Best Red LED light for reading charts?

[paulr]

All of you talking about standard flashlights like the Peak Led or Surefire L1, or about rigging up button cells to power a led at 20 mA, have to understand those things are all way too bright for this purpose. You're not trying to light distant objects with it or walk around in the dark. It's just for looking at some white dots on a chart that you're holding the light 2 inches away from. 20 mA is way too much current and even 1 mA is too much. You want something like 0.1 mA or maybe even 0.01 mA. Also, the light doesn't have to be tiny. It's for astronomy, you're lugging a telescope around, you're lugging a tripod around, plus whatever else; a normal sized (say 2AA sized) flashlight isn't going to make any difference.

I had thought Rigel pretty much had this problem sewn up. Their stuff has always gotten good reviews til now. Maybe they've improved in the last 7 years. If not, maybe there's room for someone to do a better job.

Yes, the Photon Freedom sounds very promising if the DEET doesn't dissolve it. I myself must say that if the DEET is corrosive enough to dissolve flashlights, I can't understand why I'd want to put it on my skin.

 

[Lurker]

It's probably not the DEET, but the carrier. Bug sprays use a volatile carrier that dries quickly, such as alcohol. Alcohol is not really harmful to skin, but is a solvent and can dissolve certain substances. I have a watch with a plastic crystal that shows spotting from being sprayed with bug spray. Once it dries, I don't think there is any risk remaining from the DEET.

 

[DharmaBum]

I just got a Peak prototype with red LED and it's quite dim, especially compared to the Arc. Not having ever read anything with a red light, I guess I can't say, but I think it'd still be worth the $15 to try. With the tape "lens" I think you'd be pretty happy, but then again I have no idea what I'm really talking about! /ubbthreads/images/graemlins/grin.gif

 

[MrBenchmark]

[ QUOTE ]
paulr said:
I myself must say that if the DEET is corrosive enough to dissolve flashlights, I can't understand why I'd want to put it on my skin.

[/ QUOTE ]

Well, you aren't made of plastic... /ubbthreads/images/graemlins/wink.gif DEET is far and away the best insect repellent available. It's been used for decades, and is reasonably safe if you follow the directions. It just melts some plastics. The only other really effective alternative I know of is to pre-coat your clothing with permethrin. (Sorry, OT, I know...)

The rigel starlite is a good light for astronomy. I've emailed rigel and asked them about the plastics in their new lights. I may get one anyway and try it out. (I will also probably get the Freedom and see how it fares.) If I come up with anything interesting, I'll post it here. I appreciate all the suggestions!

 

[Aloft]

Mr. BenchMark. . . just got in a "new" Gerber Infinity Ultra with red LED. I think it's quite suitable, as I'm an amateur astronomer myself. In fact, I bought a couple to send to some Coast Guard friends for use on the bridge at night. It's not really too bright, but still bright enough for some basic navigation around the scope, as well as for star charts. During my quick "closet test", I compared it to my Surefire L1 (also in red). . . the Gerber puts out a much wider, more diffuse beam, and does not look TOO bright for Star Chart work. The Surefire puts out a very prominent hotspot even on the low setting which you may find too bright for chart work but better for "navigating" and setting up or securing your scope. As you probably already know, Brightguy has the Gerber for about $17.50, as will most other supporting dealers. I paid $125 for the Surefire, and the batteries can't be had at Costco like the Ultra's! No doubt, the Surefire has a superior beam, as it should for that price.
BTW, my Gerbers are the "new" body style. . . with the twisty tailcap switch. I'm not sure if I like it better or not yet. . .

 

[MrBenchmark]

Thanks for the recommendation on the Gerber! I'll check it out. I bet the red L1 is awesome - I'd never hear the end of it from my wife if I got one of those, though! /ubbthreads/images/graemlins/icon23.gif /ubbthreads/images/graemlins/tongue.gif

 

[paulr]

The Gerber will be very similar to a Photon or similar 5mm led light at full brightness. One thing you can do if you're only using it for brief periods is simply put your finger over the bezel and uncover it just enough.

 

[PAtwood]

Another good choice might be the Nightcutter Chartlight. It's an anodized aluminum 3 LED light with decent brightness, great flood and a 400 hour runtime. A set of batteries, CR123, would probably last you a year.

 

[sotto]

PAtwood:

My Nightcutter Chartlight actually has a rather focused beam that has clear rings in it. My red LED Infinity Tasklight has a wider beam with no rings at all /ubbthreads/images/graemlins/icon3.gif. I also just ran a 48 hour test on the Infinity using a "dead" Rayovac AA alkaline cell that wouldn't run my scanner anymore. It lit the light brightly I would say for 24 hours, continued to show a useful level of light (say for navigating around the house at night) until about the 35 hour mark, and when I just shut it off a moment ago at 48 hours, it was still putting out enough light IMHO to read a starchart by. Not bad for a "dead" battery. /ubbthreads/images/graemlins/smile.gif

 

[Wolfen]

Tape won't hold on a light if the DEET gets on it. So some other type difuser is a must for the Infinity. Kevin at BatteryStation.com might have some old red Infinties in stock.
Give him a look see, one of the best dealers on the forums /ubbthreads/images/graemlins/smile.gif

 

[BC0311]

The Infinity with a red LED looks like it's still available from The Battery Station for $12.00 plus shipping. This price is found on the CPF Members' Discount page which the link opens.

I've read some time ago in this forum of members finding plastic caps from small containers that fit snugly over the Infinity's bezel that diffuse the light. If it diffuses it too much, try paulr's pinprick method for a tiny "hotspot".

Be sure and mention your CPF handle if you order. Also note that you can get Battery Station CR123A 3 volt Lithium cells for $1.00 each plus shipping. /ubbthreads/images/graemlins/thumbsup.gif

 

[The_LED_Museum]

[ QUOTE ]
paulr said:
...The Freedom at its dimmest level is very dim, though.

[/ QUOTE ]
The white LED Freedom Micro is just 30mcd on its dimmest setting.
I don't know how dim the red one is at the same setting, or if the case is DEET-resistant.

 

[MrBenchmark]

[ QUOTE ]
The_LED_Museum said:
[ QUOTE ]
paulr said:
...The Freedom at its dimmest level is very dim, though.

[/ QUOTE ]
The white LED Freedom Micro is just 30mcd on its dimmest setting.
I don't know how dim the red one is at the same setting, or if the case is DEET-resistant.

[/ QUOTE ]

I ended up getting a red photon Freedom covert. I'll let y'all know how it works out. The dim setting is really dim - I can stare into the LED with no problem. It is a tiny thing. I'll see if it has any problems with DEET. I'll use the nasty, 100% DEET spray next time I take my telescope to the dark site. I'm hoping it works out - it is a lot more pleasant around my neck on a lanyard than a 9v light.

I appreciated everyone's advice - if this light doesn't work out, I'll be trying some of the other ideas.

 

[paulr]

Cool, please do post your results.

 

[MrBenchmark]

Well, I got a chance to try my Photon Freedom Micro (covert) red LED light while stargazing from the dark site I use this weekend. Overall, I am pretty satisfied with this light as a chart light. I used mine with a neck lanyard. The nice thing about this light is that it's easy to forget you are wearing the thing. The other red lights I have (Orion and Rigel Systems) are a lot heavier!

The dim light settings on the light are quite dim enough - I used mine to thread filters onto eyepieces, read charts, etc. You can easily adjust the light to be just bright enough. The only downside to it is you have to do this every time - it would be nice if you could make the brightness setting "sticky." This would be a lot more useful than the strobe and SOS modes - since the light is a covert model these are pretty useless anyway. The covert version is nice because there's no sidespill from the light at all. This is great for reading charts without annoying your neighbor. For that matter, you can just leave the light turned on all the time on a dim setting, and the stray light won't annoy your eyes. When looking at very faint objects in the eyepiece, even the faint red glow from the LCD panels on my telescopes hand controller, and the 5mm red LED on the top that's a "chart light" can be *intensely annoying*. (These are both pretty faint - no way would anyone here consider them to be a flashlight!)

Anyway, I found the adjustable brightness to be completely adequate for doing close work or reading stuff in the dark without ruining my dark adaptation. Kind of a nifty and well made little device.

I tried navigating around the site with the light on full brightness. I didn't like that as well. There's no sidespill, and since it's a single LED, it's just not that bright. I could walk around with it, but I really didn't feel completely comfortable doing this. It just didn't seem too safe - the projects my astronomy club undertakes tend to go on for a long time, and half-finished foundations are kind of all over the place... So I found I used my Inova X5t red led light while walking around instead.

Still, I'm happy with the thing. On a lanyard you just put it on and forget about it until you need it.

Oh, I almost forgot - I didn't seem to have any problems with it with DEET based insect repellent.