DIY LED RTI array

[Charles Walbridge]

I've put together a cheap and quick lighting array for making RTIs of daguerreotypes we have in the collection of the Minneapolis Institute of Arts. I used lighting equipment we have in the photo studio, LED spots we use in the galleries, and about $30 worth of lamp wire and cord switches. 

The light stand I've used has wheels, so now two of us can shoot the 48 source images for an RTI in about 10 minutes. Because the four lights on the array are the same distance from the object, I can position the array at 12 o'clock, measure the distance to the object with my fancy RTI string, and then turn the lights on and off from the cord switches on the individual lamps. Then I'll roll the stand to the one o'clock position and repeat the process.

I've put up pictures of the array on a Google Plus page here:

https://plus.google.com/u/0/b/112094054932297248042/112094054932297248042/posts

and I can share them with the RTI community on Facebook too.

Let me know what you think --

 

 

[marlin]

Love it, looks good! Nice work.

 

Simple, cost effective, it must work well, certainly less expensive than an automated light array.

 

Continuous Lighting. How do you like those lamps? output? color temp? consistent across all four bulbs?

 

Are you getting a fast-er shutter speed at ISO 100?

 

you have seen previous work at the smithsonian, the 'Manits' light rig? very much like your model but with flashes?

I'll try to find the url

 

good work Charles! thanks for the share!

 

Marlin.

[Charles Walbridge]

Update: I've added a wifi-enabled microcontroller (like an Arduino) and a relay to my RTI lighting array so I can control the four lights from my phone while I'm shooting at the computer. I still need to move the array to each of 12 spots on the floor (when I'm shooting 48 source files for the RTI), but it's definitely a time-saver. I'd like to write a program to trigger the lights and the camera in sequence, but that's beyond my ability right now. There's a little more info at the page I made here: http://goo.gl/fMdQtW

 

Marlin, I forgot to answer your light questions in the comment above: The lights in the array are the same LEDs we use to light art in the galleries at the Minneapolis Institute of Arts. They're Philips Endura PAR 38s, 2700 degrees Kelvin, and they're rated for 45,000 hours of use. They draw 18 Watts, and they don't get hot, and we've found them to be very consistent from bulb to bulb. At about three feet, my exposure was f13 at half a second and 50 ASA, which is no trouble with my solid tripod and concrete floors.