Got that problem with some Halide lamps I have where I'd rather have them clear to see inside. Although with a mercury it does change the colour a lot.

No reason to expect a dismal average lumen output (for a 300 W lamp) if the arc tube is actually designed for a 300 W operation, as its shorter length suggests already. There are a variety of reasons why a lamp manufacturer doesn't list data. Either it simply doesn't have it, it hasn't done the proper life test (yet) to have confidence in its data, engineers haven't communicated their data to marketing people, or etc. The issue with marketing and technical literature is that the people who compile and edit the brochures and data sheets are not the lamp engineers, but most often people from marketing or other department. As a result there can be some errors and mistakes in published data. It's not a perfect world, and one should not automatically assume a worst engineering case for any missing data in the literature.

@Max - My comment has to do with this being a 300W lamp running on a 400W/H33, CWA ballast (this lamp is not rated for an RX, or HX ballast). Even thought this lamp is intended to work on said ballast, its still going to be over driven and depreciate rather quickly, hence dismal performance.

Why would you expect the lamp to be overdriven if it is designed to run at its specified electrical characteristics? The "Constant Wattage" in CWA for H33 ballasts does not mean that 400 W will be forced upon any lamps driven on this system, only that 400 W is dissipated at the standard 130-140 V arc voltage of H33-400W lamps. The "constant wattage" property of the system is a direct consequence of the inherently consistent and stable arc voltage of mercury lamps, combined with a stabilized current feed. The correct description for CWA ballasts is in fact "Constant Current", but manufacturers took a shortcut when they named this particular system (also because the series capacitor conferred a better lamp power regulation over a wider mains voltage variation). Unfortunately this can lead to some confusion as how the system works exactly, especially with other lamps such as HPS ones, whose CWA systems are certainly are not constant wattage in nature (HPS lamps do not have the constant voltage characteristic through life that is typical of mercury lamps).

Your 300 W mercury lamp achieves its reduced power dissipation thanks to a lower arc voltage, with the current delivered by the H33 CWA ballast being not much different from that for a standard 400W-H33 lamp (i.e., 3.2-3.3 A, thanks to the ballast's flat current-voltage characteristic). Knowing Westinghouse, your H33GL-300/DX lamp is made with properly sized electrodes designed to withstand the 3.30 A drawn from the ballast. So, again, there really is no reason to expect dismal performances, especially from a Lifeguard lamp designed and made at Westinghouse Bath, not in some anonymous lamp factories in the far East. Besides, its 52 lm/W initial lumen efficacy for a 300 W dissipation is in line with a properly optimized burner (this figure would be higher if the burner was overdriven, and lower if it was underdriven).

@Max - Thanks for the information...I'd thought this could be true, but wasn't sure.

No problem, Eric. We are all here to learn and to wonder at lamp and ballast technologies. The Econ-O-Watt lamp you have is a very rare one and it's certainly good to see it here!

@Max - Yes it is, but I don't think it's as rare as your Westinghouse Lifeguard H33-1GL/Y.

Fair point!