Home Newsletter Locations Diary


Photography Section Lighting Section Topic Index Studio Lighting


Cool-Lites Explained

Cool-Lites are a fairly new development, and many photographers, including some professionals are unaware of them.

Each unit holds a number of energy saving bulbs. These bulbs produce very little heat and even when a lot of them are on its still cooler than a single normal photoflood. This means that they can be used with softboxes, as well as reflectors.

A variety of bulbs are available including, daylight bulbs where the light is the same colour as daylight and flash. This allows mixed lighting arrangements.

Picture on right shows the 9 bulb units being used, soft box left, and reflector with a cap right at a lower power as a fill light. The background is a Lastolite HiLite.


9 bulb unit assembled with the reflector option

The advantage of a light over a flash is that you can see exactly what lighting effect and shadows you have.

The major disadvantage with conventional tungsten photofloods was the heat, with several you had more heat than from an electric fire to deal with, making soft box use unwise and presenting a fire risk. A second disadvantage was that the colour did not match daylight and flash making it difficult to mix light sources. Both of these disadvantages are overcome with the cool-lite.

There are a number of models available, some of the cheaper ones have limited control and don't come with daylight bulbs.

I use 4 of these units, two that have 5 bubs each and two that have 9 bulbs each. All the bulbs in the system I use are daylight bulbs so I can mix this with both daylight and with flash. All of my units have both a reflector and soft box. In each case I can switch in and out any number of the bulbs, varying the brightness from a single bulb up to the maximum on the unit. This is achieved on the 9 bulb units by having a single bulb on one switch and two bulbs on each other switch, while on the 5 bulb systems there is a switch for each bulb.

The models I have are the Interfit super cool-lite 9 and Interfit super cool-lite 5. In each case ours came as a set with a pair of matching lights with stands.  The heads will fit onto a normal lighting stand, although each came with its own lighting stand.  They have an inbuilt tilt bracket and a holder that allows an umbrella or umbrella diffuser to be used, each came with both a reflector kit and soft box kit, but the 5 and 9 bulb units go together in different ways.  Most people will manage with one or two lights, and there are probably few occasions where most people would use 4. They are quite bulky items so you wouldn't want to put 4 up in a normal modern house.

Each of the bulbs in my units are 28w, and in effect are compact florescent tubes. As a typical standard a 2ft florescent tube is 20 watts and I have 28 lamps in total, each at 28w = 784w, this is the equivalent of 78 1ft florescent tubes which would light a fairly large hall being used in a much smaller space. The manufacturers say each gives out the light equivalent of 140w in conventional bulbs, so in total 3,920w, or 39 100w light bulbs, power wise its using around a quarter of the electric that conventional bulbs would. They are said to last 8 times as long as ordinary bulbs and considering they are not on for long periods this should mean I don't have to change any bulbs for some years. Comparing the power of low energy bulbs to normal bulbs is always suspect, in part because many of us don't agree with the claimed amount of light they produce and between producers the clamed equivalent values vary, but there is a lot of light coming out of these multi bulb units, more than I actually need, allowing me to switch out a lot of lights, while still having a lot of control.


Click on images to see larger versions

<< Switches on the rear of a 9 bulb unit, one switch controls 1 light, each other switch controls 2 lights.


9 bulb unit from the front >>

Putting them together and taking them apart is time consuming, at this time I still keep these units in the boxes that they came in so this means disassembling them, taking out all the bulbs and putting them back into their boxes etc. Switching from the reflectors to soft boxes is also time consuming and requires the bulbs, or at least a lot of them, to be removed as they splay out and you cant get the pieces you are changing over them. For most people this would not be so much of a problem as they would assemble the lights the way they would usually use them and leave them in this format, but undertaking both teaching and photographic consultancy, where I don't know what I am going to use them for next, and with limited space to store them as assembled units, I have chosen for now the time consuming but for me most practical option. It also offers me a rather unusual advantage in that I rent rather buy much of the equipment I use, and while its in the box and not in use I don't have to pay rental on it, but this is not a deal you are likely to get. Although many professional photographers do rent in equipment, including lighting kit, as and when they require it for individual jobs, often charging this on to the client. I have thought of putting one 9 and one 5 bulb together with a soft box on and the same with a reflector, or putting both the 9 bulb units together with soft boxes on and the two 5's with reflectors and then changing just individual units when the need arises, and only packing down units when I have to take them somewhere else. This last option is probably the one I will eventually settle on, as I would like to use them more than I do now, due simply to the fact that it is much quicker to grab a flash unit than undertake the assembly, and disassembly tasks.


9  bulb softbox partly assembled  9 bulb softbox  9 bulb soft box and reflector
 with cap

 Click on the smaller images to see a larger version

<< 5 bulb unit set up as reflector option

Controls on the back of a 5 bulb unit, 1 switch per bulb >>

<< 5 bulb softbox part assembled

5 bulb softbox >>

 Click on the smaller images to see a larger version

Comparing Sizes


  • 9 bulb unit reflector  475mm      Octagonal soft box across flat  73mm
  • 5 bulb unit reflector  400mm      Square soft box across flat      60mm 
 5 bulb softbox and reflector
 with cap
 both 5 and 9 bulb units with softbox and reflector options rear view of all 4 options

 Click on the smaller images to see a larger version

Assembling the softboxes

In the illustration above you will see the soft boxes are made from material outside stretched over springy support rods, 4 for the 5 bulb and 8 for the 9 bulb, this gives it the shape. In the images you will see the lower ones have black ties on the ends, this is a strip that Velcro's back to a tighter position allowing all the rods to be put in place and then tightened. The softbox top fits over the ends of the 8 rods and material, and is slightly wedge shaped so once sprung in stays in place. The square softbox top for the 5 bulb unit has Velcro strips in the centre of each flat side.

The reflectors also have a stretch cap that forms a soft box effect.
<< softbox parts for the 9 bulb


All the parts of the 5 bulb kit>>

 Click on the smaller images to see a larger version

In Use


The images above were taken with two of the 9 bulb units, as shown in the image at the top of this page, the soft box on the left with 9 bulbs lit and the reflector with cover on the right, used to fill shadows, with 3 bulbs lit. I only used this arrangement as I had put the lights together in this order for this article. The HiLite being used as a background is not lit, and as you can see there is hardly any shadow, so the light boxes produce a very even soft light.


Producing the same results
with the 5 bulb outfit.

 Click on the smaller images to see a larger version

See Also:-

Introduction to Studio and Flash Lighting

Mains Flash  

There are many articles on flash, lighting and reflectors in the Lighting and Reflectors Section.


By: Keith Park Section: Lighting and Reflectors Key:
Page Ref: Cool_Lites_Explained Topic: Flash, Studio and Reflectors Last Updated: 04/2009

This page:

Link directly to this page, with text or the button on right.

Text linking: Cool-Lite's Explained on Photographers Resource

Linking Instructions                            http://www.photographers-resource.co.uk/

Photographers Resource, all the information for the photographer