Lomax
Well-Known Member
I'm currently working on a complete refit of the interior on a steel barge. The upper walls and ceiling will be insulated with 1" of spray on PU foam, and all the wiring needs to be re-done from scratch. This led me to start looking at (cheap) options for interior lights, and I went on the hunt for recessed LED downlights which would fit in the shallow depth behind the ceiling panels. With only 1" of insulation (covered by 5mm plywood), I needed to find lights which were maximum 2.5cm deep, and ideally less, which severely limits the options. Of course they also need to be powered by 12V, which limits things yet further. I quickly zoomed in on what's called "under cabinet" lights, since these tend to be both shallow and low voltage powered, and found these three potential candidates:
1: ELD DLC-SS-WW 3W COB - warm white (£12)
http://eldlighting.co.uk/products/cabinet-recessed-3w-cob-led
2: Sycamore Lighting Sirius 2.6W - warm white (£8)
http://www.sycamorelightingltd.co.uk/products/sirius-recessed-light
3: Sycamore Lighting Florence 3W Osram - warm white (£14)
http://www.sycamorelightingltd.co.uk/products/florence-sicilia
The plan is to fit two rows of 6 along the length of the cabin, divided up into three different zones for individual dimming - but which ones to get? Since they're only about a tenner each (when bought singly) I figured I might as well buy one of each and try them out...
First off, ELD's DLC-SS. This is the only COB (Chip-On-Board) light, and it has a very large light emitting surface (~17mm dia), which sits slightly recessed from the plastic diffuser. The fascia is 62mm in diameter, and the housing behind it 48mm wide. At only 9mm depth behind the fascia it is the shallowest of the three, and the cable exits horizontally from the enclosure. It is a very bright light, brightest of the three, and the light is pleasant with good colour rendering. The light cone is very wide and even, and there are no artifacts. Build quality feels *cheap*, the casing is made from stamped steel, and it is the only light to have the retention springs riveted on (the other two have removable springs). It delivers a usable amount of light at 10.5V.
The second canditade, Sycamore Lighting's Sirius is 65mm in diameter, with the recessed portion 51mm in diameter. It is 12mm deep behind the fascia, and the cable exits horizontally. It has six surface mounted LEDs behind a thick plastic diffuser. The casing is made from die-cast metal with cooling fins and feels quite heavy. The light it produces is similar to the ELD, but not as bright and with a slightly odd cast. I doubt the claimed CRI of 84 is correct. It also delivers a usable amount of light at 10.5V.
Finally, the "Florence", which is the odd one out in that it has a lens in front of the (single) surface mount LED. The inclusion of a lens makes this the deepest of the three, at 21mm behind the fascia, and the cable (which is of better quality than the other two) exits vertically, requiring another couple of millimeters. It is also the widest of the three with a 69.5mm dia fascia, though the recessed part of the body is a swelte 40mm. The lens gives the light a defined beam character, which reduces glare significantly, but the single LED means light output is weaker than the other two, and the light field has some artifacts towards the edges. Interestingly, the light unscrews into three parts, and it's possible to use only the central part on its own without the fascia, which may be useful in some situations. Unlike the other two, it delivers a usable amount of light at just 6V(!).
At the end of this, I think I'm leaning towards the ELD COB light - it has the best colour rendering of the three, and is also the brightest (by the way, all three lights consume about 220mA at 12V). Its super-shallow depth would leave valuable room for insulation and wiring. I do like the "beamy" light from the Florence, but it's not very powerful and the colour rendering is not great. It's also overly "warm" IMO. That said, I have one important test left to perform: a durability/stress test. I'm leaving all three lights on for a couple of days to see if there's any degradation, after which I will try feeding them an over-voltage to see if they can take battery charger voltages. I will torture them with 15V for 24 hours, which should weed out the weaklings...
Edit: The comparison photos have been taken at a fixed aperture/shutter speed, with white balance set to incandescent. The rolls of cable are orangey-red, yellow, green and purple in real life. The light field photos were taken with the lights 1.7m from the wall, and the object near the center is a playing card (nine of hearts). It's worth pointing out that the "Florence" light looks brighter only because the light is focussed; the other two lights chuck out more photons, but spread them over a wider area.
1: ELD DLC-SS-WW 3W COB - warm white (£12)
http://eldlighting.co.uk/products/cabinet-recessed-3w-cob-led
2: Sycamore Lighting Sirius 2.6W - warm white (£8)
http://www.sycamorelightingltd.co.uk/products/sirius-recessed-light
3: Sycamore Lighting Florence 3W Osram - warm white (£14)
http://www.sycamorelightingltd.co.uk/products/florence-sicilia
The plan is to fit two rows of 6 along the length of the cabin, divided up into three different zones for individual dimming - but which ones to get? Since they're only about a tenner each (when bought singly) I figured I might as well buy one of each and try them out...
First off, ELD's DLC-SS. This is the only COB (Chip-On-Board) light, and it has a very large light emitting surface (~17mm dia), which sits slightly recessed from the plastic diffuser. The fascia is 62mm in diameter, and the housing behind it 48mm wide. At only 9mm depth behind the fascia it is the shallowest of the three, and the cable exits horizontally from the enclosure. It is a very bright light, brightest of the three, and the light is pleasant with good colour rendering. The light cone is very wide and even, and there are no artifacts. Build quality feels *cheap*, the casing is made from stamped steel, and it is the only light to have the retention springs riveted on (the other two have removable springs). It delivers a usable amount of light at 10.5V.
The second canditade, Sycamore Lighting's Sirius is 65mm in diameter, with the recessed portion 51mm in diameter. It is 12mm deep behind the fascia, and the cable exits horizontally. It has six surface mounted LEDs behind a thick plastic diffuser. The casing is made from die-cast metal with cooling fins and feels quite heavy. The light it produces is similar to the ELD, but not as bright and with a slightly odd cast. I doubt the claimed CRI of 84 is correct. It also delivers a usable amount of light at 10.5V.
Finally, the "Florence", which is the odd one out in that it has a lens in front of the (single) surface mount LED. The inclusion of a lens makes this the deepest of the three, at 21mm behind the fascia, and the cable (which is of better quality than the other two) exits vertically, requiring another couple of millimeters. It is also the widest of the three with a 69.5mm dia fascia, though the recessed part of the body is a swelte 40mm. The lens gives the light a defined beam character, which reduces glare significantly, but the single LED means light output is weaker than the other two, and the light field has some artifacts towards the edges. Interestingly, the light unscrews into three parts, and it's possible to use only the central part on its own without the fascia, which may be useful in some situations. Unlike the other two, it delivers a usable amount of light at just 6V(!).
At the end of this, I think I'm leaning towards the ELD COB light - it has the best colour rendering of the three, and is also the brightest (by the way, all three lights consume about 220mA at 12V). Its super-shallow depth would leave valuable room for insulation and wiring. I do like the "beamy" light from the Florence, but it's not very powerful and the colour rendering is not great. It's also overly "warm" IMO. That said, I have one important test left to perform: a durability/stress test. I'm leaving all three lights on for a couple of days to see if there's any degradation, after which I will try feeding them an over-voltage to see if they can take battery charger voltages. I will torture them with 15V for 24 hours, which should weed out the weaklings...
Edit: The comparison photos have been taken at a fixed aperture/shutter speed, with white balance set to incandescent. The rolls of cable are orangey-red, yellow, green and purple in real life. The light field photos were taken with the lights 1.7m from the wall, and the object near the center is a playing card (nine of hearts). It's worth pointing out that the "Florence" light looks brighter only because the light is focussed; the other two lights chuck out more photons, but spread them over a wider area.
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