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-   -   Starting w/HMI advice (https://www.dvinfo.net/forum/photon-management/46309-starting-w-hmi-advice.html)

Ben Chiu June 16th, 2005 02:49 AM

Starting w/HMI advice
 
Greetings!

I'm at the point where I would like to invest in a couple of HMI lights and would greatly appreciate some advice on which lights might be good to start with. Just FYI, I have several halogen lights (Britek, Chimera, etc.) already and have used CTB's extensively.

- Is it true that HMI lights are about 3 times as bright as their quartz counterparts (200w HMI about equal to a 650w quartz)? I'm looking for some lights along the lines/about equal to a 300w, 650w and 1K halogens.

- Are electronic ballasts always better than magnetic versions? (e.g. is it worth the extra money spent on them--I don't really know all of the advantages)

- Are there any type/brand of HMI lights that have bulbs that are cheaper than others to replace, easier to find replacements for, or last longer than others?

- I understand that physically smaller sized lights have an advantage when you move them, but there's sometimes a cost in light output. Do smaller lights generally cost more or less than their larger cousins?

Finally, other than the usual issues with buying used items, are there any things I should watch out for if I were to look into buying used HMI's?

Any and all advice on brands, models, etc., or any general HMI guidence is greatly appreciated.

Thank you!

Ben

Walter Graff June 16th, 2005 07:24 AM

Sounds like you want to look into the k5600 Jokers.

http://www.k5600.com/

they will do what you want. Yes they output more light. They also cost much more than incandescent. Electronic ballasts are becoming more standard and if its a matter of shooting off speed you want them.

Ben Chiu June 16th, 2005 08:22 PM

Jokers
 
Hi Walter:

Geez, those things are expensive!! I know HMI's cost a lot of money, but I had no idea they were that expensive. Gotta pay if you want to play I suppose.

Thanks for the reply!

Ben

Scott Anderson June 19th, 2005 12:10 PM

If you think the Jokers are expensive, price out the Dedolight HMI's. Those are really the Rolls-Royce of small HMI instruments. But wow, are they sweet - the optics produce a superb, even light from edge to edge with a phenomenal flood to spot range.

That being said, the best values in small, kit-size HMIs right now are the Mole-Ricardson Digi-Moles, at about $2900 for a 400W kit, $2500 for a 200W.

I'm also partial to the Frezzi Super Sun Gun, in 200 or 400W. They are extremely popular with network news crews on location shoots, as they can be run off standard brick batteries with the DC kit.

You're right, Ben - you gotta pay. But, sometimes, there's just no other way to compete with the sun. Except the old fasioned way, of course - reflectors. For a sunny outdoor shoot, I'll often pull out a few beadboard reflectors, big sheets of famcore and flag or scrims and do a lighting setup that would take a generator and 10K HMI to do otherwise. More than one way to skin that cat...

Ben Chiu June 21st, 2005 02:08 PM

Hi Scott:

Thanks for the reply and heads up on the digimoles.

As you might imagine, I've been looking at what's out there pretty closely lately. Unfortunately, more questions than answers have sprung up. Perhap you or one of the other guys can help me.

1. It looks like most 200w HMI can use the same bulb (single end). Is this correct?

2. If this is the case, the only real difference in lamp housings would be the reflector, correct? It seems they all have barn doors, and scrim support, but some use lenses to change the beam, while others "zoom".

3. Am I correct in assuming that all electronic ballasts' dim?

4. Am I also correct in assuming that when you dim an HMI, the color temperature changes?

5. Do all/most HMI ballasts use a standard (the same) connector/cables for a given wattage?

6. Are ballasts downward compatible (e.g. a 400w ballast can power a 125w and 200w fixture)?

Thank again for your guidance. It's been an eye opening experience!

Ben

Scott Anderson June 21st, 2005 05:32 PM

1. Yes, several brands use the same lamps (bulbs). Also, the same lamps may be available from several manufacturers (osram, g.e., etc.)

2. Don't short change the differences in reflector designs - it can make a huge difference in the quality of the light beam. A dappled reflector will ouput a more diffused light, wheras a polished reflector puts out a more direct beam. The choice between a fresnel, open face or PAR design is much the same as thier Tungsten equivalents - it all depends on what YOU value in a light, and what your intended uses are. Also, the design of the barn doors, scrim housings, replacement lenses, support yokes, etc. all have much to do with the overall useability of the instrument. Do you value a lightweight instrument over one that is more durable? Do you want it more compact, or would you prefer it to be full-featured? Questions, questions....

3. Most all electronic ballasts' on small HMI's dim. It is a commonly requested feature that most manufacturers supply.

4. When you dim an HMI, the color temperature may not change significantly in the first 25-50% of dimming. after that, it gets hairy.

5. Each manufacturers connectors and cables are proprietary. I do not think they are interchangeable, often not even within a line of products - say different wattages of the same brand.

6. I'm not aware of HMI ballasts that are upward/downward/cross compatible. Check with the manufacturer.

You should feel free to call or email the different manufacturers with your questions. Film & video equipment is, after all, still a niche market. I find that most manufacturers are quite happy to answer your questions, even if it means educating thier customers. No question is a stupid one, and nobody has all the answers.

It seems to me that each type and brand has its own pros and cons. The trick is to figure out your primary use, then pick the light that suits that use best. There is no one light that is best for each situation. That's what 10-ton grip trucks full of lights are for - not for brute force, as much as for variety.

Ben Chiu June 24th, 2005 12:59 PM

Hi Scott:

Thank you again for the answers.

Contact the manufacturers? Doh! I should have thought of that! Will do.

Thanks again for all of your help and advice.

Ben

Anthony Marotti June 28th, 2005 09:50 AM

Hey Guys, any book recommendations on Hi End Lighting?

Philip Skaist August 2nd, 2005 03:10 PM

I saw this "budget" HMI company at the DV expo. I have no idea if they are any good or not though...anyone heard of them?
http://alzovideo.com/

Matthew Wilson August 2nd, 2005 05:52 PM

Haven't heard of them but looking at their webisite, they look like they may have some great products at incredible prices. I'm tempted to just buy one of their small HMI ballasts and lamps to try. Thanks for the tip.

regards,
Matt

Philip Skaist August 2nd, 2005 07:39 PM

No problem! If you do try them out, please let us know how they go!

Christopher C. Murphy August 2nd, 2005 09:44 PM

Hey, they do seem to be worth a look!

A complete HMI kit for so cheap?? Is this possible?? $295.26??

Replacement Bulbs are only $25.00!

I might buy one.

Bill Ball August 3rd, 2005 07:35 AM

I looked these over at DV Expo after being shocked by the price tag. I do not have a lot of expertise in this area (never worked with HMIs) but here are my impressions.

The build quality seems ok but not as sturdy as an Arri Fresnel, for example. Still, not bad for the price.

A few things that ultimately turned me off: the ballasts are built into the lamp heads. They are not heavy but it makes for a lamp head that is a rather awkward shape and not well balanced. The lamps are actually 425 watts, not the usual 400 or 575. Notice that the color temp is 5200k not 5600k. The color temp thing really was a killer for me.

These take screw base metal halide lamps. Are they essentially repackaged aquarium lights? Is this really the same as HMIs used in film/video. I'm curious myself.

By the way, ALzo had some light stands that seemed well constructed but the legs were amazingly short, creating a very tippy situation with one of their lights and a softbox attached.

Anthony Marotti August 3rd, 2005 09:27 AM

Quote:

Originally Posted by Bill Ball
I looked these over at DV Expo after being shocked by the price tag. I do not have a lot of expertise in this area (never worked with HMIs) but here are my impressions.

The build quality seems ok but not as sturdy as an Arri Fresnel, for example. Still, not bad for the price.

A few things that ultimately turned me off: the ballasts are built into the lamp heads. They are not heavy but it makes for a lamp head that is a rather awkward shape and not well balanced. The lamps are actually 425 watts, not the usual 400 or 575. Notice that the color temp is 5200k not 5600k. The color temp thing really was a killer for me.

These take screw base metal halide lamps. Are they essentially repackaged aquarium lights? Is this really the same as HMIs used in film/video. I'm curious myself.

By the way, ALzo had some light stands that seemed well constructed but the legs were amazingly short, creating a very tippy situation with one of their lights and a softbox attached.

Hmmmmm

They may be HMI lights based on the gas used inside, but I think that is where the comparison ends. HMIs for film that have been used traditionally, use a starter to jump the arc inside the bulb, I didn't see any reference to this here, and they burn bright relative to the wattage pulled! However if this light puts out a nearly daylight temperature and plenty of light with low amperage requirements, that's great.

The traditional HMIs also are very rugged and can be used indoors as well as outdoors in inclement weather. They also have interchangeable lenses that shape the character of light from a great flood to a precisely controlled spot. This all adds to their value, and yes, their price tag.

These lights look like a great alternative to halogen lights, but they don't totally compare to traditional film HMIs.

I just purchased some fluorescent lights from the Prompter People for those very reasons (alternative to halogen lights/relatively high output for relatively low wattage). A new product, they have their slight imperfections, and their shipping is not exemplary, but they are nice lights for a soft characteristic. These other lights may give better shaping opportunities and a harder edge, which is desirable within a lighting mix. I'll probably get some in my next acquisition cycle.

Thanks for the Link !

Dean Sensui August 3rd, 2005 02:13 PM

Something else to consider is that HMI's put out a lot of UV which can be harmful to eyes and skin. Some of the outdoor HMI bulbs at Home Depot have warnings on the packaging about this.

I wonder if HMI's used for film have a filter or coating on the lamps to keep this problem under control?

Otherwise, the Alzo lights are an incredible value. Sort of like the Smith Victor's of the HMI world.


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