I would expect that electronic ballasts would compensate for this, as they be "smart", and control the power.
The real problems come when you have a "dumb" magnetic ballast.

Most electronic ballasts don't really care what you feed them with, after the inrush protector and filters the first thing a switched mode power supply ( ballast ) does is convert that AC power into DC and the filtering caps will take care of any ripple and then it switches it at a high frequency so they can use a tiny transformer.. Most are also capable of running at much higher or lower voltages then the rating plate shows simply because they can modify the switching frequency/ turn on / turn off times on the fly, I've seen a hatch 70 watt metal halide ballast that will run from about 80 volts right up to 300 volts and from DC to 1000 Hz and because of the diode bridge it doesn't care if its a sine wave, square wave ( common in MSW inverters ) and the storage / smoothing capacitors will deal with the MSWI large trailing edge spike so the light will work flawlessly. 
 

But to the original poster if the buzzing sound is annoying simply get a larger inverter they contain fans which should mute out the buzz..   

Some ballasts have power factor correction - basically some sort of boost converter. The controller for those things is designed to drive them so the current they pull from the line is a sine wave. Some of them malfunction on square wave and square wave with 0 step (what is most commonly found in "MSW" inverters)

Some ballasts have power factor correction - basically some sort of boost converter. The controller for those things is designed to drive them so the current they pull from the line is a sine wave. Some of them malfunction on square wave and square wave with 0 step (what is most commonly found in "MSW" inverters)

Yep and depending on the type of ballast used and some magnetic ballasts like CVA,CWA and CWI may also damage the cheaper inverters if they don't shut down, but normally the larger core and coils ballasts will survive and protect the light bulb as well...

If one must power a HID light from a low voltage DC source they might consider building a small inverter you can get a nice sinewave from the simple 555 IC, a few small transistors like the cheap 2N3055's and a transformer from 12 to 120 VAC, but it might almost be easier to just build a 12VDC to lamp output and just remove the ballast all together, and most high voltage current controlled simple designs will allow one to power a multitude of different lamps, I've seen one running on 12 VDC that can power up a LPS, HPS, MH, and MV without changing anything but the bulb screwed in the socket and the socket for the LPS lamp and all the parts came from radio-shack, admittedly it didn't power anything over like 100 watts but it worked while in the truck for some good area lighting in a pinch..

Or they could hack a 12VDC CFL bulb for a ballast depending on what they are looking at powering...   

The problem with DIY inverters is that they usually don't provide much power.

Depends on how you do them..

The problem i see with "self oscillators" is that they may noe be good enough (stable, low frequency drive) for HID lamps. But at HF (so Fluorescents) they are fine

For worklight on a truck use consider Halogens, they have decent efficacy at low voltages and dont need any gear at all. Basically hack a headlight socket into some standard ex-120V luminaire housing with reflector..

With IGBT prices falling you could run design one to run a 1000 watt without much effort,the problem is the input current, maintaining a the 90 to 120 amps at 12 volts from an automotive alternator will end up killing it fairly quickly and if you go batteries and factor in the peukert law you need a huge array of batteries, removing the portability of it making a small generator a much more attractive option,  if you take a 100 AH deep cycle   running a 1000 watt lamp add in the ballast losses, inverter losses,  you end up with about 20 minutes run time before a recharge is needed, and for the same cost/size/weight you could get a 1000 to 1200 watt generator from a big box store that will run the same lamp for 4 to 6 hours on a gallon of fuel, so unless you need it real quite a generator is the way to go for large lamps.

If people need cheap pure sine wave inverters, like in the 10 to 20 dollar range and 1000 VA or better, look for used APC smart UPS's that need battery replacements in the classified adds you can strip them out and they work great but most are 24VDC input some are also 48VDC..   

But to run a 35 watt SOX /39 Watt MH / 35 watt HPS you only need like 4 to 5 amps at 12VDC and a Sealed lead acid, like a wheel chair battery (33 AH) will power that for a few hours with to much problem, even my 35 watt automotive HID spotlight running on a 7AH battery so it's handheld will do an hour easy.

And alot of the schematics on the net are people going solar so they normally try to get the most lumens for the least amount of input watts so that leaves them with LED's, which is becoming way more common or very small HID lamps or a small SOX like the 18 watt.     

If you got a truck you got 24V - which is allready better. Alternatively you might just build a stack of batteries up to some 170V DC and then power an Electronic ballast from that directly

For the everyday carry in a car there is no need in more than few 1000's W - and that is within reach at just few 10's W lamp power. On the other hand the thing must be small and lightweight, so it does not take much space and you dont waste fuel just for taking the extra weight for the ride everywhere, so all generators etc are out of the game. Simple PL-C26 CFL (that can work with fairly simple ballast circuit) puts out 1800Lm which is a lot. 50W Halogen puts over 1000Lm and that one can be as simple as a hacked cheap 120V floodlight with headlight lamp inside + lighter socket plug, without any gear at all

For bigger lighting (when you specially take it with you) then do all you want and there the generator makes sense

As an IT-related Pokemon master, i do have some 15ish UPSs laying around right here. But most of them are "MSW". Got 3 rack mounted APC SmartUPS 1500VA units - for free with dead batteries. Those need a 2Sx2P array of the standard 12V 7Ah bricks

Those APC Smart-UPS 1500VA offer a sine wave output, which is a stepped approximation of a sine wave, which for all intense purposes is close enough, it only looks ugly on the scope at under 20 watts, as soon as you go above that you can't visually tell the difference without really zooming it in on the scope and they also have cold start, so you don't need to plug them in, just push and hold the power button. You can also install a much larger battery arrays without much worry of overheating them, but you might need a second case for bigger batteries.

But if you need something that's bright, easy to carry, outputs between 1000 to 1600 lumens, and runs for 8 to 12 hours between refills you could always get a coleman lantern, they also seem to last longer then any thing battery operated I have one from 1932 with a mica globe they just never seem to die, and when camping you stick them behind your chair to truly enjoy the cooler nights longer sitting around the fire...   

Interesting! How about the larger, 2000w or 3000w pure sine wave inverters?  They always seemed close enough in my experience.

I'll dig out the scope and the 1000 watt pure sine wave that I have ( Made by Xantrex for a big box store, Canadian tire ) and shoot a couple of images under no load and load so you can see what it looks like, but I don't have anything bigger but I can't see them being really different, just more transistors and larger coils...   

Recently the real pure sine wave inverters fell down in cost (contributors are cheap microcontrollers, power components and rather smart topologies for the "class-D" output stages needing filter coil only in the phase line; the final inverter stage needs just 2 fast and 2 slow switching transistors, their predrivers, a power filter only on the fast switching side and a cheap micro for the controller - and you get perfectly regulated nice sinewave output). So when the task is really an inverter (normal supply goes from the battery for long period of time) and not UPS (only few minutes backup in case of the main power failure), practically all boxes are using the high frequency DCDC frontend (converting the battery to 400VDC for the 230V output) and the consequent "class-D" amplifier like stage to generate the real sinewave output.
The low frequency transformers would be too bulky and expensive for a long term load (on UPS they get away with small transformer just because of the short runtime), the mains side switching 3-level MSW tend to overload the filters of the supplied electronic, more level MSW's (topologies proposed in the 90's, when the low loss high power IGBT's were too slow for high frequency switching of a true sine output stage) are way more complicated and expensive than true MSW (too many transistors, complex predrivers,...).

The true sinewave is way easier to handle by the inverter manufacturers: No compatibility problems with any mains rated device...

Inverters intended for true years on end continuous duty such as those intended for off grid use tend to be transformer based.  The problem there is the high cost new and their weight and size.  The Outback VFX3524M I use in my system weighs 55lbs and was almost $1,800 US.

Back home, I'm using a 1997 (as old as me!) Trace 'Mariner' 2000w modified-sine-wave inverter/charger.  Good unit, but HEAVY!  It's 20 years old but was NOS until about 8 or 9 years ago.  Since then it's been in more or less continuous use sans a few summers when we were out of town/away from home when it was turned off.  It was a high-tech unit for its day, LCD crystal display, etc.  MSW but somehow filtered or something, it was new technology at the time but is kind of a dinosaur by today's standards.  Has a good probably 100 amp charger in it, draws a good 10+ amps from the 120v AC line when in bulk charge mode on discharged batteries.  At one point I only had a 2000 watt generator and thus had to let the batteries come back up before I used anything big, other than lights, etc...which took about an hour, getting two 8-D batteries down to 11.7v or so up to the point where they'd hit about 14.7v and the charger's current would start to taper off.  When fully charged and just in float charge mode the batteries would float at around 13.3v. 

If it ever dies, Xantrax (which is actually what's left of both Trace and Heart Interface) makes a real nice 3000w pure sine wave model with lots of nice features, that's what I'd use to replace it.

There's still a lot of Heart Interface "Freedom 25" units out there from the '80s, a 2500-watt modified sine wave inverter/charger.  The house came with one but after sitting in a damp unheated vacant house for 8 years it smoked itself upon power-up.  It was ridiculously heavy, I had to go get a hand truck to haul it away! (solid copper transformers in there).  Scrap metal was worth a lot at the time, to the point people would buy surplus military 6X6s at auction and drive to the scrap yard and cash out... should have scrapped it along with all the old copper plumbing we ripped out in favor of PEX (house had freeze damage so we had to repipe anyway). 

Inverters intended for true years on end continuous duty such as those intended for off grid use tend to be transformer based.  The problem there is the high cost new and their weight and size.  The Outback VFX3524M I use in my system weighs 55lbs and was almost $1,800 US.

I was talking about new designs...

It is not that long ago, when the required components (yielding high efficiency with fast switching on mains voltage) became cost wise viable competitor against the transformer systems.
Moreover the simplified pure sinewave control topologies are not that old either (although the older power components would benefit from them way more than the new ones).
So older designs indeed use the mains frequency output tranformer, to shift the high speed switching to a lower voltage domain and mainly isolate the HF disturbance from the grounded Neutral output.

Resurrecting this topic as I have a question.

Here in the UK we have a 230/240V supply at 50Hz, whereas of course the US uses 120V at 60Hz. Running magnetic ballasts designed for 60Hz at 50Hz is problematic, so after I saw a Youtube video the other day where a guy used a 12VDC to 120V 60Hz inverter (fed from a UK 12V power supply rather than a battery) to power some old American electronic equipment, I was wondering if I could do the same to power US discharge lamps with the correct ballasts instead of trying to find an equivalent, which for some lamps is not easy if possible at all.

This is the inverter the guy in the video used, it's pure sine wave output so I think it should be ok..? It's rated at 400W so ought to be enough for the 100W or so lamps I want to use..? The power supply I intend to use to feed it is this one which is rated at 32A continuous load at 12V.

Anyone got any opinions..? Will this work, I need to know before I shell out for the inverter, as it's not cheap when you add shipping..!