Light Coverage - spill-diameter Pics

[UnknownVT]

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]

 

[LEDependent]

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.

 

[stephenanderson2]

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

 

[Aten_Imago]

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?

 

[jtice]

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

 

[UnknownVT]

[ 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.