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Bob_W

Member Since 20 Jun 2007
Offline Last Active Yesterday, 10:30 AM
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Posts I've Made

In Topic: Sea&Sea YS-D1/YS-D2 Not Designed For High Speed Sync

09 May 2018 - 05:21 AM

If you have any problem with TTL setup, i can help. 

By the way, i heard positive reviews from D500 users, who installed TTL board.

 

I don't believe the problem is one of setup, but rather inconsistency of the TTL converter. For example, a series of shots of the same subject yields widely varied results. Some overexposed, some underexposed, some right on. Also, same subject, varying the aperture, one would expect the TTL to do the compensation and provide very similar results. Nope, results all over the place. And for some strange reason, everything works fine on the bench.

 

Given that everything made falls within tolerances, and that 2 devices that have to work together can be at the extreme, opposite, ends of their tolerances. So it's possible that that is what's happening here. I've considered trying a different camera body to see if that makes a difference. I just don't happen to have a spare D500 body laying around.

 

So for now, for us, the converter remains unreliable and only used in the manual position.

 

Bob W


In Topic: Sea&Sea YS-D1/YS-D2 Not Designed For High Speed Sync

08 May 2018 - 12:21 PM

Hi Bob,

 

I tested YS-D1 at 1/250 and 1/320 on several cameras in TTL, - no problem. I tested it also at 1/500 in TTL (Nikon D50 + #11031 TTL-Converter),

- YS-D1 works perfect even at 1/500. 

YS-D1 works fine at all "normal" sync speeds of camera (without FP), because underwater strobes cannot work in FP mode (FP = 40 khz long time flicker). Underwater strobe can make only a single short pulse.

This is actual for all underwater strobes. 

 

Dark part on your image, - is a shutter curtain. Camera mechanical shutter has concrete speed for fully open window, only at this speed the underwater strobe can light the full shot. For modern cameras it is about 1/200 sec. For sync speeds faster than 1/200, the window is not fully open but just as open strip, and we need FP flicker to light the shot evenly when that open strip moves through the shot.

This is in short words. If you evaluate term "sync speed" deeper, everything will become clear for you.

 

According the Olympus E-M1 User's Manual (page 110), your camera maximum normal sync speed is 1/125. In reality it can be some better, even up to 1/200. 

The maximum sync speed 1/320 in User's Manual is pointed to original flash FL-LM2 only. I suppose, this flash FL-LM2 can work in FP 40khz flicker at such fast sync speeds. I guess that 1/320 is FP sync speed there. Unfortunately i don't have E-M1 camera on hands to check.

 

What happens in your case:

      At 1/250 sync speed your FL-LM2 burns (flickers 40khz FP), triggers YS-D1 by optical cable, YS-D1 emits a single light pulse (it is more visible in TTL), and you see the shutter curtain on the shot. This is because camera does not open full window at 1/250, but open just a strip. At 1/320 camera opens that strip more narrow, you see it as well.  

      But if you use sync speeds less than 1/200 (better use 1/125), camera fully opens the shutter window, the shot is lighted evenly by underwater strobe.

 

As I looked back through this thread that I started 2 1/2 years ago, I found it interesting to read all the suggestions to 'solve' the problem. In reality, they weren't solutions, but workarounds. According to Sea & Sea, the solution was 'Don't do that!. Neither the YS-D1, nor YS-D2, was designed to sync above 1/200'. My point was to make others, who might be experiencing the same problem, aware of Sea & Sea's official position. And to know that they are not alone. I solved my problem by getting rid of the YS-D1 strobes.

 

Pavel is experiencing excellent results using the Nauticam/UW Technics TTL converter. But like everything else, Your Mileage May Vary. We have found that TTL converter (but the correct part number for D500) to be completely unreliable when using it with a Nikon D500 in a Nauticam housing. So much so that we have gone through 3 different TTL converters, and it's still not working correctly. A number of friends, and someone we met on a trip to Indonesia, have had similar experiences. And when he sent his rig in for service, he was told that according to Nauticam (JP), 'No one is having this problem'. I wonder if Pavel's TTL converter is one that he built?

 

But discussion is good and we all keep learning things. Maybe we can't use them today, but will, hopefully remember them when we need them. :)

 

Bob W


In Topic: Nauticam focus gear for Oly 60mm and Nauticam 12-50 port?

19 December 2017 - 04:59 AM

I use the thumb-button AF to get on the subject, then fine-tune with the focus knob. The AF does not know I want the (say) rhinophores sharp and not the bumpy back.

 

Unless you're using a tripod, wouldn't thumb-button and rocking achieve the same result? Lock on subject and rock until the rhinophores are sharp?

 

Bob W


In Topic: FS: Nauticam 45 degree viewfinder for MIL housing (#32205)

04 October 2017 - 03:44 AM

MIL - Micro 4/3 Interchangeable Lenses camera. Also known as EVIL - Electronic Viewfinder Interchangeable Lenses. The Olympus O-MD Series, for example.

 

Bob W


In Topic: Olympus e-m5 mark 2 with 12-50 question

27 September 2017 - 02:32 PM

The E-M5 II will also do 'electronic zoom'. Not jump, zoom. The 1fish/3fish setting on page 67 jumps between 12mm and 50mm. On page 66 of the manual, set camera to assign function to each arrow. On page 68, set a button function to Electronic Zoom (for example Up Arrow). When using the camera, press to assigned function button to activate Electronic Zoom. Then use the arrow keys to zoom in or out.  In the upper right corner of the display you will see the setting of the zoom: 12mm, 20mm, 27mm, 45mm, whatever. See Item 12 on page 19.

 

Bob W