There's one in our local craigslist for $60 that I've been eyeing. It looks like it has everything I'd need, except it doesn't seem to have an analyze function and that might be handy to have.
Are you referring to the flash percentage contribution? About the percentage ambient:flash computation capabilities of a meter...
• Percentage computations are ambiguous, because it tells you NOT how the ambient vs. the flash falls on the face. For example, assuming ambient is twice as strong as flash...
• ambient could fall on TWO sides of the face, whereas flash falls on ONE side of the face. And in that situation, the ambient illuminated side gets 2 parts ambient + 1 part flash, so the two sides actually have 3:1 contrast, NOT the 2:1 that you assume from judging light source intensity!!!
• ambient could fall on ONE side of the face, whereas flash falls on the other side of the face (e.g. sun on one side, deep shade on the other, and the flash from the side illuminates only the shaded side of the page. And in that situation, the ambient illuminated side gets 2 parts ambient + 1 part flash, so the two sides actually have 2:1 contrast, which is what you assume from judging light source intensity!!!
...but while the source intensity is 2:1 in both scenarios, in one situation the subject lighting is 3:1, yet the other subject lighting is 2:1. Such are the flaws of stating lighting in terms of numrical value: source intensity does not at all factor in HOW the light falls on the scene!
So I decided to make an experiment to see what Percentage Contribution does in a meaningful way, and how it helps in setup so that I achieve a certain 'look' in my photo in a portraiture situation. I used a Minolta Autometer Vf to meter things, ambient was window light (right) and flash was very heavily reduced Dynalite M500 (500 w/s) powering a heavily filtered 1020 flashhead.
(Important TEACHING POINT: this added filtering for intensity reduction was necessary in order to drop flash intensity at 7' source distance by another -5EV to achieve f/4 reading, even after choosing only minimum setting of 30 w-s of power output from the power pack. YES, there is indeed such a thing as too strong of a studio flash! Buyer be aware!)
Five shots at ISO 1600:
- Ambient only: 1/160 f/3.2
- Flash 25% +ambient 75%: 1/25 f/5
- Flash 50% + ambiemt 50%: 1/40 f/4.5
- Flash 75% + ambient 25%: 1/60 f/4
- Flash 100% + ambient 0%: 1/160 f/4
Now look at the actual photos, (exhibiting 25% increments of changing percentage)...
...and ask yourself:
- A Sekonic meter reads flash contribution at 10% increments (unlike my Minolta meter's 25% 'limited' increments), does it even MATTER how finely it shows the percentage?!
- Can I really even see a 25% incremental difference to visually recognize even a 25% change in flash contribution?
- Does knowing a PERCENTAGE value help me at all, compared to simply visually assessing how pleasing the contribution balance is?
- If my flash is full frontal (rather than off to the left a bit, like in my examples) what -- if anything -- does having a contribution balance do, from the standpoint of source 'intensity' (vs. the issue of color balance from mixed WB sources)?
For my own purposes, this experiment showed me that although I have a flashmeter with percentage contribution feature, I have missed nothing at all in NEVER USING that feature. My prior Minolta Autometer IVf had a brightness difference feature, my Autometer Vf has the analyze function...for me the analyze function provides no advantage over the Autometer IVf.
• A Percentage analysis, for me, is valueless. I simply vary flash intensity to alter the amount of fill to what I want to achieve as a visible appearance, I can ask for flash to Equal the sun (1:1) with 0EV FEL Be weaker than the sun by 0.5EV (using FEL -0.5EV) to achieve low subject lighting contrast Be weaker than the sun by -1.0EV, (by using FEL -1EV) to achieve moderate subject lighting contrast Be weaker than the sun by -1.5EV, (by using FEL -1.5EV) to achieve somewhat contrast subject lighting contrast
• I know that my result on film was that flash intensity at -1EV (relative to ambient) gave me more contrast than I wanted, and -0.33EV flash intensity gave me not enough contrast (shot illumination would be too 'supplemental illumination' appearance for me -- in spite of some others' opinions about 30% being 'about right') My SOP is that I strive for a -0.5EV or -0.66EV flash output difference (depending upon equipment, as some have 1/2EV control and others have 1/3EV control). And be done with it...No meter percentage needed, no chimping needed (even when possible, shooting digital), not anything more elaborate or time consuming than a simple -0.5EV flash setting!