DIY Fresnel
 

i can't for the life of me find anything on DIY fresnels.
so, im going to make one.

im planning on using the arri replacement lenses on B&H. i figure i can get the cost for about $50 for a 300w and about $70 for a 650w.

i have some questions on which lamp standard (fixture type to use. in the 300w version, ill have a diameter of 3.5" to fit a light fixture in, and 6" in the 650w ver. which lamp standard will give me the best combination of low cost, durability and efficiency?

There is probably a reason you cant find anything. There isnt much need to reinvent the wheel here. If you want to do this for fun go ahead.

But you might consider picking up some older units off of Ebay and rehabilitating them instead. You get some pleasure out of the tinkering, wont spend much money, and likely will have a much more stable result.

In the last 6 months I have bought a pair of 6" units (EC, precursor to ETC), and 3" (MacAllister), and a set of 3" Altmans this way. The 6"s needed rewiring and stand adapters as they were stage units. Spent about $120 total to get 2x750 watt 6" fresnels with extra lamps. The first 3" unit was in excellent shape and just needed a lamp -- about $40 total. I got the three Altman dinkys for $30 total but they were pretty tired. Descaled the lenses (hot vinegar soak), rewired, new sockets, upgraded lamps, and added some replacement knobs and stand adapters. Mabye $70 total for 3x 3" 200 watt fresnels.

I am currently putting together snoots out of coffee cans.

So think about it. The three qualifications on the ebay route is that the cheap fixtures will be older than they purchaser (and I am in my 40s), they will probably not be Arris or other major brands, and you need to make sure you can get the lamps for them before you buy.

Holy cow, I was just going to start a new post and ask if anyone had done this! Out of curiosity, the inside of the coffee can is shiny metallic. Do you plan to do something with the inside to make it more of a matte black?

Sure--high temperature matte black spray paint does the job. You definitely can't leave it shiny.

I found that a standard 34.5 oz coffee can is just the right size for the 6" fresnels. Cut the bottom off, pop rivet it onto a sheet of metal (sized for the ears on the fixture)with a hole cut out, paint it black, and you're good to go.

Of course snoots are also cheap to buy. It's the barn doors that get pricey. When you have spent <$50 on a fixture with lamps it is hard to justify $60 for a set of doors. So I'll see how the snoots do.

I have a stage fresnel and some spots that i picked up at my local hs after they took some down because they were considered "unsafe" (most likely due to the fact they weren't safety cabled to the riggings for earthquakes).

i guess just everyone buys their own crap for lighting. either that or the $20 worklights at home depot. i guess im trying to go inbetween with a nice home depot feel yet some low-end brand name parts in there.

originally, i was going to incorporate the fixture used in the arri's but realized they're too expensive. instead, im opting for the light fixture used in most over headprojectors. they're cheap-er and come with a built in reflector.

hmm, the coffee can idea seems interesting, ill investigate that. diy barn doors anyone?

Use blackwrap for barn doors?

In some cases tinfoil would work ok.

I bought several 6" L&E fresnels from a theatrical supplier a few years ago. I think I paid well under $100 per can, plus bulbs (and I had to wire them and buy spuds). Very happy with 'em.

Here's L&E's fresnel page:
http://le-us.com/fresnels.html