Questions about studio lighting

[Mike Buckley]

Rob Ekins gave me an idea of using an inexpensive fresnel light with barn doors to limit and shape the light on labels of wine bottles as an alternative to custom making snoots using black matte cinefoil for use with my continuous lights. I have come up with a less expensive idea and would like to run it by you folks to make sure I have thought everything through, so please shoot holes in my idea and make alternative suggestions if you have them.

1. I can purchase a used Smith Victor 720-SG 1000W Focusing Spot Quartz Light from a very reliable source that costs only $59.

I understand that the lamp will be very hot and that touching the bulb with bare hands when placing it in the housing is a no-no.

2. I would use a full CTB gel in front of the lamp to change the color temperature of the light falling on the subject to about 5500K. I understand the gel can become brittle and change color over time, thus occasionally requiring a new gel. I also understand that I would need to place the gel in a separate holder rather than mount the gel to barn doors (see below) due to the danger of placing the gel so close to the hot bulb.

I understand that the gel will reduce the brightness of the light falling on the subject. However, the 1000 watt lamp is a lot more powerful than any of my other continuous light lamps. In fact, I might need to add diffusion material or a neutral density gel to the full CTB gel to reduce the brightness even more.

3. I would use the Smith-Victor 721 4-Leaf Barndoor Set for the 720SG Light mentioned above.

Is there anything I haven't thought of or have got wrong?

[Manfred M]

1. Get yourself a pair of heavy duty leather gloves with long cuffs for handling the hot light. Even the housing, barn doors, gel holders get hot and it is all too easy to get singed, even when trying to adjust the light when shooting without them (I have Lowel Omni Light hot lights with a barn door for my video work).

I don't see an adjustment handle on the Smith-Victor light you are looking at. My light has a large handle to adjust the head. http://lowel.tiffen.com/omni/ . This is an important feature on a hot light.

2. Never handle a quartz bulb with bare hands / fingers. The oils from your fingers will heat up and etch the quartz tube, shortening the life of your lamp. I can get 500Wm 420W and 300W bulbs for my light, so getting a lower wattage bulb, if they are available might be an option to consider.

3. Weight the stand with a sandbag. A hot light tipping over and falling is a fire hazard.

4. If you are shooting in your small studio, prepare to get hot while working. These lights pump out a lot of heat.

5. The light will darken and yellow over time, so doing a reference card shot is even more important with these types of lights than shooting with flash.

[Mike Buckley]

Thanks for the detailed response, Manfred. I realize the unit will be hot regardless of the bulb that I use, but do you think a 200 Watt bulb will be noticeably less hot than a 1000 Watt bulb?

[Manfred M]

do you think a 200 Watt bulb will be noticeably less hot than a 1000 Watt bulb?

Yes, only 1/5th (20%) of the heat output of a 1000W bulb; but it will also give off a lot less light. I've burnt myself on a 40W light bulb, so just about any incandescent light can cause burns.

[Max von MeiselMaus]

Mike, is there a reason you are using a gel? Will you be shooting with ambient light as well as your continuous lights and want to match it? If not, a lot easier to just set the WB for the light temperature you have.

1000W is a lot of light for still life. If it has disadvantages to go that high, this could be reduced. Still lives don't move and I often shoot at 1/50 with no problems.

[Mike Buckley]

Manfred: Thanks again!

Max: I will almost always be using the halogen lamp to light a small part of the scene while also using other lamps rated 5500K to light the rest of the scene. That explains the need for the CTB gel.

[Mike Buckley]

I pulled the trigger and bought the following items:

• Used light unit
• Two 600 watt bulbs (the unit takes only 600 and 1000 watt bulbs)
• Set of 4 barn doors
• Full CTB gel
• 3/4 CTB gel
• Frame for holding gel and/or black matte cinefoil with cutouts
• Light stand

Total cost is USD $204, though I still need to buy the leather gloves. That includes the $7 in shipping costs, as everything was free shipping except the set of barn doors.

A new light unit alone would cost almost that much, so I was very lucky to find a used one. I'll have additional uses for the light stand, the frame and even the CTB gels for purposes other than correcting the color temperature. I never know whether I will like a particular way of accomplishing something until I have tried it. So, even if I don't like using this lighting unit or using barn doors, I haven't spent a lot of money.

As for the heat the unit generates, I'll have everything else about the composition and setup done before setting up this lamp. So, I don't think I'll be using it long enough to heat up the room. If I'm wrong about that, I'll hate using it in the summer when the air conditioning in my makeshift studio isn't sufficient to keep the room cool even in normal situations. However, I'll love using the lamp in the winter when the heating isn't sufficient to keep the room warm.

Special thanks to Robbie for getting me on this line of thinking and to Manfred for clarifying the important details.

[William W]

. . .

6. Know your household electricity circuit (assuming you are doing this at home).

I guess you are using 120v Household Single Phase, so when you plug a 1000w lamp you'll be drawing over 8Amps on that on electrical item, so be aware what OTHER power outlets are ACTIVE on that particular circuit.

WW

Addendum - we were writing at the same time - the same caution applies to 600W tubes.

Noted it is an at home studio - so, for example if the Air-conditioning Unit is one that plugs into a power socket, is that on the same circuit as the lamp . . . etc.

What's the typical/rated Household Power Socket / Circuit Load for the USA - 10 Amps?

[Mike Buckley]

Thanks, William. I'll check that out, especially when the circuit breaker pops the first time.

[William W]

You're welcome.

I think you were making a funny quip about the CB - but on a serious note for the other readers: it depends how smart the circuit breaker is . . . some older CB can sit just under the rating and not trip, but the wiring (for example inside the wall or ceiling) can get very hot. I noted that you intend not to have the lamp on for long periods and I interpret that you personally are both methodical and also careful - but others are not so inclined and also many are ignorant of electricity basics or just don't think of the ACCUMULATIVE AMPERAGE on any ONE CIRCUIT even if they know not to overload on any one power socket.

WW

[Manfred M]

What's the typical/rated Household Power Socket / Circuit Load for the USA - 10 Amps?

Generally 15A on a 115V household circuit. Small room AC units (window units) can be on the same circuit, but the more common central air tend to be on separate 230V 30A circuits. Most recently built modern homes (built in the last 40 years) tend to have 200A service.

[Rob Ekins]

I think Bill and Manfred have covered everything here. I will add that I don't think that you willl have significant heat issues @600W the way you plan to use the lamp.
If you do feel that you are burning gel quickly both Roscoe and Lee make a range of high temperature gels. In lee's case full CTB 201 is known as CTB 201 HT.

[William W]

Generally 15A on a 115V household circuit. . . .

Ta.

15A makes sense at the lower voltage to ours - our single phase is typically 240V / 10A

[Mike Buckley]

That's good to know about those high temperature gels, Robbie. I had not noticed them. Thanks!

[Mike Buckley]

William and Manfred: The air conditioning is a central unit which I'm sure is on its own circuit. There is a small electric baseboard heater and a refrigerator in the room but I seem to remember that the contractor added extra circuits 20 years ago to accommodate using them in the room. I'll have to remove some large pieces of foam core to open the door that covers the circuit breakers, but it would probably be a good idea to check that out. First, I'll have to remove some cases of wine that are in front of the pieces of foam core.

[William W]

I'll have to remove some cases of wine that are in front of the pieces of foam core.

Do you require assistance?

[rpcrowe]

Mike - regarding heavy duty leather gloves. I have found the most heavy duty leather gloves in the welding section of a local home improvement store. (Lowe's).

When I was working in cinematography, we used a lot of hot lights and I always had a pair of asbestos gloves in my tool box. The heavy leather welding gloves are equally as good in protecting your hands and forearms from burns.

Don't smile - I recently purchased a pair of them when I had a mama dog who was exceptionally protective over her new puppy. She would try to bite anything or anyone who got near her or the puppy. The welding glove allowed me to feed and pet her and she soon got over her fear based aggression and now, I can do anything I want with this dog. She is a sweetheart.

Her puppy was adopted and we are presently training her to get over her fears of strangers...

[Mike Buckley]

Richard: Would you recommend asbestos or leather gloves?

[Manfred M]

Richard: Would you recommend asbestos or leather gloves?

Asbestos is a banned material in all virtually all Western countries, so gloves are no longer made with this material.

The lights that Richard used to work with were a lot hotter than the one you just bought.

[William W]

Picking Nits: those gloves and truck loads of other asbestos items are still made in India (and other places, but I think India has the biggest production output).

The law is pretty strict here, (Aus.), I expect that's because we've had such an high percentage of our population die the hideous death: as far as I know, one can be prosecuted here for buying or having in one's possession any (new) asbestos product.

Upon a quick search of legal matters, it seems that many (new) asbestos products are 100% legal in the USA, - including gloves. (Which both surprised and shocked me - the general knowledge things that one learns or investigates by reading CiC threads!) . . .

But my strong advice to Mike, is the same as Manfred's caution, and not go there. It's not necessary.

Thick Leather Gloves and common sense will be enough.

*

FWIW: I still use Hot Lights, not much nowadays but hey I am not going to bin them. My gear comprises quite a few 500w singles and 2 Stage Banks containing 4 x 2000w, each. Rarely do I use gloves at all. For adjusting the doors etc., I'll use a set of long tongs and for moving the lights, I'll wait until they cool. It is better that way because it's not a good idea to move them all that much when they're hot in case of an accidental jerky bump which can (more easily) rupture the filament.

WW