on the 16x it is easy to do the math and mark
the 35mm equivelant focal lengths since it has
the mm clearly marked on it.

How do you figure it out for the 6X ??

thanks

just answered my own question.

use the zoom increments in the view options
to show 0-99 zoom instead of the little zoom bar.

that gives you 100 increments of zoom...but the
range is 122.5 for the 24.5 to 147 (lens 35mm equivelant).

so.... add .225 to each zoom increment and Voila!
You have the 35mm markings.

example. 24.5 + (35 zoom x 1.225) = 67.38mm

Wont give you perfect 28,35,50,85 etc. markings, but will
be real close.

Thanks for sharing your calculations.

Your technique will be very useful.

I will post an excel "cheat" sheet when finished

Your formula could also be used with the 20x lens, or for any other lens.

Here is the rough table. you may want to double check
considering my poor math skills.

Thanks for the enlightenment! I'm (or was) bragging about the (incorrect) focal length of 17mm (equivelant for 35mm). Now I have to say 20 something...

Please double-check this. If you plot the actual fields of view for each zoom number, you should see that it is not a rectilinear progression. Z49 or Z50 most likely does not equal the mid-point of the zoom range. It's probably a bit more toward the telephoto end. The Z numbers should fall along a curvilinear path. Pete Bauer did a similar experiment for the 20x lens and those were the results he wound up with, if I remember correctly. If somebody can verify whether or not Z49 or Z50 on the 6x lens actually delivers a field of view equivalent to an 85mm lens, that would be most helpful. My guess is that it does not... somebody please prove me right or wrong. Thanks in advance, and thanks a bunch Will for doing this!

Hi Will,
This is just a thought.
I believe you can get the exact focal lenght in millimeters of the 6xzoom if you zoom it forexample to z 50 and take a photo with XL H1 to sd card. Then you just look at the photo's info.
I hope this helps.

So much for an easy solution. :(

I guess the photo trick will work. I'll have to get a bigger sd card and take
100 photos. Should be easy. Just open them all in Adobe Bridge
and copy and paste the EXIF data.

As Chris said, I've done this for the XH A1 and the XL H1 stock 20X lens, and the Z Number response is not quite linear. I have a 6X on back-order and will conduct tests on it as soon as I can get it. Presumably it'll show the same curvilinear response. I'm not able to post the results from the other lenses at the moment, but will do so as soon as I can.

Just captured a few...
three low zoom numbers show the same focal length (4.3MM)
in the exif data so looks like the curve starts out pretty flat!

Dear Will,

There is a chance it will always report the same info.

May I recommend that you try a mid-zoom and far zoom on the lens.

This will show if the results will ever change.

Will, check position Z30. That should be roughly the halfway point of the lens (about 85mm or so).

it is definitely changing.

Here are links to threads with the Zoom Number vs 35mm Equiv for:

XL H1 20X lens: http://www.dvinfo.net/conf/showthread.php?t=81686
XH A1: http://www.dvinfo.net/conf/showthread.php?t=81683

The 6X will probably be similar, but we'll test it and be sure.