I believe the softer look of flashbulbs has more to do with the shape of the reflector. If you use it without a reflector, bulb and electronic flash look pretty much the same.
Allen Zak On Jan 10, 2008, at 9:14 AM, Eric Goldstein wrote:
Hi Elias - Yes GNs are the same for lamp or strobe but they are only estimates and your reflector/light management device will have a major effect on light output... I wanted to comment on your observation relative to light quality from flash lamps. Others will debate it but there is no question in my mind that you are correct...the quality of the light from a "bulb" is obviously nicer than that from a strobe. I think it has to do with the longer illumination times for the lamps and also possibly color temperature differences... Eric Goldstein -- On 1/10/08, ERoustom <eroustom@xxxxxxxxxxx> wrote:Thanks Richard. Do these guide numbers relate at all to those given to electronic flashes? Elias On Jan 10, 2008, at 12:17 AM, Richard Knoppow wrote:----- Original Message ----- From: "ERoustom" <eroustom@xxxxxxxxxxx> To: <rollei_list@xxxxxxxxxxxxx> Sent: Wednesday, January 09, 2008 6:32 PM Subject: [rollei_list] Re: Rollei FlashMiscellaneous package of bulbs. Some say P25 on the top, the others just say GE. Some are blue, some are clear. No guide numbers anywhere. Are bulbs still made? E.The 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. --- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list--- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with'unsubscribe' in the subject field OR by logging into www.freelists.org- Online, searchable archives are available at //www.freelists.org/archives/rollei_list--- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list
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