So I gave it a try...

Michael Carter

Michael Carter

Veteran
Referring to this thread, where we discussed 400 watt mogul hydro/aquarium bulbs with digital ballasts.

So I found a ballast on eBay for $45, and a similar bulb for about $25.

Initial impressions - it's a lot of freakin' light for under $100. Bulb's rated at 6500k - shot some raw stills with WB set to 6250 (my other preset option's 6750). A little blue. Re-shot with 1/4 minus green - all out of 1/4 CTO, just ordered some. Have some 1/4 straw, but too yellow. Seems like this could dial in fine.

The ballast is great - silent, didn't get very hot, and no flicker - tried it up to 1/400th. Had some end-of-daylight coming in the windows so not a perfect test.

I'll do some tests when I get a proper cable for the hydro connector (I just had a couple wires stuffed in there, yikes)... but seems like some minor gelling could get it there. Nice phat 12-gauge-ish wire plug, waterproof connector.

The ballast has an overdrive switch that seems to add 1/4 stop or so - online reviews say this nudges the color temp a little warmer, I'll look into that.

Regarding UV - research tells me that with these dual-envelope moguls, the outer is just to protect from explosion and is UV shielded. Package says UV danger if the outer envelope is damaged, so... OK, but UV gel's no big deal.

I'll do some more serious playing in a week or so and see if it'll dial in, and how it compares output-wise to, say a quad biax, an Alzo bulb & ballast, a 750 or 1k open tungsten, etc. Promising though, perfect fit for a lanternlock. I'll get anal with it in a week or so and report back.
 
Can you post images? How much light did you get in tungsten equivalent? What socket were you using?
This is pretty awesome, I'm keen to hear more!
 
Hey guys -

I haven't light metered or cross-tested yet - I need a for-real cable vs. my "let's burn the house down" approach; hopefully next week;

Andrew, it's a mogul bulb, you can see the style in the original thread linked above. Very large globe, like 7" long.

The base - I remembered I had an old Amvona softbox, mogul socket and high-heat fabric (takes 500 and 1k "starlight" type moguls) - so I just stuck the bulb in that housing without sticking the softbox on - really just wanted to see if it flickered or was insanely green.

Looking at my camera, the quick test grabs I did were ISO 250, F4.5 at 1/60th, about 5' from the bare bulb. Just shooting with ( I think) 1/4 minus green held over the lens. So it's not like a 4k HMI or anything. But I seem to shoot at around 400 iso often, so not bad - seems like a good match for a china setup, the size of the globe making it tough to adapt. Figure losing a stop-ish with the china, seems like you could shoot at 4.5 - 5.6 depending on iso, distance, etc.

Might work Ok in a Photoflex starlight if you gelled the inner baffle (do those have inner baffles??) Smith Victor makes a sort of starlight knockoff for under $200, too. I'd want a look at any socket to see if it would handle the start pulse. No prob on the Amvona though, but who knows over time, MH mogul sockets are listed at 600v. But softbox moguls are designed for 1k tungsten, that's a lot of heat.

I am feeling geeky, haven't DIY'd or tested stuff in a while, so I'll get back to it and post results before long.
 
Hey Michael,
Just wondering how your tests are going? In the process of moving gear to my new storage locker I came across the same Amvona unit you have. I used it a while ago with an adapter and an Alzo bulb but it didn't have much of a kick with that big softbox on so I ended up bouncing off a foam core. Interested to see how yours works out before I make the buy and sell decision for this monster softbox.
 
Watch out for U.V. emissions, make sure the bulb glass is rated to remove U.V. The fixture lens could also remove U.V. but the bulb glass is safer all around.
 
KurtF said:
Watch out for U.V. emissions, make sure the bulb glass is rated to remove U.V. The fixture lens could also remove U.V. but the bulb glass is safer all around.
Click to expand...

From the thread starter:
"Regarding UV - research tells me that with these dual-envelope moguls, the outer is just to protect from explosion and is UV shielded. Package says UV danger if the outer envelope is damaged, so... OK, but UV gel's no big deal."

I've had no time to test with the holiday and work... about to get seriously booked up for a couple weeks, but I'd like to get it tested with CC gels soon, might be nice to have on some upcoming stuff. I'll report back soon as I can.
 
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