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Old October 4th, 2012, 05:21 PM   #1
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Spot -> flood. How does it work?

I'm curious. How can a lensless light such as the Arri 800w be used as both a flood and a spot? I assume it's something to do with the reflector? Does it rotate and thus deliver a different focal point? How would this compare to a fresnel in terms of effectiveness at both jobs?

As you might have gathered by now, lighting is not my strong point! Very basic three point set-ups are about my limit, but I'm keen to expand my knowledge.
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Old October 4th, 2012, 07:14 PM   #2
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Re: Spot -> flood. How does it work?

I have Arri fresnels. But I also have Lowel lights which don't have lenses and their focus is achieved with relative position of the bulb to the spherical reflector. Fresnels are thought to be a more pleasing light as the lighting source is the entire lens. Whereas a reflector light like the 800w his a very small hot spot (the bulb). That being said, depending on what you're lighting, generally a softbox, bounce or at least diffusing the lights would be the way to go. And for that it doesn't matter if it's fresnel or not. The only time I use a fresnel is when lighting a podium or stage. I think they might be slightly easier on the eyes of the people on stage. At that distance I don't know that it would look any different to the camera.
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Old October 5th, 2012, 02:45 AM   #3
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Re: Spot -> flood. How does it work?

Thanks Brett. Very interesting. I had nothing specific in mind, but I thought that adding one or two to my existing basic kit might give me a little more versatility. It's really the ability to alter the spread of the light that appeals to me and as the Arri 800w seems to appear on eBay quite frequently (in the UK, anyway) and at decent prices, I thought I should investigate.

So if I understand correctly, the beam is widened or narrowed by moving the bulb's position relative to the reflector? I looked at some images of the Arri 800w but I couldn't see anything obvious that enables this, which is why I thought it might rotate.

Thanks again.
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Old October 8th, 2012, 01:21 AM   #4
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Re: Spot -> flood. How does it work?

hi ian

assuming you mean the readhead style open faced light, the flood/spot mechanism moves the lampholder
back and forward in the reflector. this is operated by the big black knob on the back of
the light. turn it fully clockwise for flood and counterclockwise for spot.
almost all open faced lights work in this manner.

fresnel lensed lights move the lanp and reflector together on a slide inside the light
and is operated by knob on the back in most cases.

be very wary of the cheap redhead knockoffs from asia. these lights are cheap copies
and are cheap for a reason. they dont appear to meet any electrical standards and if you
do end up buying them get them checked by a licensed electrician for test and tag compliance
for your safety.
this style of light is handy to have in your kit and have been the backbone of the industry for
40 years..
bounce off a wall or poly, whack some white diff on the doors and you can use them anywhere.

cheers
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Old October 8th, 2012, 02:52 AM   #5
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Re: Spot -> flood. How does it work?

Thanks Ian. Since Brett's post I have invested in a second hand Arri 800W redhead. The seller was a pompous moron who - after I had given him my money - told me I shouldn't waste his time and go and look it up myself. I'd give him neutral feedback (it wouldn't be his first) but I just know he'd respond with negative feedback. Sigh . . .

On anything that requires a simple set-up I'm quite confident of getting decent results on my own with my basic Lilliputs and a couple of KinoFlo Barfly's. Until the last couple of years, though, if I was shooting anything more involved, I would bring a lighting cameraman in and hire whatever kit he/she asked for. However, I'm increasingly having to produce on tighter and tighter budgets and there are more occasions where I simply can't afford to do this, so I'm having to pick up another skillset and kit to go with it. Personally, I'd far rather leave that to the experts and focus on what I do best - the story telling side - but such is the world today . . .

I'm 100% with you on the cheap import issue. I always tick the 'UK only' box in an eBay search - if anything it narrows the results from thousands to a handful, even if some of those are still being shipped from the far east.

I will gradually grow my kit to something that will hopefully cover most situations I might find myself in. But first I need to reads those books, watch that training DVD and get a bit of practice in ;-)
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Old October 8th, 2012, 03:44 AM   #6
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Re: Spot -> flood. How does it work?

hi ian
you cant go wrong with the arri they are pretty much bulletproof i have a few on my kit.

of course they are the exception to the rule............ in that model the lamp holder is stationary
and the reflector moves for the flood and spot mode.

grab some lee filters white diffusion and it softens them up nicely.

cheers

ps i feel your pain with the budgets.................
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Old October 8th, 2012, 03:50 AM   #7
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Re: Spot -> flood. How does it work?

Yep, have a ton of filters of every type. I tend to keep the cast offs left by the lighting guys I've used, so the stuff I bought new many years ago is still in its packaging!!

Thanks again.
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Old October 8th, 2012, 01:00 PM   #8
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Re: Spot -> flood. How does it work?

I have the cheap knockoffs and rewired them with an earth. I also bought a couple brollies for them. But what I would like to know is how important are dimmer switches? As I have none I bought some lower wattage lamps to swap in.
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Old October 9th, 2012, 04:15 AM   #9
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Re: Spot -> flood. How does it work?

hi donald
lower wattage globes are your best bet over dimmers. once you start dimming
below 80% aprox the colour temp goes down and the lights go towards an orange colour.
you can overcome this by adding 1/8 colour temperature blue

there are other ways to knock the level down..... with ND or closing up the barndoors
i use dimmers on redheads because i find the dxx lamps are susceptible to start up shock and tend fail when you switch them on.

cheers
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