[cpho]

Hi all,

I was shooting an event last night and my flashgun started playing up on me.
While in pTTL mode, it seems to be randomly throwing a shot at full blast no matter what I change the settings to be. I usually dial it down to -2ish, but maybe every 10th-15th shot, it'll shoot a full power flash.
I've tried turning it on and off, different batteries, different lens.
I'm shooting on a K-5 on either M or Av.

Has anyone else had this problem before?
This has never happened in the 2 years I've owned the flash. Could it be a dodgy capacitor?

[Digitalis]

If you are using a manual lens P-TTL won't work.

[UncleVanya]

I may have. I had one shot recently where the af540the was off camera and one shot was a total white out.

Exif looks like all the other shots. A bit of a mystery to me.

Fa31 or fa77 on the camera onboard flash set to controller or master (mixed session not at home right now to read info).

[cpho]

If you are using a manual lens P-TTL won't work.

What do you mean by a manual lens? I was shooting 18-135 and fa77, both had this issue

I may have. I had one shot recently where the af540the was off camera and one shot was a total white out.

This is exactly it. Except mine was in the hot-shoe not off-camera.
Was yours just a once off or has it happened regularly?

[Digitalis]

I was shooting 18-135 and fa77, both had this issue

Check the contacts on the flash shoe and the camera shoe, there could be contact issue with the contact pins on the flash or camera.The DA18-135 and FA77 should work fine with the AF540.Also checkingthe contact pins on the camera lens mount and cleaning them with a lint free cloth wouldn't hurt either.

[UncleVanya]

Check the contacts on the flash shoe and the camera shoe, there could be contact issue with the contact pins on the flash or camera.The DA18-135 and FA77 should work fine with the AF540.Also checkingthe contact pins on the camera lens mount and cleaning them with a lint free cloth wouldn't hurt either.

Mine was off camera, fa31, cold shoe, optically controlled by onboard flash.it has happened only once.

When I'm not on my phone, I will link the files. Same exposure settings in both cases. ( one pic shows the problem, the other doesn't) the files are sooc jpgs from my eye fi card at reduced resolution. I can process the raw files later if needed.

EDIT:

Files:




External Flash was to the left of the frame and back. Halogen lights were about 15' from the subject above and to the right (of the frame). Halogen lights were also above illuminating the background. This was shot in my wife's yoga studio using existing lights. Fluorescent spot lights were providing general light from above all over the room. These are unedited and uncorrected shots. I have raw's that I plan to tinker with. Please bear in mind that I am an available light photographer primarily - this setup was rather complex lighting for me and I'm not sure how well it worked but the folks involved were all pleased.

Oh one last detail. I was getting a bad reflection from the subject's glasses with the onboard flash even in controller mode. I switched to liveview and held the camera up above her eyes and shot down towards her slightly to avoid that. She is the only person with glasses in the group so only her shots were impacted. Most shots were made that session without liveview but a few were made with liveview besides these.