Guide to Flash Specifications
To locate the specification page of a particular flash unit, please see the flash finder.
The heading on the specification page is always the units model name. This is usually the model designation you'll find for the unit on the manufacturer's homepage, but for dedicated third party units, any part of he model designation that signifies system dedication has been removed. Example: There exists a dedicated flash for Canon bearing the model name Bower SFD728C, an identical flash (except the dedication) for Nikon bearing the model name Bower SFD728N, a Pentax version bearing the model name Bower SFD728P, and a Sony version bearing the model name Bower SFD728S. The specifications for all four models are listed in the DPanswers product database under the model name Bower SFD728.
Below, we list the major fields that may appear on a flash unit specification page, and how to interprete the data listed:
- The Coverage is given in focal lengths for an FX-sized sensor.
- Exposure modes:
- TTL: this always means modern type TTL (E-TTL II for Canon, i-TTL for Nikon, etc.).
FP/HSS: ability to sync a focal plane shutter above the x-sync speed.
Auto: a non-TTL automatic mode utilising a sensor on the flash.
Manual: fixed output manual mode.
Varipower: a manual mode with variable power settings.
RPT/Multi: stroboscopic repeating flash.
GN: also known as “distance priority” and “flashmatic” mode.
OTF: misc. legacy TTL modes only compatible older film SLRs.
- Wireless modes:
- Master: the unit can be used to control other flashes using a dedicated protocol.
Remote: the unit can be controlled by a master flash using a dedicated protocol.
Plain slave: a slave mode where the flash will fire whenever it sees another flash. Nikon calls this “SU-4 mode”. Other manufacturers call it “SF” or “S1”.
Digital slave slave: a plain slave mode that ignores pre-flash. Some manufacturers refer to this as “SD” or “S2”.
- Macro: Flash is designed for macro photography
Sound: Flash provides audible feedback about underexposure, etc..
LCD: Flash has an LCD screen.
Crop aware: Flash adjust zoom head to accomodate for crop factor.
Overheat protection: Flash has fuse that shuts it down if it overheats.
Metal foot: Hot-shoe is made of metal.
Env. seals: Flash has, or can be, equipped with sealings against moisture.
Lever lock: Flash has lock lever with a locking pin.
Sync. socket: Flash has an external sync. socket (e.g. pc, monoplug or Vivitar).
Ext. power: Flash has connector for external power pack.
Bounce card: Flash has pull-out reflector card.
Hammerhead: Flash is of type hammerhead (aka. known as “potato masher“.
Strobist: the flash has at least six varipower steps, an external sync. socket, and no known issues with off-camera use.
- Flash Duration:
- The flash duration at full power is taken from the manufacturer's specifications. Most manufacturers measure the t.5 time (the time from the flash fires and until it has decayed to 50 % of maximum value). However, German flash manufacturer Metz measure the t.1 time (the time from the flash fires and until it has decayed to 10 % of maximum value). The same is the case with German flash units branded Braun and Leitz (which may or may not be manufactured by Metz). While it appears as if the flash durations at full power of Metz, Braun and Leitz flash units are significantly longer than those of any other manufacturer, this is not really the case. It only reflects different measurement methods.
- Guide numbers:
- All guide numbers are given for meters and ISO 100. For flashes with a zoom head, the guide number is listed for with the zoom set to 35mm, 50mm and maximum zoom (assuming an FX-sized sensor). For flash units that offers multiple illumination patterns, the guide numbers quoted are for the standard illumination pattern is used. For guide numbers in feet, multiply by 3.3. To convert to a different sensor speed, multiply the ISO 100 GN with the square root of the ISO ratio.
- For units still in production, this is what you may expect to pay when you buy a new unit from a retailer. Prices are collected from the web pages of leading retailers at irregular intervals. Prices goes up and down all the time, so only treat this column as a rough guideline. For discontinued units, the price is what the item used to sell for. Most used items sell for less than this, but certain hard to find second-hand items may sell for more. DPanswers do not track prices on used equipment. To find the going price for used items, search “completed auctions” on eBay.