Gaffer & Gear 98 - HMI Lamps

Gaffer & Gear 98 - HMI Lamps.
Quick tip on restoring a HMI Lamp that has changed color after a hot re-stire and wont settle back regardless of time.
And problems you can encounter which makes always having a spare globe a good idea

[@birkgroven9160]

Really appreciate your genuinely informative videos! It is rare to fund stuff with this useful, well educated information here on youtube.

[@LivingroomGearDemos]

I think I’ve watched all your videos twice the last two weeks. Thanks for a great channel 🤌🏻 You deserve a lot more views.

[@corymayomedia]

The amount of value on your channel is incredible. Thank you

[@michaeltebinka]

Thank you for this fantastic walkthrough and sharing this!

[@glebv]

Super valuable info, so clearly explained, as always. Highly appreciated! Thanks!

[@codygriggs7115]

Love your videos. I go to a film school in America and we’re getting into more advanced lighting like HMI’s. I watch your videos as like secondary schooling and it’s very useful. Keep the work up!

Oh man, there is so much valuable information in this. I think this is the most underrated filmmaking channel on KZbin. You deserve a lot more views!

[@JacoxNovak]

Really useful and well explained, thanks!

[@Dncyx]

love your work!

[@liweihuang7212]

Thx for super useful info.

[@igetitlitsoicansit2950]

thank you as always!

[@KROMAFX]

Hello, first of all congratulations for the magnificent videos you make, they are of immense help. I wanted to ask a question about the HMI lights. I just bought my first light of this type, it's a Desisti 575w fresnel with magnetic ballast. I would like to find a website or similar to learn how to use it correctly and especially in terms of precautions (minimum distance to the talent, what to do in the event of a bulb explosion and the mercury it releases, etc.) sorry for this large text but I can't find it a reliable place to learn. thanks a lot!

[@gaffergear]

The 575 fresnel won't generate enough head through the glass fresnel to be a safety risk, unless it is in full spot. Depending on the age of the light it should have a silver plate with the serial number. On that plate is usually a diagram that shows safe operating angles. Magnetic ballasts is before my time but give it a lot of time to cool down before restarting. Very unlikely to get a globe explosion on a 575. But if you do just walk away from it for a minute do you don't breathe anything in.

[@KROMAFX]

Thank you very much for your response. It is of great help to me!!

[@GroveTV]

thanks for very helpful video! pls make video about trucks that generates power fot the lights

[@artobzor]

Thanks a lot from Russia) I m totally new to the topic 1.Do you messure the color temperature by electronic device every time you start HMIs ? 2. Do you recomend to open HMI (to make the bulb visibale and to cool faster) during you wait them to cool and restart again ? 3. If the place where i shoot dosn't handale HMI for a long time from the point of electicity.... i mean it is ok.... but in is a kimd of small factory\office and they have to work... and they swich some extra devices during the same time we shoot.... so from time to time (once an hour for example) we have totall blackout and have to swich everything over and over again I know that it sounds awful and unprofessional and probally damaging to HMIs So i want to make it not happen anymore Any adwises ? (if we dont have generator.... and i dont think any UPS can handle HMIs.... but maybe it is even better for them to swith off correctly in few seconds then suddenly for this reason of power off i remember that video projectors got to cool theeir lamps with cooler inside and it is fatal for them if you exedently switch off the plug.... but luckily it is not that bad with HMIs as i guess ? am i right?

[@gaffergear]

I'll try to answer all that.... I don't check colour temperature every time with HMIs, 99% of the time I go by eye. If I have a new globe that's higher kelvin or pink I try to have them in the same van so the HMIs are a close match. I asked about opening up HMIs to cool the globe and the advise from lamp manufacturers is no. A cold rush of air can shatter the glass. Locations with limited power for HMI is a pain that sometimes we get stuck with. Tripping the power won't harm the HMI as long as you can wait before re-starting. The less strikes the better for your globe investment. One trick I do is dim the HMI about 20%. Most DPs won't even notice but it can buy you some extra leeway on the circuit. Hope that helps

[@artobzor]

@@gaffergear thanks for your answer. It will help a lot ) And extra advice from lamp manufactures is great too You make our skill better ( and less equipment is suffering) (sorry for so much mistakes in text)

[@wakkowarner8810]

How good is the joker 200w hmi lamp and ballast for somebody's first hmi light?

[@FloridaRCFlyer]

Hey Andrew, I'd love to see your videos on Odysee as well!

[@xx1simon1xx]

i learned it this way: if you have to move the lamp or recable to it for some other reason, prepare everything, kill it, pluck it in and restrike as fast as possible, if the gap in only a few seconds, the lamp just starts up without any issues, i was told this was because the gas in the bulb didnt cool down enough to cause problems. any comment on this? ive always wondered. anyways, this was on jobs were waiting 10 minutes would cost a hell of a lot more than a new globe, so maybe they just didnt care.

[@hrvoje_bazina]

From my experience, you always wanna wait for it to cool down. Whenever I've gone to do a hot restrike after the lamp has just been killed, it's always just been trouble. So it's good to wait a couple minutes for the globe to cool down before striking the lamp again

[@DeadManRunning1]

would any welding goggles do? any suggestions?

[@ArifFeroze]

Thank you for the info! I wanted to ask if the hmi drastically dims down by itself, is it an issue with the ballast or the globe? Or is because of weak or irregular power supply from the mains?

[@gaffergear]

Most likely not incoming power. If it happens directly after power up the dimmer might be set low, the dimmer doesn't engage until after the globe has fully heated up. I would put my money on a ballast issue, but a change of globe would let you know one way of the other.

[@arnicreations6792]

Thanks for sharing your knowledge. I have two questions. Some HMI fixtures use double ended lamps and some use single ended lamps. Single ended lamps have an outer glass cover for UV protection (according to the manufacturer), where as double ended has no outer glass cover. Does that mean double ended are not safe. If not, is it ok to use Single Ended with outer glass cover cracked or broken

[@gaffergear]

Assuming your HMI, like most double ended heads is a fresnel, the glass on the fresnel is thick enough to filter the UV wave length, so perfectly safe to use Never use a single end globe with a crack in the glass. It is an explosion risk, and if that happens, you will be up for a new reflector, and possibly safety glass.

[@arnicreations6792]

@@gaffergear Thanks a lot.

[@adrinaik93]

Running an HMI is as tricky as flying an airliner.

[@ROBERTPOKONSKI]

Just a idea would it be an good idea to store your bulbs in your freezer??

[@gaffergear]

I don't know how it wood effect things like the ceramic glue in the long run

[@heinrichhein2605]

I have quite a lot of 575 HMIs, because the lamps are not cheap I would like to know if I can just run them until them Fail. Or do you recommend changing them more early. How do they fail, is that a problem. For my application, it is not a problem if it fails during a shout, so this would not be an issue. And what is your experience in the runtime you can get on a lamp typical. Hope that are not to many questions.

[@gaffergear]

575 is a very reliable and stable lamp. The colour will go bad before the light stops running. That will be why you will be replacing them

[@heinrichhein2605]

@@gaffergear Thanks for the quick reply, for me, they have been quite dependable. Do you experience like catastrophic failure of such lamps when they get old? I will replace them because of the color change for sure. So you also just run them until they are not up to the job any more. Because i find it quite wasteful to replace them according to the number of hours. Sure if I would do live shows where money is not an issue this is an other debate.

[@gaffergear]

@@heinrichhein2605 nothing like that on a 575, it will just get green

[@hzubovi1]

I know Tungsten can do arround 99,8 CRI. How much CRI can an HMI do?

[@gaffergear]

Depends on the size of the globe, small ones like 200, 400 and 575w have a TM-30 score of around 85 to 90, bigger ones are around ,96 to 98. But getting two that have a matching CCT and white point is hard as the globes change the older they get.

[@tonelessbod]

dude you have to do a review of the godox vl series! Vl300 has 79,000 lux at 1 meter!!

[@gaffergear]

Let them know you would like to see me review it! Thanks

[@zoom2027]

Which HMI brand you prefer for a young gaffer, just first time looking for an HMI light. ARRI is good but expensive, does it worth it? Or can I pick another brand for 1-2 yr?? Any advice, thx.

[@gaffergear]

Where do you live?

[@zoom2027]

@@gaffergear Hong Kong, Sorry for my broken English.

[@gaffergear]

@@zoom2027 Your English is very good. I was asking because it depends where you live. If you were in Melbourne I was going to send you to a place that sells Chinese HMI lights upgraded with European parts which come with a 5 year warranty for about 45 to 60% the cost of an ARRI, depending on the quality of the fixture. The most important thing with a HMI is backup. Regardless of brand you will have provlems. So I would take some time and consider which barnd in your region has the best after sales support. For example if one brand has a repair shop in your town and the others have to be fixed by sending them overseas that's a big deal. I would find out what the experienced gaffers in your region use, and what they stay clear of. That's always a good place to start.

[@zoom2027]

@@gaffergear thank you for your suggestion I will find for some HMI has a good warranty service. Thank you for your advice will take serious consideration.

[@gangd4807]

Andrew, I have a basic question that is embarrassing to ask. I've discussed this with a lot of people, but I haven't got a clear answer. There are a total of three switches for hmi lighting, such as d12, which one should I turn on when I turn the lights on and off?

[@gaffergear]

Yes, all in the on position.

[@gangd4807]

@@gaffergear oh i mean, I wonder every time what switch is first. i hope the order doesn't matter..😅

[@gaffergear]

@@gangd4807 I got you, it makes no difference at all.