borofloat, UCL, mineral

[jayhackett03]

so, which lens is best? what good about each one? bad?

 

[DownUnderLite]

Good question. I was wondering about this myself?? :huh2:

 

[DUQ]

UCL has an anti reflective coating giving it 98% transmisability, Borofloat is almost as clear but can handle higher temps and mineral glass is good and cheap. I think UCL may chip easier than the two.

 

[VWTim]

Yup, I think mineral glass is used for cost savings. UCL has the highest light transmittance, with Borofloat not quite as good. I have switched all to Borofloat as it's much more durable, it's along the lines of pyrex for impact and thermal resistance.

hth,

 

[bwaites]

My experience, after buying literally hundreds of Borofloat, dozens of UCL and mineral glasses windows (the correct term for what goes in a flashlight, lenses bend light, windows allow it to pass) is that all three of them chip fairly easily along the edges.

Borofloat handles high heat better. I've literally shattered UCL lenses with the heat from Mag85's and especially from the USL lamps.

Bill

 

[litho123]

Everyone has nailed it correctly...

I've switched to Borofloat lenses after cracking 2 UCL lenses due to the heat generated by the 1185 and 1166 bulb during extended use.

I have yet to crack a Borofloat lens.

 

[jayhackett03]

well, i just bought 2 UCL lenses last night. hope they don't break in my Mag85.

keep the info coming...

 

[Colorado Fatboy]

FWIW, Borofloat and Pyrex are both brand names of borosilicate glass. In simple terms boron is added to the raw materials when it is manufactured. The boron gives it excellent thermal resistance.

As for strength any glass that is annealed (not tempered) will be about the same. Provided it is the same thickness. Tempered glass is four times as strong as annealed glass.

If you notice Surefire advertises their windows as "Tempered Pyrex". The tempering will give it a little more thermal resistance but it mostly adds strength.