Cold Lights...confused

[David Hughes]

I've got a shoot in a few weeks doing a whole set of nursery portraits on-site. I'd normally just use two flashes for the subject plus a couple for the background. However, whenever I do work like this I'm nervous about the kids running around with these flash tubes in operation.

My question (which is partly academic) is how much power would I need if I was to attempt to do this using cold lights. I have a couple of interfit cool-lites (3 bulbs) which I've used for some small product work but obviously haven't got enough power there to do some tests. Interfit now do head with up to 9 heads (equivalent to a 1000w tungsten light they say).

How much/many cold lights would I need to replicate the level of lighting of a typical flash set up. If I normally use a couple of 200w/s heads on location, it can't be as simple as needing 400w of light (e.g. half of Interfits 9 head light). Ignore fill / main etc for he moment. What am I missing ?

Dave

[DougAxford]

All preschool photographers that I know use flash for good reason. It's fast and causes less problems. 200ws is plenty for a flash for preschools. Just make sure cords are taped down or put a throw rug over any cords on the floor.

You might want to check out SchoolPhotoPRO - The Association for Independent School Photographers They are in the UK and the forum specializes in school (esp. preschool) related issues. There are a few members here that are in both. Not that you can't ask these questions here, but you might find more company in that forum with similar issues. I know for sure that cold lights were discussed a few months ago. BTW, there was a great post from a NZ guy on the ColorParrot a few days ago.

In answer to your original question - I have no idea, sorry.

[David Hughes]

Thanks Doug - I've done preschool before and always used flash (and plenty of gaffer tape...). Was just intrigued as to whether cold lights could work and how many would be required!

Dave

[michaelnotar]

4- key, fill, hair, background. perhaps more if your fill needs to be bounced off the walls and if you need to end up lighting the room more, maybe another 3-4 for that alone. probably do the key as hard light or slightly diffused, the fill as an umbrella, other two as hard.

[ChrisPerry]

How do you like your 'cold lights'? I am intrigued by the westcott Spiderlights, but the price has me, well, cold. I have Interfit Stellar strobes and like them very much - a great value that has served me well (a better clamp deal for the head tilt would be nice - they don't hold large softboxes worth a damn).

As to how much light is enough light...I suspect you''ll want 1/250 or 1/500 to freeze the kids if you'r e not usiing strobes, and if the wiggle about you'll want 5.6 or 8 to be sure their in focus. ISO 400 should be no problem, perhaps even 800. Color might be an issue though - I'm used to getting my strobes 3 stops over ambient so I control the color of the light - my experience with hotlights is you won't get that 3 stops, so you'll have mixed light. Perhaps you can balance for it, perhaps not (flourescent or other gym lighting, windows in the room as the light changes during the day, etc).

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