I note that the 'fashionable' way of measuring light levels is PAR. When I changed my Roma 240's T8s to a 59w LED I was concerned that I wouldn't be able to match the old light levels with the new (as I wanted a start point as close as possible to the original setup - then increase/decrease from there without 'upsetting' the plants).
But I didn't have a PAR meter. What to do?.......
I used my DSLR camera's in-built light meter.
I took a reading of the old tank's light levels at substrate which, in my case, was 1.3 seconds @f8 (ISO 100). When the LED's were subsequently installed it was just a simple case of reducing the output, in my case to 70%, to match the original light reading.
I'm guessing that I can't be the first to have thought of this method but thought I might pass on my 'find'.
I'm also curious about creating (or finding) a table that matches DSLR meter readings with PAR/LUX so non PAR meter owners can assess light levels. Given that camera light meters should in theory all be standardised (at '18% grey' and hence 'ISO') surely this methodology is viable?
Any thoughts?
But I didn't have a PAR meter. What to do?.......
I used my DSLR camera's in-built light meter.
I took a reading of the old tank's light levels at substrate which, in my case, was 1.3 seconds @f8 (ISO 100). When the LED's were subsequently installed it was just a simple case of reducing the output, in my case to 70%, to match the original light reading.
I'm guessing that I can't be the first to have thought of this method but thought I might pass on my 'find'.
I'm also curious about creating (or finding) a table that matches DSLR meter readings with PAR/LUX so non PAR meter owners can assess light levels. Given that camera light meters should in theory all be standardised (at '18% grey' and hence 'ISO') surely this methodology is viable?
Any thoughts?