Any success with Inon S-2000 sTTL with E-PL1

[under water]

I just got my new E-PL1 U/W rig.
Oly housing, Zen Dome, 2 INON S2000's and a L&M Sola 600 Focus / video light.
Just unboxed it and trying some settings above water first.

I noticed that with the S2000 set to sTTL, it seems to mirror the flash of the camera. If I set the camera flash for 1/64th, I get very weak strobe output.
If I use fill flash, it works perfectly. So it appears that sTTL really just relies on the camera quenching rather than any smarts in the strobes. This was not really what I expected, but I guess it will work. My concern is that I may be using a bit more flash (and therefore battery) than I had anticipated as I expected, perhaps foolishly, to be able to use 1/64th power and setting the S2000 to sTTL mode.

Any ideas?
BTW, I am aware of the information provided by the folks at Reef http://www.reefphoto.com/tt/index.php?action=kb&article=7 that describes the sTTL mode, so I think it is acting as it should be.

For those of you thinking about getting this configuration, here is what it looks like. I am using an Ikelite double arm tray from my old G9 housing as well as some ULCS arms. It is a much smaller setup than I had before with the G9 and Ike strobes. The Ike double arm/tray seems too big now.
These strobes and the video light really are tiny, but powerful.
I really really like this setup and can't wait to get it under water.

 

[ensio80]

I think it's basically the same as with my e-620. The camera doesn't use preflash when you are using the 1/64th flash. So basically you have to use the full flash in order to get ttl to work properly. If you want to save the camera battery and use the 1/64th flash, you have to use the magnet to turn the cancel circuit on to get the full output of the flash. This of course means you have to use the flashes in manual mode.

 

[slowhands]

Nice rig!

Yes, the strobe just follows your camera internal flash closely. That's what STTL is supposed to do. It is working as it should. All the smarts for setting flash duration are in the camera.

But because the S2000 supplies a lot of light, your camera flash is shortened versus what it would be by itself. Some have suggested replacing the strobe flash with a LED that just puts out power to the optical port; that would really save battery power, but nobody has made a successful one here. I've seen one on wetpixel.

If the housing had an electrical bulkhead (it does not of course), then you could just fire external flashes, not the internal ones. You could use wired cables. I do this on my 620, using a Heinrichs Weikamp Oly to Nikonos TTL converter and some old Sea & sea strobes. Solid as a rock, and low battery usage. I've toyed with boring a hole for a converter in the PT-EPL1 housing, but there is not a good location and I would ruin the resale value. Maybe do it anyway...

The more expensive Inon strobes have smarts in the strobe, to evaluate the exposure and control the flash. This is called EA mode. With it you can use the 1/64th strobe to trigger, and the strobe sets flash duration based on its own sensor. The D2000 and Z240 can do this.

It's a trade off. Those strobes cost more and are much bigger. If you want a simple, compact rig, what you have is as good as it gets.

 

[under water]

Nice rig!

.. It is working as it should. . ......The more expensive Inon strobes have smarts in the strobe, to evaluate the exposure and control the flash. This is called EA mode. With it you can use the 1/64th strobe to trigger, and the strobe sets flash duration based on its own sensor. The D2000 and Z240 can do this.

It's a trade off. Those strobes cost more and are much bigger. If you want a simple, compact rig, what you have is as good as it gets.

In retrospect, I knew that before I decided S2000 vs D2000, but kinda forgot it after I got everything set up.
Changing a battery isn't a big deal with the easy opening housing. I usually change SD cards after every 2 dives anyway.

I'm very happy with the trade off. I can put all my U/W camera gear plus Canon DSLR and zoom lens for land photos plus laptop into one backpack now.

 

[PHIL RUDIN]

To go back to Under Waters' first post when the Inon S-2000 or Z-240 is set to S-TTL it is designed to be used with the cameras TTL settings for the pop-up flash, most notably the lighting bolt icon is the strobe selection menu. When set this way on the camera and strobe the pop-up flash triggers firing the Inon strobes. When the cameras light meter senses that a proper exposure has been obtained, (based on ISO, shutter speed, F/stop)the pop-up flash turns off which turns off the Inon strobes. This all takes place in 1/1000s of a second.

When the cameras pop-up strobe menu is set to full, 1/4, 1/8, 1/16th it provides that fraction of light based on the guide number of the pop-up strobe. This has nothing to do with TTL and Does not allow the s-TTL on the Inon strobe to work properly. What it does do is trigger the Inon strobes when they are set to manual mode. The 1/64th setting is not always enough light to set off the Inon strobes so I recommend 1/4 power. With the camera set at 1/4 power and the strobe set to manual the strobe will fire each time the camera strobe fires. In manual mode I have shot more than 300 images in one dive without a problem with the camera batteries or the Inon strobe batteries, (I use re-chargables). To obtain proper exposure using these settings the Inon strobe power is increased and decreased by rotating the exposure setting dial on the right side of the strobe F/11, F/116 more power, F/5.6 F/8 less power. A check of the cameras histogram will indicate a proper exposure. I have found manual to be about as easy as shooting in TTL once you get the hang of it.

When shooting in TTL the same right dial is used to fine tune the TTL and works like exposure compensation does on your camera. I start with the right dial at top dead center or F/2.8.

Phil Rudin

 

[edbolson]

Phil,
Thank you for this clear explanation. I just upgraded from a Sony P&S with a D2000 to the E-PL1 and will use it for the first time on a trip to Australia this month! Knowing a bit more on how to handle the manual mode is very useful. I was also pleased that the little rubber plugs that came with the case worked perfectly with my existing bare end optical fiber after making a hole in the end of the plug!

When the cameras pop-up strobe menu is set to full, 1/4, 1/8, 1/16th it provides that fraction of light based on the guide number of the pop-up strobe. This has nothing to do with TTL and Does not allow the s-TTL on the Inon strobe to work properly. What it does do is trigger the Inon strobes when they are set to manual mode. The 1/64th setting is not always enough light to set off the Inon strobes so I recommend 1/4 power. With the camera set at 1/4 power and the strobe set to manual the strobe will fire each time the camera strobe fires. In manual mode I have shot more than 300 images in one dive without a problem with the camera batteries or the Inon strobe batteries, (I use re-chargables). To obtain proper exposure using these settings the Inon strobe power is increased and decreased by rotating the exposure setting dial on the right side of the strobe F/11, F/116 more power, F/5.6 F/8 less power. A check of the cameras histogram will indicate a proper exposure. I have found manual to be about as easy as shooting in TTL once you get the hang of it.

Phil Rudin

 

[Nemrod]

JFYI, the S/D/Z Inon strobes, when set to sTTL mode, mimic/boot strap the camera strobe. The D/Z strobes have an External Auto mode which does rely upon the Inon strobe built in exposure system but this mode is not available on the S model. The S2000, set in sTTL will mimic exactly what the camera strobe does and yes, it is checking the exposure which is why you get the sTTL OK light, if the exposure was deemed acceptable by the Inon strobe.

The sTTL feature works exactly the same on all cameras be it a dSLR, M4:3 or a Canon or other P&S.

Another bit of info, to increase the range of exposure control of your S2000, in sTTL, you can in addition to the strobe power function, use the camera's built in strobe compensation +/- function and as well the overall exposure compensation +/- settings, to alter your image exposure, strobe exposure etc.

BTW, if you set your camera strobe to a manual setting and dial in low, med, high or whatever increments the camera software allows, the sTTL of the S2000 will NOT function properly. The camera strobe must be in Auto control and either Forced or Auto activation, in Auto activation, if the camera strobe does not fire, the Inon will of course not fire.

Additionally, the Inon strobe assumes ISO100, setting to other ISO ranges will alter your exposure.

Most P&S and I believe the M4:3 do not have true TTL, a preflash is emitted which the camera uses to set the final exposure values and strobe output. The Inon, or YS strobes, are simply a mirror.

N

 

[under water]

Phil,
...I was also pleased that the little rubber plugs that came with the case worked perfectly with my existing bare end optical fiber after making a hole in the end of the plug!

You should also have received 2 rubber plugs with the strobes (or FO cables) that have two holes in them. I just use one of these and keep the others as spares.

 

[ScubaMarc]

Nice rig!
replacing the strobe flash with a LED that just puts out power to the optical port;

i would buy this product if i could!!!