360FGZ pre-flash really slows the work flow!?

Hi all,

I'm doing an outdoor shoot with models. I'm photographing several figures and on one of the shots spraying water acroos the group. So i'm setting a hi-speed camera setting and using hi-speed 360FGZ flash.

One problem!

That pre-flash will really throw the models and slow the work flow. Can I switch it off?

If anyone can help it would be great.

regards

Bluewhistle

Blue,

I was worried about pre-flash and before purchasing my 360 I e-mailed Pentax UK asking if you could manulaly set "normal" TTL.

According to Pentax UK, no

Thank you for your e-mail. The AF360FGZ flash will revert to P-TTL when used with the istDS. This can not be set to TTL.

Kind regards,

Stephen Sanderson

In TTL mode the flash "reads" the camera and if it is P-TTL capable, it sets this, if not, it sets normal TTL

Presumably it will work in "normal" auto but I don't know if you can use htis in high speed mode.

Fortunately, for my needs this is not a problem as the pre-flash is close enough to the main flash not to ruin the expression on the kids faces (or whatever) - I am not however a professional.

Hmmm. You can and you can't

I'll have to get back to you on this because the answer is not simple, and I better try it out for real first

Matt

Hi

Thanks for the reply Terry. I've been doing more tests. I can get the flash to fire in day light if I set the camera to non auto flash!

Now the weird thing is, it says p-ttl on the screen yet it doesn't do a preflash when I take the pic. It comes out exactly as I wish!!!!

So maybe here is how it goes:

MaKE SURE FLASH IS PROPERLY ON SHOE!! It does ttl is you don't

Switch off all flash symbols on the camera led

Set flash to HS

and camera to a high shutter speed


and that looks like it gives you the results you want.

Just make sure you're ambient light reading is correct and the fill - in just livens the image!

I'm off to test my logic some more.

James

James,

Ok, here's the full answer

1. If you have the AF360 in P-TTL, and the body in Green,P,Av,Tv then there will always be a preflash. Usually the preflash is milliseconds before the main flash - it's difficult to tell that a preflash fired. But then I do have friends who manage to blink at the preflash and always have their eyes closed; and "dumb" slaves will always trigger off the preflash. But...

2. If you enable "red eye reduction" on the body, there is something like a 1 second pause between the preflash and the main flash. Maybe this is what you experienced.

3. If you set the body to "M" (fully manual) you then have the option of setting the mode of the AF360 to "A" or "M". In both cases there will be no preflash, though you have to make a few more calculations

4. Putting the camera in "M" and the AF360 in P-TTL still works. In fact I tried this with an indoor image where I wanted to preserve the outside light and the shadow it cast, but still have some indoor flash to balance it. It was a doddle with M mode - I spot metered to work out the exposure difference between shadow and outside light. Then used P-TTL. Only needed two or three test shots and I managed to get a perfect exposure.

So, for your needs, setting the body to have no flash indications at all (especially not the red eye reduction!) and powering up the AF360 should be fine. If you can't get the balance automatically, do it fully manual - you can get anything you want then

Hope that helps!
Matt

Cheers Matt

But! Big But.

I have set my camera to show no flash symbols on the led and switched it to P. Guess what, no pre flash.

Took some pics with 1.1 ratio and they look exactly how I want them to!!

Arthur C. Clarke strange mystery or what.

It makes me think the pre flash was just red eye reduction all along!!!

James

James,

That's what I meant - turn off all flash symbols on the *ist-D body LCD.

No mystery at all - the AF360 will be doing a pre-flash. Always. It's just really hard to see it - there are actually two bursts of light, very, very, very close together, but still two. Ordinarily they are so close together it makes no difference in shooting But it makes a difference to "magic eye" slave flashes

The best way to see it is to hold the camera slightly away from you and fire the shutter. You should be able to just discern the two bursts, well, at least I can!

As I mentioned, the only way to completely disable preflash is to use the "A" or "M" modes on the flash, which are only available when you have the body on "M"

As you said, it was just that you had red eye reduction enabled (little eye symbol on the LCD) on the body which increases the time delay between the preflash and main flash.

Have fun!
Matt