Whats the difference between Beam angle, beam angle 2, field angle, field angle 2?

[Flavie]

Im creating my own symbol for custom LED strip and i wonder what should i write in : Beam angle, beam angle 2, field angle, field angle 2.

thank you!

[markdd]

The intention behind the two angles is so you can specify elongated lenticular beams like the ones you find in wide par lamps.

 

Beam angles and Field angles are both part of the beam from a Spotlight. Typically (If my memory is correct) the field angle is the last 10% of the intensity of the centre of the whole projected beam of light. This is always the outside edge. 

Edited September 16, 2021 by markdd

[JustinVH]

@FlavieI would agree with Mark's comment about the 10% rule.  The way I always remembered it was that the Field angle was the full outline of the beam so I always related the first letter of field and full to align with each other.  

 

For the Beam angle 1 vs. 2 and Field angle 1 vs. 2 the Field angle and Beam angle are the vertical spread of the light when it is facing upstage so the spread along the Y axis.  The Field and Beam angle 2 are the horizontal spread or the width so this is the direction along the X axis in the same position.  For a PAR that has a 30° vertical beam and a 50° horizontal beam Field angle would be 30° and Field angle 2 would be 50° to produce an oval beam.  Hope that helps.

[Flavie]

22 hours ago, JustinVH said:

@FlavieI would agree with Mark's comment about the 10% rule.  The way I always remembered it was that the Field angle was the full outline of the beam so I always related the first letter of field and full to align with each other.  

 

For the Beam angle 1 vs. 2 and Field angle 1 vs. 2 the Field angle and Beam angle are the vertical spread of the light when it is facing upstage so the spread along the Y axis.  The Field and Beam angle 2 are the horizontal spread or the width so this is the direction along the X axis in the same position.  For a PAR that has a 30° vertical beam and a 50° horizontal beam Field angle would be 30° and Field angle 2 would be 50° to produce an oval beam.  Hope that helps.

for a LED strip wich the manufacture describe with a 120 beam angle the field angle would also be 120 then?