[Pentigor]

Hello all,

I just purchased a Tamron 17-50 lens and a Metz52 af-1 flash for my K-x. Now, when I go in P_TTL mode with both on the camera, the flash has no info about the zoom, it reads 12mm all the time.

With a Pentax lens it works fine. Is there a work around? Is there something I don't know?

Thanks for any advice,

Igor

[tabl10s]

What happens if you put the flash in Auto?

[Pentigor]

What happens if you put the flash in Auto?

Thanks for your reply.
After reading the manual more thorougly I found out that this flash is more advanced then I thought. If you pull out the diffuser he knows and thinks you want to make a wide angle shot , so it stays in 12mm.

Now it reads 35mm when the Tamron is at 24mm, but I'll complete the reading of the manual before asking any more beginners questions,

Sorry all,

Igor

[sharepointalex]

Hi Igor,

Have you played around with this combination any more? I think you'll find the flash still doesn't pickup the zoom of the Tamron lens. I also have the 17-50 with the same flash and it doesn't pick up when this lens is zoomed to 70mm. It seems it's a limitation of this particular lens that it doesn't send the info to the flash.

This is very strange though as it has all the electrical connections and the camera knows exactly what the lens is doing so it doesn't make sense to me?

Can anyone shed any light on this?

Cheers

Alex

[RKKS08]

@Pentigor
Reading 35mm when the zoom is set to 24mm can be correct, have another look at the manual.
The flash just may show the flash zoom setting adapted for a 24mm lens on APS-C.

The optimized flash zoom setting (angle covered by the flash) for a 24mm lens on APS-C is the same as for a 35mm lens on FF.

@sharepointalex
See my remark above. 70mm on APS-C needs the same flash angle as 105mm on FF.
105mm may exceed the settable tele range of the flash; it then should use the maximum (tele) setting possible.
This does not effect functionality. You just lose a small portion of the theoretical guide number, as the flash will cover an area a bit wider than you would need for 70mm on APS-C.

EDIT
Just checked it with two of my older Metz flashes (40MZ and 32MZ) and my K200D with the WR kit 18-55.
Both flashes automatically compensate for the different angle of view of APS-C compared with FF, as I said before.

EDIT 2
I made an additional check and put a full frame zoom at 24mm on my Pentax MZ5n with the Metz 40MZ, and the flash corrrectly shows 24mm.
Then I used the same combination at 24mm on my K200D, and the flash shows 35mm.

So, either the body sends information about the angle of view instead focal length, or it sends focal length and sensor size (or compensation factor), and these flashes do the calculation. They always show the focal length of a lens on FF which would offer the same angle of view. And that's exactly the information which should be used for the flash motor zoom.

[Pentigor]

Hi Igor,

Have you played around with this combination any more? I think you'll find the flash still doesn't pickup the zoom of the Tamron lens. I also have the 17-50 with the same flash and it doesn't pick up when this lens is zoomed to 70mm. It seems it's a limitation of this particular lens that it doesn't send the info to the flash.
Alex

Hi Alex,
when I asked about this I didn't read the manual yet, after reading the manual I realised that nothing was wrong with the lens nor the flash. ( well, in my case) If you tilt the flash vertically or you use the difuser then the flash goes for full power and doesn't care anymore about the settings of the lens. When I encountered this problem I had the difuser out...
Most of the time I read the manual when I buy something but that time I didn't...


I hope your problem is as simple as mine...


shoot away!


Igor

[Pentigor]

Rehi Alex,


I have to check about the focus distance, I don't remember, I'.

[Pentigor]

I'll check it tomorow