January 2006 •
Lighting&Sound
America
TECHNICAL FOCUS : PRODUCT IN-DEPTH
Clay Paky has been manufacturing moving lights for just about as
long as anyone; the company’s original GoldenScan (actually, I
think the first model was the RubyScan in 1985) was seminal in
establishing the acceptability of scanner fixtures in professional
markets outside of discotheques and nightclubs.
More recently, Clay Paky fixtures have become synonymous
with the use of condenser-based optical systems. This choice
meant that their image quality and field flatness was exceptional;
however, fixture brightness wasn’t always quite up to the
competing ellipsoidal units.
The Alpha Spot HPE range diverges from this philosophy and
utilizes the now almost completely ubiquitous short-arc
lamp/dichroic ellipsoidal reflector combination. Has this change
been a good one for Clay Paky and how does the Alpha Spot
HPE 1200 measure up to the competition at the top end of the
market? This review seeks to find out.
As usual, the review works through the light in a logical order,
from lamp to lens, and tries to present results in an objective
manner. All reported results are based on multiple averaged
readings taken from one specific fixture supplied to me as
representative of the product by Clay Paky America—thus, your
tests may differ slightly. I don’t tweak or recalibrate the units; I
want the test results to represent the reality of a standard fixture
as it is shipped to the customer. (Figure 1: Unit as tested)
Although the Alpha Spot HPE 1200 is fitted with an electronic
switching lamp power supply and can run on voltages between
100-120V or between 200-240V, it doesn’t auto-sense and the
user must select the voltage via a switch on the outside of the
unit underneath the carrying handle. The unit was tested at both
voltage ranges and measurements were taken when run at 116V,
60Hz.
Lamp
The unit was supplied and tested with the Osram HMI 1200 W/S
double-ended discharge lamp rather than the HTI 1200 W/D7/60
lamp, which the literature talks about. Both the HTI and HMI
versions are nominal daylight lamps rated at 6,000K color
temperature, with almost identical specifications; both are fitted
with the XS “Extreme Seal” plated pinch-foil technology we’ve
discussed before in these reviews. This development facilitates
shorter arc gaps and, thus, high optical efficiencies. All these
lamps require forced cooling.
The double-ended lamp is mounted on a lampholder plate,
which is retained by two quarter-turn fasteners; once released, it
pulls out and down for lamp access. Lamp change is very easy
and straightforward, with all parts remaining captive. (Figure 2:
Lamp and reflector)
Figure 2 also clearly shows the faceted cold-mirror reflector
with its large slots to accommodate the double-ended lamp; this
arrangement is very common in modern fixtures and inevitably
causes the beam to be somewhat asymmetrical, although Clay
Paky has done an excellent job of controlling this through the
design of the reflector facets.
As mentioned earlier, lamp power comes from an electronic,
square-wave, “flicker-free” ballast. The supply itself is a very
familiar component, supplied by Schiederwerk. That company’s
supplies are used by many manufacturers in our industry and are
known to be solid and reliable.
The lamp is well-cooled and I saw no evidence of overheating
or other problems during my tests. The whole of the rear lamp
house is sealed off with a hot mirror and Clay Paky does a good
job of compartmentalizing the heat and keeping it away from
downstream components.
Dimmer
The dimmer flags are mounted immediately after the first hot
mirror (Figure 3: Dimmer flag showing frost glass). The Alpha Spot
uses standard “serrated-teeth” cut flags, but with the addition of
frosted glass attached to the fingers, to improve the dimming
softness and avoid dimming artifacts. The photograph shows one
flag with the attached glass inserted into the beam—the system
uses two of these flags when dimming.
The dimming system also uses the capabilities of the electronic
ballast and simultaneously reduces the lamp wattage down from
1,200W to 600W as the blades close. This combined system
worked extremely well and the dimming was possibly the best I’ve
Fig. 1
Fig. 2: Lamp and reflector Fig. 3: Dimmer flag showing frost glass
The Clay Paky Alpha Spot
HPE 1200
by Mike Wood
Copyright January 2006
Lighting&Sound
America
(24 pages)
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