Panasonic Focal length from EXIF
Graham C
digital cameras.
Spec for both is: Optical 5k zoom, fl4.4 mm to 22 mm (35 mm film
camera equivalent: 25 mm to 125 mm) /F2.8 to F5.9
The DMC-FX37 when set to full wide angle reports 4.4mm = 25mm (35mm
format). Zooming in a notch reports 4.7mm = 27mm. This is what I
would expect
The DMX-FX500 however, on full wide, reports 4.4mm = 27mm (35mm
equivalent). Now 27mm is very different from 25mm which is what they
paid for.
Any ideas / comments. Does it matter?
GrahamC
Graham C
>The physical fl of both is 4.4mm that's what really matters and is
>what was paid for. The 35mm equiv, if just a matter of a mathematical
>conversion. It could also be a factor of what actual EXIF tag was
>looked at and also using what program, if not the same. Does the
>variation happen at the long end as well?
I've used both ThumbsPlus and ExifTool to get the data and both report
the same. Both cameras have the same size sensor, and both clearly
state on the front of the lens '25mm Wide'. One review stated that
the lens had been redesigned (from the FX35, not sure about the FX37).
I am going to contact Panasonic as it appears that this camera does
not meet its specification. My colleague paid (over the odds) for a
25 mm lens.
Graham
David J Taylor
Graham.
According to the specs, the sensor has a 4:3 aspect ratio, and is "1/2.33"
inches, which would mean a nominal image diagonal of 6.87mm. A 3:2 aspect
ratio 35mm frame has an image diagonal of 43.2mm, so on that basis the
lens has an equivalent focal length of 4.4 * (43.2 / 6.87) i.e. 27.7mm.
You need to know, though, whether it's the diagonal, the horizontal, or
the vertical FoV which is supposed to be equivalent, and of course this
calculation also depends on the description of the sensor as "1/2.33
inches" being correctly related to the actual active area.
Were it my camera, and were I concerned about it, I would make some
attempt to measure the FoV by photographing an object I could measure at a
known distance (and making that distance as large as possible).
Cheers,
David
boris spydar
"Graham C" <graha...@btopenworld.com> wrote in message
news:klc60515b11i4l475...@4ax.com...
Both models offer 3 different image ratios 4:3, 3:2, 16:9
Were both shots taken using the same the image ratio ?
As the equivalent focal length is presumably calculated
using the image area rather than the sensor area as
compared with 35mm.
boris
Graham C
>I
I think you're on the right track here Boris, as Panasonic have just
sent me a similar reply. Unfortunately one camera is just two miles
from me and the other is 200 miles away. The 'problem' camera was an
ex demo camera for which my friend had to pay full price (Take it or
leave it Madam. It's the only one we have). The camera was found to
have many of the defaults altered on inspection after purchase (e.g.
Exposure compensation set to +2).
Graham