Halogen lights and dimmer switches query

[matz]

Hi, I've rigged up some ad hoc lighting for the purpose of photographing items for a website. I'm using three B&Q £4.99 500w halogen flood lights. I'm running two off one 13amp wall socket (ie off off a twin socket extension lead going into the wall socket and the third off another seperate 13amp wall socket.

My query - I've been told I can use a dimmer with these lights and need to know if this true or not! A dimmer apparently as in something you plug into the 13amp socket into which I plug in the 3 pin plug from the lights.

Can I use such a "plug in" dimmer with one light?

Can I use such a "plug in" dimmer with two lights running off it?

btw These lights run for 10 minutes at a time and are never left on unattended. I'm assuming this lighting set up though not usual is ok for temporary use???

The 3 pin plugs are fitted with 13amp fuses. What is the correct fuse rating to be used with these lights in this way?

Hopefully I'm not now going to get a dressing down for what I've been doing or what I want to do

 

[Steve]

I'm not sure what sort of light is usually used for this sort of application, but you'd need a 1000w dimmer for each light. They have a hefty startup, being halogen, so this is why you need a 1000w dimmer. I havent heard of a plug-in dimmer, wouldn't think such an item was allowed. You'd have to get a wall dimmer and a box with cord restraint, 3 times. And with 1000w dimmers, that'd be expensive.

Alternatively, i'm sure there are studio dimmer packs available that would suit this application.

 

[eggplant]

Why would you want a dimmer? just use a smaller aperture, and if you have too much depth of field, use an ND filter like you would outside if you had too much light. Dont forget colour also, though thats not much of a problem with digital as it can be corrected easy enough.
Sorry I cant help with the lights !

 

[matz]

whats an ND filter? Smaller aperture I assume is the light setting on the camera? Yes, I'm not that good at taking pics

 

[eggplant]

hmm, I assumed you were into it a bit more because of the fact you are setting up a form of additional light, an ND filter is a neutral density filter, reduces the light but without affecting anything else such as colour.
If its a snapomatic it might not have an adjustable aperture, basically the aperture size can be controlled allowing more or less light, smaller aperture = larger depth of filed i.e. more in focus, but also affecting shutter speeed. If your camera has aperture control then have a play, if not, er well you learnt something useless lol

 

[Adam_151]

Dimming halogen lights reduces the lamp life, there is an explanation, but its a tad long winded

Also, a rule of thumb is that dimmers have to de-rated by half for halogen lights, as their rateings are worked out for what normal lamps take and their change in resistance between hot and cold is smaller than halogens, if you ignore this then there is a a chance that the dimmer will go pop on startup one time, I suppose there is also a small risk of it overheating on low brightnesses (but if its always attended and only short duration, I personally wouldn't worry about it too much - but then again I do quite a few things I wouldn't advise others to do )

If you wanted a better solution, look for an old analogue 0-10v dimmer pack on ebay and knock up a control for it with a couple of pots (or get a electronically minded mate to do so)

 

[matz]

thanks all. I'm glad I posted here. I think I'll pass on the dimmer arrangement!