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Hummingbird Experiment No. 3


WJT

Exposure was 1/1000th second at f16. Illumination was by means of two #6B focal plane class flashbulbs. Pentax SMC 300mm f4 lens on Extension Tube #2. Gitzo 1325/Acratech ball head. Levels adjusted in Ektaspace using Photoshop CS. If you have the time, please examine this using the LARGER view. Thank you.


From the album:

WILDLIFE by WJT

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Yet another in this experimental series, I used two #6B focal plane

flashbulbs to light this fellow. These are special bulbs which have a

very long peak duration. This allows me to sync at the fastest shutter

speed instead of the normal 1/30th second. As always, your thoughts

are welcome.

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To answer an earlier question, the light source that I employed consisted of vintage flashbulbs. They are a special class of bulb known as Focal Plane. These were manufactured to have a slow build-up (about 20msec) and a very long peak duration (in excess of 40msec). The Pentax 6x7 has a normal x-sync of 1/30th second but also has provision for using these bulbs using the FP sync terminal. This provides the needed 20msec delay before the shutter opens. Since it requires 30msec for both shutter curtains to traverse the film plane, the flash duration of 40msec allows complete exposure at the highest shutter speed of 1/1000th second.

This method of flash photography has been somewhat duplicated today on some higher-end DSLRs and their dedicated flash units. These cameras can achieve a higher sync speed by pulsing the flash at 50kHz. Unfortunately , this comes with a much reduced light output. With the flashbulb technique one enjoys considerably higher Guide Number factors than what electronic flash can deliver in this mode of operation. Regards.

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Walter, thanks for your explanation (very helpfull). Again I have only to bow, because those are good pictures just in the view of the technique (and brain) used. But as you successfully added also compositional issues, the picture's beauty is pushed way up. IMO it's a great sign of your mastery... Jiri
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WOW... Walter, you are becoming a master on hummingbirds... and flash photography. This is exquisite! Love it very much!
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