Ok so what’s the deal – surely your camera has a light meter built in right? Yes and even to use off camera flash you do not need to step beyond “through-the-lens” metering – there are now all kinds of offerings beyond the pocketwizard for this – I have the tt1/flex stuff and use it with my Elinchrom Ranger (with the power ST4) but that is for another post – one definitely to read as the ST4 / light meter combo behaves very oddly.
Absolute reasons for using a light meter?
1. Skin tone. End of. If you are using reflected metering (inside your camera) and then “chimping” by using the jpeg preview (yes even if you shoot in RAW the screen shows you a jpeg) then your histogram will be very dependent on the colour (or picture styles in canon terms) settings you have. Try it – the histogram will change depending on the picture style.
2. Reproduceability. Two great things about this light meter of mine the first being that I can measure reflected spot meter readings also. Initially thought I would use it to measure the dynamic range of a scene see if my camera could take it all in – i.e. at sunsets. But the reality is that I use it to gel a grey background and get the colour dialled in the same time after time. As you may know it is easier to colour a grey b/g with a gel than a white one (the grey seems to hold onto the colour better) and by knowing that I am getting the right shade of blue or red by knowing the f stop I can forget about light distances and power outputs on the flashes – lovely – especially if you are doing a series of corporate portraits on different days.
3. The radio trigger. I use both pocketwizards (the dumb plus II) and the El skyports at times. Latter great cos you can adjust the power remotely but you cannot trigger a skyport from the Sekonic light meter. Therefore I have a PW plusII typically on the camera, the skyport in a pocket and attach both a plus II and the Skyport Rx to the ranger. Works great.
Enough for tonight – but I will go into the bizarre world of high speed sync with the ST4 soon. Y’all come back y’hear!