I wonder if there are HIDs smaller than 50w. 

I wonder if there are HIDs smaller than 50w. 

35 watt HPS lol. There's also PSMH that's under 50 watt.

CMH lamps of 35W and 20W and HPS of 35W (Rare).

40w MV lamps were made for some markets too. GE also made a 32w Halarc quartz MH lamp at one point. Those required a special ballast as they operated on DC.

35 watt HPS lol.

Looks very similar to 50 or 70w HPS.

35W MH with E27 socket is very rare and expensive in here. G12 or RX7S version is cheaper and more common. They use them in various stores.

The E27 does not offer any position control accuracy, so it is offered just as a legacy socket, so only with the higher wattages or with PAR lamps, where no precission is required.
Because these low wattages are used mainly in flood lights, they require their positioning to be precise in the reflector, the would be practically no demand for the Edison socket. Except for the reflector lamps, but these are very complex so expensive, so not used that much (Europeans dont like to throw away so much, so preffered the complex and expensive optical assenbly to be part of the permanent fixture and not a throw-away lamp).

This fixture has an 35W MH lamp with E27 socket: https://www.lighting-gallery.net/gallery/displayimage.php?album=1105&pos=11&pid=154435

20w Ceramic Metal Halides (track lights)... and also 25w (Philips) 24w (Sylvania) and 23w (GE) Par38 Self Ballasted Ceramic Metal Halides. (screw in)
As far as smallest CMH track lights, and as far as screw in Self Ballasted CMH, that's all I know of.

I have a 35W PAR20 CMH reflector lamp with an E27 cap on order, it's not arrived yet though, photos in the gallery when it does. Colin has a similar one, see here.

@sox35 I have seen those HM par floods before.

Yes they're nice little lamps. Got a couple of PAR38 25W ones as well, well worth getting if you can, they're becoming rarer, especially the 230V ones, which were never made in quantity.

Yes they're nice little lamps. Got a couple of PAR38 25W ones as well, well worth getting if you can, they're becoming rarer, especially the 230V ones, which were never made in quantity.

Interesting that 220-230v ones are rare, since that voltage is the most used worldwide. Here 35w par metal halides are still being selled (as you may seen in the link), but those are chinese, but have decent specs.

When I seen your 25w par, if the box where not in the picture, I would have trough that it was an LED par. 
(I hope that it can be my last LED joke  )

Interesting that 220-230v ones are rare, since that voltage is the most used worldwide. Here 35w par metal halides are still being selled (as you may seen in the link), but those are chinese, but have decent specs.

When I seen your 25w par, if the box where not in the picture, I would have trough that it was an LED par. 
(I hope that it can be my last LED joke  )

Oooh, you really are after a aren't you

Oooh, you really are after a aren't you

Im sorry! 

I can't avoid to see LED references almost everywhere and joke about that.