Jump to content

HMI vs Tungsten?


Recommended Posts

Hi,

I own a 650w Arri spotlight and 3 lowell pro 250w lights. This has been my base package for a few years now and they have served me well. Reading these forums I am constantly hearing about HMI lights, so I checked the lighting department at B&H photo to check out what these lights can do.

 

The sales guy was showing me how they are daylight balanced and run on a lower wattage but produce brighter light than typical tungsten lights. This is basically the limit of my knowledge of HMI lighting. Oh yeah the other thing I know is that they are damn expensive!!

 

One question I have is if you are shooting a typical night scene that contains practical lights. They are tungsten balanced so wouldn't you normally want to use tungsten balanced kits for additional lighting.

 

If shooting indoors during the day with sunlight coming in thru windows, use of diffused HMI light makes sense as a fill.

 

Any additional info would be great, just to get me up to speed.

Link to comment
Share on other sites

  • Premium Member

HMI's are mercury based metal-halide iodide lamps. They have a multiline spectrum that is the same as daylight (5600 degrees Kelvin). A 4k HMI will be marginally brighter than a 10k quartz. They are also a lot more money but when it comes to getting a generator, you can cut your amperage in half or more. You might want to look at some k5600 jokers (http://k5600.com/).

Link to comment
Share on other sites

So for lighting indoor at night with practials in the shot you should use tungsten lights like the arri series of spotlights...right?

 

If you could only buy one HMI light which one would you choose?

 

Which HMI has the best value for the money?

 

Does the ballast supply power?

 

Is HMI 2x the light per wattage?

Edited by Jason B
Link to comment
Share on other sites

  • Premium Member
So for lighting indoor at night with practials in the shot you should use tungsten lights like the arri series of spotlights...right?

Is HMI 2x the light per wattage?

 

For a night interior with practicals in the shot. I would use an HMI bounced off bead board coming through the window either ungeled, with 1/4 or 1/2 CTO. This will give you that blue night look. For your interior lighting, tungsten lights are the way to go. Then either white balance with the HMI off or use tungsten balanced film (depending on your medium).

Some HMI lights are up to 3 times the output of quartz per wattage. I might not count on quite this much though.

Link to comment
Share on other sites

Does the ballast supply power?

Check out this page for a detailed explaination on HMI ballasts.

 

If you could only buy one HMI light which one would you choose?

If you're seriously thinking of buying one, you might want to look into a 1200w PAR because it's the highest output head that you can plug into a wall. Visual Products usually has some good deals on HMIs. Arri, K5600, Desisti are good; I'm not a big fan of Moles though (their HMIs leave something to be desired).

Edited by Matt Irwin
Link to comment
Share on other sites

Check out this page for a detailed explaination on HMI ballasts.

If you're seriously thinking of buying one, you might want to look into a 1200w PAR because it's the highest output head that you can plug into a wall.

 

 

Does anyone have a simple resource that breaks down lighting vocabulary, so I don't have to keep asking things like...

 

...what exactly is a PAR light? :rolleyes:

 

I am starting to dive into the more professional level of super16 filmmaking and want to get these terms under my belt, so I can make the best decisions when I am shooting a feature.

 

Do HMI lights make people "look" better?

 

In Charlie and the Chocolate Factory, and other tim burton films, he always makes people look this pale almost glowing white. Is that all about HMI or can you get that effect with tungsten and just good makeup?

 

Also do they make a good range of daylight balanced Vision 2 for HMI use or is there a filter to compensate for tungsten balanced film?

Link to comment
Share on other sites

...what exactly is a PAR light?

 

Parabolic Aluminum Reflector. It's a sealed-beam (non-focusing) light that can put out intense light over longer distances when compared with other types of fixtures (like fresnels, open faced, and broads). Fixtures are either tungsten or HMI.

HMI PAR:

b785.jpg

HMI Fresnel

b800.jpg

 

PARs have a "dirty" pattern, ie. the center of the spread is very intense (you can sometimes see the filament projected) while the outer area is less intense; becasue of this, some PAR heads allow the use of lenses to widen or soften the beam. PARs are usually what I use for "punch"-- they're great for slashes through a window, backlight from a distance, etc.

  • Upvote 1
Link to comment
Share on other sites

  • Premium Member

Tungstens can also come in PAR or Fresnel designs, not just HMI's.

 

HMI's are just daylight-balanced lights. They aren't "better" for lighting faces. They are just for when you need a 5500K light instead of a 3200K light. They are also more power efficient than tungstens (although also more expensive), so a 1200watt HMI PAR is almost as bright as a 5K tungsten. A 575 watt HMI is as bright as a 2K tungsten.

 

A car headlamp is an example of a PAR light.

  • Upvote 1
Link to comment
Share on other sites

Jason If you are considering buying an HMI Par consider a Booster 1200 Par. Less expensive than LTM, ARRI, K5600 and very well built. Globes last a long time in Booster fixtures due to better cooling and the 1200 wat Par is as bright as a 2500 watt Par, better optical design and boosting of the lamp current. The one thing no one talks much about is that HMIs are full spectrum light sources, if you need accurate color reproduction with either film or Digital HMIs provide that. Tungsten lamps are really heavy in red and light in blue and green so getting really accurate color is sometimes difficult.

 

I do work for Booster Lighting but I was floored by the first demo I saw of their lights 4 months ago. I just started there last week as the marketing director so if you have any questions please contact me off list. I think the Booster HMI Pars are really good products and in 30 years of shooting and lighting I can't say that about most lights.

 

Cheers

Robert C. Fisher

www.rcfisher.com

bob@rcfisher.com

Link to comment
Share on other sites

  • Premium Member

HMI's have about 4 times the light output as a comparable tungsten unit. That means that a 1200W HMI Par will kick out at least as much as 5000w tungsten unit, at least in theory.

 

This is great when you're tying into house mains or on a "lean current" budget. When I started doing cheapo music videos, a genny was often the biggest obstacle and cost (it needed someone with a truck license to drive it an it cost a fortune to rent), so we went for small portable suitcase-gennys and HMI's and Kino's instead.

 

Today, when juice and a genny is not a problem, I prefer tungsten lights. Tungsten just has a nicer quality in my eye. They're also easy and qick to setup, no hideous ballast, no flicker, you can dim them and they're light. That speeds up the rigging time.

 

As a sidenote, when are lighting rental houses going to offer a small pickup truck with a smaller genny on it that you can drive on a regular license (say, 20-40kva)? Today, it's either the suitcase, 2000W genny's, or the 150kva semi trucks - nothing in between.

Link to comment
Share on other sites

  • Premium Member
As a sidenote, when are lighting rental houses going to offer a small pickup truck with a smaller genny on it that you can drive on a regular license (say, 20-40kva)? Today, it's either the suitcase, 2000W genny's, or the 150kva semi trucks - nothing in between.

 

 

Adam,

 

Thats about the 1 thing the local rental house in Zurich does have 50KVA trailer!

 

Stephen

Link to comment
Share on other sites

  • Premium Member
Adam,

 

Thats about the 1 thing the local rental house in Zurich does have 50KVA trailer!

 

Stephen

 

But I bet they built it so heavy that you need a special license to tow such a heavy load, right?

:D

 

I've actually looked into this years before and a 20kva silent genny doesn't weigh more than about 750kg's. A 40kva is about 1000kg's - both easily fittable on even the smallest of pickup trucks. And 40-50kva goes a long way.

Link to comment
Share on other sites

In Charlie and the Chocolate Factory, and other tim burton films, he always makes people look this pale almost glowing white. Is that all about HMI or can you get that effect with tungsten and just good makeup?

 

--

 

(can someone please answer that???? I'd like to know too :D )

Link to comment
Share on other sites

  • Premium Member

Tim Burton often employs big soft lighters. Emmanuel Lubezki and Philipphe Rousselot both fall into that category. In the case of Sleppy Hollow it's a combination of soft light, makeup and production design - beautiful film. I visited the sets of Willy Wonka and can tell you that much of the light was buit in to the production design - very organicic and soft. Augmented by lots of soft front/toplight.

  • Like 1
Link to comment
Share on other sites

Thanks Adam.

 

Those soft lights cetainly add a sort of ghostly, ethereal beauty to the image.

Any diffusion on the lens in Charlie and the Chocolate Factory?

 

Did you meet any of the cast or crew when you visited the set?

 

-Jonathan

Edited by TSM
Link to comment
Share on other sites

Digital diffusion can never replicate what the real thing gives you. I know this is an overused term but glass filters look much more ORGANIC. :-p

 

With actual filters, the amount of halation is dependent on how bright that particular subject is. With digital diffusion, the amount of halation is dependent on what lumininace value the pixels are. I.e., something at maximum brightness will halate the same amount as something twice maximum brightness, if you catch my drift.

 

Someone on the boards explained it this way a while ago... much better than I just did. :P

Link to comment
Share on other sites

  • Premium Member

I don't think it's a right or wrong issue, just that they look different. Digital diffusion sort of has the opposite effect on grain; with optical diffusion, the contrast loss from halation can make grain show up better; whereas digital diffusion tends to defocus grain, making the shot look degrained compared to surrounding shots.

 

I just saw "The Island" and there was some distracting use of digital diffusion on just Scarlett Johanson's close-ups, as if they were trying to erase a blemish or mole, but it was really annoying because she had the degrained fuzzy patch on her face in half her close-ups, intercut with Ewan MacGreghor's more rugged and sharp (and grainier) face.

 

The used digital diffusion for "Charlie and the Chocolate Factor", which looked weird and made the fat German kid look like the CGI PIXAR baby, but at least you could justify it (maybe) as part of the fantastical world of the movie.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...