Help me understand this particular light kit at DVinfo.net

Marius Tatarasanu · November 20th, 2012, 03:45 PM

So I was browsing through Ebay, and I stumbled upon such a lighting kit:

8 x 135W 5500K Lamps Daylight Continuous Lighting Softbox Soft Box Kit Four Head | eBay
I also saw kits with 8 or even 10 slots (lightbulbs)
Also consider a lightbulb such as this one:
Kast Lotus bulb - bec fluorescent 85W E27 - F64
It says that is has an output equivalent with 525W incandescent.

If I put 4 of these bulbs on that lamp, will I get an 2100W light?
If I put 10 of these bulbs on a bigger lamp will I get 5250W light?

Help me understand here. What am I missing?

Arthur Gannis · November 21st, 2012, 09:16 AM

If you put 4 of those 85W rated flos together,I do not think you will get close to a 2100W light. Flos roughly are about 4X more energy efficient compared to the common halogen filament. That is roughly. In my quick calculations the 4 flos will consume 340 watts of power as they are rated as such and will be theoretically equivalent to efficiency factor 4 X 85 watts each X 4 flos = 1360 watt equivalent filament.
If you put 10 of these together, they will draw a total of 850 watts for a roughly ( again very roughly) 3400W
of filament equivalent, again far less than the 5250W expected. Another factor to consider is the light loss in using diffusers/softbox/scrims etc. That alone will drop the output by a large margin roughly by half or more.
If they state that their 85 watt flos are equivalent to a 525 watter, I will eat my extension cable.

Donald McPherson · November 21st, 2012, 02:04 PM

It would help if you described what situation you need the light for.

November 20th, 2012, 03:45 PM	#1
Marius Tatarasanu New Boot Join Date: May 2012 Location: Bacau, Romania Posts: 22	Help me understand this particular light kit So I was browsing through Ebay, and I stumbled upon such a lighting kit: 8 x 135W 5500K Lamps Daylight Continuous Lighting Softbox Soft Box Kit Four Head \| eBay I also saw kits with 8 or even 10 slots (lightbulbs) Also consider a lightbulb such as this one: Kast Lotus bulb - bec fluorescent 85W E27 - F64 It says that is has an output equivalent with 525W incandescent. If I put 4 of these bulbs on that lamp, will I get an 2100W light? If I put 10 of these bulbs on a bigger lamp will I get 5250W light? Help me understand here. What am I missing? Last edited by Marius Tatarasanu; November 21st, 2012 at 04:12 AM.

November 21st, 2012, 09:16 AM	#2
Arthur Gannis Major Player Join Date: Jan 2012 Location: New Jersey USA Posts: 504	Re: Help me understand this particular light kit If you put 4 of those 85W rated flos together,I do not think you will get close to a 2100W light. Flos roughly are about 4X more energy efficient compared to the common halogen filament. That is roughly. In my quick calculations the 4 flos will consume 340 watts of power as they are rated as such and will be theoretically equivalent to efficiency factor 4 X 85 watts each X 4 flos = 1360 watt equivalent filament. If you put 10 of these together, they will draw a total of 850 watts for a roughly ( again very roughly) 3400W of filament equivalent, again far less than the 5250W expected. Another factor to consider is the light loss in using diffusers/softbox/scrims etc. That alone will drop the output by a large margin roughly by half or more. If they state that their 85 watt flos are equivalent to a 525 watter, I will eat my extension cable.

November 21st, 2012, 02:04 PM	#3
Donald McPherson Major Player Join Date: Jun 2010 Location: Aberdeen Scotland Posts: 815	Re: Help me understand this particular light kit It would help if you described what situation you need the light for.