Which aspect ratio renders 12mm as 24mm?

Started Jul 17, 2017 | Discussions thread
James Pilcher Veteran Member • Posts: 9,448
Only 4:3 aspect ratio

When wondering about "24mm" I understand you mean the field of view (FOV) of a 24mm lens on a 35mm camera.

In m4/3, only the 4:3 aspect ratio will give you the same FOV as a 24mm lens on a 35mm FF camera. As soon as you start cropping a m4/3 image to 3:2 or 16:9, the FOV shrinks, despite having used that 12mm focal length. So, Picasa is reporting to you correctly about the cropped image being equivalent to 26mm in FF-speak.

I leave out the previous discussions of multi-aspect ratio implementations since no modern m4/3 camera does that.

Donald M Mackinnon wrote:

I shoot jpeg mostly and use Picasa for pp. When I have the 12-32mm lens mounted on any mft body and choose the 16.9 aspect ratio Picasa records the focal length as 12mm and the 35mm equivalent as 26mm not 24mm.

Until recently I stupidly thought this was simply an error in Picasa. However I discovered that this is not the case when I compared shots from a GX80 /12-32mm with an LX7.

Set to 16.9 Picasa not only shows the LX7 35mm equivalent length to be 24mm but when compared with the GX80/12-32 combo at 26mm the missing 2mm is very obvious.

So my question is which aspect ratio renders 12mm as 24mm ?

Hoping this makes sense, example below shows the extra 2mm in the second image taken with the LX7.

Jim Pilcher
Summit County, Colorado, USA
Life is good in the woods. All paths lead forward.

 James Pilcher's gear list:James Pilcher's gear list
Panasonic Leica Summilux DG 25mm F1.4 Olympus M.Zuiko Digital ED 12mm 1:2 Olympus M.Zuiko Digital ED 75mm F1.8 Fujifilm X70 Olympus PEN-F +9 more
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow