Thursday, May 19, 2011

Off Camera Flash – Blog post 2 of 3

example
(8+ Nikon SB900s) = (1 Alienbees 1600)
(8 x $510 = $4,080) vs ($360)

Comparing my AlienBees 1600 manual flash to my Nikon SB900 TTL flash can be tricky.  It is more like apples and oranges they would say.

One thing you can compare is the guide number.  This translates into what the f/stop would be at say 10 feet.

The guide number for an AlienBees 1600 is 354 with a standard 7" reflector. That means it will provide f/22 at 10 feet, full power at 100 ISO. The 11" reflector will get you f/45 at 10'.  The Nikon SB900 provides a guide number of 132 giving you about an f/13.2 at 10 feet full power.

The Nikon SB900 has a zoom head, which is like having a few different reflectors build in.  The f/stop can go up as you zoom from 14mm to 200mm.


Manual Flash Advantages
  • The studio strobes system AlienBees has more available modifiers, ie. Soft boxes, grids, etc.
  • Modeling light for studio work, letting you see approximately what you will get before you fire the flash
  • Can be used with an inverter, when away from available AC power. While this does cost more you will be able to use it just about anywhere.
  • Faster recycle times.
  • No overheating issues as compared to the Nikon SB900.  They recommend you stop shooting after 10 shots on SB900 to let it cool.  (I just sent my unit in for overheating)
  • It would take 8+ SB900s to equal the output power of 1 AB1600.  With SB900 running about $510 it would cost $4,080 to equal the one AlienBees 1600 priced at $360.
If you need to shoot at f/16 outside the only way to do that is to either buy 8 – SB900s or 1 – AB1600.

TTL Flash Advantage

  • Works on "AA" Batteries
  • Can shoot above the sync speed of 1/250.  You can take flash photos outside at 1/8000 second if you choose.
  • Can shoot at lower f/stops outside life f/2 or even f/1.4
  • Light and much more portable than studio strobes
  • Small enough to hide behind objects in the scene of a photo, verses the larger studio lights
Stay tuned for more information.

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