I have both flashguns but I prefer to use the Metz more than the Pentax with my K5, K20 & K10. I like to use manual mode & with the Metz it switch to Manual automatically. I just need to change the power ratio once & even when I turn off the power & on again the setting will not changed. With the 540GFZ there's no such thing. I have to change the mode to manual & adjust the power ratio. When I turn off the power & on again it switch back to Auto TTL.
Last week I took a wedding using my K5 & K20 using 18-135mm & 14mm lenses & Metz 50AF with a Peri diffuser. The 14mm coverage was superb at 1/60 F4.0 & iso400 & the Metz was at 1/2 power. There were no dark spots at both sides & the light was evenly spread. I did the printing myself up to A3 size. Now I hardly use the Pentax flash & relegate it to spare tyre status
Last week I took a wedding using my K5 & K20 using 18-135mm & 14mm lenses & Metz 50AF with a Peri diffuser. The 14mm coverage was superb at 1/60 F4.0 & iso400 & the Metz was at 1/2 power. There were no dark spots at both sides & the light was evenly spread. I did the printing myself up to A3 size. Now I hardly use the Pentax flash & relegate it to spare tyre status