Falcon 4M Camera Manual
03-032-20044-03
Teledyne DALSA
38
Snapshot Mode
The Falcon 4M60 and Falcon 4M30 cam eras inclu d e a featu re called Snap shot Mod e.
Snap shot Mod es 1 and 2 allow the cam era to p rod u ce u sable im ages w hen intervals
betw een EXSYN Cs are large (>200 m s).
Previou sly only snap shot m od e 0 w as available (no fast fram e d u m p ) w hich w ou ld
eventually result in a completely saturated ‗first‘ image after a very long EXSYN C idle
p eriod (second s), as show n below .
First Frame Elevated Offset - efd 0,sem 4, External EXSYNC and exposure (smart EXSYNC)
By altering the internal tim ing, Snap shot Mod e 1 p erform s a fast clearing of a fram e
concu rrently w ith integration. Thu s, any d ark cu rr ent that cau sed elevated d ark offset
levels, FPN or hot p ixels, is cleared from the sensor p rior to read ou t. The end resu lt is that
the cam era p rod u ces a u sable first im age.
With Snap shot Mod e 1, p lease note that the tim ing of EXSYN C w ith resp ect to the
integration tim e has changed . The figu re below illu strates Snap shot Mod e 1 tim ing. The
d ifference is that the Integration Tim e, Z, is now equ al to the EXSYN C high tim e, X, p lu s
the tim e it takes to clear the im age, Y (p lu s 3.1 µs of ad d itional overhead ). The total tim e
to clear the fram e is Y (ap p roxim ately 500 µs). Therefore, the m inim u m integration tim e in
Snap shot Mod e 1 is Y + 3.1 µs. The exact valu e of Y is listed in the
gcp
screen as DUMP
TIME.