Mini Review of Panasonic LUMIX G Leica DG Summilux 15mm f/1.7 ASPH

f/2.5
All photos taken with the OM-D E-M5 Mk II with the
Panasonic LUMIX G Leica DG Summilux 15mm f/1.7 ASPH

I've been looking for a wide-normal lens to complement my Olympus 12mm, 45mm, and 75mm prime collection.  I didn't want to spend too much money since the 30-70mm equivalent range is generally not all that appealing to me, or, more precisely, I am rather challenged to make compelling images with perspectives corresponding to those focal lengths.  I tend to be mainly a short to long tele user, but will also make a good effort to use wide angle (mainly ultra-wide-angle lenses) in the 14-28mm range.

f/1.7

I found a great deal on an Olympus dedicated speedlight (used), and the owner was also selling the pretty impressive Panasonic 20mm f/1.7 (~pancake) lens, which I tried and found to be technically excellent, but I took a pass as 40mm equivalent was unappealing.  I was also looking at f/.95 17.5 and 25mm exotics, but realized that I would be less likely to carry them due to size/weight and because they mostly aren't truly sharp wide open.

f/1.7

A used Panasonic LUMIX G "Leica" DG Summilux 15mm f/1.7 ASPH came available, and after checking reviews, I decided to contact the seller and take a look.  The handling and built quality were both better than they appeared from pictures and even from reviews.  I decided to take a chance with the semi-wide 30mm equivalent focal length (almost the 28mm that I'm used to on Nikon full frame).  I'm glad I did!

f/5
There is zero CA SooC even in the areas of harsh contrast here.
I was blown away when I zoomed to 400%.

The reviews suggested that the IQ was excellent.  In fact, Kai on digitalrevtv said that the lens had no chromatic aberration!  Yeah, right!  Well, I was stunned to discover that in harsh light conditions (e.g., leaves against sky, this is the first lens that I have ever used that seems to display almost zero detectable CA -- not just sub-pixel level, but almost completely undetectable even at 400% magnification.

f/1.7
Close focus is excellent (down to about 1:10 magnification, which is pretty good with a small m43 sensor).  This lens is great for casual closeup work and things like food images when you don't want to carry around a special lens for this purpose.

f/1.7
This is a great nighttime walk-around lens.  Even wide open, there is plenty of DoF for a relatively wide-angle (30mm equivalent) lens, and DoF is inherently wider with m43.  Creatively, f/1.7 is also a pretty wide aperture when you are working at very short subject distances, so you can still get nice subject separation from the background.

f/3.2
This was intended specifically as a test for flare and internal reflection.  In person, those floodlights were blinding, yet the lens handled this ridiculous scene beautifully.  Nothing was done in post to mitigate bad optical problems.

f/2.8
Bokeh for a wide angle is nice and undistracting.

Much more importantly, the micro-contrast (or whatever you want to call it) is stunning.  Processing files is a joy, even when pushed hard and especially in B&W conversions.  This lens has quickly become one of my main lenses to carry (generally, I try to pick no more than two to carry around, and lately I've been going with the 15/1.7 and Olympus 75/1.8 or Olympus 45/1.8 combination.  The lens really does live up to its (fake) Leica designation, but this is the closest that I'm going to get to real Leica glass.

f/6.3

f/3.5
Sharp at all apertures, and critically sharp everywhere by f/2.8.

Technically, the lens has superb manual AF handling with just the right feel.  The lens has an aperture control ring, but it is non-functional on Olympus bodies like my E-M5 II, which is actually a blessing -- the ring does not lock firmly into its "A" automatic setting, so it would be too easy to dislodge from aperture priority mode on Panasonic bodies.  I love the unusually-shaped metal hood (included), which never leaves the body.  But, I especially love the brilliant rubber lens cap that fits the lens hood!  Other lens makers should steal this design.

f/5.6

After pushing myself, I am enjoying the 30mm equivalent field of view, which is greatly preferable to me vs. the conventional full frame 35mm wide standard lens.

f/7.1
Sharp and pleasing micro-contrast.  The images are very easy to process with little additional sharpening or structure needed.  They offer a nice 3D realism, which works well with the 30mm effective perspective.

Overall, I highly recommend this lens, especially for the price.  It is a great value and performs brilliant on my Olympus E-M5 II body, including the automatic manual focus override (with settable automatically-invoked focus peaking).  I use this lens with MF override much more than any of my other lenses.

f/2.5
A very dark scene, which the E-M5 II handles well for a compact package (ISO 3200, 1/40th second)

f/7.1

f/2.8