Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Brian Garrett]

I have several Chauvet Intimidators, 4 of the 255's and 4 100's (amateur, I know).  I'd love to convert some of them to beams.  I ordered a chauvet fresnel lens, from another light.  I first held it up to a small 3-LED mag-lite that I had in the house and the wash on the wall across the room turned into 3 distinct dots that match the LED's in the source. Super excited, I eventually got one of my movers out and played with it for about an hour and could not get the beam to tighten up at all.  I tried moving the lens in/away from the existing external lens looking for a focal point, but saw no impact.  I then removed the nose of the light to allow me to play with the focal point all the way down close to the source and out to the existing lens' focal point.  Still didn't see the impact I was looking for. 

Am I thinking about this correctly?  I actually ordered a nose assembly (called lens socket) and intend to try to replace the existing lens with the fresnel just to see if it is my lack of capability to replicate the focal point accurately, assuming it is in the same spot as the existing lens. 

Any ideas? 


This is the lens I bought, not sure if you can tell anything from it. 
https://www.chauvetparts.com/product.htm?pid=162499&cat=14527
It's used in several of their smaller beamy products, such as the Beamer 8 and the Rotosphere, which are super beamy and appropriately sized for what I was trying to replace.   

Brian

[Dave Garoutte]

Optics don't always do what you expect.  The relationship between focal points, etc can make all the difference.  Fresnel lenses are generally used to make a soft edged wash, as the ridges tend to scatter some of the light.  Have you tried it in both directions? 

[Don T. Williams]

There is a relationship between the physical size of the lens and how narrow and sharp of a beam that can be produced.  The Intimidator 355 IRC "beam light" has the largest diameter of any of the Intimidator LED series.  I believe it has a plastic Fresnel lens.  The reason for choosing a Fresnel lens in this application (in any application) is so that the lens can be thinner, and in this case much lighter in weight.  A plano-convex lens would have to be much thicker in the center and thus much heavier.

[Brian Garrett]

So, Don you think that I need a much larger diameter fresnel to really affect these lights the way I want?  I get what you're saying.  The 350-Beam version has a giant lens face compared to the "spot" version (which is the 14-ish degree beam).  You may be right.  I don't quite understand though.  I'd assume that whatever part of the light's current beam hit this little fresnel would tighten up and give a dense beam in the middle. I didn't see that to be the case.  The 350's lens is $18... and if it worked, then I'd have to make some crazy contraption to hold it... which as you guys say would be a weight factor and I wouldn't go down that path.  I'm too amateur to be spending $50 for each light all while putting the mechanics at risk.

David - I'm pretty sure Fresnels are for aligning a beam more so than softening the edge of the wash.  The ridges are slight adjustments to the light in that portion of the lens' diameter. It's like having a larger convex lens, just all condensed to be effective in the thinness that Fresnel's offer.  I did try it both directions, but assumed the ridges should be away from the source.  At least, that's my understanding. 

[Jeff Lelko]

I'm pretty sure Fresnels are for aligning a beam more so than softening the edge of the wash.

I wouldn’t say you’re wrong, but you’re not entirely right either.  At the heart of the matter, as already stated, a Fresnel lens is a type of compact lens that allows for applications where a conventional convex or plano-convex lens would be prohibitive due to size and weight.  Historically, yes, these lenses were originally made for lighthouses to focus the beam and project it for great distances.  In theatrics and general lighting applications, the Fresnel is a type of wash light (soft edge). 

There’s more to optics in a light fixture than just the type of lens in use.  An equivalent would be saying that everyone who’s nearsighted gets one generic type of glasses while the farsighted folks get another...which we know isn’t correct in its entirety.  Just like glasses are made to fit the individual who wears them, light fixtures and lenses need to be matched appropriately to yield the desired effect. 

An example are the Martin Mac Wash to Beam conversion kits - swapping one lens for another - both intended to work on that exact fixture only.  The lens(es) inside S4 lens tubes also aren’t interchangeable.

Honestly, and this goes for all DIY mods to light fixtures, if you want a beam light, buy a beam light.  If you want a spot, get a spot.  If you want a hybrid, they make those too.  At the end of the day you’re probably going to spend just as much money trying to shoehorn something to work with inferior results compared to just buying the right thing to begin with...not to mention taking into account the risk of damaging the original fixtures.  Hope this helps!

[Brian Garrett]

...this goes for all DIY mods to light fixtures, if you want a beam light, buy a beam light.  If you want a spot, get a spot.  If you want a hybrid, they make those too.  At the end of the day you’re probably going to spend just as much money trying to shoehorn something to work with inferior results compared to just buying the right thing to begin with...not to mention taking into account the risk of damaging the original fixtures.  Hope this helps!

These are the thoughts that I had going in, but saw a similar sized fresnel to my little movers lens at a very reasonable price.  I thought maybe I could swap it out, focal point is probably the same (ignorance is bliss).  Maybe I could swap the nose/lens in/out depending on the show/look I'm going for. 

Realistically, I'm a musician... who has lights. I'm not a pro light guy, you can tell by my gear.  I'm raising the bar in the very local area on what can/should be done as far as gigging musician light setups go, but if I clear $100/gig after a few beers I'm lucky. Therefore, I'm lucky (or even financially wasteful) to have what I have. Can't really justify having what I have, much less a nicer set of lights that zoom/focus or an additional set of lights to be beams.  I need to learn to be satisfied with what I have!

[ProSoundWeb Community]