Loss of TTL in Canon manual mode

"Using the strobe in Manual Mode

When the Inon S2000 is used in manual mode (turn the left switch to "M"), the magnet switch is used to tell the strobe whether to ignore pre-flashes or not. Normally the magnet is not inserted into the hole, but when using Canon point and shoot cameras like the Canon S90, G10, or G11 on manual mode, you want to insert the magnet, and set the Canon flash power to it's lowest setting. This is because Canon compact cameras do not preflash or support TTL when in manual mode."

"The above sums it up best I think, but the G11 is about the best SLR substitute out there at the moment. I set one up in an Ike housing the other day for a student, and although you lose the TTL option when in manual mode, you have a 1 or 2 button push (can't remember which) path to controlling stobe power from within the camera! That give's you a ton of controll for lighting without having to futz with the stobe at all."

Why do you lose the TTL in manual? And how does that affect my shooting? I'm still a bit confused with how the camera exposes correctly without "knowing" that there's an Inon S2000 strobe providing the light! Unless with TTL the strobe exactly mimics the strength of the onboard flash?

Cheers

Mithere,

The whole point of TTL is that it will automatically read the strength of the internal flash and replicate that for underwater use.

These cameras, in manual mode switch to manual flash control too. This on the G11, is accessed by the standard func/set button and adjusted with the dial (the flash symbol with a +/- sign). So whats it doing is asking you to set and control everything has affects the exposure of a shot. Hence TTL is lost in the strobe as it reads and duplicates this power setting. With this, the strobe will always fire at that set level, so you could set your AP or SS to compensate this, but this is prob not the reason for using manual settings.

You can switch it back to automatic flash in the flash options (flash button, then disp button) so that the exp is manual but the flash is auto to compensate. In this menu, you can also adjust 1st/2nd curtain synch, preflashes etc.

The camera does not need to "know" there is an ext strobe connected. It will expose correctly for its own internal strobe and the inon will correct itself, being a bigger, brighter light source, but it also knows you are underwater, when the G11 doesnt!

This would mean the s-2000 could still run in TTL mode off the internal flash but you would have control of the AP and SS. Im not sure how this set up works for that, and you may be better on manual strobe power too, to have more control over ur lighting.

Hope this helps

Olly

Why do you lose the TTL in manual?

Design choice by Canon ... TTL CAN work in manual exposure modes ... and does on DSLRs ... but Canon has chosen to not to give this to G-series cameras (and other things like HD video) to keep them from being TOO good!

Sad, but true.

Jeremy is correct (and Olly's post reads as incorrect, but I may not be understanding him well). There is no way to make the camera do "automatic" flash power control when the camera is in M mode. This also means that there is no way to make the underwater strobe do "automatic" power control either.

Cheers

James

I posted this as its own topic but i thought it might be worth continuing the discussion here.. and stopping that post..

I have read my inon D2000 manual and im still not sure what technique to use when diving with my G10 and inon D2000

ok so i have a G10 that does not fire a pre-flash when you have it in manual mode and also a Inon D2000

just for all the people like me out there that need it spelled out to them.. can someone answer these questions for me.

1)

So when you are in modes (on the strobe ) STTL , STTL Low it does not matter what setting (magnet in or out) you have on the ACC (Advanced Cancel Circuit) it will expect a pre flash correct.? Ie the strobe ignores the ACC setting for STTL and STTL low?

2)

The magnet in or out will only affect the flash when you have the strobe in manual and auto settings correct?

3) so on the same dive with the magnet in I could do the following and correct flash exposure would work every time.

Shoot in modes (on the camera ) Tv, Av and P I use STTL on the strobe.

Shoot in Manual (on the camera) I turn the strobe to manual also.

4)

what do you think will happen if i put the camera in Av, Tv or P and shoot with the magnet in turning the ACC (Advanced Cancel Circuit) on.

Any help would be great with this one.. im going on a liveaboard in a week and want to shoot in manual .. but dont want to waste any dives testing the ACC in out out.. biggrin.gif

Thanks

Chris

hey people i just wanted to Enable email notification of replies and the only way new how to do this was to post a reply..

hey people i just wanted to Enable email notification of replies and the only way new how to do this was to post a reply..

Go to "My Controls" (link along the toolbar near the top of the page), and Email settings (link along the left, towards the bottom) and change the last entry to whatever setting you'd like, so your default sends you future modifications.

I posted this as its own topic but i thought it might be worth continuing the discussion here.. and stopping that post..

 

 

I have read my inon D2000 manual and im still not sure what technique to use when diving with my G10 and inon D2000

 

ok so i have a G10 that does not fire a pre-flash when you have it in manual mode and also a Inon D2000

 

just for all the people like me out there that need it spelled out to them.. can someone answer these questions for me.

 

1)

So when you are in modes (on the strobe ) STTL , STTL Low it does not matter what setting (magnet in or out) you have on the ACC (Advanced Cancel Circuit) it will expect a pre flash correct.? Ie the strobe ignores the ACC setting for STTL and STTL low?

 

2)

The magnet in or out will only affect the flash when you have the strobe in manual and auto settings correct?

 

3) so on the same dive with the magnet in I could do the following and correct flash exposure would work every time.

Shoot in modes (on the camera ) Tv, Av and P I use STTL on the strobe.

Shoot in Manual (on the camera) I turn the strobe to manual also.

 

4)

what do you think will happen if i put the camera in Av, Tv or P and shoot with the magnet in turning the ACC (Advanced Cancel Circuit) on.

 

Any help would be great with this one.. im going on a liveaboard in a week and want to shoot in manual .. but dont want to waste any dives testing the ACC in out out.. biggrin.gif

Thanks

Chris

I would be interested in hearing how things worked out. I have the G10 and S2000. I have always used P, Av or Tv with the strobe set to sttl.

I would like to shoot M mode and want to know how to set the strobe.... mainly shoot macro so once I get the proper setting I probably won't need to change it.

What's all this about needing to insert the magnet??

Also, if anyone knows where I can find an online manual for the s2000, please send me the link. I think I left mine in Lembeh and can't seem to find one online.

Also, if anyone knows where I can find an online manual for the s2000, please send me the link. I think I left mine in Lembeh and can't seem to find one online.

I'm not sure if the manual for the D-2000 is sufficiently similar to the S-2000 to be helpful, but just in case: http://www.deduiker.nl/pdf/INON%20D-2000%2...ed%20Manual.pdf

I'm not sure if the manual for the D-2000 is sufficiently similar to the S-2000 to be helpful, but just in case: http://www.deduiker.nl/pdf/INON%20D-2000%2...ed%20Manual.pdf

There are some difference so I emailed Yuzo and he sent me the S2000 manual as a pdf. Am now in Dominica... things have been in spawning mode the past few days and now it is pouring rain! Hoping that the viz gets better since it's around 20ft right now!