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Lens tests

We don't normally perform lens tests in digital SLR reviews, we have in the past for a few kit lenses in the past, certainly when the first sets of 'affordable' kit lenses appeared on the market. The DMC-L1 is fairly unique in that it is sold as a complete package including the pretty remarkable Leica designed 14-50 mm F2.8-F3.5 Image Stabilized lens which integrates with the camera and provides an aperture dial for quickly jumping out of Program exposure into Aperture priority. Because of the Four Thirds sensor size the focal length range of 14-50 mm provides an equivalent field of view of 28-100 mm on a 35 mm camera.


Resolution and sharpness

Below you will find a range of crops from a shots of our standard resolution chart. Each shot was taken at a different focal length and aperture combination. This should provide you with a good impression of how well the lens works from wide open to smallest aperture and at both full wide angle and full telephoto zoom.

Panasonic / Leica 14-50 mm F2.8-F3.5 OIS lens

Wide angle: 14 mm (28 mm equiv. FOV)

At full wide angle (28 mm equiv. FOV) the L1's kit lens delivers its optimum corner-to-corner sharpness at around F5.6 / F6.3, wide open the corners of the frame are clearly soft and at anything over F11 diffraction begins to affect sharpness, you can almost make out the disk' diffraction pattern at F22 which is best avoided.

F2.8 (wide open) F5.6 F11 F22 (smallest aperture)

Telephoto: 50 mm (100 mm equiv. FOV)

At full telephoto (and although not shown here but also from around 50 mm equiv. onwards) the lens performs just as well wide open as stopped down to its optimum F5.6 / F6.3, again beyond F11 diffraction begins to soften the image and you simply wouldn't want to use F22.

F3.5 (wide open) F5.6 F11 F22 (smallest aperture)

Macro Focus

As we would expect the optimum macro performance for the L1's kit lens was at full telephoto with a focus distance of about 29 cm (the specified minimum focus distance). Obviously this lens isn't optimized for macro use and we wouldn't call a frame coverage of 10 x 8 cm macro either. Luckily there are some Four Thirds macro lenses available (Olympus 35 & 50 mm and Sigma 105 & 150 mm) for those who need them.

Wide macro - 239 x 179 mm coverage
13 px/mm (333 px/in)
Distortion: High
Corner softness: Medium (with slight CA)
Equiv. FOV: 28 mm
Mid-zoom macro - 105 x 79 mm coverage
30 px/mm (753 pix/in)
Distortion: Low
Corner softness: Low (with virtually no CA)
Equiv. FOV: 100 mm

Barrel and Pincushion Distortion

The L1's kit lens produced just 1.0% barrel distortion at full wide angle, 28 mm equiv. FOV (14 mm actual), this is a very good performance considering the field of view coverage (we have seen 35 mm lenses with worse distortion). It's pretty unlikely that you would ever see this level of distortion in normal everyday shots unless you managed to align the top of the frame with a horizontal detail. At telephoto we could measure no distortion at all. Overall Kudos to Panasonic / Leica.

Wide angle - 1.0% Barrel distortion
Equiv. focal length: 28 mm
Telephoto - 0% Pincushion Distortion
Equiv. focal length: 100 mm

Purple Fringing (Chromatic Aberrations)

The L1's kit lens delivers very little chromatic aberrations even in the worst possible situation; high contrast scenes at full wide angle and maximum aperture. A very impressive performance.

28 mm equiv., F2.8 (maximum) 28 mm equiv., F2.8 (maximum)

Vignetting & Light Falloff

Testing


Measurement Areas
We aim the camera at a white wall (about 0.5 m away) which is evenly lit by two soft boxes (producing about 10 EV across the entire wall), the lens is manually focused to be about 1m out of focus (to avoid picking up texture detail from the wall). A sequence of shots are now taken at every aperture from maximum to F11 (beyond this there's only a very slow roll-off from the lens & camera combinations we tested), for zoom lenses at both wide angle and telephoto.

These images are then processed by our own analysis software which derives an average luminance (Lum) for the four corners of the frame (5% each) as well as the center (10%), the corners are averaged and the difference between this and the center of the frame is recorded. This value can then be plotted (see graphs below) as a representation of the approximate amount of falloff (as negative percentage).

Range of falloff

The chart below demonstrates the difference that these figures above can make, we took the blank wall luminance value of 75 (about 190,190,190 RGB) as our normal level. Remember that these patches are solid and the actual effect of shading is a softer gradual roll-off which would not necessarily be so obvious.

The images below were produced from our test shots, they have been deliberately 'posterized' to indicate different levels of falloff. Each band represents a 10% drop in luminance. At wide angle and maximum aperture (F2.8) there is some falloff (as we would expect) but it's unlikely you would be able to see this in normal everyday shots, go just one stop down for a marked change. At full telephoto we see a minimal amount of fall off at maximum aperture (F3.5), again nothing that would be noticeable in everyday shots. To see how this compares to a typical DSLR lens see this page of our Nikon D200 review.

 
14 mm (F2.8 max)
(28 mm equiv. FOV)
50 mm (F3.5 max)
(100 mm equiv. FOV)
Max
F4.0
F5.6
F8.0
F11
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