harry dalek wrote:I did mean the the indoor light Gary Ok 500 watts yakes ! .
And I could have done with a lot more - however I was using a very insensitive set up.
harry dalek wrote:The reflected light is the thing to measure not the sun or lamp i think..
Well the brighter the source the more light is reflected - but no need to measure as there is never going to be anything brighter than the sun (at least not in my life).
harry dalek wrote:I see a sunny day is 100000 lux but is that pointing at the sun the sky
Well that is what you then have falling on your subject if you position the camera and the subject correctly, the amount of reflected light is irrelevant as the attenuation percentage is the same for whatever your source is - in other words the more light falling on the subject the more makes it to the sensor.
harry dalek wrote:- the amount
as it would have to change depending on the reflective surface ..depending on your light distance would that 500 watt light be the same as the sun shining off the toby jug illuminating that small area ...the reflective light measured might show its similar...don't know speculating...
Well I suppose if you had a focussed beam of light that was arranged to hit the subject and bounce straight off into the camera lens that may be true - but that is not what you would normally have.
I think the sun being effectively a point source makes things easier - you might be able to get a 500 watt lamp in a position that is as effective but it would probably be in front of the camera lens!
harry dalek wrote:But sounds like out door nbtv is easier than indoor ?
Oh I wouldn't necessarily say that - after all it is more difficult to build a portable unit than one that is just lashed up on the bench (as mine normally is). But you should, I am told, get more light to the sensor outdoors (on a sunny day) - there is NEVER enough light no matter how sensitive your set up is - with the possible exception of using a photo multiplier - so more light good less light bad.
I should point out that one of the disadvantages of bright indoor lights, as Bairds subjects found, is the heat they generate. This is one of the major reasons I feel an FSS is an easier approach for a first time attempt.
Having said that it gets pretty hot under an Australian summer sun - and there is more UV!
Anyway I am just repeating an idea I attribute to Doug Pitt - I have never tried it myself.