Thread: Lamps, Lumens and LEDs - Advice Sought.

G'day Bob

I can't help with the actual lamp, but can offer a couple of guidelines. The globe you are referring to has a power rating of 6 watts, if it's 6V, 1A (P=VxA). In my recent experience of replacing household lamps with LED globes, I think a good rule of thumb is that a LED globe is about 1/6 the power of an incandescent for the same light output (lumens). So you'd be looking for a 1W LED. Btw, a LED globe for the same light output is about 2/3 of the power of a Compact Fluoro, and without the annoying delay in full brightness.

Lumens = total light output (unfocused)
Lux = amount of light falling on a given area.
This means that two different light sources can have the same lumens, but different lux, depending upon how they are focused

It is actually the Lux that will determine how much light you have falling on the subject.

HTH a bit
Brett

Just had a look at the lamp you linked to. It will be a very cold light source - quite blue in colour. This is determined by the 6000* Kelvin rating (colour temperature). That means it's pretty much straight up unfiltered LED light (which is quite blue in the raw state).

A normal incandescent globe is around 2400-2800* K, so quite warm. The replacement LED globes I purchased from Aldis are 3000*K, and so are slightly warm, and quite acceptable.

Daylight is 5500*K but I've always found that a Fluoro tube of this temperature was cold and nasty light (speaking as a photographer). 5000*K is better, but my preference is for a bit of warmth. This is because when they talk about daylight they are actually referring to the illumination produced by the blue sky, not the direct sun - in other words the colour temp of shade (you know how pics taken in the shade are always blue? - that's why).

Hello Brett,

Given your much appreciated advice and interest in my plight, I will post a few photos tonight of the particular application of the lamp and its rather complex mounting.

Bob.

Hi Bob,
Like Brett I have gone to LEDs in one of our shops, and did a lot of research first. As a guide an incandescent bulb will put out about 12lm per watt, although I'm not sure that stands with such a small bulb. Keep in mind this is a pathetic efficiency of about 2.5-3%.
That at least gives you a lumen output to aim for, about 70lm.
When looking for a suitable replacement avoid bulbs that say "equivalent to x bulb". This generally means that the lux is similar but the beam angle is a lot narrower.
Cheers,
Ewan

Hi
Another complication is they have polarity so if it does not work, turn it around. And the light is usually very directional. I have replaced some leds in the dash of my car with mixed success. If the fitting takes light axially with the holder then should be ok. But if light is radial then the brightness can be very poor. You can always take the old incandescent bulb an remove glass and substitute in some LEDs and a resistor.

Another problem I have encountered is the light is not full spectrum. Sunlight produces the full rainbow. Leds are verging on mono chromatic. If the led output at a specific wavelength is low or missing it can cause problems. So if the yellow of the bulb is there so it causes highlights in the image, it may not look right.
White light is red green blue added together and most white leds are just several "matched" chips so the light looks white. In household bulbs they can use phosphor to correct the colour by fluorescing to fill spectrum gaps. See fluorescent bulbs called tri and quad phosphor, same application of phosphor.

Basically it may be trial and error to get the desired result. I am still searching for a suitable BA7S for my car.

I work for Philips but medical not lighting. Just scored an LED fluorescent lightbulb replacement / retrofit. Very nice, instant on at full brightness and half the power!


James


Sent from my iPad using Tapatalk HD

Is that a 15mm balloon type globe Bob? If so they are available from a company in Melbourne for around $2.00ea plus postage although not tinted yellow.

Hi BT,

I'm currently looking into going all solar powered led strip lighting for the workshop, battery backed off-grid.

But back to your query, what about this one LED 1W Miniature E10 T3 1 4 6V Mini Screw E10 Base Warm White 1446 1449 1487 | eBay

Regards
Ray

Ray, you might find some useful info in this thread then (it's the slightly OT posts in the middle of the thread)

U

Originally Posted by RayG

Hi BT,

I'm currently looking into going all solar powered led strip lighting for the workshop, battery backed off-grid.

But back to your query, what about this one LED 1W Miniature E10 T3 1 4 6V Mini Screw E10 Base Warm White 1446 1449 1487 | eBay

Regards
Ray

Going ot, but renew mag had an article some time back about solar/led "skylights", a very good idea were typical skylights would not work. And these days no more expensive either. I couldn't go solar on the shed, but I like the idea. My NE facing roof is 90% covered in panels already, greedily taking all I can from the governments feed in tariff....
Cheers,
Ew

Brett, Ew, James, Techno and Ray. Thank you.

Let me post a few photos of the lampholder. It maybe that I rissole the existing holder for something a touch more convenient.

And Techno, it was a 15mm balloon before nimble fingers here dropped it.

BT

ps. Ray, I (more than likely WE) need to hear more about the shed lighting.

Originally Posted by Anorak Bob

Brett, Ew, James, Techno and Ray. Thank you.

Let me post a few photos of the lampholder. It maybe that I rissole the existing holder for something a touch more convenient.

And Techno, it was a 15mm balloon before nimble fingers here dropped it.

BT

ps. Ray, I (more than likely WE) need to hear more about the shed lighting.

Hi BT,

Not wishing to hijack the thread... but...

Nothing new or startling about the led strip lighting, I'm just aiming to replace fluorescent lighting and at the same time improve the general lighting over a few machines at the same time. When I do the conversion I'll put up a new thread with details on what I've found.

The 12V led strips are 5M long and give off 780-900 lumens per meter, so that's about the same as a dual fluoro.. I'm going to run them in series for 24V and that means I can use the more common 24V 250watt panels, I'd like 200 Ah of battery or better, that's 10 hours at 20 amps ( enough for 10 strips... I think ) Not siure how many panels I'll need, but I'm thinking at least 2 will do for a start.

I'll save detailed discussion for a new thread in a few weeks time...

Regards
Ray

Originally Posted by RayG

I'll save detailed discussion for a new thread in a few weeks time...

Yes please Ray. Bobl & Geoff Sims have some good input on this as well, so it'd be great to start a dedicated thread. Bob found that he ended up disappointed with his LED system (too dim), and Geoff's doesn't look bright enough for general use either (but excellent in his chosen application). Then you end up with too many strips (and more $$) to get the required illumination level blah blah.

Maybe you're looking at some higher output strips than they are? Not sure that we can compare them either - your talking lumens and they're talking watts (IIRC).

Originally Posted by Anorak Bob

Brett, Ew, James, Techno and Ray. Thank you.

Let me post a few photos of the lampholder. It maybe that I rissole the existing holder for something a touch more convenient.

And Techno, it was a 15mm balloon before nimble fingers here dropped it.

BT

ps. Ray, I (more than likely WE) need to hear more about the shed lighting.

I would have thought that it would be easier to just replace it with the same type of lamp that the unit was designed to run, even if you have to tint the glass to achieve the yellow light. Orbitec P/no - E2809

Originally Posted by Techo1

I would have thought that it would be easier to just replace it with the same type of lamp that the unit was designed to run, even if you have to tint the glass to achieve the yellow light. Orbitec P/no - E2809

There are a couple of issues with a straight replacement. The original Mazda bulb has an enlarged flange that is "positioned" by means of the three tiny grub screws. This may have been intended to allow a more accurate centring of the filament and also provide some minimal axial adjustment to facilitate focusing ( assuming that was of importance and I'm only guessing). The Berec lamps shown below are 15mm in diameter. The original lamp was larger than 15mm. Sadly I have no record of the actual size. So the first issue is whether I could obtain a lamp exactly the same as the original.

Secondly, it would be more convenient not to have to use the delightful as it is but unwieldy transformer and its clutter of cables. The wires tend to work loose in the plugs, maybe a French design flaw. Still, this is 50 year old technology and I dare say, probably pretty whizzo and unaffordable stuff in its time.

The photos show the lamp holder and it installed in the optical micrometer. The images from both an LED torch jammed into the lamp holder recess and with 0.5 Amp lamp are pretty murky and the left hand LED illuminated image, uneven. The idea is to be able to position the projected scribed line accurately between the parallel lines on the ground glass screen. Needs improving.

BT