Watt's a lumen?

To understand the lamps you need to understand some common terms. Amps are the measure of electrical current that flows through a circuit of part of it. The standard Oldham caplamp bulb runs at 1 amp. Volts technically defined as potential difference or electromotive force can be equated to pressure like the pressure of water in a tap. Turn on the tap the pressure drops and you have a current. Watts* are units of power and are arrived at by multiplying the amperage by the voltage. The standard Oldham caplamp has a 1 amp bulb and the battery is rated at 4 volts, so its classed as 4 watts.

(* Defined as a duration of energy equal to 1 joule for 1 second)

Lumens are units of light that are actually produced at source, and should not be confused with Lux which is a measure of light falling on a specific area. The standard Oldham caplamp produces 48 lumens of light for a consumption of 4 watts. LEDs produce a lot more light, a Cree Q5 XR-E will produce 228 lumens at 4 watts, a Cree R5 XP-G about 360 lumens.

A 220volt 100 watt light bulb produces about 1000 lumens, this is the league we are in with my lamps.

However, lumens do not tell the whole story, second to this in importance are the optics, its no good having a powerful LED if half the light goes to waste. This explains why you will sometimes see a lamp rated at say 500 lumens beat one rated at 600 lumens.

The relationship between lux and lumens is fully dependant on the way that the light output of the LED is managed, this a bare emitter could have a very high output expressed in lumens, but would have a very low lux, equally a miners lamp such as an Oldham DL 16 will have a very high lux for its relatively low lumen of 90 lumens. This is becuse all of the light generated is focused into a very tight beam.

So if we widen the beam say by 100%, in order to maintain the lux rating and therefore the throw, we would have to increase the output of the LED by 100% to 180 lumens.

We have a wide range of caplamps suitable for caving and mine exploring, these include what must be the most powerful lamps designed for this purpose available in the world. All of our lamps are based on the well proven and reliable Oldham GT headset and range from economical £50 conversions up to the more expensive lamps such as the Trigon and MagnumStar. Expensive? well not in the sense of some on the market. Our most popular lamp is the Trigon which produces on full power 1750 lumens which makes it the most powerful mining and caving lamp available to purchase in the world. It is beaten only by our own MagnumStar range, currently being redeveloped. This compares very favourably with the competition, some of which should be available on Hire Purchase or a mortgage!

All the lamps share some common features:

#1 At least 2 independent circuits.

#2 Full 'mix 'n match' interchange ability. You can have any lamp and use it with helmet or a belt mount power pack for different types of use.

#3 With the exception of the WorkStar series which is usually offered as a conversion of you existing Oldham lamp, the lamps are built on virtually unused Oldham headsets of recent manufacture and acquired as ex Royal Navy surplus.

#4 Full upgradeability if new emitters are announced.

#5 Power packs are solid cased and based on Lithium Ion (Li Ion) technology. All power packs can be, and indeed its recommended, 'top up' charged. They cannot be overcharged.

Post and Packing.

All shipping is by Royal Mail insured Special Delivery which ensures that the lamps will arrive at your home the very next day. We do not accept any money unless we have the goods ready to ship.

See what our customers are saying about our lamps:

What they are saying

There are 2 series of lamps, the 4V and 8V series. The 4V series lamps come without a charger as they are designed to be recharged from the standard Oldham charger including electronic chargers and rack chargers.

There are chargers and spare battery packs available from us for those who require them.

The attraction with the 4v range is economy of use and the fact that they can utilise a customers existing Oldham charger, also they will happily go for 6 or 7 hour trip on a small light 2 cell helmet mount battery pack. They are also by design, possibly the most potentially reliable lamps on offer anywhere due to the 2 independent circuits and the use of multiple parallel linear constant current chips, each of which can continue to function if its neighbours fail for some reason.

Batteries, Power Packs and Chargers

The 8V series of lamps all include a dedicated charger with the lamp, these are the Trigon and MagnumStar.

If your helmet does not have a proper lamp bracket you will need one, the best I have seen are here:

http://www.caving-gear.co.uk/show_product.asp?id=1203

Petzl brackets strain the caplamp blade on Oldham headsets, they are OK but remove the lamp with care, don't twist it about it bends the headset blade. Use a small screwdriver to lever it off.

4 Volt Series

The WorkStar (Working lamp)

This is the entry level lamp and offered as an exchange conversion of your existing Oldham Caplamp. It is simple, reliable, and highly suitable for outdoor and adventure centres who take young people underground. (It does not pull apart, no connecting plug)

You will need to get your old Oldham caplamp to us for conversion. Chop off the lead as close to the battery as possible and send it to us at the address at the bottom of the page.

The price is £50 with 2 cell power pack (fixed) or £55 for the Pro version, (as below). Add £4 return P and P

To learn more about this lamp, click here: Workstar Lamps

The WorkStar Pro

This is the next step up and offered based on one of our stock of as new headsets. It gives choice of either a tight spot beam similar to the excellent Fenix TK11 tactical torch, plus a wide beam, both of 125 to 150 lumens.

Just like the rest of our range it connects to a detachable power pack, the 2 cell helmet mount is best choice and will give about 7 hours on either lamp.

This has now been improved with MOSFET circuit protection in the same way as the EcoStar, zero volts drop. I have had one running on 4 AA cells since 1600, its now 2017 as I type this, the lamp is still going strong. RF 30/12/11.

The price is £70 built on a stock headset. Add £4 return P and P

Or £55 as a conversion of your existing good condition Oldham headset. Add p and p

To learn more about this lamp, click here: Workstar Pro

This is the next step up from the 2 WorkStar lamps. It features 1 Cree XP-G R5 as a bare 'Room Light' plus the latest Cree XM-L emitter which is the latest Cree technology. This lamp as supplied 'off the shelf' is built on a new or nearly used headset acquired as ex Royal Navy surplus.

The maximum output of this lamp is about 520 lumens, and yet it has no external heatsinks and weighs no more than the standard Oldham headset. Of the 2 emitters, one is bare and mounted up against the glass, a situation that makes it ideal for cavers who want to duplicate the light quality of the old carbide lamp. The other emitter is behind a good long range reflector that provides a broad yet powerful beam.

The Standard Mode of this lamp outputs about 150 lumens and yet it will burn for 12 hours on one of my little 2 cells helmet mount power packs. After this it will continue to burn for hours but at a reduced rate.

The price is £85 with 2 cell Li Ion helmet mount power pack, and helmet fixing cord. Add £10 P and P, total £95.00 This does not include a charger because these lamps will charge of a standard Oldham charger which many people have. If you need a charger with the lamp, we can provide our own dedicated dual pack charger which can do 2 packs at a time, add £20. Total price with post and packing now is £115.

 I can also offer a 4 cell AA battery holder with built in short circuit protection for an extra £8.

I can also offer this lamp as a conversion of your existing Oldham GT headset, same as for the WorkStar Pro, please deduct £15 for this deal.

PLEASE NOTE THAT I WILL ONLY ACCEPT HEADSETS IN GOOD CONDITION FOR CONVERSION. BATTERED RELICS WILL BE REJECTED.

To learn more about this lamp, click here: The EcoStar

8 Volt Series

This combines a Standard Mode of 150 lumens for 1.2 watts battery draw with a High Mode of 725 lumens and Turbo Mode of 1750 lumens. All this light is in the form of a controlled beam.

Alternative switch positions give 920 lumens of Daylight Mode from 2 bare 'tandem mount' XP-Gs  mounted up against the glass, a situation that makes it ideal for cavers who want to duplicate the light quality of the old carbide lamp. There is also a Survival Light that literally lasts for days as well as a low battery warning.

This lamp as supplied  built on a new or nearly new Oldham headset acquired as ex Royal Navy surplus.

To the best of my knowledge at this time if writing the Trigon is the worlds most powerful caplamp designed for underground use, beaten only by the yet to be announced XML MagnumStar.

The price is £165 with 4 cell helmet mount power pack and fixing cord. Add £10 P and P insured next day special delivery, total £175

To learn more about this lamp, click here: The Trigon

NEW MODEL BEING DEVELOPED

From time to time I buy in batches of lighting products which will only be available while stocks last.

Special Offers

Our Guarantee

All lamps are guaranteed for 12 months from date of purchase. Refunds of postage will be included in certain cases. Lamps are described as waterproof, but not suitable for diving. This does not affect your statutory rights.

Post and Packing Policy and Charges

Workstar lamps are returned normal delivery and the cost is £4. All other lamps are signed for and insured because of the value. 

Ordering a lamp

Check stock level at bottom of this page, if "no stock" please check availability.

Subject to this, its dead simple. We do not require you to open an account, create a username and password, give us your phone number so that you can receive unwanted calls from our 'carefully selected partners', or attempt to take control of your computer. You just send us the money, we send you the lamp. Just like in the good old days.

Amount plus postage to:

Iris Computers Ltd

 Greengables

        Stafford Road.

         Great Wyrley

    Walsall

            WS6 6AX

Cheques to Iris Computers Ltd please.

IMPORTANT

If in doubt email me first. Rates shown are United Kingdom Only. email me if overseas email for postage quote. PayPal is OK but attracts an extra 3.4% for UK customers, 3.9% for overseas.

roy@iriscom.co.uk