Max temp/load of UCL with LDF film?

[wquiles]

I just got my order from Flashlightlens and I can't be hapier with the "D" size M*g UCL lens with LDF. The beam is absolutely beautiful. All artifacts gone - nothing but a nice beam!

Questions:
1) Using this lens with "standard" low wattage bulbs is of course OK, but will this lens/film combo be capable of really hot temperatures such as those encountered with a Mag85 usage?

2) Does using a metal reflector with LOP or MOP but with a "simple" clear UCL lens give me as nice beam as using the stock reflector and the lens with the LDF film?

Thanks in advance,
Will

 

[wquiles]

Trying again /ubbthreads/images/graemlins/crazy.gif

Is it OK to use the UCL-LDF with the mightly 1185 lamp?

Will

 

[pyro]

The LD film is Lexan, so i highly doubt that it will stand angainst the heat.

 

[KevinL]

I've heard things that it may not be safe for anything more than short runs. After all, LDF = Lexan Diffusion Film. It's probably the reason why we all upgraded to glass lenses as opposed to using polycarbonate - heat messes up plastic.

 

[wquiles]

Thanks. That was exactly what I though as well. I am glad I asked before trying /ubbthreads/images/graemlins/grin.gif

Will

 

[NewBie]

Schott Glass makes some nice glass diffusers, forget the name of the product right now. Poke around on their site.

 

[Thertel]

I can give first hand usage on that product actually, It works fine in about 5 minute bursts on the light with little or not down time between bursts. I used it like that for about a week just constantly depleting batteries, and never noticed any damage, though what I did was face the glass inwards and the LDF outwards.

Thomas

 

[kubolaw]

You may want to ask at flashlightlens.com. I've used LDF lenses on Carley 808's and WA1185's and WA1318's with no noticable lens degradation, but I don't think I've ever had a runtime of more than about 10 minutes or so (probably less with the 1185).

John

 

[paulr]

Use a textured reflector to get rid of artifacts. Borofloat is the recommended lens for hot bulbs.

 

[Xenon]

I'm using the Borofloat LDF with the 1185 and never noticed any melting of the film so far. Of course I've never kept the light on for longer than a couple of minutes, not that I'm worried the LDF might melt, but rather the bi-pin socket melting.

Ginseng, if you're reading this, anymore of those mica heat shields for the bi-pin socket that I may purchase from you? I'm now using aluminium foil to protect it, but don't know if I'm doing more harm than good.

 

[NewBie]

There is also this material, which will stand up to the heat, but may be a bit heavy on the diffusion side:

http://www.sgdisplayglass.com/products/smoothlite.html

http://www.sgdisplayglass.com/Fiches_produit/DataSheetSmoothlite.pdf

 

[wquiles]

I went ahead and tried for brieft bursts my MC85 with the UCL-LDF - I had to see for myself what would happen. As expected, the beam goes from ultra bright and ugly, to a very bright flood-type beam that is simply beautiful.

To my untrained eye, it looks less bright since the intensity is not concentrated in one central spot but rather spreaded around. It would also look to have lost trow compared to the stock clear lens, which makes sense.

I should note that for this test I used the lens with the LDF film on the outside (side opposite to the hot lamp!).

Will

 

[AW]

Does anyone have any idea of what is the light transmission rate of the LDF? My guess is 70 to 85%. The beam is certainly less bright with such kind of loss. In addition, there maybe color shift, however, not always observable for an incan yellow beam.

 

[bwaites]

OK guys,

This has been brought up before and Quickbeam did some tests a couple years ago:


http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Number=357794&page=0&view=collapsed&sb=5&o=&fpart=1

Here are the results if you don't want to go find it:

"I finally got around to trying out a bunch of replacement lenses in my "Lightbox apparatus" with a 4-D Mag. There are the results.

No Lens ---- 4000 (Baseline)
UCL Lens --- 3980
UCL LDF ---- 3950
Stock ------ 3800
Acrylite --- 3650
Writeright - 3650

So there you have it! This was a measure of the overall output from the 4-D with the various lenses in place, focused to the tightest point.

With my apparatus the UCL shows about a 5% improvement over the stock lens.

The UCL-LDF, although it diffuses the heck out of the beam, still lets almost all of the light get through!

The Acrylite and WriteRight perform about the same for overall light output through the lens.

The stock lens cuts out about 7% of the light coming from the reflector! Ouch!"

So far as heat resistance, Chris at flashlightlens.com thinks that over time the coating may yellow as lexan does, but that the bonding process used to bond to glass should make it pretty stable. He doesn't THINK it should deform in any way. I've run one in front of a MC60 for extended periods and it it looks new.

YMMV.

Bill

 

[wquiles]

/ubbthreads/images/graemlins/bowdown.gif

That was TOTALLY AWESOME /ubbthreads/images/graemlins/buttrock.gif

Thanks much for searching back and sharing this data with us. I guess I deserve this /ubbthreads/images/graemlins/whoopin.gif for nor searching this better /ubbthreads/images/graemlins/oops.gif

Will

 

[bwaites]

Credit is due Chris, who I asked, he keeps incredibly good track of all the info on his products, and I just went to the source and asked!

Bill

 

[Xenon]

bwaites,

Thanks for the useful statistics!

But I find the UCL-LDF reading rather high, my LDF certainly let through less light than a writeright, in fact by a fair margin. In fact I tried two layers of writeright and its still let through more light than the LDF. Sounds strange. But then again, mine's a Borofloat.

With B-LDF, my MC85 is only as bright as a 9P, thats how much loss I am experiencing.

 

[bwaites]

Interesting,

Your talking about essentially a 90% loss!

MC85 is around 800 torch lumens, 9P is roughly 100-120. Thats a loss of 700 lumens!

I know mine don't lose anywhere near that much.

Bill

 

[PlayboyJoeShmoe]

My really hot (1274 and 1185) lights have no lense, as I have no glass.

I don't find either light to be ugly, except maybe on a white wall. I can see very clearly for a good ways off outside!

Now on any regular KPR or XPR bulb, I will NOT tolerate the crappy ugly beam, instead going for Writeright or Acrylite instead. Perhaps it's because the stockish bulbs ain't bright enough to overcome the artifacts, because the superbulbs just PUT OUT LIGHT!

 

[wquiles]

Xenon,

/ubbthreads/images/graemlins/wow.gif

I just tried my P90 side by side with my MC85 (with the UCL-LDF) and it is not even close!. When the MC85 fires up, you simply want to hide /ubbthreads/images/graemlins/aaa.gif

I am using 7 el-cheapo RadioShak 1600mA and 2 Rayvac 1600mA, and all of these are old!

Maybe something wrong with the batteries on the 1185 setup? /ubbthreads/images/graemlins/poke2.gif

Will