Maker Pro
Maker Pro

Painted MR16s?

T

TKM

Jan 1, 1970
0
A lighting designer colleague is lighting a residential sculpture gallery
with suspended track and 20 watt MR16 lamps. MR16 lamps, of course,
typically utilize dichroic reflectors and there is some back light off of
the reflector --even from the GE "Constant Color". Because the ceiling in
the gallery area is decorative and the designer wants to focus attention on
the sculpture, she would like to eliminate all of the back light and is
thinking of painting the back of standard MR16s with heat resistant black
paint.

The fixtures being used are minimal -- no enclosures -- and the lamp is held
in place by the socket.

I know there are some MR16s around with standard opaque reflectors, but the
designer doesn't like the beam spreads available. Painting the reflector of
a dichroic reflector lamp will certainly increase the heat in the beam and
the temperature of the reflector surface, but I can't think of any other
reason not to go with painting the reflector (other than it spoils some
great lamp engineering). Any other thoughts?

Terry McGowan
 
T

TKM

Jan 1, 1970
0
A lighting designer colleague is lighting a residential sculpture gallery
with suspended track and 20 watt MR16 lamps. MR16 lamps, of course,
typically utilize dichroic reflectors and there is some back light off of
the reflector --even from the GE "Constant Color". Because the ceiling in
the gallery area is decorative and the designer wants to focus attention
on
the sculpture, she would like to eliminate all of the back light and is
thinking of painting the back of standard MR16s with heat resistant black
paint.

The fixtures being used are minimal -- no enclosures -- and the lamp is
held
in place by the socket.

I know there are some MR16s around with standard opaque reflectors, but
the
designer doesn't like the beam spreads available. Painting the reflector
of
a dichroic reflector lamp will certainly increase the heat in the beam and
the temperature of the reflector surface, but I can't think of any other
reason not to go with painting the reflector (other than it spoils some
great lamp engineering). Any other thoughts?

Terry McGowan

I would be concerned with locally heating the reflector and causing it
to crack. Ushio offers MR16 lamps with opaque reflectors in a variety
of colors (including matte black) with a variety of beam spreads. Has
your friend considered them for the application?

Jonathan Scheuch

Yes, she evaluated literally dozens of lamps, but likes the beam
characteristics of the GE MR16s best. She is a perfectionist when it comes
to lighting patterns from reflector and projector lamps and her work shows
it; so I'm trying to find a good solution. I agree with your concern about
heat; but it is the 20 watt lamp that's involved here and those same
reflectors are capable of handling filament tubes up to 70 watts.

Terry McGowan
 
TKM said:
Because the ceiling in the gallery area is decorative and the designer
wants to focus attention on the sculpture, she would like to eliminate
all of the back light and is thinking of painting the back of standard
MR16s with heat resistant black paint.

I am not a pro, but here are some thoughts.

It might be interesting to measure the temperature of the lamp glass and
compare that to the specs for the paint.

Even if the temperature is within the limits for the paint, I suspect
the paint will outgas (i.e., stink) a little when the lamps are first
powered. It might be a good idea to paint the lamps, then operate them
for a few hours in the shop before they are installed.

It might also be a good idea to supply some spare lamps that have been
painted, or at least some instructions to the customer on what kind of
lamps and paint to use. The paint may cover the markings on the lamp,
and it may not work so well if the customer replaces a burned-out 20 W
lamp with a 70 W one painted with $2 rattle-can black.

An alternative would be a metal cup that exactly fits over the back of
the lamp, maybe with little tabs or fingers to clip over the front edge
of the lamp. It wouldn't be attached to the fixture - it would just
clip over the lamp. It would need a hole for the base of the lamp where
the pins are, and this hole might still leak a little light. Also, if
this doesn't already exist, it might be too expensive to make them in
small quantities.

Matt Roberds
 
A

Andrew Gabriel

Jan 1, 1970
0
While I've never doe it, I would not be too concerned about
painting the reflectors.

However, since the dichroic reflectors are there to reflect
IR that passes through the glass anyway, you could first put
on a layer of aluminum paint to reflect as much IR as
possible back through the reflector and out the front of the
lamp and then overcoat that with a layer of black paint. Or
just byte the bullet and try a layer of black paint. The
glass reflector will probably be OK.

You used to be able to buy non-dichoric MR16s with painted
aluminium opaque reflectors. They seemed to suddenly get very
scarce around 8 years ago, but might be worth hunting around
to see if you can still find a supplier.
 
L

Liron

Jan 1, 1970
0
What about coloured LED based MR16s? Any thoughts?

Liron
 
Top