F280

Summary	Main Characteristics	Notes - Related Units
The first electronic flash in the world to permit full synchronisation at all focal plane shutter speeds (when used with the OM-3Ti, OM-4Ti or OM-707). Opens up new realms of expression in flash photography, including flowing movement, creative use of fill-in flash, etc. In addition to Super FP Flash with full synchronization at all shutter speeds, also offers TTL "OTF"Auto Flash and Manual Flash.	A clip-on type flash unit with with a Guide Number of 28m (100 ASA, TTL "OTF"Auto Mode or Manual Mode). Offers a selection of three modes: Super FP, Normal OTF and Manual. The flash duration in Super FP Mode of about 1/25 sec. is some 40 times longer than normal electronic flash, affording full synchronization at all shutter speeds. Use of fast shutter speed for daylight fill-in flash assures subject movement is fully arrested. The freedom to select desired lens aperture allows use of wide open apertures to blur background and put emphasis on main subject. Use of slow shutter speeds makes it possible to creatively express flowing subject movement.	With the OM-707, automatic selection between Super FP and Normal OTF Mode is achieved, depending on shutter speed. The built-in AF illuminator will only operate in combination with the OM-707 for automatic flashing in dark situations. Super FP Mode can only be achieved with the OM-3Ti, OM-4Ti and OM-707. The optional Full-Synchro Flash Wide Adapter F280 can enlarge the coverage angle of the F280 to the angle of view of 21mm lenses. Off-camera operation is possible with the optional TTL Auto Cord F0.6m.; TTL Auto Cords T cannot be used. This flash can be mounted in the Power Bounce Grip 2 for off-camera bounce operation, but the batteries in the Grip are not used for additional power.

Main specifications

Type: Full-Synchro Flash System	Recycling time: Super FP Flash Mode: 5~9 sec, depending on shutter speed Normal "OTF"Flash Mode: 0.2~9sec. (depending on distance, aperture, film speed) Manual Flash Mode: 9 sec.
Guide Number: 28m. (100 ISO, Normal "OTF" Auto Flash or Manual Flash)	Flash duration: Super FP Flash Mode with OM-3Ti, OM-4Ti: 1/50~1/25 sec. Super FP Flash Mode with OM-707: 1/70-1/30 sec. Normal "OTF" Flash Mode: 1/40.000~1/1000 sec. Manual Flash Mode: 1/1000 sec.
Coverage Angle: 53º vertical, 74º horizontal	Flash Mode selection: OM-3Ti, OM-4Ti: Super FP Flash, Normal "OTF" Flash and Manual selectable with mode selection switch. OM-707: Automatic selection by camera between Super FP Flash and Normal "OTF" Flash. Other cameras with Normal "OTF" Flash support: Normal "OTF" Flash and Manual selectable with mode selection switch. Other cameras without Normal "OTF" Flash support: Manual.
Number of flashes (with alkaline batteries): Super FP Flash Mode: 80-260 (depending on shutter speed) Normal "OTF" Flash Mode: 80-600 (depending on distance, aperture, film speed) Manual Flash Mode: 80.	Flash synchronization: Super FP Flash Mode: 1~1/2000 sec. With the OM-4Ti on Auto, the 1/60 shutter speed is used as a lower-treshold. To achieve longer shutter speeds with Super FP, the OM-4Ti must be set to Manual. Normal "OTF" Flash mode: 1/60 sec or longer. Manual Flash Mode: 1/60 sec or longer.
Color Temperature: 5800ºK	External Synchro Socket: 7-pin quick release plug accepts TTL Auto Cord F0.6m.
Camera mount: Clip-on method: shoe-inserting, lock-screw	Power source: 4 AA batteries (incl. Ni-Cd batteries).
Electrical connection with camera: 1) Clip-on method: direct contact-point type 2) With TTL Auto Cord F0.6m	Dimensions and weight: 110x68x71mm, 250g. (without batteries).

Super FP Flash Guide Numbers (m.)			Normal "OTF" Flash Range Guide (ISO 100)		Super FP Flash / Range Chart
Shutter speed	OM-707	OM-3Ti, OM-4Ti	Normal "OTF" Flash Range Guide (ISO 100)		Super FP Flash / Range Chart
1/2000	3.1	2.6	F1.2	3.4~23m	See remarks below (*)
1/1000	4.3	3.7	F1.4	2.8~20m
1/500	6.2	5.2	F2	2~14m
1/250	8.8	7.3	F2.8	1.4~10m
1/125	12.4	10.4	F4	1~7m
1/100	15.6	-	F5.6	0.7~5m
1/60 or slower	-	14.7	F8	0.5~3.5m
			F11	0.36~2.5m
			F16	0.25~1.8m
			F22	0.18~1.3m

(*) Daylight Fill-in flash with he F280
The range of subject distances that can be covered by Super FP Flash varies depending on the available light, lens aperture, film speed and shutter speed. The OM-4Ti and OM-707 utilize TTL Direct Light Measuring to measure the combination of available light and flash light, and control the exposure by setting the shutter speed. This chart displays the range when there would be no influence of available light. In actual photography the addition of the available light factor permits greater latitude in selection of photo distances.
The OM-3Ti works differently. Because the shutter speed can't be adjusted during exposure, Guide Number calculations should be used to determine the correct aperture/shutter speed combination for a given distance. The chart above can be used for assistence. Same is true for the OM-4Ti set to Manual.