The MV ha s an ultimate efficacy of 70lm/W (~100 atm, >100W/cm), but this require forced water cooling... And CMH's already are above 100lm/W with technically possible light tone nearly anything-you-want, stable color. And their lifetime is matter of manufacturing techniques, what will improve a lot in near future, so allow the shift for higher temperature operation, so even higher efficacy...

Yeah CMH is basically a redesigned improved MV lamps....believe it or not! It has everything a MV has...except redesigned arctube, added stuff.....

Sure lighting community some of em (mostly old fashioned stuff lovers) don't like MH...due to short life, too bright (really its not the MH that's "too bright" its really cuz they whoever uses em chose that wattage........

Eve its possible for a CMH to last longer.....and adding a positive of not dimming out and staying dim for next 10 years or more......it could even be made to get an exact same color as a clear merc if one wanted to...like I got a nice 20,000K MH.....so really look at the positives...I'm starting to accept the fact....

Yeah CMH is basically a redesigned improved MV lamps....believe it or not! It has everything a MV has...except redesigned arctube, added stuff.....

Sure lighting community some of em (mostly old fashioned stuff lovers) don't like MH...due to short life, too bright (really its not the MH that's "too bright" its really cuz they whoever uses em chose that wattage........

Eve its possible for a CMH to last longer.....and adding a positive of not dimming out and staying dim for next 10 years or more......it could even be made to get an exact same color as a clear merc if one wanted to...like I got a nice 20,000K MH.....so really look at the positives...I'm starting to accept the fact....

Yeah, I am accepting the fact that CMH is the way to go. There that bonus of the CMH not exploding at EOL. There are a huge amount of wattage to choose from the tiny 20w to the big 400w (Haven't heard of a 1000w CMH yet, but it's possible. )

Off-Topic - Jace you are the 5000th poster of the forums. Congrats. The 5000 posting is every posting we did here over the years.

It would be nice if they made them suitable for streetlight ballasts that way the old classics could stay a little longer. I guess CMH is the only option left.

... There that bonus of the CMH not exploding at EOL. ...

I would not be so sure, unlike HPS, CMH operate really at high pressure (above atmospheric), so arctube rupture yield an explosion. It only might be, because they leak too soon, they do not explode violently... Once the technology improves, so these leaks will be eliminated, we might see exploding arctubes again...
I would be careful at least with those long lasting advanced arctube designs (Powerball,...), as they are targeted to improve running characteristics, with the assumption the explosion is not a problem (as adequate luminaire protection and/or lamp internal shroud is perscribed as mandatory).

although there is high pressure in the arctube,an explosion wouldnt be all too viloent owning to the small volume of gases in the burner,the main consequence of an exploding burner,is harm to a person standing near an exploding lamp,or the hot quartz and glass landing on something flamable and setting fire to it.

Speaking of CMHs, I was told that PCA arc tube ruptures are more easily contained than quartz arc tubes because PCAs only explode into a few pieces. Philips makes their Retro-White lamps with just wires wound around the arc tubes to hold the pieces together, tho I think shrouds are still better. Still, nothing beats a good ol' mercury!

In here Rovaniemi(thats the city where I live) They have already installed some metal halide streetlight fixtures that replaced old MV fixtures. Those new one's arent regular looking, but little more artistic but still. Also some new smaller streets got installed HPS streetlights. 5 years earlier they would have installed MV for sure. But I guess this is the moderntime. 

By improving Mercury Vapor Lamps...i mean Improving only Mercury Vapor Lamps....not Metal Halide Lamps...since these Lamps have Additional Elements besides Mercury i do not consider them an Improvement to mercury Vapor lamps as they are a compleately diffrent Lamp Type.

Would Triphosphor on MV lamps work better? What is used right now ? CMH lamps operate at higher temps and pressure cuz when you shut them off they glow red hot for like a minute,and the re strike is longer than MH.

Would Triphosphor on MV lamps work better? What is used right now ?

I would think the Triphosphor would not react well to the longer-wavelength UV from high-pressure mercury discharge.
For the last few decades, the Europium-activated Yttrium vanadate phosphors became the standard for mercury lamps, this type of fluorescent coating is the most efficient in converting the UV from HP mercury discharge into red light. However I noticed it actually adds too much red, at least new mercury lamps have a pinkish tint to them. So, I would think making a blend of red and lets say green or cyan phosphors could raise the efficacy and make for more white light.

And again, I'll quote a paper on UHP mercury lamps, which says: "Adding a certain amount of oxygen and halogen to the lamp atmosphere prevents the tungsten evaporated from the lamp electrodes to condense on the wall, as in the colder regions the tungsten atoms react chemically to form oxyhalide molecules"

Note that this is not making it a METAL HALIDE lamp, as these added elements do not participate in light generation. This would just be a way to extend the useful life of mercury lamps, to decrease arc-tube blackening rate.

Philips recently introduced a new line of reduced wattage CMH lamps with a new "All-Start" technology. They will work on BOTH probe start and pulse start MH ballasts. I wonder if they are suitable for use on mercury vapor ballasts. They come in a 205w ED-28 and a 330w ED-37, replacing 250w and 400w MH lamps, respectively. They'd be cool lamps for old mercs if they'll easily start on such ballasts.

Philips recently introduced a new line of reduced wattage CMH lamps with a new "All-Start" technology. They will work on BOTH probe start and pulse start MH ballasts. I wonder if they are suitable for use on mercury vapor ballasts. They come in a 205w ED-28 and a 330w ED-37, replacing 250w and 400w MH lamps, respectively. They'd be cool lamps for old mercs if they'll easily start on such ballasts.

Daveman showed me those Lamps....those look real nice!