to the other as well as provide a conduit for electrical leads similarly convection can better cool the region covered by the shroud portions for an embodiment having a central opening between the fins also the portion of the fins that is within the shroud can be coated with a layer of thermally insulative material that reflects light concentrating the radiative cooling in the area of the fins not enclosed by the shroud fig1 shows an embodiment similar to that of fig1 but with an axial opening including apertures 257 and 258 the axial opening encircled by a shroud including shroud portions 260 and 265 the embodiments shown in fig1 and fig1 can be attached to a base such as base 65 shown in fig1 fig1 and fig1 show perspective views of an illumination device 300 similar to that of fig1 but with fewer fins 303 309 in fig1 leds 320 321 and 322 are shown mounted on respective fins 306 307 and 308 an opening 330 is defined by a gap between the inner edges of the fins at a central location of device 300 in fig1 the leds and central opening are encircled by a translucent shroud including shroud portions 333 and 335 the embodiments shown in fig1 and fig1 can be attached to a base such as base 65 shown in fig1 fig1 shows a perspective view of an illumination device 400 similar to that of fig1 but with more thermally conductive light reflective fins 410 419 in one embodiment fins such as fin 416 are divided into several fin portions 422 423.