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Panasonic Lumix G 20mm F1.7 ASPH Review

September 2009 | By Andy Westlake
Buy on From $510.00

The Panasonic Lumix G 20mm F1.7 ASPH was announced earlier this month as the natural companion to the compact Lumix DMC-GF1 Micro Four Thirds camera, alongside a Leica-branded 45mm F2.8 Macro (the camera is also available with a 14-45mm kit zoom). The H-H020, as Panasonic curiously likes to call it, is a large maximum aperture 'normal' prime in a very compact 'pancake'-type body. It gathers a stop and a half more light than Olympus's M. Zuiko Digital 17mm F2.8 pancake (which is only marginally smaller), and is therefore sure to be of interest to E-P1 owners who want to shoot in low light using a lens well-matched to that camera's size.

The F1.7 aperture is impressively fast for a pancake lens, and to achieve this Panasonic has managed to squeeze a 7 element, 5 group design into that compact barrel, including two aspheric elements to help reduce distortion and chromatic aberration. There's a 7-bladed aperture system, using curved blades designed to give an attractive, smooth effect to out of focus highlights. Rounding off the spec is a minimum focus distance of just 20cm. However it's worth noting, that unlike many of Pansonic's lenses, this doesn't have built-in optical image stabilisation.

The 40mm-equivalent angle of view may initially appear unusual, but this is in fact a 'perfect normal' lens, with a focal length equal to the sensor diagonal. This means that it renders images in a very neutral fashion, free of the 'perspective distortion' associated with wideangle or telephoto lenses. While this focal length was historically less common than the ubiquitous 50mm prime on 35mm cameras, it still occupied an honorable niche as the standard lens for a number of high-quality compacts, including the Leica / Minolta CL. Indeed with that 45mm F2.8 macro and an upcoming 14mm F2.8, Panasonic appears to be positioning the GF1 as the spiritual successor to the likes of the CL and the Contax G series - as a high quality portable camera system for serious photographers. Let's see if the pancake's image quality can live up to such lofty ambitions.

Click here for our review of the Panasonic DMC-GF1

Headline features

  • 20mm 'perfect normal' fixed focal length; fast F1.7 maximum aperture
  • Ultra-thin, lightweight design 
  • 'Focus by wire' manual focus system
  • Micro Four Thirds mount for Panasonic Lumix G and Olympus Pen systems

Angle of view

The picture below illustrates the lens's angle of view (taken from our standard position):

20mm (40mm equivalent)

Panasonic Lumix G 20mm F1.7 ASPH (H-H020) specifications

Price • US: $400
• UK: £300
Manufacturer's product code H-H020
Date introduced September 2009
Maximum format size Micro Four Thirds
Focal length 20mm
35mm equivalent focal length 40mm
Diagonal angle of view 57°
Maximum aperture F1.7
Minimum aperture F16
Lens Construction • 7 elements/ 5 groups
• 2 Aspherical elements
Number of diaphragm blades 7, rounded
Minimum focus 0.2m / 0.66ft
Maximum magnification Approx 0.13x
AF motor type DC Micro motor
Focus method Unit focus
Image stabilization No
Filter thread • 46mm
• Does not rotate on focus
Supplied accessories* • Front and rear caps
• Lens case
Weight 100g (3.5 oz)
Dimensions 63mm diameter x 25.5mm length
(2.5 x 1.0 in)
Lens Mount Micro Four Thirds

* Supplied accessories may differ in each country or area

Foreword / notes

If you're new to digital photography you may wish to read some of our Digital Photography Glossary before diving into this article (it may help you understand some of the terms used).

Conclusion / recommendation / ratings are based on the opinion of the author, we recommend that you read the entire review before making any decision. Images which can be viewed at a larger size have a small magnifying glass icon in the bottom right corner of them, click to display a larger image in a new window.

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Dpreview use calibrated monitors at the PC normal gamma 2.2, this means that on our monitors we can make out the difference between all of the grayscale blocks below. We recommend to make the most of this review you should be able to see the difference (at least) between X,Y and Z and ideally also A, B and C.

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Total comments: 5

Has anyone experienced the banding with this lens
That some other review sites have reported


This is a fine lens. The colors will knock your eyes out.

Yes, AF isn't blazing, but it's fast enough for the type of photography I do. I've been shooting Manual lenses, so I might be sensitive to any lag, no matter how small.


no mention of AF performance....which is for me...decidedly lacklustre (at least on an OMD em-10).

Ive found this to especially in low light and backlit situations. If you have moving targets in these situations and this lens can be frustrating by missing focus on otherwise great shots.

Bill from Oregon

Am I correct in assuming that the Panasonic 20mm/F1.7 lens will fit on the Olympus E-M1 camera?



Total comments: 5