[mymage]

Hello, I take pictures using a combination of ambient light and flash to highlight the movement (the moving object with typical ghost strip that "follows" the right image). I tried to use an external flash connected via hot-shoe contact or through the PC after setting the machine on trailing curtain, but always fires on first. With built-in flash or with FGZ540 work properly.
It's a "limit" of the system or I am I missing something?
Since I use the studio flash, the only solution is to use the manual FGZ (or camera flash) at reduced power as a driver of the other (set to the photocell), but how do I set it manually if it always activate P-TTL just turning on the camera?
Thanks in advance.

[Canada_Rockies]

Hello, I take pictures using a combination of ambient light and flash to highlight the movement (the moving object with typical ghost strip that "follows" the right image). I tried to use an external flash connected via hot-shoe contact or through the PC after setting the machine on trailing curtain, but always fires on first. With built-in flash or with FGZ540 work properly.
It's a "limit" of the system or I am I missing something?
Since I use the studio flash, the only solution is to use the manual FGZ (or camera flash) at reduced power as a driver of the other (set to the photocell), but how do I set it manually if it always activate P-TTL just turning on the camera?
Thanks in advance.

You need a Pentax dedicated flash, as you have discovered. You can use optical triggers on remote flashes, and trigger them with the 540, but you will need to use the 540 in manual or auto mode, not P-TTL. P-TTL will trigger the remote flashes with the exposure pre-flash. If the 540 is not contributing to the exposure, you could experiment with 1/16 power manual, trailing curtain and see how much range you can get, aiming the 540 head towards the remote flash.

[mymage]

But the problem is set the FGZ in manual mode and sincro on the trailing curtain: if I set the camera on trailing curtain (and the FGZ too and M mode) when I half-shot, the FGZ will change to P-TTL mode.

[Canada_Rockies]

But the problem is set the FGZ in manual mode and sincro on the trailing curtain: if I set the camera on trailing curtain (and the FGZ too and M mode) when I half-shot, the FGZ will change to P-TTL mode.

Is your camera set perhaps to green mode? There are restrictions on what the camera does in green mode. As an experiment try setting the camera to M.

[clm]

Rear curtain sync will only work in P-TTL, according to chart on page 65 of the flash manual. You could use wein digital slaves to trigger the studio flash. Breaking News Articles

[mymage]

Great, luckily someone read and remember all the manual!
So there is no possibility to set up camera and flash to have a single flash (without the preflash of the P-TTL) on the trailing curtain, right?
So it comes another question: why is not possible to set trailing curtain sync in manual mode? It's a Pentax choice or it's something technical limit? I think that with a enough long time (eg. 1s or bigger) there was no problem to do the flash start on the trailing curtain.


For Canada_Rockies
I set the camera in M, Av, X and camera-flash setting on TC; FGZ flash on TC. But how sed clm is a "system feature".

[Russell-Evans]

So there is no possibility to set up camera and flash to have a single flash (without the preflash of the P-TTL) on the trailing curtain, right?

With the Metz 48 AF-1 and I assume also with the Metz 58 AF-1, you can have manual flash with trailing curtain.

Trailing curtain is also a TTL thing with Pentax flashes and with an older TTL only Pentax flash, you will get the flash firing at full power and no preflash, but with trailing curtain if the flash supports it. This assumes you are using a Pentax DSLR without TTL support. With TTL support, the flash will behave as a TTL flash with trailing curtain, of coarse.

So it comes another question: why is not possible to set trailing curtain sync in manual mode? It's a Pentax choice or it's something technical limit?

This is a Pentax choice. I personally think it is a bad choice for Pentax to have put the trailing curtain function on the digital pin of the flash instead of simply letting the camera fire the center pin as the shutter closes. I have read that with Canon the trailing curtain is on the center contact only, and thus radio triggers or any flash on the hot shoe has the ability to do trailing curtain. It is all contained in the camera. Score one for Canon.

Thank you
Russell

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Last edited by Russell-Evans; 08-15-2010 at 08:16 AM.