I am about to purchase the 70-180mm F2.8 zoomlens for my kit that already includes a Metz 40MZ3i, but have been told that, despite the fact that the zoomlens has the ROM capacity, the lens and camera do not "talk" to each other and therefore the focal length information (and perhaps the F stop and ASA as well??) are not conveyed. I usually use the "TTL" mode but how do I correct for the focal length, F-stop, and ASA?? Do I just plug all the numbers in each time and hope? Do I actually have to worry about the F-stop and ASA or is this information automatically transmitted leaving only the focal length to correct each time?? For a variety of reasons, I would like to avoid using the "A" or "M" modes. Thanks.....

-- Albert Knapp MD (albertknappmd@mac.com), March 17, 2002

Answers

Albert

It does depend on the body you are using. Presumably since you mention ROM you are using an R8, in which case the flash does receive information about focal length and aperture. At least I know it does with my ROM-equipped 28 and 80. The information appears in the LCD screens of both of my Metz guns, a 40 and a 50. I can't say for other lenses or zooms, but I was under the distinct impression that this was the whole point of ROM.

You do need to have the correct adapter for the hot shoe: 3501/2.

Suggest you try before you buy!

That said I think the whole thing is a bit of a waste of time. Nine times out of ten I use a Stofen diffuser or bounce my flash, in which case flash gun knowledge of the focal length of the lens becomes irrelevant.

Matt

-- (matt@pulzer.org), March 17, 2002.

Matt: Yes, I have an R8 and yes the F-stop, ASA, and focal length are transmitted without problems in all the other lenses of the R system. The question focuses on the peculiarities of the 70-180 zoomlens where the focal length information ( and ??the ASA and F-stop info) are not passed on to the R8 despite the ROM contact....

-- Albert Knapp MD (albertknappmd@mac.com), March 17, 2002.

Albert I suspect you know at least as much, if not more than me. A cursory glance in Leica's 'the System' catalogue reveals remarkably little about ROM. Seems to me that a call to Leica would be the best way to get an authorative answer if you cannot try one out.

Sorry not to have been more use!

Matt

-- (matt@pulzer.org), March 17, 2002.

Unless the R8 differs wildly from from other modern, TTL-equipped SLR's, the f/stop and ISO info are passed to the flash unit by the camera body. Of course the f/stop comes first from the lens, but it's processed by the camera (think about your exposure measurement). The focal length info comes via the lens. If the zoom doesn't pass along the focal length, it's no big deal, as manually zooming a Metz flash is easy. And as Matthew said, if you're using a diffuser (Omnibounce, etc.) -- and you should, the flash head setting is largely irrelevant. Set it wide and forget it.

-- Robert Schneider (rolopix@yahoo.com), March 17, 2002.

> despite the fact that the zoomlens has the ROM capacity,

> the lens and camera do not "talk" to each other and therefore

>the focal length information (and perhaps the F stop and ASA as well ??) are not conveyed.

The 70-180/2,8 ROM will lock the flash zoom head on 70mm, and the F stop is conveyed.

The ASA has nothing to do with the ROM.

-- Lucien (Lucien_vd@yahoo.fr), March 18, 2002.

Thank you all for your answers. I will keep the Flash in TTL and manually put in the correct focal length each time. I guess it is a small price to pay for such a marvelous lens!! Incidentally, I do use the omnibounce frequently and have always bracketed in the past: I don't think that I can simply ignore or minimize the focal length as I use 'chrome only and this is most unforgiving. Does anyone have experience with this issue (ie, ignore the focal length with 'chrome?)

-- Albert Knapp MD (albertknappmd@mac.com), March 18, 2002.