Steven Studio 2K Fresnel Halogen Light - Unauthorised handling notes. at

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Old October 20th, 2010, 09:46 AM   #1
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Steven Studio 2K Fresnel Halogen Light - Unauthorised handling notes.



Following below are some notes I have written for this light kit for which there is currently no available English-Language user-documentation.

I am no lighting technician so my notes below do not assure effective operation of the system or safety for the operator.

Comments and additional information and in particular, safety cautions by lighting guys are therefore sought and will be most welcome.

The comments below are based on my own observations of one of these lamps recently purchased. I have published the notes below for the purpose of prompting purchasers/users to a need to educate themselves in the use and maintenance of all lighting fixtures, not to simply aquire or hire, then plug in and switch on.

I have taken the attitude that not to publish is more neglectful than publishing unauthorised notes which may be incomplete or miss an important detail.

Owners or users of the "Steven Studio" 2K Halogen Fresnel Lamp and other lamps imported from China should conduct their own careful researches and observations and develop a best practice based on the best advice.



The unbranded 2K Halogen Fresnel lamp kit vended by Steven Studio is generally patterned after the style of ARRI and similar lights.

The lamphouse construction consists of two-piece cast aluminium ends, which carry channels into which a combination of aluminium extrusion strips and pressed aluminium sheetmetal as vented side covers, steel sheetmetal internal heatshields and supports, are inserted and secured by hardened self-tapping sheetmetal screws.

Finish is a blue paint coat over the end pieces and silver anodising for the sides with the steel support cradle finished in black with the spigot in natural polished chrome metal.

The upper front endpiece carries a hinged holder for barndoors assembly and fresnel lens. The lens glass of 7 inches diameter is retained by three double-ended compression strips riveted to short outriggers secured by single self-tapping screws.

These compression strips impinge on the flutes of the fresnel lens glass from the front. They are stiff and are not thin compliant spring steel.

My sense on checking the local pressures imparted by this fastening method on the glass is that it is a bit too firm. Beneath the rim of the glass under the points of pressure are three clear silicon cushion strips.

The upper rear endpiece is a vented cover to which is fastened a small metal loop for a safety lanyard, chain or cable.

The lower front and rear end pieces support a worm and roller shaft and plain shaft which actuate the spot and flood focus. This functions by moving the lampholder and rear reflector towards or away from the fresnel lens by a helicoid and follower arrangement. Both shafts are also the lampholder support.

The ceramic lampholder is for the G38 mount type 2000watt halogen filament globe. It travels on a robust cast aluminium carriage of good build quality.

The helicoid channel followers are threaded studs firmly mounted from the upper face of the carriage rim and secured by locknuts. I did not dismantle them to see if there are rollers on the end of the followers like the 1.2K HMI.

The smooth left shaft supports the carriage by two open clasp forms cast into the carriage. To me this is a pleasing design. There should never ever be an incidence of jamming or jittery operation with this arrangement.

I would like to see this feature carried over onto the 1.2K HMI.

Spot and flood adjustment is operated by two knobs, one each at front and rear attached to a common shaft.

Within the lower lamphouse, there are two leads clad with clear insulation inside white covers which travel with the carriage and are attached with screws and closed eyelets.

These leads feed through another loose fitting sleeve through the lamphouse wall into a junction box. Within the junction box, an earth lead is connected to the lamphouse body by a closed eyelet and setscrew.

Within this junction box is a ceramic terminal strip for internal wiring and the thick rubber-clad supply lead. This lead is clamped by a saddle and feeds out through a collar with a rounded contour. The box cover is secured by two self tapping sheetmetal screws.

The on-off switch is an inline cable switch. Both conductors of the cable are switched as in the 650watt lamps and the switchbox is of an identical design with illuminated rocker.

On the specimen I received, the small screws holding the two halves of the switch enclosure were beginning to pull their threads. I replaced the screws with larger pieces. Within the switch box, the cable ends are secured by clamps.

The cable has a blue two-pin plug attached. Buyers may have to have a plug suited to their own mains power supply system fitted to the cable.

A slotted base panel on the lamphouse is retained by four self-tapping sheetmetal screws. There are two translucent panels above the vent slots. These appear to be intended to double as light shields but to pass enough light to be useful for workplace lighting.

They also appear to do double duty as a partial safeguard against loosened carriage wiring touching the metal of the lamphouse.

Ventilation is by convective airflow.


The lamphouse with barndoors, lamp bulb and assembled switched supply cable will most likely arrive within a white foam two-piece pack in a cardboard box. The barn doors are supported by a raised rim which locates in channels in four brackets attached to the front-opening door.

The top bracket is pulled upwards against spring pressure, then turned to allow the barndoors assembly to be lifted up and out.

The support cradle and industry-standard spigot is secured in a channel molded in the upper piece. The cradle support bolts and fittings are enclosed in plastic bags.

The arrangement of the cradle fittings takes a bit of working out. Once assembled the design works well with an easy tightening action, thanks to a thrustbearing which comprises part of the combination right fastener, friction material and tightening lever.

My assembly of it was from left to right :-

Left side - Bolt > Flat Washer > Cradle-end > Shouldered spacer with shoulder inside hole in cradle end > Lamphouse body bracket which contains captive nut for bolt to thread into.

Right side - Lamphouse body bracket which contains captive nut for threaded stud and handle assembly to thread into > Grey friction washer > Cradle-end > Thrust bearing outer housing > Thrust bearing caged ball set > Thrust bearing inner rotating piece > Threaded stud and handle assembly, which screws into a captive nut.

The lever can be pulled outwards against spring pressure off a spline and rotated to any of four positions for convenient operating.

A stand must be ordered separately.

The supplied globe was a 230V watt with G38 base. Despite being packed inside its own stock box with foam wrap, withn the larger package, the quartz envelope was found to be broken at the ceramic junction where there is a crimp in the envelope.

The ceramic base which forms part of globe is very heavy.

The box the globe was contained in was not damaged in any way. I can only assume there were some very violent handling events during shipping. This is evidenced by several screws which were found loosened despite there being serrated lock washers in place.


It is recommended that purchasers unpack, then pick up the lamphouse, turn it over several times in several directions and listen carefully for the sound of internal fasteners or fittings which may have come loose during the sometimes violent stresses of shipping.

Then perform a visual inspection. Pay particular attention to the ceramic lampholder, its metal cradle and fasteners, for chips, cracks or excessive looseness.

The ceramic lampholders normally have some looseness between the two clamping components when the globe is not fitted. In this lamp, there was no apparent harm done to the cast metal carriage by the violence of the shipping.

There will be seen some permitted looseness in the fitment of the sliding lampholder assembly on the rods which carry it.

Check the polished metal reflector. It should be found supported in a cradle of three ceramic hooks. Avoid touching the polished metal surface of the reflector as any skin oils will become baked on and create a permanent stain.

Check tightness of all visible external fasteners including the two screws for each of the support claws for the barndoors assembly.

Check the tightness of the rear safety cable loop fastener.


Do not move the lamp when it is operating.

Allow plenty of time for the globe and the lamphouse itself to cool before moving the lamp or packing it into its transport case.

If the lamp fails, assume always that the globe may explode and wear appropriate personal protective equipment when troubleshooting or changing the globe.

This lamp is not intended to be operated in rain or under water sprays. Fluid spills or droplets might not enter the enclosure directly but may wick in along joints and cause the globe to explode or the ceramic components to crack due to shock cooling.

There is also a risk of of lethal electric shock when moisture is involved. Do not assume the heat of the lamp will boil off small amounts of moisture. This may condense elsewhere inside the lamphouse, cause corrosion or conductive carbon tracks across insulation and make the lamp fail.

Do not look directly at the operating lamp.

Do not operate the lamp if the fresnel lens door is opened, the fresnel lens is missing or cracked. The light is very intense and will injure eyes. Furthurmore, in this state, there is no protection from debris thrown forward by a globe explosion.

Route the cables systematically and sensibly to avoid tripping hazards or the lamp being pulled to ground.

The lamphouse can become very hot and is a potential burn hazard to unprotected hands or skin. Loose flammable materials should not be directly mounted to the lamp as diffusers.

The lamp should not be placed and operated where flammable materials like curtains or foliage may brush against it.

Because of competitive costs, this lamp may become favored by some small or low-budget independent film makers and purchased outright, rather than rented.

Small or low budget projects often are supported by crew multi-tasking and may be populated by untrained onlookers or keen enthusiasts. All should be discouraged from approaching the lamp to assist move or operate it unless already properly trained in its use.


My personal preference for on-set crew maintaining or servicing this lamp, would include use of industrial eye protection from glass fragments moving at high speed. Hands should be protected by heat resistant gloves.

The lamp should be removed from set for servicing or troubleshooting.

Before the front hinged door is opened for repairs or globe change, the lamp should be positioned to face a natural shield like a wall to prevent any fragments of glass flying freely and injuring anyone else nearby.

Any suggestions or corrections which can be made by competent and qualified lighting technicians to put right anything wrong I have suggested here will be much appreciated.

With the lamp, I also purchased a heavy duty lamp stand and two C-Stands. I am not too sure where a description of these items would be posted. They are near-identical to familiar industry equipment so likely need no notes to be published.

Last edited by Bob Hart; October 20th, 2010 at 10:01 AM. Reason: added text
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