Match's Mods: Homemade Integrating Sphere

Flashlight Modding and DIY Parts Featured Mods
101

For the US/UK users I see most people use Lux. 1 FC x 10.76 = 1 Lux. Other than way bigger numbers while using Lux, any reason not to use Foot Candles?

For whatever reason my 14.5” IS/Meter combo uses in LUX:10.40697674418605. The correction for 172/1790. After looking at the correction number for my (only) ANSI/NEMA FL-1 certified light of 172 lumens, I switched to FC on my meter. Basically same readings but now can use direct readout. I understand if I change meter or repaint sphere, everything changes.

I see that many others got correction numbers from 7.xxx to 12.xxx, so while fun, I would need to send IS, meter and light to BLF laboratories, INC? I like the suggestion to buy a few more calibration lights, so will continue to enjoy using the IS.

102

Going to build one of these! :smiley: Thanks Match!

103

Welcome to the ball-of-light measuring group. :slight_smile:

104

What is the dome made of?

105

Bort, you look different, did you cut your hair?

106

The sphere top and bottom halves were originally two large round thermoplastic salad bowls.

107

I did, about a month ago

I also recently shaved, have considered selling a few lights, and started a new health regimen

108

i think you could make more of your spheres and sell them for profit :slight_smile:

109

The one i built above took a bit of time to build, not sure if there is any profit in it for the time and parts used.
I have it calibrated very well now though.

110

But you can undercut professional model prices by a huge margin, perhaps by more then 90% :wink:

111

This would not likely be close to as accurate to a professional “laboratory” Integrated sphere.

112

Of course, but since we like budget, a reproducible integrating sphere will suffice just like a Convoy will suffice vs a surefire :smiley:

I think you should create a build thread for your device, i am curious where you got those salad bowls

113

I thought it did, but realized that i never did a build thread on it yet.

114

Nice work DBSAR! It looks very handy with all the mounting options around it.

The accurateness of professional spheres has much less to do with the actual sphere, much more with the better measuring equipment and calibrated sources, a home made sphere like we make already has excellent integrating properties.

115

Good point. for most of us the only way to “calibrate” our Integrating Spheres is calculations based on testing our stock known ANSI measured Lights, in my case is a few fenixes, Nitecores, Olights, thrunites, etc.

116

Modding flashlights to advanced for me but messing with papier maché I am in!

117

For the purpose of consolidating information regarding IS's here are a couple of links for those who may be interested in a source for Barium Sulfate products for the inside coating if one were to choose that method.

This is just one supplier that was mentioned in another forum. It is not known if they are more or less expensive than any others.

Labsphere, Inc.

A Halma Company
P.O. Box 70
231 Shaker Street
North Sutton NH US 03260
+ 1.603.927.4266 (ph)
+ 1.603.927.4694 (fax)
labsphere@labsphere.com
www.labsphere.com
And their coating products page: http://www.labspherestore.com/category-s/8.htm
as well as a highly technical data page about their coatings: http://www.labsphere.com/products/reflectance-materials-and-coatings/white-coatings/6080-white-reflectance-coating.aspx
Best wishes
118

Well… I found a globe …:slight_smile:

119

great idea. thanks!

120

Welcome to BLF!
Match’s coating was plain flat white paint without BaSO4 what I remember, but his sphere was made many years ago and Match is not around here anymore.
A BaSO4 coating can indeed be 0.96 if done well, but I doubt that DIY formulations containing BaSO4 will be anything close to that, and even if someone did a good job at it, the experiment for testing the reflective value is difficult without proper laboratory equipment. And then you also want to measure the reflectivity across the spectrum…