G-15

[Interceptor121]

That is not the only possible problem, TTL circuitry has got response time of few milliseconds, to test if it works well you need to actually shoot macro at say 1/1000
If the circuit has a problem the picture will be overexposed systematically as the TTL circuit can't send the quench signal fast enough
Not difficult to test

 

[rks]

That is not the only possible problem, TTL circuitry has got response time of few milliseconds, to test if it works well you need to actually shoot macro at say 1/1000
If the circuit has a problem the picture will be overexposed systematically as the TTL circuit can't send the quench signal fast enough
Not difficult to test

Are you saying that TTL doesn't work at all with the flashes on this camera, or it only will work with a fibre optic cable? Your description here makes non sense if you're saying the second thing, because the same circuitry has to quench, the only difference is is the quenching controlled by an electric pulse, or does it go through one electrical pulse to an on camera flash, through a fibre optic cable (at the speed of light) to another sensor, where it has to be seen, and then quench a second flash. Clearly from a standpoint of complexity it's far simpler when it's wired. None-the-less I'll make the test you request but I can't see it working with fibre and not working with a wire.

 

[Interceptor121]

The internal flash responds quicker than the one circuitry of the wired TTL (depending on how it is implemented)

 

[James R]

rks, this is interesting. What mode are you shooting in? Like the G12, the G15 doesn't support TTL in manual mode.

 

[rks]

rks, this is interesting. What mode are you shooting in? Like the G12, the G15 doesn't support TTL in manual mode.

I was testing Interceptor121's theory that you couldn't get flash sync out of a wired flash over 1/250th of a second. I wasn't testing TTL so I shot in manual mode to force the shutter and aperture.

I'll have to do further testing on the TTL issues he is bringing up, but honestly I'm not buying his explanation. Basically the only quenching circuitry is in the flash itself, so if the flash would quench optically it'll quench electronically as well, I clearly can't test the optically because I don't have a fiber optic based slave. But I'm guessing (and note I'm saying that I'm guessing) that really the only one of the advantages he's mentioned of optical vs wired is the lack of the connector that might leak. I dislike F.U.D. so I was trying to find out what's real and what's F.U.D.

 

[Interceptor121]

I don't think the Ikelite has a full TTL meter independent from the camera? It will still need the camera to determine if the exposure is correct or not. The internal flash and the optical connection are faster than then TTL circuitry that has 4 ms response time by design (this is where the 1/250 comes from) unless it is a new fast version
Anyway it there is no point testing in manual to determine if it would do it correctly or not and I think you can apply my hack for the S95 also on the G15 as it works with the S100 and S110 and enable TTL in manual

 

[James R]

I think you can apply my hack for the S95 also on the G15 as it works with the S100 and S110 and enable TTL in manual

will this work on the g12?

 

[Interceptor121]

will this work on the g12?

Should do

I found a document the DS-151 is limited to 1/250 in TTL, the G15 has an electronic shutter so the issue is the flash firing time being longer than the shutter time

 

[coralcruiser]

Tell about this hack... what is it and how do you install it on the camera

I'm guessing you're talking about some type of software hack that will allow me to use my stobe in ttl mode with the camera in manual.

Does it impact anything else in how the camera functions and does it void the warranty??

 

[Hetland]

The canon hacks I'm aware of aren't available for the G12.... oops, look's like I spoke too soon: CHDK Wiki