Attaching gels to Arri 650 Plus

[Tom Morrow]

The instructions don't give any suggestions for attaching gels onto the Arri 650 Fresnel light that I have.

I'm thinking about getting a ring that will hold them:

Arri 650 Fresnel Filter Frame 531620 - Arri 650 Watt Tungsten Fresnel Light 531600

but concerned that might put them so close that they melt, wondering if rosco filters survive being that close to the light.

And for that reason I'm wondering if I should order some wire scrims for when I want to diffuse the lamp, or whether it's okay to put the diffusion materials that I already have in the above frame right next to the light.

Oh, and one more question while I have y'all here: The manual doesn't say not to move the lamp while it's turned on... can I safely make adjustments to the position of these lights without destroying the bulb, or do I have to turn it off and wait for it to cool down to adjust the position?

[Josh Bass]

Generally the way we do this is much more low tech than what you're thinking of: you simply take some clothespins (that we cleverly call C47s for some reason. . .something to do with the military, I heard) and use them to clip the gels to the barn doors on these lights.

Unless this is some special new technology you can move the light just fine while on, in terms of swiveling it or tilting it. Might be safer if you're going to move the whole stand to turn off. I've heard these should NOT be operated pointed straight up or down. . .somehow damages the bulb or something over time.

[Brian Drysdale]

Medium sized crocodile clips are also commonly used. They work well if you've got more than one gel fitted on the light. Don't used plastic clips, they'll just melt.

Your gels will last longer on the barndoors and the diffusion is more effective,

[Garrett Low]

Hi Tom,

I see you're in SF. I'm up in Marin but do a lot of shooting all around the Bay Area.

As for you're question regarding gels, don't waste your money on the holders. You can go buy a hole box of C47's for $5 and you'll have a lifetime supply of gel holders. It's pretty much standard practice. Rosco gels are specifically made to be able to handle the heat. I've never had one melt on me and I've had them with Lowel Tota's which get a lot hotter than your Arri 650.

If all you need to do is cut the light definitely get some scrims or better yet get a few dimmers. Dimmers work best except be aware that the color temp changes as you lower the wattage.

Arri's are pretty solid lights so I wouldn't worry about adjusting the light when it's on. after all you can't possibly set up your light without having it on. So if all your doing is aiming and adjusting the light nor worries. But as a generally safety practice I usually turn off lights before picking up stands and making a move. Can't tell if something is going to get banged when moving and it could always pop globe. And again as a safety precaution always yell out when moving equipment. You don't have to wait for the light to cool down though. Just make sure you use your grip gloves on. The lights do get rally hot.

As an aside, what types of projects are you working on? If you're interested in making Indie movies there's a great film coop in the Bay Area. If you're interested let me know.

-Garrett

[Chris Ficek]

Just some urban trivia, they're called "C47s" because that was the original part number in the Panavision catalogue back in the day (like the 1950s dude). :)

[Joe Lumbroso]

An old timer once told me on set that in "the old days" (ye ol' film days) commercial productions used to call clothespins C47's and pad the budgeted price appropriately so when accounting would look over they budget, they would be just as likely to to put $10k up for CP47's as they would ARRI650s thus affording the company men a few dollars to spend on cocaine.

That said, I've also heard several other versions of why my favourite set tool is called a C47 or CP47 but, this is the one I'll leave right here.

[Josh Bass]

I swear I heard something about the military having that as their official name for that item.


If you push the gels a little more "inside" the barn doors, that is closer to the lens/light, instead of puffed out away from the light/doors, you get a little more control over the light shape with diffusion gel.

[Bob Hart]

30mm foldback paper clips, ( silver handles, black spring/grip ) work well and resist being flicked off by the gels if they flap in wind. Glove your fingers though, otherwise your fingerprints may get brandmarks burned into them.

[Garrett Low]

There's about 5 different stories of why they got the name C47's. The military one was explained to me that that was the number on the bin they use to be stored in. I also heard a variation on the budget thing that was attributed to the tax boys not letting gaffers write off "clothes pins" so they called them C47 clamps to make them sound more official. I've also heard that they were #C47 in the Acme catalogue. In any case they are pretty much found on every set.

-Garrett

[Battle Vaughan]

My experience with moving halogen lights while lit is seriously different --- I managed the photo studio at a large newspaper for several years, and one of my biggest budget-wasters was having to buy replacement lamps because the photographers would constantly bump or jar the lights and blow the lamps. The halogen lamps, in particular, are very hot and compact filaments and they are very fragile when lit. Yes, you can carefully adjust a lit lamp if you can with out jarring it, but a good bump and you're out large bucks and at an inconvenient time. I marked all the fixtures to remind the photographers to TURN OFF BEFORE ADJUSTING but, well, some of 'em couldn't read.....

[Garrett Low]

Wow Battle that's interesting. We're constantly adjusting lights when on. No major bumps or jarring ever really occurs but we routinely raise, lower, and aim lights while on. I couldn't imagine having to strike every time we needed to adjust it. Also, I've had scene's where we've had to walk with the light or for bigger lights have them on a dolly to follow the talent.

Do you recall what lamps specifically you were using? Were they lights for stills photography or motion pictures?

-Garrett

[Battle Vaughan]

@Garrett, we had a variety of Mole-Richardson lights made for movie work, as they were durable and even our ham-handed crew would have a hard time abusing them. As to the lamps, some were tubular halogen--don't recall the specific codes, as I am retired and they are not available to me---and some were bi-pin, burn-base-down types used in some 8" fresnels. All were vulnerable to shock when lit. Ordinary focusing or gentle manipulation were ok, but our folks could always be depended upon to leave a stand lock unfastened and drop a head, or to run the stand over a cable, or something. The lamps were, as I said, a significant part of the studio budget. We used hot-lights for illustration work, mostly...people got strobes.

That said, I think I only blew one lamp in this way in my whole career, and I did a lot of studio work. If you're careful, halogen lamps are fine. But they are, as I said, fragile while lit.

[Sigmund Reboquio]

Originally Posted by Tom Morrow

The instructions don't give any suggestions for attaching gels onto the Arri 650 Fresnel light that I have.

I'm thinking about getting a ring that will hold them:

Arri 650 Fresnel Filter Frame 531620 - Arri 650 Watt Tungsten Fresnel Light 531600

but concerned that might put them so close that they melt, wondering if rosco filters survive being that close to the light.

And for that reason I'm wondering if I should order some wire scrims for when I want to diffuse the lamp, or whether it's okay to put the diffusion materials that I already have in the above frame right next to the light.

Oh, and one more question while I have y'all here: The manual doesn't say not to move the lamp while it's turned on... can I safely make adjustments to the position of these lights without destroying the bulb, or do I have to turn it off and wait for it to cool down to adjust the position?

Hi Tom,

I have the same light and filters you mentioned just arrive last week.and here is what I did
buy a barn door. then use clothespin to clip your gels it works.

i move the lamps even when turned on, the bulb is housed inside- no problems moving it.

hope it helps.

[Brian Drysdale]

I wouldn't physically move the light around with the lamp switched on when rigging, but making adjustments like flooding, spotting and setting the barndoors for the correct cut is usually done with the lamp on.

It's vibrations or shocks which will shorten the life when moving the light around. That's not to say you can't do it, because you may need a light to be moved during a shot for an effect and battery powered tungsten lights are moved, but it can risk a shorter life.

[Mike Watson]

I had understood they exerted 47 pounds of pressure. I recently heard somebody call them C-74's, and I corrected him. He told me that when you take off the spring and turn it around, so that the long (typically handle) part was the jaws, and the short (typically jaws) part was the handle, it was stronger, and then because it was backwards it was a C-74. Clever, I thought.