Steven Studio 650 watt fresnel lights. at
DV Info Net

Go Back   DV Info Net > The Tools of DV and HD Production > Photon Management

Photon Management
Shine an ever-loving light on you.

Thread Tools Search this Thread
Old January 14th, 2010, 01:21 PM   #1
Inner Circle
Join Date: Dec 2003
Posts: 4,476
Steven Studio 650 watt fresnel lights.

Here follows some informal and unauthorised handling notes for the Steven Studio 650watt tungsten Fresnel Light. When ordered direct from the vendor in China, this light may not be accompanied by any handling notes or operator manual.

The following notes are not intended to be a definitive manual for the lamp and should not replace appropriate research and careful vigilance by the owner-operator of the lamp. The notes are not authorised by the manufacturer of the lamp type or the vendor.

The lamphouse is constructed of solid cast aluminium end pieces in which are molded slots for locating aluminium strip extrusions. These strips function as side covers and mechanical structure. There are hinge pillars for an upper opening door for access to globe and reflector. The end pieces are finished in a blue paint and the sides are a natural silver colour anodised finsh. The appearance of the lamp is generally styled after its ARRI equivalent.

The end pieces are each retained to the strip extrusions by five long self-tapping screws which locate into "C" sections in the extrusions.

An eye for a safety lanyard is cast into the top of the rear end piece.

Lugs to carry four-leaf barndoors are attached to the front cover. A retention latch/lug is attached in centre front on top.

The latch is operated by lifting against spring pressure clear of the rear rim of the barndoors assembly and turning right or left 90 degrees before releasing. The barn doors can then be lifted free directly upwards out of the other lugs.

The front end piece also carries the frensel lens element which is fixed to the inner face of the end piece by three screws and padded clamps. A mesh screen is fastened to the front of the end piece from the outside by three small selftapping screws.

Two round rods serve as rails to carry the moving globe holder. A third smaller rod with a helical groove rotates when a knob at the centre rear is turned and adjusts the spot and flood function. The rail rods are supported in pillared holes cast into the end pieces. They come free when the end pieces are removed.

The power supply cord is of the familiar pliant rubber insulated style and carries an inline switchbox which supports an illuminated rocker switch. The switch rocker glows when power is on to the light. This rocker switch does not appear to be of a weather resistant style and should not be exposed to any moisture.

There are no logos, symbols or labels on the lamphouse to indicate how to open it for changing the globe or cleaning the reflector.

The front of the lamphouse is not hinged to open. Access to the globe is through an opening hatch in the top of the lamphouse. This hatch is not readily apparent but can be found as an extrusion which does not fit within the end pieces like the others.

On both sides of the lamphouse, there are two small "C' section extrusions which support the lamphouse in the cradle. One on left as viewed from the rear carries a simple bolt. The other on right carries a wingnut which is a friction adjustment for lamp tilt.

Inside an extended upper edge of the "C" section with the wingnut on right of the lamphouse as viewed from the rear, there is a channel in which a metal edge of an upper cover fits loosely.

For opening, the upper cover is squeezed slightly to force the metal edge inwards from the channel to allow the right side of the cover to be raised and swing open to the left. The cover is hinged at the left by two small pillars cast into the end pieces. The raising of this cover provides ample space to gain access to the globe.

The globe is of an upright style and mounts to the holder by two uneven pins on the bottom in a ceramic base. It is retained in the holder by two flat pieces of chromeplated springsteel.

When fitting the globe into the holder, difficulty will be experienced in inserting the ceramic base past the chromed spring retainer blades and lining up the uneven sized pins at the same time.

It is recommended to leave the cushion bubble wrap on the globe when fitting it to avoid contamination of the quartz envelope and to wear leather work gloves to protect the fingers against cuts if the globe shatters. The gloves will also offer some burn protection in event the lamp has been left connected to power.

The louvres cast into the rear end piece are canted upwards. The vent slots in the side and upper covers are not weathershielded, therefore the lamp should not be operated where water spray or drops will fall onto it. An internal glareguard covers the vent slots so the globe itself can be regarded as somewhat protected against shock cooling from direct strike by a stray drop or two only.

The power supply wires to the lamp base run through woven shields.

Periodic checks by a lighting electrician should occur as is best practice for all lighting systems to ensure that earth continuity from plug to the metal lamphouse is maintained and no conductive path has developed from any live wiring to the metal casework in the course of normal ageing, wear and tear.

The stand for this style of lamps consist of a familiar arrangement of three legs, six stays in pairs attached to the legs, a lower fixed attach point for three legs and a travelling collar attach point for the stay pairs which is locked by a winged bolt bearing against a friction insert which itself bears agsinst the upright support post.

Inside this post are two telescoping extentions which are locked also by a winged bolt. IN the upper extention, there is a short post on which a socket in the lamp support bracket rests. The lamp bracket is retained on the post by a winged bolt. The post itself is retained in the end of the upper telescoping tube by a blind rivet.

The last three inches or so of downward travel of each section is cushioned by a spring to avoid or minimise pinch injury to hands when lowering the sections. It is recommended when using all lamp stands of this style for leather work gloves to be worn to avoid or minimise pinch injury.

When transporting the stands, it is recommended that all clamping winged bolts be tight to avoid them from falling out and friction pieces becoming dislodged. I have not yet dismantled any of these to see if the friction pieces do fall out.

It is also recommended that a piece of plastic electrical conduit, irrigation pipe or cardboard carpet roll core, about 1" or 25mm longer than the upper telescopic section when it is retracted, is slipped over the end of the upper telescopic section to avoid the section being forced so far into the tube by impacts, dropping etc., that the blind rivet is forced inside the tube. If this happens the section may become jammed or the rivet sheared off or both.

In normal use, the stand will be found fit for purpose. The clamping winged bolts should not be overtightened. They are adequate for purpose moderately tight.

The stay pairs and leg hinge points are simple rivetted fixtures. My personal preference would be for pillar passthrough collars inside the tubes for the rivets or anticrush end inserts in the tubular sections. The existing fixture arrangement is however common practice and fit for purpose.

The stands will be found to be steady and comfortable to use.

The free fit before tightening of the lamp brackets on the posts will be found to be generous rather than snug. The brackets tighten to the posts with their winged bolts adequately and lift free easily when the bolts are loosened.

The winged bolt which secures the lamp support to the post can be moved to another threaded hole opposite for left-handed operators. My guess this extra threaded hole is a hedge against brutal overtightening and stripping of the thread. If you are paranoid and want to have two winged bolts there you could do this.


Any repairs to this lamp should only be undertaken by a qualified lighting electrician if for no other reason than to ensure the job is properly and safely done.

On an unpaid voluntarily crewed low-no budget indie shoot where these low-lost lamps will likely prevail, sooner or later, the lamphouse may be found to have been partially dismantled and abandoned.

The likely culprit may be an untrained "kid eager" intent on trying to get at the globe, check for damage if the lamp is dropped or remove invading vermin (all excuses for idle and unproductive curiosity).

Re-assembly of the lamphouse can be very awkard. The same "kid eager" may disappear and call in sick or be upfront and honest and say he ( or she ) broke your lamp. You will have a jigsaw puzzle of loose parts on your hands. Ideally you will have a lighting electrician check and re-assemble it.

All the extrusions and side panels have to fit in their grooves before the end pieces will position correctly. Co-ordination of all the parts into their places at once is difficult.

So here is a sort of assembly order.

Check for existence of all parts. Likely to have been lost are two short ( about 3/4" ) small metal spacer rods which fit between the "C" section support bracket mounts and the front end piece inside of grooves in the upper edge of the side extrusions. You could get away without them but the "C" sections will then be free to slide about 3/4" in their channels, not a satisfactory or safe condition. There are two more longer ones between the "C" sections and rear end piece.

You should have five long self-tapping screws for each end piece, three along the bottom edge and two either side of the lens guard. Each of two flat side covers are fastened onto threaded stud pillars by two machine screws.

If the two flat side covers are still in place but the front end-piece if already off, remove the side covers.

If the globe is still in place, remove it. The two chromed spring blades have slots in them to retain the globe by its ceramic base. Both blades have to be eased away from the ceramic base of the globe to release it.

If the support bracket remains attached to the "C" sections, remove it.

If the two upper side extrusions have been removed from the rear end piece, refasten them to the rear end piece and re-install the rear spacer rods, the "C" section brackets and then the front spacer rods by sliding them into the channels from the front.

The "C" section bracket with latch channel for top opening cover and winged bolt is on right side and "C" section bracket with simple bolt and collar is on left as viewed from rear. Both bolts attach into captive nuts which slide into channels in the "C" section brackets. These nuts are likely to have slipped out and will need to be searched for. Both "C" section bracket extrusions are identical.

The "C" section bracket on the left must be re-installed upside-down with the latch channel at lower edge or it will stick up and interfere with the opening movement of the top cover.

Offer the front end piece up to the two rod/rails of the lamp base spot/focus movement and locate them in their pillared holes. Make sure the rear ends are already located in the rear end piece.

Slide the lower edges of the front end piece over the two lower corner sections and lower centre cover. This is a tricky business. The rod/rails may fall out a few times until you get it done.

Install the three lower self-tapping screws to loose snug fit only sufficiently to stop the rod/rails from falling out. Do not worry about the upper side pieces or top opening lid at this stage.

Offer up the left edge of the top opening cover to the longest of the small pillars on the rear end piece on the left upper side as viewed from the rear. You will find it helpful to have just enough closure on the three self-tapping screws that you have to bend the front cover forewards slightly to allow its longest pillar to slip into the hole then spring back to retain it.

You will now find it helpful to have the front end of the lamphouse elevated slightly to prevent parts sliding out of the two upper side cover sections. Move both upper side covers with "C" section brackets attached so that the two front holes on each accept the shorter two pillars on the front end piece into matching holes in the extrusion. The upper holes are the same ones the spacer rods and "C" section brackets slip into. Check that the top openling lid has not come off.

Tighten the three lower self-tapping screws more snugly to prevent the front end piece from slipping off but do not yet tighten to security.

Hold the front end piece firmly in place and install the two long self-tapping screws in the holes either side of the lens to snug fit.

Gently twist the front cover clokwise and anticlockwise slights a few times to ensure the pieces are bedded in their grooves and holes. Tighten all five self-tapping screws to security. You can observe the penetration of the two lower lower screws in their channels via the opened upper cover. All screws will feel as if they are stripping their threads however their action is more by wedging in the channels rather than by cutting threaded in complete holes. They will tighten to security.

Slip the side covers into their grooves from the top or from the bottom and fasten them with the machine screws. The covers should insert from top or bottom. Top seems easier.

Check the motion of the spot/flood movement.

Install the globe.

Check with multimeter or test lamp for shorts to casework from live conductors. Check earth circuit for continuity from casework to the earth pin on the plug. If the casework to earth pin continuity is interrupted by the in-line power switch being switched off in an unplugged test, the lamp has been incorrectly rewired, is totally dangerous and should not be used until a lighting electrician has repaired and signed off on it.

Re-attach the support bracket cradle to the "C" section brackets, winged bolt, friction washer on the right, simple bolt and stepped sleeve on the left as viewed from the rear.

The lamp is offset forward of pole centre when the cradle is correctly fitted.

I repeat that the text above is neither a definitive handling note nor authorised by the manufacturer and vendor. It is your responsibility to conduct your own research and use a qualified lighting electrician for repairs and maintenance.

Last edited by Bob Hart; January 15th, 2010 at 12:10 AM. Reason: error plus update footnote
Bob Hart is offline   Reply With Quote
Old January 14th, 2010, 03:57 PM   #2
Inner Circle
Join Date: Nov 2005
Location: Lowestoft - UK
Posts: 4,037
For anyone not familiar with the fitting of the ceramic based lamps (as we call them in the UK or more commonly 'bubbles') also needs to note that the standard lamps used in these types of luminaire are Tungsten Halogen - and therefore need some handling instructions. As it mentions above,you must not touch the glass envelope with your fingers. Here's why. The natural oils in your skin will leave fingerprints on the quartz glass. The Halogen cycle means very high envelope temperatures, and the oil from your finger will burn and darken. This makes the glass hotter still, darkening the stain further. Eventually the lamp fails because of over temping, often cracking the seal where it meets the ceramic at the bottom. These type of lamps always seem to have the aluminium spring clip which gets in the way during re-lamping. Some brands of lamp are supplied with a polythene sleeve. Fit the lamp with this on, then pull it off. Other lamps come in cardboard sleeves, same idea. Never touch them - you can easily lose half the life!
Paul R Johnson is offline   Reply With Quote
Old January 14th, 2010, 10:30 PM   #3
Inner Circle
Join Date: Dec 2003
Posts: 4,476

Thanks for the added note on the halogen lamps.
Bob Hart is offline   Reply With Quote
Old January 15th, 2010, 04:58 AM   #4
Inner Circle
Join Date: Nov 2005
Location: Lowestoft - UK
Posts: 4,037
I've always tried really hard to keep the glass clean. It's really quite odd to take a failed lamp out and clearly see the stained areas from somebody else's thumb and first finger. If you do touch the glass accidentally, you can use some spirit to remove the grease.

All that said - I still reckon I break more lamps by jerking them when the thing is on! Barn doors always seem to get very loose and flop around, or seize up, and the jerk, when they unstick is enough for the filaments to touch and poof!

These particular Fresnels (pedantic mode on here- not fresnels as it's the proper name of the inventor of the stepped lens) are styled on the Arri luminaires, and the lead screw focus is a nice gentle way of adjusting beam spread. Watch out for similar units that have the lamp tray on a simple slide, with external knob to release it. These things always jam, and suddenly give - popping lamps.

Us Europeans have more problems than my American colleagues because our lamp filaments are different to cope with our higher voltage - and they're generally a bit thinner than yours too.
Paul R Johnson is offline   Reply With Quote
Old January 15th, 2010, 10:26 AM   #5
Inner Circle
Join Date: Dec 2003
Posts: 4,476
A shoot I assisted about three years back had some open faced lights which used similar globes.

The owner had bought a batch in from an offshore eBay auction, about 10 of them and went through the lot in very short time.

One nasty party trick was to pick up the light and move it whilst it was working.

The Steven Studio lights have spot and focus control via a turning knob in centre of the rear, a gentle action as you describe. The one I took apart to check for shipping damage has a moving pressed sheetmetal carriage which slides on round rods and is driven by a helical groove on a third rod.

The holes through the sheetmetal base are a generous clearance and should not bind. There is what appears to be a high temp grease on the rods. The spot and flood action is smooth and does not baulk.

Now I have to work out what to do with a 12K light which I got confused with a 1.2K light. At the time I thought it was bigger because it was just old. It is even bigger than I thought. Apparently if I turn it on, the fuses all the way out to the pole on the street will blow.

The passage of time plus wear and tear may tell a different story down the track but mechanically they should not be hard to maintain as the rods and helicoid track can be got at through the top cover.

I have not been up close to a real ARRI light to study its gizzards and tell the future so I have no reference to go by.

My new venture into fresnel lights has been to respect the efforts of a genuine DP who has been giving me pro-bono assistance, by providing within my limited means for the project, something close to the toolset he is accustomed to.

Last edited by Bob Hart; January 15th, 2010 at 10:42 AM. Reason: error
Bob Hart is offline   Reply With Quote
Old January 15th, 2010, 04:03 PM   #6
Join Date: Nov 2005
Location: Sydney Australia
Posts: 1,570
Now I have to work out what to do with a 12K light which I got confused with a 1.2K light. At the time I thought it was bigger because it was just old. It is even bigger than I thought. Apparently if I turn it on, the fuses all the way out to the pole on the street will blow.
12,000W / 240V = 50 amps

It'll sure trip a domestic circuit breaker which will be 20A however down here the service fuses are around 100A. If you really want to fire it up at home it could be done, just need a sparky to wire in the correct sized cable and suitable outlet. Probably best saved for winter though

I'm curious, you recently bought a 1.2KW HMI. Why now add a tungsten instrument into the mix.
Bob Grant is offline   Reply With Quote
Old January 15th, 2010, 09:40 PM   #7
Inner Circle
Join Date: Dec 2003
Posts: 4,476
The 1.2K HMI came after I had committed to the much bigger used light which is also a HMI. I discovered afterwards it had the portability of a medium sized refrigerator, the power draw of an industrial welder and had another zero on the number. I found out from my DP that this was not one of my wiser adventures. This is the downside of my being a jack of all trades.

It may end up fortuitously as there is a streetfight scene or two to be lit for an upcoming paying gig if we get it. On the other hand they may just use a Crommelins lighting tower and gel that.

I will either resell, or see if it will rent here as it is apparently the only one in town.

The tungsten fresnels are more controllable than the redheads we have been borrowing and fresnels were recommended by the DP who has been helping out most recently. True, gelled for daylight, they will lose power but you provide the workman his kit if you want the results.

With the price of fuel and personal time, two trips from up here down onto the flat and across town for the redheads every time or even furthur for rental gear was going to break even on buying these in fairly soon.

Last edited by Bob Hart; January 15th, 2010 at 09:42 PM. Reason: error
Bob Hart is offline   Reply With Quote
Old January 22nd, 2010, 06:58 AM   #8
Inner Circle
Join Date: Nov 2005
Location: Lowestoft - UK
Posts: 4,037
I've had some more arrive and this batch were for a project - so I'll be keeping them myself as stock.

I've noticed a few small changes to the products.

The 1000W Fresnel has mismatched yoke holes - where you attach the yoke to the pivot point. The bolts supplied are too small for the hole. They still work, but clamping is a little compromised. A couple of washers cures this. Cable quality has gone up. Now hard wearing rubber with decent size conductors.

The lamp supplied is not much use here in the UK. Over here, we have what is called harmonised mains supply voltage across Europe. The UK was originally 240V power and most of the rest of Europe was 220V supply. Now we're all friends, we have 'harmonised' and our power supply for the whole of Europe is 230V. The trouble is of course, nobody actually wanted to change, so the specification was drawn up to allow a small + and - from the 230V figure. Enough so that we still get 240V! Nothing changed. The big snag is though that if 230V lamps from say, Germany are sold here in England - their life is shorter (but brighter!)

The lamps supplied with the Chinese lighting equipment is all labelled 220V - my mains supply here killed the first one in two minutes - which is very annoying.

Quality control has also dropped a little - the housings being assembled not quite square. It doesn't impact light quality.

One word of warning on these when it comes to cleaning. The reflectors are of good quality - BUT the surface coating is very thin. Any attempt to clean the reflector dulls the surface, and light output and quality will suffer. Dust - which is likely to be the only dirt that can get inside should be removed with either canned air - or one of those rubber photography soft brushes that waft air through the bristles.

The other warning comes on the 650W lanterns - the mains cable is not rubber, but appears to be probably PVC, and much stiffer. The cable colours are also wrong for use here. The ground wire is black. This is not appropriate for use here, and before sale it should be replaced and tested. The build quality of the 650W units doesn't seem top have changed from my original batch - and optically they are rather good - as is the design they are modelled on.

Arri have remodelled much of their range so from now on, the similarities should help people spot an Arri from a clone/copy.
Paul R Johnson is offline   Reply With Quote
Old January 23rd, 2010, 12:48 AM   #9
Inner Circle
Join Date: Dec 2003
Posts: 4,476

Thanks for updating on the 1000w and 650w lights.

The cord on the 650w received here in Australia is a thick black rubber style cord. It bears the printing "245 IEC 531 (YZ) 3 X 1.0MM* 300/500V.

It came already plugged in the Australian household plug pin style which is three flat conductors, the active and neutral as an upper pair slanted inwards towards each other at about 30 degrees and the earth vertical below them in centre.

In principle the cable is more secure in the supplied plug than in our plugs in that there is a strain clamp across the cable where it enters the plug body. Our common plugs rely solely on a threaded collar which screws back over a tail which is a tapered sleeve over the cable.

WARNING: The active and neutral on the example I have are transposed, that is blue is connected to the active pin, brown to the neutral. The way this lamp is wired, the blue is connected to the large pin on the lampholder. Our domestic standard is brown to the active and blue to the neutral. The EARTH connection is correct and there was earth continuity from lamphouse body to earth pin at all times, globe installed, globe out, switch-on, switch-off.

The inline switch appears to disconnect both the active and neutral so there should not be live conductors at the lamp socket when the switch is off. Thus it remains prudent for a lighting electrician to check the wiring

It in effect the tail on our plugs becomes a collet clamp. My guess is that our plugs are intended not to apply overpressure to a clamped area and thus avoid compromising the insulation between conductors by crushing. In use, the cable eventually works its way out of the sleeve and the insulated wires become mechanically loaded, stretched and exposed.

The wires on our plugs are looped forward around the plug centre body so that some strain relief is effected by the friction of this loop and less flex is imposed on the actual connection to the pins. The loops are visible from the front and are an instant telltale if the plug is incorrectly wired.

This style of pin arrangement is apparently used as a standard in China but the takeout lead goes in from the top edge, not centre or lower right side as it is here. Unlike our plugs, there is no way to visually check if the active, neutral and earth wires are correctly pinned without dismantling the plug.

I intend to replace the plugs with our locals because of the bad habit of people to yank them out by the cable rather than unplug by hand. The supplied plugs are of lighter construction and appear more likely to be damaged by this abuse or be more likely because of the cable offset, to tilt in the socket, bind and then transfer the damage to the power outlet.

I intend to advise the vendor, Steve Fu of this.

FOOTNOTE: I have sent the email.

Last edited by Bob Hart; January 23rd, 2010 at 11:02 AM. Reason: error
Bob Hart is offline   Reply With Quote
Old January 23rd, 2010, 01:47 PM   #10
Inner Circle
Join Date: Nov 2005
Location: Lowestoft - UK
Posts: 4,037
I'd not worry about the GY9.5 socket being wired differently. There's no common way of wiring these - as the socket bases when bought can be fitted either way in most modern lamphouses. It's more common to see the 3.2mm pin as live and the 2.3mm pin as neutral but there's no real reason as this type of lamp is symetrical. It's more important on discharge lamps where the anode and cathode of the lamp need to be identified.

I've been fiddling a little more today with some of the ones I'm going to use, mainly burning off the internal dust - which is essential on these kind of things. The black paint finish in particular needs to steam for a bit, and the smell is headache inducing! The 650W unit jammed up the focus when hot - refusing to return to flood focus. I'll have a look tomorrow.

The 1K is fine. One thing I did notice was that the 650W is a little 'light leaky' the ventilation on these has some convection cooling via side panels that have a gap, and overlap. The silver internal finish does bounce around and leak out of these slots. There's no direct fillament light escaping, but quite a bit of spill light gets out. Compared to a theatre type Fresnel, they're not so good. For video, of course, this is rarely an issue.

In these images, you can see the the smoke during the burn off, and the inside of the 650W unit - plus the open front face of the 1000W version.
Attached Thumbnails
Steven Studio 650 watt fresnel lights.-650insidesmall.jpg  
Attached Images
Paul R Johnson is offline   Reply With Quote
Old January 23rd, 2010, 09:13 PM   #11
Inner Circle
Join Date: Dec 2003
Posts: 4,476

Thanks again for that. I had wondered about the light spill issue and even contemplated using some black automotive high temperature matte paint on inside of the aluminium panels if it became a problem. The surface finish of the glare shields is quite fine. I imagine with use, it may become less reflective.

For the jammed spot/flood, the centre rail or shaft may be bottoming in the front support hole and against its thrust washer in the rear if the clearance is already a bit tight and jamming.

Check if there is any free play of the shaft the spot/flood knob is attached to. If there is, open the top door and next observe the carriage as you attempt to adjust the spot/flood.

If the carriage rocks sideways as if solidly attached to the centre shaft, then the movement under the carriage itself has jammed on the shaft.

If it seems free and the carriage can be moved slightly back and forth on the shaft with a poke from a finger (power off of course) but the shaft itself is jammed in its holes in the blue end pieces, try backing off all the front and rear end piece screws about a half-turn each from security.

Don't take them any furthur as some panels may fall out of their grooves and that will be a mongrel to refit. Give the two blue end pieces a bit of a twist in case an end piece is propped high on a side panel that did not quite make it into its groove.

If that unjams it, re-tighten the two top screws either side of the fresnel centre axis on the front and rear to security.

Test again if the spot/flood is still free, and if it is fine, re-tighten the two of each lower row of three screws screws either side of the centre screw incrementally until both are secure.

Hopefully that will fix it. If it does, then tighten the two centre screws which retain the drop-out door on the bottom but don't pull these two screws down to security, only tighten enough to retain the door without pulling the bottom of the end pieces inwards.

Overtightening the two centre screws might be enough to warp the end pieces enough to tilt the holes the shaft is supported in and jam the movement of the shaft itself after the lamphouse cooks up a bit. That's my guess. I have not been able to repeat your problem.

Unlike the 1.2K HMI which took a beating during shipping, I have not been compelled to take the spot/focus assembly apart. The spiral groove in the 650watt is a rounded groove not a squarebottomed channel.

Unlike the 1.2K there are three rails. The centre rail carries the groove and the traveller is a metal cylinder which appears to be a tidy fit on the centre rail.

My first imagining was that there may be in this cylindrical piece, a threaded stud or a fixed pin with a rounded end to be driven by the the groove similar to the arrangment of the 1.2K HMI. If this stud or pin has become backed off out of its hole, the groove might have cammed the end upwards and out of the groove causing the jam.

However, I could not find a pin or stud in the traveller and there is quite a bit more freeplay in the movement than a simple pin or stud would allow.

This leads me to think there may be a matching groove cut inside the cylinder and a few ballbearings to cam the cylinder forward and backwards, or maybe just one in a hole in the traveller doing duty as a floating fixed hard chromed follower.

There is a thin circlip around the end of that cylinder which appears to retain a loosefitting outer cylinder over an inner one and likely caps a hole with a ball or pin in it.

If the clearances are a bit loose, it might be possible for a floating fixed ball or pin to partially ride out of the groove and wedge in the gap, jamming the movement. This might be a QC thing Steven has to look at. Can you move that little outer cylinder with finger pressure or is it dead tight.

There seems to be about 0.2mm clearance between the outer and the inner cylinder. The outer cylinder does not spin freely around the inner one but has a little bit of rotational play. Short of gutzing the lamp out to have looksee it is impossible to peer more closely at it. If it is still jammed, try grabbing that outer cylinder with a pair of ratnose pliers and agitate it a little. Something might click back into place and set it free.

I am only guessing at this from what little I can see. If I have sent you on a goosechase, please accept my apologies in advance.

Last edited by Bob Hart; January 23rd, 2010 at 09:46 PM. Reason: error
Bob Hart is offline   Reply With Quote
Old July 9th, 2011, 07:10 PM   #12
New Boot
Join Date: Dec 2010
Location: Brussels, Belgium
Posts: 5
Re: Steven Studio 650 watt fresnel lights.

this thread is really what I needed to find, great!

I think I need some little further explanations about wiring... I lives in Belgium (220V).

I recently own: 1x 150W + 1x 300W + 2x 650W + 1x 1K and all are fresnel.
I changed all the wires because only the 150w had the earth (ground) connection! It takes me 2 days to change them... yep discovering it. (but are so beautiful, cinema look).

A) I put new cables all 3G 1.5MM2 (neutral blue + brown phase + yellow-green earth ground) : is that right, ok, secure ? I connected the earth ground wire to a screw (internal) to the rear : is it safe, too ?

B) So, my question is : why the other lights didn't have the earth connection ? it it not so important in these symetric models? Or was it a mistake from the supplier ?

C) some lights, as the 650w and 1K w "smokes" : I can see some smoke on top-front just above the lens when in use. Is it always the same smoke smell with that kind of bulbs ? What is it burning : the bulb, the metal carriage or the lens or the thin metal grid ? (+ some idea to place little fan behind with solar panel? )

D) Is there more safety bulbs than the originals ? Does someone know the references of that bulbs at Osram or another ... mine have no number reference indications.

E) I have too : 3x 800w open face "mandarines" : do I need to put them a 3G 1.5mm2 cable too ?

F) someone know where to find some safety recommendations for use in studio, I mean when shooting people (ex : not move the light when burning, not touch the lights, no kids playing around, ... ) : because I suppose I can not imagine all the basic situations.

G) is ARRI fresnel more robust ? more secure ? ...

well, it seems elementary to know the how-to's, because it could be dangerous not-to know...

Thank you all - have a nice day, Alain
Alain Van Haecke is offline   Reply With Quote
Old July 10th, 2011, 12:08 AM   #13
Inner Circle
Join Date: Dec 2003
Posts: 4,476
Re: Steven Studio 650 watt fresnel lights.

Please accept this reply as general hints only. I am not a qualified electrician or gaffer. Please do you own research to find if my comments are truth or misguided.

A) Earth wire is very good to have. Make sure use proper connection and "star" lock washer, beneath and on top of connector so less likely to loosen due to metal heating and cooling. Check lights before each new job with multimeter for earth continuity.

B) Some countries have different wiring and safety standards. If the appliance is not CE standard double-insulated, as far as I know, it should be earthed.

C) "some lights, as the 650w and 1K w "smokes" " ----- The black finish in the chinese light appears to be paint, not dye anodised. Paint in the chinese lights burns off - faster in the big lights. I think this is where the smoke and smell comes from.

D) I don't know Osram numbers. Here for Australian 240V, the globes are Philips Broadway ---- for 650watt, 650W 240V GY9.5 6638P FRM - CP/89 --- BARCODE 8 711500 184511 ----------- for 2K, 2000W 240V G38 6994Z FKK/FKP - CP/73 BARCODE 8 711500 186584

E) "I have too : 3x 800w open face "mandarines" : do I need to put them a 3G 1.5mm2 cable too ?" ---- I have seen both types of cable used on redhead lights here. From the in-line switch to the lamp, was the flexible rubber coated cable.

F) someone know where to find some safety recommendations for use in studio, I mean when shooting people (ex : not move the light when burning, not touch the lights, no kids playing around, ... ) : because I suppose I can not imagine all the basic situations. ----- Use sandbags or concrete-filled light-aircaft tyres to stop lightstands from tipping over. Organise your cables tidy. Keep cables away from walkways. Lay safety mats over cables where they cross walkways. Keep plugs, sockets, breakout boxes away from water. Do not leave cables tightly coiled when in use. Choose the right cable. If it is too long, run the entire cable out. Do not change globes with lamps facing towards other people. Be sure power is "off" and plug is disconnected before changing globes. Use gloves and eye protection when changing globes. If a lamp or cable becomes faulty, put a label on it so nobody else tries to use it and gets hurt. Do not operate lamps near flammable material like lightweight curtains. If you must operate a light near something flammable, do not leave the light unattended. Hang a pair of short leatherfaced gloves on the stand of big lights. Do not use canned air to dust off hot fresnels or reflectors. It may cause thermal shock to the fresnel lens and globe explosion. Remove dead insects and moths from the lamps after use. Control rodents and insects where lamps are stored. Mouse and cockroach leavings are very corrosive and ruin metal fittings and circuit boards. This could cause a combination of damaged insulation and corroded earth connection to make a lamp deadly dangerous.

G) is ARRI fresnel more robust ? more secure ? ... ----- ARRI is the pattern the chinese light makers follow. Black finish inside ARRI may be better for not burning off and smoking. ARRI is designed in Europe so has to comply with european standards. If you are using the chinese lights for your business, you should ask a licenced lighting electrician to check them.

Last edited by Bob Hart; July 10th, 2011 at 01:03 AM. Reason: added text.
Bob Hart is offline   Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Photon Management

Thread Tools Search this Thread
Search this Thread:

Advanced Search


All times are GMT -6. The time now is 07:57 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network