[nozoom]

The more I think about this the more I am confused. If "zoom size" recalculates from FF to APS-C, why do I see 55 mm in the flash display when I have set my lens to 55 mm and not the APS-C equivalent?

Look at this way: It does not recalculate. The flash is customized for the Pentax camera. It knows that it is mounted on an APS-C camera. It will zoom correctly according to what lens you mount on the camera (to the nearest wider zoom position so it will not vignette) and will indicate that in the display (the 58 AF-2 shows what the reflector is zoomed to, not the actual focal length mounted). If you want to, you can let the flash show you what 35 mm "equivalent" focal length that would be. To do that you will have to turn "zoom size" off (gruber_69 indicated that "zoom size"=off will not stick on the 64 AF-1, though it will on my 58 AF-2, but why on earth should I want to turn zoom size off?).

I guess the confusion is that the manual tells what zoom positions it wold show with zoom size=off (what the flash would cover on FF). Another example of how easy those ridiculous crop factors leads to confusion. These numbers are of no interest. You have to divide all those numbers by ~1.5. Then you get (I guess they have rounded these numbers to the nearest commonly used focal lengths): 16-19-23-33-47-57-70-120-133.

---

Last edited by nozoom; 05-08-2015 at 11:54 AM.

[Anguel]

Hi! I tested with the K-30. With zoom size ON (default) the flash displays the same focal length as engraved on the lens: 55 mm up to 70 mm. With zoom size set to OFF, the flash displays 85 mm - 105 mm. What confused me first was the fact, that the flash always jumped back to zoom size ON as soon as the shutter was touched and displayed the non FF numbers. Therefore, I thought that there was something wrong. gruber_69 reported the same zoom size reset problem above.

Update: A far more annoying thing is the fact that all pictures in P-TTL are underexposed. A-Mode seems to work much better for some reason...

[sterretje]

Update: A far more annoying thing is the fact that all pictures in P-TTL are underexposed. A-Mode seems to work much better for some reason...

That's the camera incorrectly interpreting the exposure; pTTL does not have the best reputation. If it's consistent, you can easily dial in some flash compensation.

In A-mode, the flash decides on correct exposure instead of the camera. As the 64 'copies' the camera settings (when used in the hotshoe) it's just as convenient as pTTL (unless you need HSS).

[emsee]

I got the Metz flash today. It came with the latest firmware for Pentax (1.1). If I use this with Pentax 24-70mm lens, the auto zoom is working fine. Now when I tested this with Pentax 70-200mm lens, the autozoom works up to 105mm and after that it is not showing anything more. If the zoom is at 135mm or 150mm or 200mm, the LCD on Metz 64 AF-1 shows 105mm.

This seems to be the similar issue faced on the APS-C cameras. Somehow Metz 64 AF-1 cannot get the zoom information from Pentax (may be Pentax is not sending it properly).

Did anyone test Metz 64 AF-1 with longer zooms (anything over 105mm)?

[Schraubstock]

Hi
To be honest I hadn't even noticed this problem as I have not yet used the flash past 70mm.

For those who are able to read German, I found a statement issued by Metz.

Basically it says it is not Metz's fault. The K-1 is communicating with the flash correctly but not past 70mm (105mm)
It cannot be rectified by Metz.

I am not sure, but it is plausible Pentax/Ricoh are not aware of this problem. We now have to find a way to lobby Ricoh to rectify this in one of their next FW updates.

How do we do this. I will see if any of my Japanese friends can be of assistance.

Quote:
Blitzgerät mecablitz 64 AF-1 digital verfügt generell über einen Motorzoom-Reflektor von 24 mm bis 200 mm mit verschiedenen festen Stellungen. Dabei wird normalerweise der Zoomreflektor automatisch an die Brennweite der Kamera entsprechend angepasst. Dazu wird von der Kamera der Brennweitewert über den seriellen Datenbus an das Blitzgerät übermittelt.

Wir mussten nun allerdings feststellen, dass Pentax-Kameras zwar diese Übertragung durchführen, jedoch aber als maximalen Brennweitenwert 105 mm bzw. 70 mm (bei Zoom Size) an das Blitzgerät weitergeben. Falls eine längere Brennweite an der Kamera genutzt wird, überträgt die Kamera aber trotzdem nur den maximalen Wert von 70 mm bei Zoom Size. Aus diesem Grund kann das Blitzgerät leider keine längere Brennweite an der Kamera erkennen.

Dies kann auch leider nicht durch eine Modifikation des mecablitz 64 AF-1 digital geändert werden. Aus diesem Grund kann der Motorzoom-Reflektor des mecablitz nur entsprechend manuell eingestellt werden, falls eine längere Brennweite genutzt und die maximale Leitzahl benötigt wird.
End of Quote

[Anguel]

Hi!

If I remember correctly I also spoke to Metz here in Germany on the phone some time ago. As Schraubstock states, they explained to me that the maximum of 70 (105) mm is due to the bit width of the Pentax interface, i.e. there are no more bits to communicate bigger numbers. Also, I think they told me that there are no Pentax flashes that can zoom past those numbers. Please correct me if this is not the case.

Anguel