Why is it so troublesome to check one gentle to a different? It might be dangerous sufficient to say that watts, LUX, watt-seconds, and information numbers aren’t immediately comparable. And until you’ve been round lights for a very long time, these measurements received’t even make intuitive sense.
Born from this frustration, I provide the Strobepro Energy Scale we developed over at Strobepro! Earlier than we get into it, listed below are just a few disclaimers:
1. Practicality was the aim
If I got down to do an apples-to-apples comparability in each respect, I consider the usefulness of the information would have suffered. Totally different lights are meant for use in numerous methods. For instance, a studio strobe will often be modified indirectly, whereas transportable LED panels are finest suited as onerous, unmodified lights.
For that reason, all studio strobes, speedlights, and COB LED lights have been examined with a 24×36″ softbox hooked up. Most different lights have been unmodified until in any other case said (see the legend beneath).
2. Evaluating steady lights to strobes is assumptive
When a strobe flashes, it releases its vitality over a really quick time period. That vitality is launched over the identical time period no matter your shutter velocity. Due to this fact, we should consider the time worth for a flash publicity as fastened. That’s why shutter velocity (as much as your most sync velocity) has no impact on flash publicity.
Then again, a steady gentle will gentle your scene for the whole length that your shutter permits. The time worth for an publicity with a steady gentle is variable.
Due to this fact, in an effort to evaluate steady lights and strobes, we should set a benchmark shutter velocity. As a result of we wish this to be comparability, I selected 1/125 of a second (an honest shutter velocity for a typical portrait topic). If you will get sharp outcomes with slower shutter speeds, then energy to you!
1/50 to 1/60 of a second could be extra typical for video manufacturing (assuming you’re taking pictures at 24-30p), however we are able to’t precisely do a video-based comparability with strobes on the identical checklist! Nonetheless, you may usually count on to achieve a cease of sunshine whenever you’re taking pictures video.
3. Distance is at all times an element
If a number of the publicity outcomes I recorded appear underwhelming, please observe that my check goal with my gentle meter was 6 toes away from the supply (measured from the entrance of the sunshine floor or the entrance diffuser). If you need your gentle to punch above its weight class, one of the best factor you are able to do is to maneuver it nearer! In the event you cut back the gap from 6 toes to three toes, your gentle turns into an efficient two stops (4x) brighter.
It’s precisely due to this habits (the inverse sq. legislation of sunshine) that I selected to place my lights somewhat additional again than I’d in a typical portrait session. From 6 toes away, I might acquire just a few inches’ margin for error with my measuring tape.
Setup and Methodology
I used a Sekonic L478-D light meter positioned (as talked about) 6 toes from the entrance floor of the sunshine. A goal gray was additionally used in order that I may cross-reference picture information to the information I collected from my meter. All lights have been in contrast at their most energy. Within the case of bi-color LEDs, the colour temperature that produced the brightest end result was used.
As soon as the information was collected, I rounded every end result to the closest third of a cease and charted it on the dimensions beneath.
Word: Merchandise have been modified for the check as indicated:
Strobepro 24×36” Speedy Professional Softbox: Studio Strobes, Speedlites, COB LED Lights
Product-specific Softbox: Flex LED Panels, Strobepro Quadstar
Unmodified: LED Panels, LED Tube Lights, LED Ring Lights
Easy methods to Learn the Information
The Strobepro Energy Score compares most energy.
All of those lights may be adjusted down from their maximums to various levels.
To learn this information, you’ll want to know what a cease of sunshine is. In case you are new to pictures, you must familiarize your self with this time period. ‘Cease’ is shorthand for f-stop, however we are able to apply it to any type of gentle and never simply to the sunshine being let in via your aperture. Every time you add a cease, you might be doubling your gentle.
Every complete quantity in both column represents a cease of sunshine.
The 2nd column exhibits the information I collected based mostly on the goal publicity. For the goal publicity, I used 1/125 of a second, f/4, and ISO 100 at a 6-foot distance from my gentle meter (measured from the entrance of the sunshine floor or the entrance diffuser). A constructive quantity signifies overexposure on the goal settings, and a damaging quantity signifies underexposure. For instance, the complete energy flash from our QS600II was an entire 3.7 stops overexposed at these settings.
The third column merely offers distilled information utilizing our weakest gentle (the R1) because the baseline.
To find out how a lot brighter one gentle is than one other, take the Strobepro Energy Score of the stronger gentle and subtract the score of the weaker gentle. The result’s the brightness distinction in stops.
Instructed Makes use of by Energy Score
Past evaluating one gentle to a different, there are different helpful issues we are able to do with this information. We’ve ready some common suggestions within the chart beneath that will help you determine which lights would possibly meet your minimal energy necessities.
I hope you discovered this info helpful. I sought to declutter the method of evaluating numerous forms of lights. With out seeing the lights in actual house, it was at all times a selected problem to elucidate how steady lights would possibly stability with strobes. Not!
Concerning the writer: Kevin Greenhough is a portrait and journey photographer, and the media coordinator for Strobepro Studio Lighting. You could find his work on his personal website. This text was additionally revealed here.