Sea & Sea YS-17 (Olympus UFL-1) questions, TTL not working with Canon s100

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

saridnour

Registered
Messages
46
Reaction score
13
Location
Seattle, WA
# of dives
200 - 499
Hello everyone. I have a Sea & Sea YS-17 (Olympus UFL-1) strobe. Been doing a lot of reading on the strobe for facts on functionality. I am trying to confirm what I “know” and what I should expect from this strobe being my first. I am well vesting in surface photography. This was bought 2nd hand and was told it was unused. No scratches to unit seem to confirm that or very low use. Manual mode seems to work as would expect but the TTL never seems to work as the sync seems off and I always get black frames when camera is set to ttl (auto).

I am shooting with a Canon s100 in an ikelite housing with an optical sync. The cameras flash is masked out with black tape feeding the optic sync cable. The sync cable is home brew(modified sea life cable) but works 100% of the time in manual mode so doubt this is the issue? The canon s100 is setup per others guides on the web and the internal flash has been set to both auto and manual in my testing.

I believe it is an issue with the pre flash triggering the strobe to fire on the “pre” vs post flash. I never see the “green” ttl light on the strobe after it fires.

Here are some facts I have gathered on the strobe. Please correct me if this is not right.

1- When Strobe is set to TTL mode, strobe should fire 2x just as (and in the time/power) that the body’s flash does.
2- The strobes “power” knob selections are FULL and Half and only in effect when strobe is set to manual. ?This does nothing when set to TTL?
3- When Strobe is set to manual mode the Power knob does effect the sync.
a. Full: triggers the strobe on the pre flash
b. Half: triggers on the full 2nd “post” flash.

Now on my Canon S100 there are two flash settings. Auto and Manual. Auto does the preflash and Manual does not. I understand that the camera only does TTL in auto? Need confirm that. I have used both modes and while set to auto (preflash) I only get black underexposed frames when strobe is set to TTL or Manual:Full which leads me to believe the sync is firing on the preflash. When I set the strobe to Manual:half (camera still set to auto [preflash]) I do get a correctly exposed frame. This seems to prove 3a/b above.
When the cameras flash is set to Manual, I can get exposed frames in both of the strobes TTL and Manual:Full/Half settings but the TTL green light never comes. The exposure also does not taper off and I assume the TTL is not working and it is firing in FULL manual mode regardless of the strobes TTL setting. Note: I do see the TTL light turn green for 3sec when I turn on TTL after the flash has charged so assume the switch is working as this is never seen in manual.

Am I missing something or is the TTL function of this flash not working? From what I understand it should work when strobe set to TLL and the cameras flash is set to Auto.

- Should TTL work when strobe s set to TTL and cameras flash is set to manual?
- Are there other was on the camera to force ttl?
- Are there any incompatibilities with this strobe and camera model (Sea & Sea YS-17 and canon s100)?
- Any ideas?

I shoot mostly in Seattle’s Puget Sound which is a green murk 8-30ft viz is standard. I will most likely need shoot manual for most of it but would like the TTL option if I can find a way to make it work.

Any and all comment or ideas are greatly appreciated and a big thanks in advance.
 

Back
Top Bottom