Mikespirito
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inhave a Dynalite B4 which is 400 w/s and a speed light. At 8 feet away they are metering at f8 at full power? There's no way the speed light is that powerful. Thoughts?
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How is this possible?
- Thread starter Mikespirito
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Nixon Glenn
Leading Member
What modifier you use on the dynalite?What is the
What is the flash zoom settimg on your spspeedlight?
Tot compare them, both have to have the same spread angle of light.
Nixon Glenn
Leading Member
From my comparison test with Godox AD360 (360ws) and Godox V860 speedlite, where the AD360 use it's standard reflector and V860 speedlight at 28mm zoom (approximately the same light spread), at 6 feet :
AD360 = f/40
V860 = f/13.1
Its about 3 1/3 stops differences
AD360 = f/40
V860 = f/13.1
Its about 3 1/3 stops differences
Mikespirito
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I just did the same test with my photogenic Pl1250 (500 w/s) against the b4 ( 400 w/s). I put the standard reflectors on them and placed them
In the same exact location on full power. Photogenic registered at f32 and the Dynalite at f11
Jacques Cornell
Forum Pro
Do the two reflectors throw the same size circle of light? If the Dynalite reflector throws a wider circle, that would at least partially explain the lower intensity.
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Photomonkey
Senior Member
One needs to minimize the effects of the hotshoe mount reflector to get a truer sense of what is gong on.
Monolight and pack and head system reflectors are engineered to produce a relatively even light pattern throughout their circular area of coverage whilethefocusable reflectors that are built into most modern hotshoemount flashes notonly restrict the beam angle but also inside those angle areas most produce areas where the lighting is either more or less intense.
There are two ways to lessen this do you can more directly compare relative output between a light that uses a circular and generally interchangeable reflector, and a hotshoe mount flash (aka Speedlite or Speedlight):
1) pull down the wide-angle diffusion panel on the hotshoe mount flash so its beam angle and relative brightness dispersion throughout the beam angle.
And/or:
2) Point both lights from the same distance at the same reflective surface and compare the readi gs from the bounced light.
There is also the matter of efficiency. While it takes less energy to energize a small amount of Xenon gas in a speedlights flashtube, the larger volume of gas in a larger size flashtube can take relatively more and also some flash heads are far more efficent than others.
Finally there is the dimension of time. What was the shutterspeed you set the meter to when you measured the two light sources? If less than 1/200th it make be that your meter reading was clipping a fraction of the monolight's total output.
Monolight and pack and head system reflectors are engineered to produce a relatively even light pattern throughout their circular area of coverage whilethefocusable reflectors that are built into most modern hotshoemount flashes notonly restrict the beam angle but also inside those angle areas most produce areas where the lighting is either more or less intense.
There are two ways to lessen this do you can more directly compare relative output between a light that uses a circular and generally interchangeable reflector, and a hotshoe mount flash (aka Speedlite or Speedlight):
1) pull down the wide-angle diffusion panel on the hotshoe mount flash so its beam angle and relative brightness dispersion throughout the beam angle.
And/or:
2) Point both lights from the same distance at the same reflective surface and compare the readi gs from the bounced light.
There is also the matter of efficiency. While it takes less energy to energize a small amount of Xenon gas in a speedlights flashtube, the larger volume of gas in a larger size flashtube can take relatively more and also some flash heads are far more efficent than others.
Finally there is the dimension of time. What was the shutterspeed you set the meter to when you measured the two light sources? If less than 1/200th it make be that your meter reading was clipping a fraction of the monolight's total output.
Hi Mike,
You have to be very careful when making this sort of comparison. First you need to be sure that you are using a reflector on the B4 with a specified angle of view. The RNR-285 reflector for that strobe is their narrowest with angle of view of 50 degrees. Next you must set the zoom of the hot shoe flash to a focal length with a 50 degree angle of view. This latter focal length will vary, depending on the sensor size of the attached camera. I am not looking at an angle of view table as I type, but roughly for a full frame sensor, this corresponds to a 50mm lens focal length; 31mm for a camera such as the 70D; 25 mm for a 4/3 camera etc. With all this care, be sure, also, that both lights have full and healthy batteries.
Repeat your experiment and bounce back.
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