Light colours

W

Walrus

Guest
Different rocks absorb more light than others, meaning the same light looks darker insome mines/caves than others. Is there a better light for one type of mine than another  based on the lamps light colour?

E.g. tungeston/halogens give a more yellow/white light than LED's which give a more blue/white light.

Suggestions please!
 
S

SLP

Guest
If you want my advice, which is based upon 25 years of refining my subterranean lighting systems.... don't worry about it and certainly don't waste anytime debating or observing the debated subject.  Just get something using current state of the art LED's (not cheapo imports) and devote your time doing something constructive underground, or watching Fiona Bruce reading the news because she's really foxy, which is what I'm off to do now.....
 
P

potholer

New member
There is a bit of a 'hole' in the spectrum of white LED light in the green area, so I suppose if rock was dark green (some kinds of slate?), LEDs might seem less good relative to incandescent lights when compared to their performance on limestone, which does tend to be shades of grey.
 
andysnook

andysnook

New member
Having just switched to a Nova3 (from an FX2) - which is pretty much white, with maybe a blueish hue, I have to say I quite quickly completely forgot about the change in the colour of the light.

Once in the cave the sort of things I was thinking about went more along the lines of :-

(1) I no longer have a heavy battery sitting on my belt which i constantly have to re-position when thinking about approaching any tight passage.
(2) I no longer get my lamp cable caught on rock flakes as i walk past on get it caught on something in the middle of a tight bit forcing me to reverse and start again with the cable repositioned.

The only major disadvantage I can see with LEDs is that it doesnt seem to throw the beam large distances.  Given that I've only caved on mendip, this is rarely a problem.

Essentially - I think that reliability of your lighting and how "practical" it is takes priority over which colours the rock are reflecting/absorbing.

From a purely technical standpoint, I'd suggest you are exactly correct - but would you really consider a light you consider impractical in the interest of seeing the rock in it's true colours ?
 
P

potholer

New member
To me, LED colour rendition seems fine - if anything, it seems more realistic than halogen/incandescent much of the time.
The only thing I've noticed seeming to look odd/different is grass when walking back from a cave, but I've never bothered stopping to do a proper comparison with halogens.

Distance is really a matter of beam formation rather than type of light source.
Long-distance LED spot beams are perfectly possible, it's just that there are other options, like the wider Nova-style beam, which can be a good choice for some kinds of usage.
 
graham

graham

New member
andysnook said:
The only major disadvantage I can see with LEDs is that it doesnt seem to throw the beam large distances.  Given that I've only caved on mendip, this is rarely a problem.
Click to expand...

Obviously it is a problem in G.B.
 
andysnook

andysnook

New member
graham said:
andysnook said:
The only major disadvantage I can see with LEDs is that it doesnt seem to throw the beam large distances.  Given that I've only caved on mendip, this is rarely a problem.
Click to expand...

Obviously it is a problem in G.B.
Click to expand...

Indeed Graham, alas I've not had the pleasure of visiting GB yet  :cry:
 
graham

graham

New member
andysnook said:
graham said:
andysnook said:
The only major disadvantage I can see with LEDs is that it doesnt seem to throw the beam large distances.  Given that I've only caved on mendip, this is rarely a problem.
Click to expand...

Obviously it is a problem in G.B.
Click to expand...

Indeed Graham, alas I've not had the pleasure of visiting GB yet  :cry:
Click to expand...

You'll love it when you do; it's got the largest chamber in Britain, you know.  (y)
 
andysnook

andysnook

New member
graham said:
andysnook said:
graham said:
andysnook said:
The only major disadvantage I can see with LEDs is that it doesnt seem to throw the beam large distances.  Given that I've only caved on mendip, this is rarely a problem.
Click to expand...

Obviously it is a problem in G.B.
Click to expand...

Indeed Graham, alas I've not had the pleasure of visiting GB yet  :cry:
Click to expand...

You'll love it when you do; it's got the largest chamber in Britain, you know.  (y)
Click to expand...

I've heard that once or twice before :)

Maybe I wont know !  Maybe i wont even see the sides with my puny LED light  :-\

Walrus - Where are you doing your caving ?
 
graham

graham

New member
potholer said:
There can come a point where a large chamber is pretty much like being on the surface at night.
Click to expand...

Apart from the whole ongoing negative moon & stars thing.
 
W

Walrus

Guest
I mostly visit Mendips ATM but I also see a fair few mines (with quite large chambers) - I was really wondering if there was much difference between light-types when used in a slate mine, for example, where the rock colours are quite dark - basically which type of light would allow me to see better (if there is much of a difference) or even if a coloured filter might help.
 
andysnook

andysnook

New member
Walrus said:
I mostly visit Mendips ATM but I also see a fair few mines (with quite large chambers) - I was really wondering if there was much difference between light-types when used in a slate mine, for example, where the rock colours are quite dark - basically which type of light would allow me to see better (if there is much of a difference) or even if a coloured filter might help.
Click to expand...

In that case I'd say simply go for the brightest light you are prepared to carry.

Something like an FX5 will have an incredible beam for distance stuff.  Although i have no experience with them, oldhams still have quite a loyal following.

I would also say that filters couldnt possibly help, they will only dim your light.  If you want to see a long way in big chambers i think you simply need the brightest thing you can possibly carry/afford.

What are other people that you cave/explore mines with using ?

Perhaps you need two setups, using whichever is most suitable for the trip.

(1) Great big powerful halogen "searchlight" for big caves/mines (almost certainly with big battery on belt)
(2) Small LED system with helmet mounted battery for tight stuff.

I think overall brightness will win over any discussion about whether it's LED based or not.  If it's bloody bright, you are going to have no problems seeing things.

What do you currently use ?
 
W

Walrus

Guest
andysnook said:
Perhaps you need two setups, using whichever is most suitable for the trip.

(1) Great big powerful halogen "searchlight" for big caves/mines (almost certainly with big battery on belt)
(2) Small LED system with helmet mounted battery for tight stuff.

I think overall brightness will win over any discussion about whether it's LED based or not.  If it's bloody bright, you are going to have no problems seeing things.

What do you currently use ?
Click to expand...

I currently use a Nova3 which is great for short to medium range and I'm going to try to modify a halogen lamp I got when I first started that gives a good spot light but poor spread (and its not waterproof). 
 
W

Walrus

Guest
Walrus said:
andysnook said:
Perhaps you need two setups, using whichever is most suitable for the trip.

(1) Great big powerful halogen "searchlight" for big caves/mines (almost certainly with big battery on belt)
(2) Small LED system with helmet mounted battery for tight stuff.

I think overall brightness will win over any discussion about whether it's LED based or not.  If it's bloody bright, you are going to have no problems seeing things.

What do you currently use ?
Click to expand...

I currently use a Nova3 which is great for short to medium range and I'm going to try to modify a halogen lamp I got when I first started that gives a good spot light but poor spread (and its not waterproof). 
Click to expand...

Grr, cant edit: Continued:

To use in addition to the Nova but I want to mount it on the helmet, and it uses a belt mounted battery pack - going to see if I can run both from one battery pack using a home-made mod. (save a bit of weight on my head!)
 
andysnook

andysnook

New member
Walrus said:
Walrus said:
andysnook said:
Perhaps you need two setups, using whichever is most suitable for the trip.

(1) Great big powerful halogen "searchlight" for big caves/mines (almost certainly with big battery on belt)
(2) Small LED system with helmet mounted battery for tight stuff.

I think overall brightness will win over any discussion about whether it's LED based or not.  If it's bloody bright, you are going to have no problems seeing things.

What do you currently use ?
Click to expand...

I currently use a Nova3 which is great for short to medium range and I'm going to try to modify a halogen lamp I got when I first started that gives a good spot light but poor spread (and its not waterproof). 
Click to expand...

Grr, cant edit: Continued:

To use in addition to the Nova but I want to mount it on the helmet, and it uses a belt mounted battery pack - going to see if I can run both from one battery pack using a home-made mod. (save a bit of weight on my head!)
Click to expand...

Ahhh - i see where you are going.

There is of course the FX3 style LED/Halogen hybrid type options.  (LEDS & a halogen) - but it seems a shame to waste your Nova3

I know the Nova3 can be run from an FX3 battery - perhaps that's where your solution lies ?  FX3 halogen is pretty bright.  Two lamps, one battery.

Is it going to get rather cluttered on the helmet with two big lamps ?  I find that even my very slim backup is a little annoying (princeton attitude)
 
P

potholer

New member
Walrus, does your Nova3 have a regular Headlite battery connector?
If so, are you planning on making a twin-light setup permanent (rewiring the Nova?), or doing something like putting a socket in the cable from your waist-pack to plug the Nova into, allowing you to switch back to a helmet-mounted Nova if you want to?

FX3 halogen is pretty bright.
Click to expand...
I reckon that one of my 1W LEDs gives a better beam than a 2.4W FX3 halogen.
 
E

emgee

Guest
Walrus said:
I mostly visit Mendips ATM but I also see a fair few mines (with quite large chambers) - I was really wondering if there was much difference between light-types when used in a slate mine, for example, where the rock colours are quite dark - basically which type of light would allow me to see better (if there is much of a difference) or even if a coloured filter might help.
Click to expand...

For a slate mine there's a lot to be said for taking one of the big rechargeable spotlight thingies you often see on sale in car accessory shops. They'll only last twenty minutes or so but that's fine cos you only have it on for a minute or so at a time.
 
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