I'm asking for advice about a Canon S110 and strobe YS01 problem

[Nemrod]

Well, I do not know. For your camera flash, yes it should be in the Forced or ON mode but under the MENU botton scroll down and make sure that in the Av mode the camera flash is selected to Auto and not Manual.

Here are similar shots from my Canon FIX/S90 and dual Inon D2000 strobes. Camera in Av, f5.6, Inon strobes set to sTTL mode and Low power, camera strobe set to Auto and set to Forced ON and 0 flash compensation:

-2 stops:

0:

+2 stops:

Your last set of pics look normal to me which indicates your strobe is in dTTL mode and functioning normally with your camera in P mode and is mimicking your camera flash signal. This makes me think you have a (flash?) setting issue in the Av mode with your camera. Is your ISO set to 100?

Changing your f stop in Av mode with the exposure compensation at 0, camera flash in Auto (flash compensation 0) it is true that the exposure in the near field should be fairly equal. Here are mine in that condition:

f4.0:

f5.6:

f8.0:

Since I had my Inon D2000 strobes in sTTL and Low power I think they are simply maxing out at the f5.6 and more so at f8.0. Sorry that I have not been more helpful.

N

 

[KeithG]

There is a green light after TTL exposure ...

Not a solution, just some clarification about S&S strobes (and a thought...)

Ignore the green light! When using a fibre optic cable, the green light on Sea & Sea strobes simply indicate that the strobe did not perform a full dump. It does NOT mean a correct TTL exposure has been achieved. The strobe turns on when it detects light from the onboard flash via the fibre cable and turns off when it detects no light from the onboard flash via the fibre cable. Depending upon your camera, in cases where lots of light is required, the onboard flash may become exhausted before TTL has been achieved and before your strobes have fully dumped. In this case your strobe will indicate green, but your shots will be under exposed. Green does not mean TTL. Green means less than full dump.

If you use a wired sync cable (on strobes that support it), then the camera decides TTL, instructs the strobe to turn off via a wire and the green light on the strobe will reflect that the camera has declared that TTL has been achieved.

----------------------------------
a thought... how well masked is your housing? (Hence the original issue about Canon vs other housing).

Onboard flash masking must accomplish 2 things:
- restrict the amount of light from the onboard flash being projected forwards in order to eliminate backscatter.
- totally eliminate any light from the onboard flash from reaching the camera lens INSIDE THE HOUSING.
Many people are aware of the first issue, few are aware of the second.

The Canon P&S housings (and some others) have a flexible black rubber shield inside the housing that surrounds the lens. This shield prevents any light bouncing around the inside of the housing from the onboard flash being reflected back off the inside port surface into the camera lens.

For proper TTL, the camera lens must detect light from the external subject only. If some of the light from the onboard flash can reflect into the lens from inside the housing, then the camera TTL can not work.

Maybe try some test shots without the housing?
-------------------------------
another thought... TTL works great for about 80% (give or take) of the situations. In the remaining types of shots it will NEVER work. Are your test shots in that 20%? There seems to be a lot of white shiny surfaces that may be confusing the camera.

Maybe try some different test shots?
-----------------------------
and another thought.... what metering mode are you using?

The camera is trying to achieve TTL, but what criteria is it using? Your test shots are very challenging for any camera to achieve good TTL.
--------------------
Bottom line: TTL is great when it works. But it will only work in well behaved scenarios.

So try some other less challenging scenarios...

 

[world_traveler]

Well, I do not know. For your camera flash, yes it should be in the Forced or ON mode but under the MENU botton scroll down and make sure that in the Av mode the camera flash is selected to Auto and not Manual.

Here are similar shots from my Canon FIX/S90 and dual Inon D2000 strobes. Camera in Av, f5.6, Inon strobes set to sTTL mode and Low power, camera strobe set to Auto and set to Forced ON and 0 flash compensation:

-2 stops:

0:

+2 stops:

Your last set of pics look normal to me which indicates your strobe is in dTTL mode and functioning normally with your camera in P mode and is mimicking your camera flash signal. This makes me think you have a (flash?) setting issue in the Av mode with your camera. Is your ISO set to 100?

Changing your f stop in Av mode with the exposure compensation at 0, camera flash in Auto (flash compensation 0) it is true that the exposure in the near field should be fairly equal. Here are mine in that condition:

f4.0:

f5.6:

f8.0:

Since I had my Inon D2000 strobes in sTTL and Low power I think they are simply maxing out at the f5.6 and more so at f8.0. Sorry that I have not been more helpful.

N

Hello Nemrod

Thank you for trying to help. I also learned at which settings to pay attention.

---------- Post added June 4th, 2015 at 09:25 PM ----------

Hello Giffenk,

Thank you for answering and trying to help.

I tried already different objects, so I don't think that's the problem.
I'll try different metering modes and also to try to prevent the camera flash light reaching the lens inside the housing.

Not a solution, just some clarification about S&S strobes (and a thought...)

Ignore the green light! When using a fibre optic cable, the green light on Sea & Sea strobes simply indicate that the strobe did not perform a full dump. It does NOT mean a correct TTL exposure has been achieved. The strobe turns on when it detects light from the onboard flash via the fibre cable and turns off when it detects no light from the onboard flash via the fibre cable. Depending upon your camera, in cases where lots of light is required, the onboard flash may become exhausted before TTL has been achieved and before your strobes have fully dumped. In this case your strobe will indicate green, but your shots will be under exposed. Green does not mean TTL. Green means less than full dump.

If you use a wired sync cable (on strobes that support it), then the camera decides TTL, instructs the strobe to turn off via a wire and the green light on the strobe will reflect that the camera has declared that TTL has been achieved.

----------------------------------
a thought... how well masked is your housing? (Hence the original issue about Canon vs other housing).

Onboard flash masking must accomplish 2 things:
- restrict the amount of light from the onboard flash being projected forwards in order to eliminate backscatter.
- totally eliminate any light from the onboard flash from reaching the camera lens INSIDE THE HOUSING.
Many people are aware of the first issue, few are aware of the second.

The Canon P&S housings (and some others) have a flexible black rubber shield inside the housing that surrounds the lens. This shield prevents any light bouncing around the inside of the housing from the onboard flash being reflected back off the inside port surface into the camera lens.

For proper TTL, the camera lens must detect light from the external subject only. If some of the light from the onboard flash can reflect into the lens from inside the housing, then the camera TTL can not work.

Maybe try some test shots without the housing?
-------------------------------
another thought... TTL works great for about 80% (give or take) of the situations. In the remaining types of shots it will NEVER work. Are your test shots in that 20%? There seems to be a lot of white shiny surfaces that may be confusing the camera.

Maybe try some different test shots?
-----------------------------
and another thought.... what metering mode are you using?

The camera is trying to achieve TTL, but what criteria is it using? Your test shots are very challenging for any camera to achieve good TTL.
--------------------
Bottom line: TTL is great when it works. But it will only work in well behaved scenarios.

So try some other less challenging scenarios...

 

[KeithG]

and we forgot to ask the obvious question: how does the camera perform all by itself?

Did you think to try your test shots with no housing or external strobes?

 

[DelrayDM]

It's not you, it's the camera. I believe that Canon will NOT do "TTL Flash exposure" when the camera is in manual mode.

When using the camera in manual, put the strobe in manual mode, also.

And as long as the strobe is in manual mode, you can turn down the camera flash to minimum. That will be enough light to fire your YS-01, but will not take much from your camera battery, and the camera will be ready to shoot again very quickly. (Though the time for the YS-01 to recycle will not be affected by the camera cycle time.)

 

[Nemrod]

It's not you, it's the camera. I believe that Canon will NOT do "TTL Flash exposure" when the camera is in manual mode.

When using the camera in manual, put the strobe in manual mode, also.

And as long as the strobe is in manual mode, you can turn down the camera flash to minimum. That will be enough light to fire your YS-01, but will not take much from your camera battery, and the camera will be ready to shoot again very quickly. (Though the time for the YS-01 to recycle will not be affected by the camera cycle time.)

He is not shooting in Manual exposure. He is shooting the Av mode supposedly with the camera flash in Forced ON and the in Auto compensation. My S90 will most definitely sync sTTL in this mode and settings and there is no reason his S110 should not. Manual exposure, on the other hand, by default, sets the camera flash to Manual (no Auto compensation and no preflash).

For dTTL exposure on a YS strobe such as the OP owns he does need the strobe set to the double lightening symbol (preflash mode) and the camera flash operating in Auto compensation.

N

 

[world_traveler]

As Nemrod said, I try to shoot in TTL mode.
I tried to follow Giffenk advice but until now I didn't mange to find something similar to the Canon flexible rubber shield inside the housing and effective enough.
I shot some pictures without the housing and the strobe, just the camera in AV mode, center weighted average and some less challenging scenarios - there is a clear difference between apertures 2, 4 ,8.
I don't know if the camera by itself should have compensated the aperture change. Nemrod, can you please check if your camera does it? if it does, maybe the problem is with the camera AV mode.
thanks everybody

 

[Nemrod]

Okay, I will but I do not understand your apertures 2, 4, 8? What is the 2, 4, 8? You mean f2.0, f4.0 and f8.0? Changing the aperture in Av mode will not alter the exposure, however, changing the expoure compensation+\- will. And you can change flash compensation as well in the Menu.

N

 

[world_traveler]

Yes, I meant f2.0, f4.0, f8.0. In the photos I took with the camera flash only, without any exposure compensation, the exposure changed, and if it shouldn't, there is a problem with the camera.
For me, the TTL meant to have the possibility to get well exposed photos even without changing other settings .

 

[Nemrod]

Yes, I meant f2.0, f4.0, f8.0. In the photos I took with the camera flash only, without any exposure compensation, the exposure changed, and if it shouldn't, there is a problem with the camera.
For me, the TTL meant to have the possibility to get well exposed photos even without changing other settings .

Okay, S90 in Macro and set in Av mode, no exposure compensation, camera flash Forced On and set in Auto with no compensation. Camera removed from housing and using the built in flash only:

f2.0:

f4.0:

f8.0:

As far as I am concerned my camera is behaving correctly and the exposures are essentially the same. At this distance even a slight difference in aim point can vary the exposure. I would say my results indicate my camera is functioning and producing similar/equivalent exposures across the full range of f stop. The shutter was 1/60 in all three shots, which means the flash is increasing output with each increase in f stop. This was clearly observable. This was as well observable when I performed these shots with the camera installed in the housing with the twin Inon D2000 in sTTL mode. At the low f2.0 shot the strobe flash was weak increasing noticeably in output at f4.0 and probably nearly maxed output at f4.0 thus in the previous shots slight darkening at f8.0. I would also say that the final shot of the dragon at f8.0 is slightly darker for the same reason, the little onboard flash is close to full dump at f4.0 and at f8.0 there is a slight under exposure because there is not quite enough flash to compensate (and the camera software is trying to keep a shake free shutter by bumping the flash to higher and higher output.

N

---------- Post added June 9th, 2015 at 09:31 PM ----------

Hello Nemrod,
In P mode on this camera I can change the exposure just by exposure compensation and it's not the same as changing apertures.
I have also a Canon DSLR, and there I can change exposure but if I change it the camera changes the shutter speed and it's not what I want.
Anyway, I'm willing to try everything that can solve the problem - here are the 3 pictures in P mode. The basic aperture that I can't change is 2 and then from left to right +3, 0, -3
the shutter speed equal, for all of them.
The darkest picture is the one with exposure compensation +3. I expected a bigger difference from -3 to +3 and it's strange that the darkest one is the +3.

View attachment 209666View attachment 209667View attachment 209668

does it help?

Thanks

And BTW, these photos appear normal to me. The (-) decreases/darkens exposure and the (+) compensation increases/lightens exposure. So, your strobe is functioning normally in dTTL and the camera in P is working normally. You just confused your images, yes, I guess I am saying I do not believe your + compensation is on the left and the - compensation is on the right.

I still suspect, either your camera is working fine and your YS strobe as well in the Av mode and your camera flash is incorrectly set in the Menu and sub menu.

N