400w Metal Halide, 6500k - anyone tried it?

Michael Carter

Michael Carter

Veteran
This came up on a forum some time ago and I saved the link - 400 watt mogul base Metal Halide lamp. Thirty-five bucks. Add an electronic ballast for another hundred.

Vendor says 6500k, CRI of 90 and feels it would work for photography; said they sell a lot of 'em for DIY projectors. The difference between 5200 and 6500 isn't really visually a big deal.

I have a couple knockoff starlight units with softboxes and grids (mogul lamps), built for 1k tungsten. Would be pretty cool to get 1600 watts daylight equivalent out of 'em.

Wondering if any of you DIYers have tried these? Ballast is returnable, bulb isn't. Hmmm... could maybe take one for the team. There's tons of those Amvona mogul softbox kits out there used - not the greatest softbox setup but pretty servicable. And I've seen other mogul based fixtures from time to time. Could be a great space light for greenscreen sets, too.

Could be a lotta daylight for a few bucks.
 
Mogul sockets meant for tungsten lamps are unsuitable for metal halide, or any discharge lamp. You need something that can handle the high ignition voltage (pulse start rated).
 
Well, they sell various lamps, reflectors and kits there - I've bought several 600v rated bipin sockets for 150 HID with no problem. My understanding is the voltage rating of a given socket has to match, and the 600v G12's I've bought were all rated for pulse start. So I think proper sockets can be found.

My 150 Alzo ballasts won't strike on a wimpy socket or through a cheap switch; don't know if all ballasts have that sort of safety cutoff though.
 
Moseph said:
Mogul sockets meant for tungsten lamps are unsuitable for metal halide, or any discharge lamp. You need something that can handle the high ignition voltage (pulse start rated).
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Most mh grow fixtures use mogul bases with 1000 watt bulbs. Never heard of any issues.
 
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Didn't say that socket doesn't exist, but the ones found in fixtures meant for tungsten typically are not what you want. You need one that has a 4000v pulse start rating.
 
Are you going to have issues with high UV output from this lamp? I'm only mildly familiar with DIY fixtures of this sort but I've read that some put out very high amounts of UV and can cause problems on exposed skin.
 
Without data, I'd just make sure to add UV gel or protection to be safe. It's cheap & easy.

I think these could make a great space light - wire safety cage, wrap that in UV gel, and hang in a large diffusion bag with a rated socket. Would be easy to get a granny to sew up a bag and skirts, etc.
 
Hi Michael, that would be a very very good system if it works out. A 400 watt Hid would be equivalent to a 1500/2000 watt tungsten. It would be easy to gel it with some CTO with very little power loss to 5600 if need be. I just saw the coollight 150 hid and was favouring it to some 650 watt Arri tungsten. But when I saw that the 5600k bulb is rated at 80 cri it cooled me off.

It would be fantastic if we could retrofit them into tungsten Fresnel fixtures. Just a last question, is it confirmed that it is 90 cri, because I can't see it in the bulb description and are there any other bulb on there website that could be interesting in different wattage.
 
Couple things -

I'd imagine even 1/4 CTO would be fine if the overall CRI is right;

But CRI is a little overrated - a bulb can have low CRI but its particular rendering can still be quite good. The cool lights 150w daylight bulb's an example - nice lamp, very pricey ballast at $299 - but you do get a real cable and a purpose-designed ballast. But supposedly about any HID ballast will light a single ended HID like that, finding one without flicker is the ticket. There's an aquarium ballast for just over $100, electronic, manufacturer says frequency is over 48khz. Going to try one when I get a minute since ballasts are returnable.

The Alzo ballast will light it, but at some angles it flickers like a strobe light - with more like a physical shaking of the filament. I'm still going to try some 150 HID ballasts as I stuck that cool lights bulb in an old fresnel and it's pretty kickass. Unlike the alzo 150's, it's a true "projector" style bulb, you just need to get it in the right position relating to the reflector.

The vendor of the 400 mogul said a cri of "about 90". But with any sort of flo or HID in the 80+ range, it would need some testing.

If it spikes a little green, it may not be a problem - or could be great for green screen? to me, a long mogul like that is crying out for a bag/space light vs. a fresnel or par. Or maybe as an open faced behind a big scrim.

By the way, the Alzo bulb & ballast kit? it's really nice, clean 5200k. It's a soft, frosted bulb, but has UV protection. Seems like in the 700-800 tungsten range. I adapted a speedotron strobe head for one, so i can use my grids/etc - it's not enough kick for a softbox in most cases. Their 150 HID fixtures are... OK. Rickety. I overheated one on a shoot and it died. Took it apart, but no breaker or anything inside, could see the heat sensor on the circuit board. Put it back together and it works again. Strange. I have three, and 2 bulb/ballasts. If you plug 'em all in it's a lot of light behind a scrim for pulling about 6 amps. Used they're a good deal. New, I'd buy Cool Light's fresnel, it's a better light.
 
Yes CRI is not 100% reliable, but it is at least a good start to know the quality of light and unfortunately the only widely used standard for quality of light. The "about 90" is not that reassuring, but if it is the case it could be a very good solution for diy lighting.

It is a little strange why people did not investigate a bit more the HID CMD tech for video. I think it is because in the mindset of everyone the bulb should be either 3000k or 5600k. Some have been advocating 4500 as being ideal because you could gel without do much loss to get to daylight or tungsten. doing some research about high cri HID I fell on this http://1000bulbs.com/search/?page=1&filter[category]=5034&filter[cri%28float%29]=90..0 . There is a whole bunch of bulbs and the ballast are not that costly. Most of them are either 3000k or 4200k.

Some bulb that come out a bit is like this one which looks very close to the one you listed but at 250 watt

http://1000bulbs.com/product/57206/MHS-025026683.html

Another one which 1000 watt is a bit pricey but even 5500k with 92 cri

http://1000bulbs.com/product/70124/MT1000D-HTL.html

Very high cri of 95, for 150 watt and 4000k

http://1000bulbs.com/product/60007/MHS-CMP150T6942.html
 
Danielvilliers said:
...But when I saw that the 5600k bulb is rated at 80 cri it cooled me off.
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The bulbs we sell and send with our fixtures are CRI 85 and above depending upon which color temperature bulb it is. 5400K is CRI 85 and 3000K is CRI 90. There are CRI 95 bulbs that will work in our fixtures but they are in the $100 range whereas our bulb is $29.
 
So, generally speaking, is a cri below 100 because of a gap in the spectrum, as in missing colors or is it the addition of colors that don't belong, like green taking up to much room on the color wheel?
 
Al MacLeod said:
So, generally speaking, is a cri below 100 because of a gap in the spectrum, as in missing colors or is it the addition of colors that don't belong, like green taking up to much room on the color wheel?
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Could be any or all of the above that could cause the score to be lower.
 
That was to easy. In your experience, where does the the fault typicaly lie? I assume you have looked at this issue with a critical eye?
 
Al MacLeod said:
Hmmm...must have been a tougher question than I thought.
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If you're familiar with Richard's input on these boards and the time he's spent helping others, I think you'd lighten up a bit about not seeing a reply overnight.

I started this thread and one of my early replies dealt with the cool lights daylight 150 bulb, which I described as (IIRC) "nice clean daylight". It's a great bulb, especially for the bucks. It'll replace a 750 tungsten - it'll replace about 2K of tungsten with full CTB and pull a couple amps.

CRI scores don't always have a lot to do with how aesthetically pleasing the bulb is, which has been discussed above as well.
 
No disrespect intended. Input like Richard's is the reason many of us keep coming back to this board. Folks involved intensely with any one aspect of the craft tend to have really good insight into the the hows and whys of it all. I thought "could be any and all of the above" seemed a bit vague, but hey...maybe it was a tougher question than I thought.
 
No its not a tough question, I may just be busy. I don't look in here every day.

You have possible gaps or possible spikes or both or none. Those are the possibilities. Every type of source may be different so no hard and fast rule can be given. Therefore my answer above was accurate.

Gaps in the spectrum cause inability to render colors perfectly that correspond to that part of the spectrum.

If a part of the spectrum is spiking, as commonly happens with green, then that calls for correction the other way with the color opposite that one on the color wheel. In the case of green, its magenta. Spikes can be corrected, gaps not so much. It is therefore possible to have a CRI 95 light with a green spike and a CRI 70 light with a green spike. The green spike in and of itself doesn't necessarily mean the source is low CRI.

There are about 15 colors used as the benchmark for measuring CRI and the testing instrumentation therefore tests the spectrum of whatever source being tested against those 15 colors to see how they fare. The most common gap (or not necesarily a gap but rather a rolling off in the spectrum) in any flo, HID or LED is in the red region thereby causing skin tones to not be as good as possible. So often, in CRI 90 or so, the main thing keeping it from reaching 100 is usually some issue where the main red tone isn't as good as we like. But there aren't too many complaints in CRI 85 and above in performance.
 
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