Light Coverage - spill-diameter Pics

Link to previous post -
Light Coverage - spill-diameter

I combined two (CPF members') brilliant ideas together to get these shots -


[Note: these are Redone photos attempting to align the protractor better as suggested in 2 responses]


The actual measurements I got from the previous post were:
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All lights with front bezel 12" away from wall

Light/ Diameter/ Angle/ Lens equiv on 35mm camera
Ray-O-Vac Lantern/ 43"/ 122deg/ 12mm (extremeWide - almost fisheye)
Streamlight Scorpion/ 36"/ 113deg/ 14mm (extremeWide)
SureFire 9P/ 26"/ 95deg/ 20mm (ultraWide)
Ultra-G/ 22"/ 85deg/ 24mm (very wide)
Dorcy 1AAA/ 21"/ 82deg/ 25mm (very wide)
ArcAAA/ 15"/ 64deg/ 35mm (semi-wide to normal)
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Set Up -

I used tape to stick the lights to the inside front of the jug then tried to align the protractor on the front face - which was difficult for the photo - later I found leaving the protractor taped to the front and then taping/aligning the light to the inside of the jug was somewhat better.

More lights:


and finally a Photon 2 Yellow and a 20 for $20 body with an old Photon I Yellow LED and 7 year old battery....


Comments please?

[edit - to replace first 3 photos for better protractor alignment]

One comment - on the first few shots, line the protractor up with the light source itself. Notice how the edges of the beam are not parallel to the protractor lines - they should be.

Yeah, what he said.... It will make a huge difference in your readings... /ubbthreads/images/graemlins/thumbsup.gif

Vincent
Nice idea!. Hey, couldn't you simply hang a piece of say 8'Widex8'Tall Photo background paper on a wall, draw the protractor lines on it and position lights at the floor agaist the wall pointing up at the ceiling- like you did but on a bigger scale. It would also give you accurate reading since you'll be measuring the beam further away from the source?

That is very creative and brilliant!

Those do an excellent job of showing the spread patern on those lights.

May I please add those to the BeamShot DataBase?
Or do you have those on a site of your own, that I can give a link to?

Great work.
Look forward to seeing more shots done like this. :thumbs:

-John

[ QUOTE ]
LEDependent said:
One comment - on the first few shots, line the protractor up with the light source itself. Notice how the edges of the beam are not parallel to the protractor lines - they should be.

[/ QUOTE ]

[ QUOTE ]
stephenanderson2 said:
Yeah, what he said.... It will make a huge difference in your readings... /ubbthreads/images/graemlins/thumbsup.gif

[/ QUOTE ]


Thanks for the input -

I've replaced the first 3 photos in the original post with Redone ones - attempting to align the protactor better -

Just so people won't think these two were complaining about nothing -
here's the original photo of the Ultra-G - showing the misalignment -



In fact even on my Redo of the Ultra-G - when I took pains to align the protractor with the beam -
somehow the photo still showed it mis-aligned -
so I redid the redo - this time looking from the camera to align the protractor -
still not perfect - but a lot better than any of the previous attempts........

Hope those first 3 (Redo) photos are better.