----- Original Message ----- From: "ERoustom" <eroustom@xxxxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx> Sent: Wednesday, January 09, 2008 6:32 PM Subject: [rollei_list] Re: Rollei Flash
Miscellaneous package of bulbs. Some say P25 on the top, the othersThe bulbs with P25 on top a Wabash/Sylvania Press-25 types. If the GE bulbs are the same size they are General Electric Syncro-Flash No.5 bulbs. The two are nearly identical. Both came in both clear and blue types. Blue is for color using daylight film and have a color temperature of approximately 5000kelvins. Guide numbers depend on the size of the reflector and shutter speed. For the relatively small reflector of the Rolleiflash, a film of ISO-100, and a shutter speed of 1/100th the guide number for the clear bulb will be about 250 and about 200 for the blue coated lamps. The largest flashbulbs were the GE No.50 and Sylvania/Wabash No.3 with light output of 140,000 lumen seconds. These bulbs were meant to be used in full sized photoflood reflectors. With open flash in a 12" reflector the guide number for ISO-100 film is about 800.just say GE. Some are blue, some are clear. No guide numbers anywhere. Are bulbs still made? E.
--- Richard Knoppow Los Angeles, CA, USAdickburk@xxxxxxxxxxxxx
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