> Harold Edgerton used flash to produce a stroboscopic effect. He was famous for > his high-speed stop action photos. The high-speed photography was > instantaneous. Flash bulbs are not instantaneous. They require what was called > m or f synchronization. Camera shutters used to offer either x for > instantaneous for electronic flash, or m or f delay which represented the time > between when the shutter was fired and when the flash went off. You have the > possibility of 3 delays for the flash when you click the shutter on older > cameras. Only x has been retained, and they don't even call it x. > > Ed Farber brought the electronic flash to the populace. He used a 510V battery > to obtain enough voltage to produce the flash. The studio units utilizing low > voltage battery packs were often very large and heavy and not practical. > Eventually with the advent of the transistor to produce enought voltage the > units were smaller and more practical. In some cases too small. He invented a > high speed electronic flash in a company called Strobo Research in Rochester, > NY. Which was bought by Graflex and permitted him to retire at an early age. > rather than use a very large electronic flash to produce high speed result, Ed > Farber (I edited his column about flash) used what I think was a rectifier to > take the low voltage from the batteries and make it a high voltage. These > rectifiers were very large. With the advent of the transister in 1959, > Multiblitz in Germany did away with the rectifier and used transisters to > increase the voltage from the battery pack to produce a practical hand-held > electronic flash unit. > > Ed Meyers > Instantaneous though relatively speaking. Flash duration is a thing we talk about. Studio strobes can have shockingly long flash duration. A subject jumping in the air will show motion. But the flash durations on on camera flashes are much shorter than people realize. If your are closer in it can be 1/41,600 of a second. Enough to make any rushing water look like ice. Freeze the eyelashes off a Superman. The flash I use most often now is the SB-800 Nikon 1/1050 sec. at M1/1 (full) output duration 1/1100 sec. at M1/2 output (approx.) 1/2700 sec. at M1/4 output 1/5900 sec. at M1/8 output 1/10900 sec. at M1/16 output 1/17800 sec. at M1/32 output 1/32300 sec. at M1/64 output 1/41600 sec. at M1/128 output As Jodi Foster said in Maverick: "Was that fast? I thought that was fast. Was it fast? Was it?" Mark William Rabiner --- 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