Mark K.
Well-known member
Hey gents,
So I tested the Forza 500 up against my Profoto 1200w HMI today, and figured some of you might be interested in the results.
Long-story short? I was sadly underwhelmed by the output of the Forza.
Colour-wise the Forza was very impressive. Effectively equivalent to the HMI bulb according to my spectrometer. And the beam from the LED is remarkably even too (evidently a COB has significant advantages over an open-faced point-source light in this regard)
Output-wise however, there's clearly still no replacement for displacement. At 800 ISO and somewhere around 4-5 meters away from the lights (I didn't measure the distance, as I was only interested in comparative output), using a 50 degree Profoto Magnum reflector on the HMI (focussed to an evenly-spread beam), and the Forza's slightly tighter-beamed standard reflector, the numbers came in at:
- Profoto 1200w HMI: f/11 + 2/10
- Forza 500w LED: f/5.6 + 8/10
So approximately a 1.5 stop advantage to the HMI (that's three times more output - you'd need three Forza 500s to match the output of the 1200w Profoto)
Pairing the Forza up with it's Fresnel attachment (which works well, and has a pretty remarkable 45-10 degree range) I got:
- Forza 500w LED @ 45 degrees: f/5.6 + 1/2
- Forza 500w LED @ 20 degrees: f/8 + 6/10
- Forza 500w LED @ 10 degrees: f/11 + 1/2
Zooming the Magnum reflector on the Profoto in to create it's most intense hotspot (the hotspot being about twice the width of the Forza at 10 degrees - but the outer edges of the beam still spreading close to 50 degrees overall) I got:
- Profoto 1200w HMI: f/22 + 8/10
That's just a hair shy of f/32 (and with broad-beam reflector). With a tighter reflector that didn't lose as many lumens to the broader surrounding beam/spill those numbers would go up even higher.
Which suggests to me that these higher-output COB LEDs are basically still on par with HMI on a lumens-per-watt basis. Now if we were comparing to an HMI fresnel, we'd lose around a stop to the lens, and there'd be less in it (maybe only half a stop). But compared to any open-face HMI (bug-lights like the K5600 Jokers or this Profoto of mine, or any Arrimax HMI like the M18) there's still a massive difference in output.
I was kinda hoping there wouldn't be, so I could pick up the Forza 500 or the Aputure 600 and have all the output delights of the smaller HMIs, without the all bulb-blowing/5-minute warm-up times/and the joys of proper colour-shiftless dimming. But I fear we'll be waiting some time yet before we get there.
So I tested the Forza 500 up against my Profoto 1200w HMI today, and figured some of you might be interested in the results.
Long-story short? I was sadly underwhelmed by the output of the Forza.
Colour-wise the Forza was very impressive. Effectively equivalent to the HMI bulb according to my spectrometer. And the beam from the LED is remarkably even too (evidently a COB has significant advantages over an open-faced point-source light in this regard)
Output-wise however, there's clearly still no replacement for displacement. At 800 ISO and somewhere around 4-5 meters away from the lights (I didn't measure the distance, as I was only interested in comparative output), using a 50 degree Profoto Magnum reflector on the HMI (focussed to an evenly-spread beam), and the Forza's slightly tighter-beamed standard reflector, the numbers came in at:
- Profoto 1200w HMI: f/11 + 2/10
- Forza 500w LED: f/5.6 + 8/10
So approximately a 1.5 stop advantage to the HMI (that's three times more output - you'd need three Forza 500s to match the output of the 1200w Profoto)
Pairing the Forza up with it's Fresnel attachment (which works well, and has a pretty remarkable 45-10 degree range) I got:
- Forza 500w LED @ 45 degrees: f/5.6 + 1/2
- Forza 500w LED @ 20 degrees: f/8 + 6/10
- Forza 500w LED @ 10 degrees: f/11 + 1/2
Zooming the Magnum reflector on the Profoto in to create it's most intense hotspot (the hotspot being about twice the width of the Forza at 10 degrees - but the outer edges of the beam still spreading close to 50 degrees overall) I got:
- Profoto 1200w HMI: f/22 + 8/10
That's just a hair shy of f/32 (and with broad-beam reflector). With a tighter reflector that didn't lose as many lumens to the broader surrounding beam/spill those numbers would go up even higher.
Which suggests to me that these higher-output COB LEDs are basically still on par with HMI on a lumens-per-watt basis. Now if we were comparing to an HMI fresnel, we'd lose around a stop to the lens, and there'd be less in it (maybe only half a stop). But compared to any open-face HMI (bug-lights like the K5600 Jokers or this Profoto of mine, or any Arrimax HMI like the M18) there's still a massive difference in output.
I was kinda hoping there wouldn't be, so I could pick up the Forza 500 or the Aputure 600 and have all the output delights of the smaller HMIs, without the all bulb-blowing/5-minute warm-up times/and the joys of proper colour-shiftless dimming. But I fear we'll be waiting some time yet before we get there.
