Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-18-2013, 03:13 AM   #1
Forum Member




Join Date: Apr 2010
Location: Cairo
Posts: 77
Using built-in flash as controller ??

I want to use the built-in flash as a controller to the external slave flash ,,, but i noted the the built in flash give some light appear specially when i use wide apertures ,,, i want to use the built in flash to fire the external slave yn-560 flash without giving any leaking light ..

01-18-2013, 03:55 AM   #2
Veteran Member




Join Date: Mar 2007
Location: U.K.
Posts: 685
You could try a piece of developed film stuck over the popup flash. This will let IR light through and may be enough to trigger your external flash but reduce the popup's visible light.

I haven't tried this sort of thing on my K-30, but on my K100D for light tent use I had a hot shoe flash on camera in manual mode (to stop any pre-flash) pointing up at low power (so as to not contribute hardly to the exposure) to trigger external flashes that had those cheap hot shoe cube optical triggers fitted. I can't remember if the popup flash works like this, perhaps it always pre-flashed even in manual, the K-30 may be different, dunno.
01-18-2013, 04:08 AM   #3
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
Since you're using a manual flash anyway, getting a cheap radio trigger is a much better and more reliable solution. The simple PT-04 triggers sold under many brands are very cheap and work well.
01-18-2013, 05:17 AM   #4
Pentaxian
gjtoth's Avatar

Join Date: Apr 2011
Location: Louisville, Kentucky, USA
Posts: 1,962
QuoteOriginally posted by elliott Quote
Since you're using a manual flash anyway, getting a cheap radio trigger is a much better and more reliable solution. The simple PT-04 triggers sold under many brands are very cheap and work well.
I agree. You may also want to check out the Cactus V2 & V5 line, too.

01-18-2013, 05:56 AM   #5
Pentaxian




Join Date: Jan 2012
Location: Slovenia
Photos: Gallery
Posts: 2,180
I think there might be a setting that sets the flash to fire at 1/3 power or something like it. I remember reading it on this forum somewhere.
01-19-2013, 05:20 PM   #6
Senior Member




Join Date: Jan 2009
Location: Watertown, NY
Posts: 267
I don't have the K30 I have the Kr. In it's menu is a setting to use the onboard flash as the controller. The flash will fire as a trigger but it does not contribute any light to the shot. It flashes milliseconds before your off camera flash. I suspect that the K30 is similar.
01-19-2013, 05:40 PM   #7
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
QuoteOriginally posted by geru2000 Quote
I don't have the K30 I have the Kr. In it's menu is a setting to use the onboard flash as the controller. The flash will fire as a trigger but it does not contribute any light to the shot. It flashes milliseconds before your off camera flash. I suspect that the K30 is similar.
I believe that only works with P-TTL capable slaves, his Yongnuo does not allow that, it is a "dumb" slave.
01-19-2013, 10:21 PM   #8
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,198
QuoteOriginally posted by geru2000 Quote
I don't have the K30 I have the Kr. In it's menu is a setting to use the onboard flash as the controller. The flash will fire as a trigger but it does not contribute any light to the shot. It flashes milliseconds before your off camera flash. I suspect that the K30 is similar.
Can you please tell me where you got this piece of info (the part "It flashes milliseconds before your off camera flash") from. Thanks.

This issue has been discussed many many times. Here's a recent thread: link.

For p-TTL remote flash, there is NO WAY to prevent the built-in flash from firing during exposure. It does not matter whether you set it up as a control or master. This is the sequence of event:

1- The mirror is down and the shutter is closed.
2- You hit the shutter release button.
3- The built-in flash fires the pre-flash strobe.
4- The remote flash fires a response strobe. This strobe is used for light metering.
5- The mirror raises.
6- (See below)
7- The shutter opens.
8- The built-in flash fires the main strobe to trigger the remote flash.
9- The remote flash fires the main strobe.
10- The shutter closes.
11- The mirror goes down.

In step 8, the built-in flash fires when the shutter is open. The contribution of the built-in flash to the exposure may not be significant, but it's there nonetheless.

If you set the camera in 2 sec. delay mode, step 6 will be:

6- 2 second delay

Don't trust me, verify this for yourself by:

1- Take a photo with both the built-in flash and the remote flash visible in a mirror, and
2- Take a photo with the camera in 2 sec. delay mode.


The problem the OP experiences is not p-TTL remote flash, however, because the Yongnuo does not support p-TTL remote flash. Instead, it works in the "dumb" slave mode, with the pre-flash strobe from the built-in flash suppressed.

In "dumb" slave mode, the remote flash needs a strobe - any strobe from any flash - to trigger, and the triggering is with the speed of light. The Yongnuo has a mode with which it can ignore the first strobe (the pre-flash strobe from the built-in flash), and is triggered by the main strobe of the built-in flash.

As above, the main strobe of the built-in flash happens when the shutter is open. There is no way to prevent this.

Note that there are ALWAYS two strobes from the built-in flash, the pre-flash and the main. The only time the built-in flash fires only one strobe is when used with manual lens, and then it fires at full power.

Here's another thread that can be of interest: link.


Last edited by SOldBear; 01-19-2013 at 10:35 PM.
01-20-2013, 12:21 AM   #9
Pentaxian




Join Date: Jan 2012
Location: Slovenia
Photos: Gallery
Posts: 2,180
The flash will always contribute something to the exposure, there's just no going around that. I mean, it has to fire for the slaves to activate.
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!
built-in, built-in flash, controller, flash, k-30, k-50, light, pentax k30, pentax k50, slave
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Using Built in Flash in Wireless mode with External Flash i.e AF-360fgz disco_owner Flashes, Lighting, and Studio 7 05-16-2012 07:41 AM
Using the built-in flash as controller vs. slave external jpzk Pentax Camera and Field Accessories 12 10-13-2011 07:09 PM
K200D ISO when using built in flash? BobG Pentax DSLR Discussion 7 03-09-2009 01:10 PM
wireless flash using built in flash k200d dtra Flashes, Lighting, and Studio 3 04-04-2008 12:34 AM
Using built in flash dvdman45 Pentax DSLR Discussion 9 11-29-2007 05:32 PM



All times are GMT -7. The time now is 03:33 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