Calculate focal range of a lens

[Absynthe]

Hi everybody.

I try to do something but this is not a thing for pixelpost, in spite of that, I thought you could maybe help me.

I have done a website in order to display exif of pictures hosted on internet.

Now I would like to calculte focal range of the lens used to take a picture. I know it can be done, flickr does it, but I don't know how to do it.

This is a exemple of the data I can use to calculate it.

I will be extremely grateful if you can help me.

Kind regards.

I moved this to the Lounge as it no topic for bugs / hacks / development of Pixelpost

[Absynthe]

After more research it seems that it can not be calculate but it's contained in the exif data.

The thing is I do not arrive to extract it

[blinking8s+]

yes, it is from the exif information.

[GeoS+]

First array has got:

[FocalLength] => 39/1

and I would treat it as 39/1 mm = 39 mm and from image EXIF I know Im right (Irfan View said it to me :P ).