Using A and M modes on K10D/*ist-D with the AF360/540


MattMatic

Link Posted 25/02/2008 - 10:07
Hi all

(Long story mode on)
I decided to pull out the old Metz 50MZ5 and see what it could do with the K10D. It's a great flash, but really a bit large for general use. Still, with all the issues over P-TTL and people blinking etc, I thought I'd see what would happen.
Of course, the only modes available on the K10D are "A" and "M", since the Metz doesn't support P-TTL, and the K10D doesn't support old-style TTL. So, I plumped for "A" mode.
Interestingly the Metz knows and tracks the ISO and aperture from the body, so the A-mode flash is fine every time - and there is no preflash.
So, I thought I'd try a few other things on the AF360 & AF540...
(Long story mode off)

There are a few reasons why you may not want P-TTL, including:
* People who blink on the preflash
* Shooting wildlife with flash that would be scared off by the preflash
* Exposure issues with P-TTL


The bottom line here is you CAN use the A mode without preflash on an AF360/540 on the camera Here's how:

1. Attach and power up camera and flash
2. Switch the camera mode to "M"
3. Press the "Mode" switch on the AF360/540 once to enter "A" mode
4. Switch the camera mode to Av (or whatever mode you choose)

Now, the flash will NOT issue a preflash. However, bear the following things in mind:
a. You must dial in the correct ISO rating on the flash. Do make sure that the K10D is set to a fixed ISO and is not using automatic

b. You must also dial in the correct aperture on the flash and camera. That's why the Av mode is the best option.

c. If you press the flash's "Mode" button it will flick from "M" straight back to "P-TTL". You won't get the A mode back unless you go through steps 2-4 again.

Unlike the Metz, the AF360/540 will not track the ISO or aperture of the body. It's swings and roundabouts... the Metz will not let you set a flash exposure compensation as a result. With the Pentax guns you can create a differential between the ambient and flash (particularly for outdoor fill in) -
i. Turn off the flash
ii. Use Av mode and set the aperture so that the shutter speed is slower than 1/180 (let's say it's f/11 at 1/125 ISO100)
iii. On the flash, enter a different aperture (you are lying to the flash). If you enter f/8 on the flash then the flash will be 1-stop lower than ambient (and f/5.6 will make it 2-stops lower)


I've also stumbled on something regarding the dreaded P-TTL underexposure issue... nearly sussed it out I think but need more time!

Hope that clarifies rather than muddies the flash issues
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

Clarky

Link Posted 25/02/2008 - 10:26
Thanks Matt helpful as always
Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|

hefty1

Link Posted 25/02/2008 - 11:26
Very useful - thanks Matt
Joining the Q
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