Strobe lighting

DebSturm · Jan 25, 2013

Hello everyone, I have been struggling to understand the concept of the settings on my monolight (strobe). Could someone with strobe light and studio experience please explain the strobe settings that vary in percentages vs. the modeling lamp with adjustable F-stops. When and why would I use less than 100% of the strobe? What's the best setup to capture a true black background and keep it black? Should the settings on my lights be the same as the settings on my camera? Are there really any answers, or am I just going to learn from trial and error? I shoot with NikonD3100 and NikonD5100, my strobes are Impact VC-500LR 500w MONOLIGHT 2-LT KIT and I have backup lights and reflectors. ANY help or advice is greatly appreciated, I'm a student. Thanks!:blushing:

Derrel · Jan 25, 2013

Example: One flash to the right of the camera, aimed in toward a seated person at about a 30 degree angle, with the flash at 100% power from 10 feet away. This is the "main" or "key" light.

The second flash is placed at eye-level of the subject and aimed STRAIGHT AHEAD, and is placed immediately to the left of the camera, also from 10 feet away. (Again, this fill-light is set A) close to the camera position, and is B) aimed straight ahead--it is NOT---I repeat it is not,not,not,not supposed to be "angled in from the side"!!!!!!!!!!!!!!!!!!)

Using identical ligh modifiers (same size and brand of umbrellas or softboxes, for example), this second light is adjusted to 50% power output level (AKA HALf-power), and is the "fill-light".

With these identical brand and type of lights,one at full, the other at half power, this will create more or less a three-to-one lighting ratio on the subject's face.

Black background???? Keep light off of a gray paper or wall, and it will "drop to black" is the light level on the subjects is somewhat brighter. Using black felt or black velvet, the background will tend to stay quite black, even if a little bit of light from the main or fill light strikes the background.

With today's D-SLR cameras that have,m say ISO 200 lowest settings, many studio monolights are simply overly powerful when used at f/stops like f/8, at ISO 200, at 1/200 second...sooooo....we didal the flash output levels down....to half power, or even quarter power, or even 1/8 or 1/16 power.

Full-1/2-1/4-1/8-1/16...each different level is one f/stop more, or less light, depending in which direction one is headed.

DebSturm · Jan 25, 2013

Thanks Darrell, every time you give great answers that really help me. Looks like I really need to tone down the lights, and I need more room to be 10' away from the subject. I'm determined to understand strobes and learn to "paint with light" to make great photos. You are very kind to take the time to share your expertise, thank you very much, Deb

Derrel · Jan 25, 2013

And thank you Deb--you gave me my 4,000th "Like" here on TPF. I appreciate the kind words. Yes, with today's new, super-light-efficient sensors, base level ISO values of 200 mean that even 150 Watt-second monolights can be "too powerful" at close distances. I had a 300 Watt-second JTL mono (it's out on loan now), and man, that doggone thing was almost always used at 1/4 down to minimum power output...it delivered wayyyyyyy too much light in most indoor scenarios that I used it in.

I find that at "portrait" ranges indoors, I am often haoppy with fairly low flash output levels, which is the main reason that for portrait kits, I suggest that most people (not all, but 'most') start with 150 Watt-second monolights. Now, 30 years ago, when we were shooting on ASA 25 to ASA 64 slide film, like say Ektachrome 64, then it made perfect sense to use more-powerful lights...back then, 400 Watt-second lights were fairly normal...today, 150 Watt-seconds is perfectly usable.