Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
06-05-2016, 01:40 AM   #1
Senior Member

Join Date: Jul 2010
Posts: 271
K-3 body or AF-540FGZ - which light should assist?

Yesterday I found strange behaviour of the above combo (paired with Pentax DA* lens+shade): I was shooting indoors, with some daylight coming in through windows & doors (more or less 1/100, 1:5.6, 400 ASA). When focussing I noticed than green K-3 body assist light was on (visible on thick DA* lens & shade), not the AF-540FGZ red stripped light. Flash was set for indirect bounce head position (with Omnibounce flash head attachment).
I believed the combo should use in-flash focussing assistance rather than in-body one.
In-menu AF Assist Light setting was on, camera in P[rogram] mode, camera Flash On mode setting, flash unit in P-TTL and one of the three 'white' other than green modes ('trailing curtain' mode I believe, but camera body setting overrides this mode).
When K-3 body + AF-540FGZ combo uses in-flash focus assist light, and when it uses in-camera focus assist light?

06-05-2016, 02:02 AM   #2
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 1,811
The camera AF assist light needs to be switched off in your camera settings.

Then use the 'SB' (spotbeam) mode on your flash, accessed via the mode button.
06-05-2016, 08:58 AM   #3
Senior Member

Join Date: Jul 2010
Posts: 271
Original Poster
QuoteOriginally posted by mcgregni Quote
The camera AF assist light needs to be switched off in your camera settings. Then use the 'SB' (spotbeam) mode on your flash, accessed via the mode button.
You are right, the AF Assist Light in K-3 menu has to be switched-off.
What is more:
* While in-camera focus-assist light operates when in Live View, the flash-unit near-infrared spot-beam does NOT assist when K-3 is in it's Live View;
* Autofocus mode has to be set-up as Single (AF-S);
* K-3 shooting mode might be in Continuous Shooting mode;
* AF-540FGZ settings overide in-camera K-3 body settings (slow speed / trailing curtain sync);
* When K-3 is in Live View, one cannot set AF-540FGZ flash metering mode to Auto nor to Manual, but you can set AF-540FGZ Auto metering mode before you switch K-3 to Live View;
* Some of the AF-540FGZ modes are not accesible when K-3 AE metering (incl. AE-Lock) is engaged.
Actually, it's a little bit weird (and AF-540FGZ manual does not cover K-5 nor K-3 bodies).

Last edited by Prakticant; 06-05-2016 at 09:42 AM.

  • 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!
af-540fgz, body, camera, combo, flash, focus, k-3, light, mode, pentax help, photography, troubleshooting
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax K-3 frozen AF when AF confirm light lit Wolfeye Pentax DSLR Discussion 2 03-06-2015 09:20 AM
AF assist light alternatives!??! Belushi Troubleshooting and Beginner Help 12 03-04-2015 08:48 AM
Which Camera Body K-3 or K-50 WVRICK Pentax DSLR Discussion 30 01-23-2014 10:17 PM
AF assist light HSV Pentax DSLR Discussion 7 09-10-2012 07:03 PM
Kx user here - should i go to K-5 or K-30 or wait for K-3 ladybug Pentax K-5 17 08-18-2012 08:39 AM

All times are GMT -7. The time now is 10:34 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]