RonFrank:
.........The IKE's don't have much in the way of manual control, or an auto aperture setting.........
As far as any Ikelite DS series strobe lacking manual control latitude......may I offer my opinion, please.........
The new DS 51 has 6 intensity levels built right into the strobe head. I would consider that more than adequate.
The DS 125 and DS 200 each have 4. imho 4 (full, 1/2, 1/4, 1/8) is still plenty of latitude.......especially if you factor in other intensity control options such as aperture, distance from strobe to subject, and the1 stop rated diffuser. The diffuser when added reduces 1/8 power to 1/16. Minimizing a strobe's intensity to 1/16 may be useful for macro work with compact digital cameras (typically digicam smallest aperture @ f/8-11)....but digicams also have the ability to set low (vs dSLR) ISO sensitivity levels (ISO 50 vs 200).........
Generally speaking, small apertures are chosen for macro work on dSLR's to maximize DOF, therefore higher strobe intensity levels {say f/16-f/22 at 1/2 power?} are commonly chosen. So the need for minimizing the intensity of the strobe's GN beyond 1/16 is less a factor. If the need to reduce intensity still existed, for each 12" (30cm?) of strobe to subject distance, on average an f/stop of strobe intensity level is lost underwater (6" = @ 1/2 intensity lost). Fine tuning a strobe's intensity influence between full and 1/2 stops can be accomplished by position (distance).
As Ron pointed out, the Ikelite DS series does not offer Auto or External Auto. External Auto may be useful in close macro work where aiming the strobe directly at the subject would not increase the chance of capturing backscatter as much as when attempting to use the strobe set to Auto for Wide Angle work. External Auto may be quite useful for macro work if some form of TTL were not available and Manual strobe control was not desired.
Less common today are Ikelite DS series strobes operated by themselves, without added manual control features. Access to additional EV control, either as Ron noted conveniently built into the housing itself or attached by sync cord to the 10 step Ikelite EV controller is the norm with Ike strobe systems.
imo,
b