[Eddieth6]

Hello everyone,

I am developing my first exposure unit and by doing some research I found out that Metal Halide bulbs are the best ones.

When I searched for this kind of bulbs I only found "Cool White" bulbs and not even one with only UV light (black Light). The question I have is if they still work for getting good quality screens? Or should I get only UV light metal halide bulbs?

I am planning on buying these ones:

http://www.lighting.philips.com/mai...metal-halide/mh-nasc/928480400097_EU/product#

Thank you for your time!

 

[NoXid]

Do some more research before buying anything. There are a number of differences between various bulbs that you need to consider when ordering the bulb, as well as when ordering the base and power supply, and the various types are incompatible.

Though before that, and more to your question, there are grow lights for hydroponic agriculture (growing tomatoes or pot or whatever), where some UV is a desired part of the output, so it is not filtered out. Then there are more general purpose bulbs for commercial/industrial lighting; these come in two types: Protected (filters out the UV) and Unprotected (no UV filter). That latter type or a grow light would be what you want. NOTE Unprotected bulbs have a bump on the base that prevents them from being used with a base that was intended for a Protected bulb--so get the right type of base. (Unprotected bulbs are intended to be used in fixtures that filter out the UV, thus the bump is to keep anyone from putting them in a fixture that provides no UV protection.)

Then there are bulbs made to work with analog power supplies and others to work with digital ones. The analog ones include an extra element that is there to get the rest of it hot enough to light up. Doesn't matter which type you get, just need to make sure power supply and bulb are of the same type.

All MH bulbs make some UV, it is just a matter of whether it is filtered out (a Protected bulb), and whether the bulb is designed to produce extra blue/UV spectrum (grow bulb).

Normal glass filters UV. You want at least low iron glass for your exposure unit, many spend the extra for one of "optically clear" glasses.

Also, if you are going to do MH, I would do 1000w. That is what I have. ~24 second exposure time with Saati PHU.

You know these bulbs are not on/off types of things, right? You need a shutter between the bulb and your screen to control the exposure time.

If I were doing this today, I would take a close look at the LED options. No shutter needed. Runs cooler. Sucks less power. Either way, searching the threads on here should turn up some useful info.

Enjoy

 

[Eddieth6]

Do some more research before buying anything. There are a number of differences between various bulbs that you need to consider when ordering the bulb, as well as when ordering the base and power supply, and the various types are incompatible.

Though before that, and more to your question, there are grow lights for hydroponic agriculture (growing tomatoes or pot or whatever), where some UV is a desired part of the output, so it is not filtered out. Then there are more general purpose bulbs for commercial/industrial lighting; these come in two types: Protected (filters out the UV) and Unprotected (no UV filter). That latter type or a grow light would be what you want. NOTE Unprotected bulbs have a bump on the base that prevents them from being used with a base that was intended for a Protected bulb--so get the right type of base. (Unprotected bulbs are intended to be used in fixtures that filter out the UV, thus the bump is to keep anyone from putting them in a fixture that provides no UV protection.)

Then there are bulbs made to work with analog power supplies and others to work with digital ones. The analog ones include an extra element that is there to get the rest of it hot enough to light up. Doesn't matter which type you get, just need to make sure power supply and bulb are of the same type.

All MH bulbs make some UV, it is just a matter of whether it is filtered out (a Protected bulb), and whether the bulb is designed to produce extra blue/UV spectrum (grow bulb).

Normal glass filters UV. You want at least low iron glass for your exposure unit, many spend the extra for one of "optically clear" glasses.

Also, if you are going to do MH, I would do 1000w. That is what I have. ~24 second exposure time with Saati PHU.

You know these bulbs are not on/off types of things, right? You need a shutter between the bulb and your screen to control the exposure time.

If I were doing this today, I would take a close look at the LED options. No shutter needed. Runs cooler. Sucks less power. Either way, searching the threads on here should turn up some useful info.

Enjoy

Thank you for your reply. So I will be able to even grow pot with this bulb, excellent hahaha. Ok, I will make sure the bulb is unprotected from UV.

Also, I don't know what you mean by the base, I know MH bulbs need a Mogul socket and a ballast in order to work, which one is your base?

I didn't know about the analog or digital power supply, I'll do some research.

I would love a 1000w bulb but I believe they are only 220 volts and not the 127 volts that I use at home, I would need a transformer from 127v to 220v and in that case I would just buy another 400w reflector to have a total of 800w near the 1000w and no needs for a transformer. Or do you still recommend me to choose a 1000w bulb instead?

Thank you a lot for your help!!

 

[NoXid]

Thank you for your reply. So I will be able to even grow pot with this bulb, excellent hahaha. Ok, I will make sure the bulb is unprotected from UV.

Also, I don't know what you mean by the base, I know MH bulbs need a Mogul socket and a ballast in order to work, which one is your base?

I didn't know about the analog or digital power supply, I'll do some research.

I would love a 1000w bulb but I believe they are only 220 volts and not the 127 volts that I use at home, I would need a transformer from 127v to 220v and in that case I would just buy another 400w reflector to have a total of 800w near the 1000w and no needs for a transformer. Or do you still recommend me to choose a 1000w bulb instead?

Thank you a lot for your help!!

Oh, sorry, yes I meant "socket." You need a Mogul socket that is compatible with unprotected bulbs. They have a slot to accept the bump/rod that the unprotected bulbs have.

I run my 1000w off regular USA 110/120 v. In any case, your power supply is a transformer (AC to DC). Mine has multiple taps, so could be used with 120, 220, and a number of other industrial voltages. If you can plug a hair dryer into your outlet, it can run a 1000w MH.

 

[Eddieth6]

Thank you for your reply. So I will be able to even grow pot with this bulb, excellent hahaha. Ok, I will make sure the bulb is unprotected from UV.

Also, I don't know what you mean by the base, I know MH bulbs need a Mogul socket and a ballast in order to work, which one is your base?

I didn't know about the analog or digital power supply, I'll do some research.

I would love a 1000w bulb but I believe they are only 220 volts and not the 127 volts that I use at home, I would need a transformer from 127v to 220v and in that case I would just buy another 400w reflector to have a total of 800w near the 1000w and no needs for a transformer. Or do you still recommend me to choose a 1000w bulb instead?

Thank you a lot for your help!!

Oh, sorry, yes I meant "socket." You need a Mogul socket that is compatible with unprotected bulbs. They have a slot to accept the bump/rod that the unprotected bulbs have.

I run my 1000w off regular USA 110/120 v. In any case, your power supply is a transformer (AC to DC). Mine has multiple taps, so could be used with 120, 220, and a number of other industrial voltages. If you can plug a hair dryer into your outlet, it can run a 1000w MH.

Thank you so much for your help. You had helped me a lot. One last question, what is the model of your bulb and your ballast? Maybe I'll copy you if I can afford it hehe.

Thank you again

 

[NoXid]

Thank you so much for your help. You had helped me a lot. One last question, what is the model of your bulb and your ballast? Maybe I'll copy you if I can afford it hehe.

Thank you again

It's been some years now, so don't have that info at hand, and would be outdated info by now anyway. My light is intended for stadium lighting, and the like, not one of the grow bulbs. But the source had a chart showing it's spectrum, and it had a good amount of UV. But a grow bulb is probably better ... from what others on here have said.

One other consideration. Most bulbs are made to operate in only ONE position, and the most common is vertical. I mounted mine horizontally with a reflector, which I assumed was a better orientation for an exposure unit, and seems to be how the commercial units are made. Anyway, make sure the bulb is rated for the position you want to use. Vertical (and whether Up or Down pointing), Horizontal, or Universal.

These things make a LOT of heat. Design your unit with that in mind, with materials that won't burst into flames, and so there is a way for air to circulate. Also, this spectrum of UV is bad for your eyes (cataracts), so you do want an enclosure that is going to contain the light. That is why there are safety precautions preventing the installation of an unprotected bulb in the wrong kind of fixture.

 

[Eddieth6]

It's been some years now, so don't have that info at hand, and would be outdated info by now anyway. My light is intended for stadium lighting, and the like, not one of the grow bulbs. But the source had a chart showing it's spectrum, and it had a good amount of UV. But a grow bulb is probably better ... from what others on here have said.

One other consideration. Most bulbs are made to operate in only ONE position, and the most common is vertical. I mounted mine horizontally with a reflector, which I assumed was a better orientation for an exposure unit, and seems to be how the commercial units are made. Anyway, make sure the bulb is rated for the position you want to use. Vertical (and whether Up or Down pointing), Horizontal, or Universal.

These things make a LOT of heat. Design your unit with that in mind, with materials that won't burst into flames, and so there is a way for air to circulate. Also, this spectrum of UV is bad for your eyes (cataracts), so you do want an enclosure that is going to contain the light. That is why there are safety precautions preventing the installation of an unprotected bulb in the wrong kind of fixture.

Well don't worry about your bulb model. But, thank you very much again!! I'll try to find a universal position bulb or an horizontal one.

About the heat, I will put in a fan to cool it all down. And about the materials that won't burst into flames, what do you recommend me to use? because the table is made with wood and that can burst into flames

 

[NoXid]

...
About the heat, I will put in a fan to cool it all down. And about the materials that won't burst into flames, what do you recommend me to use? because the table is made with wood and that can burst into flames

Yes, realistically, most of us end up using wood of various sorts, as that is what we have ready access to and tools to work with.

My bulb is in a reflector, and the reflector is spaced a good distance from the surrounding structure. So that keeps direct radiation off of everything the reflector shields and allows for airflow around it all. But the upper portion of the unit gets direct rays, and gets hot.

I did not do this, but am reminded that it would be a damn good idea everytime I leave the thing to warm up (takes about 5 minutes) and forget about it
... so wiring in a thermostat or timer might be a VERY good idea, to ensure the thing shuts off all on its own if left for too long. That said, I do have a smoke alarm installed directly above it

Shield what you can with metal and an air gap. Provide good ventilation (it is a 1000 watt heater!). And provide for some sort of failsafe, at minimum a smoke alarm.

Oh, and remember that these bulbs do not like to be cycled on and off. For the most part, they need to fully cool after being shut off before being turned on again, else they will fail.