I much prefer strobes myself - but doing video got me trying out all sorts of daylight stuff.
And back in the film days, I got very good at balancing my strobes to tungsten and using tungsten lights to do things like blurred backgrounds while the strobes froze the subject. So I get it that there are various reasons to be intrigued by testing this stuff.
I finally gave up on spiral flos and the bigger 100 watt screw-ins. There are lots of Kino knockoffs out there (55 watt biax tubes in banks of 2, 4 and 6). a 4-bank is equivalent to about a 1k tungsten light, but it's 5500k, can be found for $200 or so. But that's just big soft light (which can be modified, but will never be focused and hard).
If you really want an HMI-type fresnel, here are two threads to a DIY ballasted 150 watt light that can be made for around $100, depending on the fresnel fixture you find to modify. I'm not much of an engineer, but I came up with these and they can be made with a cheap drill press (or even a hand drill) and soldering iron - no electronics knowledge really needed, you just have to wire an on-off switch and a ballast cable - really easy. It's about a 500 watt tungsten equivalent, but daylight, and pulls only 150 watts of power and has heat equivalent to a 150 tungsten.
It's a great daylight fresnel in two versions:
The first is more suited to a 6" or 8" fresnel (like a 650 or 1k) and is very close to pure awesome 5500k - a little bit of pink in the color. The other is more for a 3" (300 watt style) fresnel, and is perfect, gorgeous daylight. BOTH OF THESE BULBS PUT OUT A LOT OF UV and should be used in a housing with a glass lens (and maybe add a sheet of cheap UV gel??). Also, the first version, I used Speakon connectors which work fine and are over-rated for the voltages… but powercon connectors cost the same and are more of a standard.
6" Fresnel - read this first, even if you want the 3"
3" Fresnel - this is a badass little light.
These links have detailed instructions, parts lists, parts links and color tests, and suggestions on donor fresnel fixtures. A very very easy build for you or a handy friend. The main thing is that what little wiring is done is properly soldered and grounded, but anyone who's done a little wiring should be able to do it.
And best of all? They don't look at all DIY - the ballast is housed in a nice metal enclosure with power switch, handle, and head cable jack. You can take it to client gigs and look like an adult!
