Photo 35 mm Black&White

Meopta_Light_Bulbs_2After 50h of intensive use, the Meopta Opemus 7 enlarger bulb died!

Fortunately, I found the Opemus 7 and the Meograde original manuals available on the Web.

The Meograde manual advises the use of the following light bulbs (all in the class of 12V 100W eps models):

Reflector Halogen Lamp 12V/100W

Manufacturer Reference Lamp base
Narva 55102 G2 6.35 – 18
Tungsram (Now GE) 55220 G2 6.35 – 18
Osram 64627 G2 6.35 – 18
Philips 6834 G2 6.35 – 18
Thorn A1/231 G 6.35

Meopta enlarger and the meograde heads were all discontinued some time ago.

I investigated and discovered some developments in this class of bulbs since then… namely important developments in 12V 100W Dichroic lamps technology: the original filling gas was Krypton now Xenon, which allows the evaporated tungsten filaments come back to the filament himself (contrary to old technology, where the tungsten burns and deposits in the lamp glass turning the it dark and thinning the tungsten filament, making their life shorter). This development reduces the need to burn tungsten and increases dramatically the bulb life span (from 50h to 1500h or more!).

I selected the OSRAM MR16 64637 100W 12V and the PHILIPS 8634/25H FO 100W GZ6.35 12V 1CT/10X5F models. Both have a life span higher than 1500h (PHILIPS have the greater life span, but it costs almost twice the OSRAM model), with the same color spectrums (3200K), a Luminous intensity of 420 cdi and a 100 color rendering index. Both are widely available (I brought new from eBay). Both are relatively more expensive than the original OSRAM 64627, but their longer life span worth the higher cost!