K5 flash problem study

Started Dec 1, 2010 | Discussions thread
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Ivar__A Regular Member • Posts: 128
K5 flash problem study


This is the second body of K5 I have. The first one had an electronic level problem (it was about 3 steps wrong) and widely discussed external flash problem. To be honest, I didn't mess with the flash issue for long and returned the first camera just after two days.

Now having the second body with the external flash issue, I performed a deeper analysis.
I think I have found something.

Here are my conclusions (let's start with the positive):

  • The built in flash works perfectly within its power range and whatsoever the shooting program is used

  • Both direct and bounced give good results if the external flash is in A mode and camera is set to Av, M or X. And of course, the ISO can't be floating, it must be fixed.

  • Wireless mode , External flash is set to slave, camera to control, flash bounced --- whatever you do (P, Av, M, X, floating or fixed ISO), everything stays perfect including aperture/ISO values in P mode (like my K20)

  • Direct external flash in P-TTL mode works fine if Av, M or X is used and even if the ISO is set to floating in Av mode

  • (troubles start here) The same as above (external, direct, P-TTL) but in P mode and floating ISO , camera sets aperture mostly between 11 and 22 and ISO close to the allowed maximum (even if the distance is about 1m/3ft). If ISO is set manually to lower values like 100-400, aperture becomes normal as well. But most important, here starts the over exposure problem. Some shots are just too bright.

  • (Here comes the most important) Bounced flash in P-TTL mode is a real s... --- (shortly) except you follow the line

F4 - ISO100
F5.6 - ISO 200
F8 - ISO 400
F11 - ISO 800

It's simple in Av, M or X mode but it's definitely a bug in K5 which leads flash to constant output.

For me the problem is 50% solved and I will not return the camera as the rest of it is perfect. The second 50% of the problem is the reputation of Hoya-Pentax company and how fast they can fix it.

Used equipment:

  • K5 (firmware 1.01)

  • Pentax 16-50/2.8 SDM

  • Pentax AF-540 FGZ flash

  • human brain (experienced with SLR-s about 25 years and 15yrs with Pentax)

Firstly I thought I will write a review about K5 vs D700, but came out this.

I'm sorry about my English if it doesn't sound as it must be.

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