Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-24-2014, 10:22 PM   #16
Site Supporter
RGlasel's Avatar

Join Date: Sep 2013
Location: Saskatoon
Photos: Gallery | Albums
Posts: 1,301
QuoteOriginally posted by tabl10s Quote
Is this still true when using a Metz flash
If the Metz flash supports P-TTL auto flash, then you have to use the optical method (pulses of light) to take advantage of P-TTL. I don't know of any radio triggers that support P-TTL, but depending on the complexity of your lighting setup, you may prefer to go full manual instead of using Pentax's programmed flash modes anyway. By the way, I discovered for myself how sensitive a Metz flash can be to the on board flash when set to controller mode. Somehow the flash placed on the floor behind the chair was triggered by light bounced off the ceiling and walls, even though the camera was almost 10 feet away and the walls were at oblique angles.

The penny dropped for me when I realized that the power output of the flash is a function of time, in other words the instantaneous intensity is constant, but longer flashes exposure the picture more (and our brain perceives it as being brighter). If the light pulses for wireless communication are 1/50 of the duration of a full power flash, then it is the equivalent of reducing the aperture by several stops and the contribution of the pre-flash to the overall exposure is reduced accordingly.

Attached Images
View Picture EXIF
PENTAX K-30  Photo 
01-24-2014, 11:20 PM   #17
Site Supporter
RGlasel's Avatar

Join Date: Sep 2013
Location: Saskatoon
Photos: Gallery | Albums
Posts: 1,301
QuoteOriginally posted by gosman Quote
Do any of you set your on-board flash to a lower power and let the remote flash be the main light?
Assuming that wireless P-TTL flash works in a K-3 much like it does in a K-30, there is a contrast sync control mode for P-TTL flash, and if you have the built-in flash set to be the master flash, it will contribute 1/3 of the light and the external flash will contribute 2/3. Setting the external flash to be master in contrast sync mode reverses the proportioning of flash between it and another external flash. Setting flash exposure compensation in the camera affects the total amount of flash applied, so it's not an effective way to throttle back the output from just the built-in flash. In most situations your external flash will have 3-5 times as much power, so using contrast sync will also limit how much light you can effectively use from the external flash in P-TTL mode, and in manual mode, the dinkiest external flash will outshine the built-in one. I haven't found a good way to use the built-in flash with a remote flash, other than as a controller.

I've experimented with flash EV compensation on both my K-30 and a Metz flash that supports P-TTL, in various combinations along with non-flash EV compensation, and setting flash EV compensation to negative values just pushes the camera to expose for ambient light. Depending on the required shutter speed for ambient light, the camera's programming may still underexpose and if you set regular (non-flash) exposure compensation to positive values, the camera will tend to apply too much flash and overexpose, regardless of what you set flash exposure compensation to. If I want fill-in flash to be more prominent, then I set the camera's EV compensation to -1.0 and flash EV compensation to +1.0. To make things somewhat more unpredictable, setting exposure compensation on the Metz has a different effect than setting flash exposure compensation on the camera, even though the camera is supposed to add the two together.

Last edited by RGlasel; 01-25-2014 at 01:05 AM. Reason: to be clearer on using the built-in flash
01-24-2014, 11:27 PM   #18
Site Supporter
tabl10s's Avatar

Join Date: Jun 2011
Location: Sacramento(formerly from B'Ham, England).
Posts: 1,394
The Metz does support P-TTL. I'm not sure what protocol is used if I have one as the master and the other a slave.
01-25-2014, 01:19 AM - 1 Like   #19
Site Supporter
RGlasel's Avatar

Join Date: Sep 2013
Location: Saskatoon
Photos: Gallery | Albums
Posts: 1,301
QuoteOriginally posted by tabl10s Quote
I'm not sure what protocol is used if I have one as the master and the other a slave.
If you aren't using P-TTL, then your flashes have to be operated in manual mode, so setting them to be a master or slave doesn't do anything. With radio triggers you set a radio connected to the camera to be a transmitter and the other radios to be receivers, but the flashes connected to the triggers just know they are supposed to fire, no other settings are communicated. Wireless communication with P-TTL is done with light pulses from a flash directly connected to your camera, but it doesn't have to be the built-in flash. You can mount one of your Metz' to the hot shoe on the camera and set it to be master or controller and any flashes you want triggered wirelessly using P-TTL have to be set to be slaves. Or set the built-in flash to be controller, don't have any external flashes directly connected to the camera and set the external flashes to be slaves. And don't forget to pop up the built-in flash.

Just to make it more confusing, both the camera manual and the Metz manual I have refer to Pentax's hot shoe adapters and extension cord, but the camera manual says you can set an external Pentax flash connected this way to be the master flash, even with contrast sync, and the Metz manual says that if you connect an external flash this way, it has to be set to contrast control and the built-in flash still contributes. The Pentax Hot Shoe Adapter F has a low enough profile that you can use an extension cord with it and pop up the built-in flash, so perhaps that is the only way to use a Metz flash with contrast control, but it would have to be set to be a slave.

Or you could give up trying to understand how P-TTL works with external flash and set your Metz' to be Servo slaves. In this mode, simple flashes of light from any other flash will trigger the Metz to fire, although there are settings to compensate for premature triggering because the camera is pre-flashing to eliminate red-eye. This mode could be a problem at weddings and school concerts where more than one person is doing flash photography.

Personally, I think P-TTL gets a bad rap because you have to rely on the camera's programming, instead of controlling every variable yourself. However, if you are just trying to get reasonably well-lit pictures without special effects, it is more convenient and is somewhat predictable. In general, I think flash photography is more challenging because you need a good eye for the effects of flash without actually having the true lighting conditions visible to you when you compose the shot. And that applies no matter what protocol or triggering method you use.

04-28-2014, 03:10 PM   #20
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 9,044
QuoteOriginally posted by Fig Quote
Any aftermarket radio slaves that will work with the K-3?
Have a look at the Cactus V6 because you would be able to remote control the power level of your 540 FGZ and trigger it via radio. No more "line of sight" required. Power control is purely manual (no P-TTL support). Some (including myself) prefer that, some want P-TTL.

QuoteOriginally posted by RGlasel Quote
I don't know of any radio triggers that support P-TTL
The Aokatec AK-TTL do that by converting the optical P-TTL signal into radio waves and then converting the radio waves back into optical signal.

I personally think that P-TTL has too little to offer in order to invest into it, in particular when you want to do multiple light setups.
04-28-2014, 03:30 PM   #21
Senior Member




Join Date: Jan 2014
Location: Texas
Posts: 256
It is such a pity that pocket Wizard doesn't support Pentax PTTL like it does with Cannon and Nikon flashes:


Thank you for your interest in PocketWizard. Sorry, we don't have a TTL system for Pentax. For Manual flash you can use the PW Plus X units. You will need a Plus X on camera and another Plus X attached to the flash.

If the flash doesn't have a sync port you can use the PW hot shoe adapter "HSFM3".
05-29-2014, 02:44 PM   #22
Senior Member
Naim Khan's Avatar

Join Date: Mar 2010
Location: Wakefield, West Yorkshire
Posts: 177
Hello all,
Back after a long time and knowing it is a Pentax family, I will still be welcomed
I have a question regarding the flash setting on the K3. What is the use of the 'Manual Flash Discharge' setting. I note that you can decrease the power if wanted.
Thanks and cheers.

Naim
05-30-2014, 05:48 AM   #23
Pentaxian
awaldram's Avatar

Join Date: May 2008
Location: Hampshire
Photos: Gallery
Posts: 720
QuoteOriginally posted by Naim Khan Quote
Hello all,
Back after a long time and knowing it is a Pentax family, I will still be welcomed
I have a question regarding the flash setting on the K3. What is the use of the 'Manual Flash Discharge' setting. I note that you can decrease the power if wanted.
Thanks and cheers.

Naim
The most obvious use is on a studio/manual multi flash setup where your triggering the remotes from the PC-sync

You can use the pop-up as a mobile catch-light controlling the power it delivers via the factional power levels

You could also use it for catch light under high ambient where flash was not required to add to the exposure

Its a creative feature that actually makes the weak built in flash some use. because besides its ability to control real flashes wireless it is IMO woefully inadequate as a single flash source.

This isn't a 'Pentax' problem but a global issue the on-board flash of all makes are not suitable for single flash use and them being 'sold' as such is bordering false advertising.

......rant off.....

05-30-2014, 08:54 AM   #24
Veteran Member
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,795
QuoteOriginally posted by Naim Khan Quote
Hello all,
Back after a long time and knowing it is a Pentax family, I will still be welcomed
I have a question regarding the flash setting on the K3. What is the use of the 'Manual Flash Discharge' setting. I note that you can decrease the power if wanted.
Thanks and cheers.

Naim
AFAIK the manual setting uses the setting made by the user for flash power, ignoring any through the lens metering technology.
08-30-2014, 12:34 AM   #25
Site Supporter
jbarry's Avatar

Join Date: Dec 2011
Location: Melbourne, Victoria, Australia
Photos: Gallery | Albums
Posts: 298
I need to operate my K3 in art galleries, sometimes poorly lit where FLASH is unacceptable and even banned.......can someone help me please..........how do I turn off the on board flash????????????????

I know how to turn it off on my Pentax K r.
08-30-2014, 07:22 AM   #26
Loyal Site Supporter
Mikesul's Avatar

Join Date: Sep 2009
Location: Phoenix, AZ
Posts: 2,565
this has already been answered in another thread but the answer is easy - do not pop it up.
08-31-2014, 11:07 AM   #27
Site Supporter
GeneV's Avatar

Join Date: Oct 2008
Location: Albuquerque NM
Photos: Albums
Posts: 9,772
FWIW, most of the time when I use wireless P-TTL, I am bouncing the off-camera flash, and I like having the on-board flash contribute fill. I am more likely to use wireless P-TTL when I am traveling or visiting, and I set up the off-camera flash on a shelf somewhere. If I had time and opportunity to set up a softbox or umbrella, I'd probably go with manual flash as some others mentioned.
12-09-2015, 07:23 AM   #28
Site Supporter




Join Date: Feb 2014
Photos: Gallery
Posts: 86
You all rock! Was looking for this exact information today and found it here! Thank you!!!
10-17-2016, 04:07 AM   #29
New Member




Join Date: Oct 2016
Posts: 5
K-3 Wireless with Sigma 610 Super

I.Cole and WizofOz,

I too am new to this forum and I found both your posts very interesting. I am having similar problems as described by I.Cole with my K-3 and Sigma. I think I understand the difference between the K-3's Master and Controller settings better now. However, I still have a problem understanding how to set the menu items on the Sigma. I'm guessing I need to figure out how to dump the P-TTL, set the Camera as Controller, and somehow figure out how to set the Sigma as Manual Slave - all to just let the Sigma control the light on the target. If I want the camera to contribute as well, that's when I set it to Master and adjust the exposure settings to affect how much the popup contributes. Almost makes P-TTL practically useless with external Flashes not mounted on the camera. However, if you mount the Sigma on the camera as the sole Flash, it is very handy. Could you please help me out with the Sigma? I like the Flash, but the menu settings drive me nuts - seems like you need to set channel, and other settings to get it to fire - What are the proper settings to interact with the K-3 as the wireless Controller vs Master? Please advise.

Respectfully,
PentaxJunky
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, dslr, fire, flash, help, k-3, k-3 wireless flash, k3, menu, mode, pentax k-3, wireless flash mode
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-3 and wireless flash trigger? zantaphia Pentax K-3 20 12-03-2013 03:35 PM
K-x and wireless flash triggers CRMassart Pentax DSLR Discussion 9 11-26-2013 04:02 AM
K-01 wireless flash compatibility? raider Pentax K-01 10 04-06-2013 04:55 PM
Wireless flash triggering on a K-30? gorski Pentax Camera and Field Accessories 2 06-21-2012 05:33 AM
People Night Portrait With Wireless Flash 3 Victor HK Post Your Photos! 3 03-10-2012 06:00 AM



All times are GMT -7. The time now is 05:23 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top