming the lights down individually until you like it.


          I’m the person with less experience here but I could suggest you something that Is helping me in understanding the behaviour of light and Its connection with exposure. If you have a smartphone you can download a free  exposure meter app. They use the phone light sensor and the one i use Is completely free. I’m of course aware that these can’t sobstitute a true exposure meter (but they are expensive) and experience above all (and that comes by trials and errors and time), but I’m beginning to be aware of differences in lights strength and i’m beginning to be able to set the lights accordingly to the exposure i want. I check the result with the camera metering to see of It indicates the 0. Again, i am aware of the limited valute of my advice but it’s working for me and, well, It’s free after all… 🙂


            @dmullenasc, thanks that methote works great, but let’s say i have a small corridor and 1 led 60 watt light. i want a mood horror look. it would only look moody between 10-40 %. but than i don’t know what i should choice.

            thanks i will try 🙂


              Surely whether a light looks moody at 10% or 100% is also a matter of ISO and f-stop chosen — after all, you can expose 10,000 foot-candles of full sunlight so that it looks like the .1 foot-candles of moonlight.

              But you select an ISO and f-stop you like for noise & depth of field, then the light looks correct dimmed to 10% on your monitor/viewfinder, then what’s the problem?

              When I was a beginner shooting on Super 8 film, I had one big light, a 650w open-faced tungsten made for Super 8 filmmakers.  I did a short film on Plus-X b&w reversal, which was only 40 ASA and shot a moonlight scene using that light. Someone saw my short and said “wow, you worked in very dim light!” I was scratching my head because I worked in very bright light, it was just exposed to look dim.


              Roger Deakins

                OK! I’m confused. You work by eye but how can you ‘work by eye’ if you can’t judge what you are seeing in front of you? Either you need experience or you need a light meter. Using one will give you an understanding of exposure and contrast ratios. Then you can through it away.

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