Focal length

User1593833104 said:

What does DP mean when they lis a focal length of 3.7, for inlstance, on a 24-2000 mm lens in the review of the Nikon 950?

Click to expand...

I don't know where you found this 3.7 number.

For the P950, the actual FL of the zoom is 4.3 -357 mm

But if you take the sensor size into account, you can calculate an "equivalent" FL, wich is, for the P950 24-2000 mm expressed in "full frame" (24mm x 36mm) terms.

That means that to have the same reach with a full frame (24mm x 36mm) camera, you'd need a 24-2000 zoom.

This is also an interesting issue with regard to photo organizers and editors like Lightroom, Photoshop, Cyberlink Photo Director, ACDSee, Gimp and others.

Some (not all) of those organizers and editors include both the relatively useless (in my opinion) "basic" focal length (mm), and some will also include the "35mm equivalent". I assume the equivalence is calculated in the app based on the known sensor size in the app's database. But maybe it's a calculated field in the camera's EXIF file - I'm not sure.

I do know that I have not yet discovered a way for Cyberlink Photo Director to display that value. But cheaper or free software does. Go figure.

Even the long-defunct Picasa provides that focal length equivalence in that program.