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Off camera flash

Mannesty
Posted 28/03/2013 - 12:34 Link
MarkTaylor wrote:
Using option 2 the built-in flash fires to trigger the external flash, but is timed to go off before the shutter curtain opens so it has no effect on your exposure.

The above is not true I'm afraid.

When the onboard flash is set to act as Controller (not Master), the shutter is open before the onboard flash fires (as Controller) to trigger the off-camera flash, so it will contribute a small amount of light to the scene.

This can be easily proved by firing off a shot into a mirror, you'll see the onboard flash in the resulting image.

A simple solution has already been noted by Don, move further away from your subject. Alternatively as has already been stated, radio triggers are necessary to completely eliminate the onboard flash.
Peter E Smith - flickr Photostream
Edited by Mannesty: 28/03/2013 - 12:35
MarkTaylor
Posted 28/03/2013 - 13:49 Link
Mannesty wrote:
MarkTaylor wrote:
Using option 2 the built-in flash fires to trigger the external flash, but is timed to go off before the shutter curtain opens so it has no effect on your exposure.

The above is not true I'm afraid.

When the onboard flash is set to act as Controller (not Master), the shutter is open before the onboard flash fires (as Controller) to trigger the off-camera flash, so it will contribute a small amount of light to the scene.

This can be easily proved by firing off a shot into a mirror, you'll see the onboard flash in the resulting image.

A simple solution has already been noted by Don, move further away from your subject. Alternatively as has already been stated, radio triggers are necessary to completely eliminate the onboard flash.

Well I have never noticed any obvious effect on my photos using this method, but then I'm usually taking the shot from at least twice as far away from the subject as the external flash and not photographing highly reflective subjects.

If it's more than an opportunistic scenario where I have just gotten the flash out on the spur of the moment I will generally take the time to set up the radio triggers. To be fair Cactus v5s are quite affordable and in my experience, completely reliable. You do lose the benefits of P-TTL but assuming you want to do something as least vaguely creative, gaining full control over the power output of your flash by using it in manual mode more than makes up for this.
My Flickr Pentax K-5 K-5 II Sigma 8-16mm F/4.5-5.6 DC HSM Tamron SP AF 17-50mm F/2.8 XR Di II LD ASL SMC Pentax-DA* 50-135mm F/2.8 ED [IF] SDM SMC Pentax-DA 55-300mm F/4-5.8 ED SMC Pentax-DA 18-135mm F/3.5-5.6 ED AL [IF] WR Vivitar 100mm F/3.5 Macro AF Metz Mecablitz 58 AF-2
Edited by MarkTaylor: 28/03/2013 - 13:58
DaveHolmes
Posted 28/03/2013 - 16:11 Link
I'm still on V4's (although I only have one receiver now due to 'droppage') and find them pretty reliable. Had one issue when I first got them when shooting outside but swapping the batteries for AAA-Eneloops solved the problem
........................................................................
Digital:
Pentax K5- Vivitar 19mm 3.8; FA35mm f2; D-Xenon 100mm macro f2.8; DA50-200mm WR...
Flash:
Yongnuo YN-560; Vivitar 285HV; Cactus V4 triggers...
Film:
Pentax-MX & M50mm f1.4; Spottie & 55mm f1.8; MG & M40mm 2.8...

https://www.flickr.com/photos/daveholmesphotos/
Posted 10/04/2013 - 22:58 Link
Hi Guys,

Maybe you can help. I have K-5 and Nikon SB-700 set as a slave on remote mode and is fired by the on-board flash. I have tried every possible setting and each time the off camera flash fires too early as the on-board flash does the pre-flash. So, in result I have a picture with the light from the on-board flash. Do you know how to turn off the pre-flash???

Thanks in advance.
Edited by SkilakDeZoo: 10/04/2013 - 23:01
doingthebobs
Posted 10/04/2013 - 23:08 Link
Sounds like you are using a Nikon dedicated flash with a Pentax camera.What you need is a Pentax dedicated flash that uses PTTL, the system found on Pentax cameras.

The different camera makers have two different ways to work their flashguns, that's why they are dedicated.
Bob
Mannesty
Posted 10/04/2013 - 23:18 Link
SkilakDeZoo wrote:
Do you know how to turn off the pre-flash???

Use a manual lens (M42, K or M series) on the camera, or put a basic flash set to a very low power on the camera hot-shoe, otherwise you can't turn off the pre-flash.
Peter E Smith - flickr Photostream
Edited by Mannesty: 10/04/2013 - 23:25
Mannesty
Posted 11/04/2013 - 08:24 Link
In my previous post, I forgot to suggest using a radio trigger, which is probably the best solution to your Pentax Camera/Nikon Flash problem.
Peter E Smith - flickr Photostream

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