Full review of the Panasonic X Vario 12-35mm F/2.8     Box and contents     The Olympus E-M5 was used for this review.    For a better understanding of terms and methods used in this review, go here.   The usual center, mid-section and corner crops are located at the very bottom of the page.     Introduction.   The Panasonic X Vario 12-35mm F/2.8 (Made in Japan) is a compact and light-weight lens, especially when you consider the constant F/2.8 aperture. This is a brand new lens from Panasonic for the micro 4/3 system, first available in 2012.  Features include 'Nano surface coating' which is just a fancy word for multi-coatings on some glass surfaces, 'HD' for high definition video, and 'power OIS' which is optical stabilization.  Olympus camera owners with 5 axis stabilization may wish to turn off the power OIS as the Olympus in body stabilization seems to work better.  The specs for this lens says there are four aspherical elements used in its construction, plus a single dash of 'UED' (ultra extra low dispersion) and UHR' (ultra high refractive index) glass.  Also note the stylized 'X' which apparently is used to help identify Panasonic's 'better' lenses---alrighty. The Panasonic 12-35mm is splash and dust proof according to the manual.   For use on micro 4/3 mirrorless cameras only.   Fit and finish are quite good.  The lens is clad in high quality plastic, with a single plastic extension tube along with a metal mount.  Focus and zoom rings have a ribbed design, but the focus ring is not rubberized for some reason, probably because they don't expect you to use it.    The zoom action is smooth and damped properly in my opinion, (one finger zooming is possible) and holds its position well, so there is no zoom creep during normal use; which is good as there is no zoom lock.  Focal length index marks come at 12mm, 14mm, 18mm, 25mm, and 35mm.  The EXIF data matches those lengths.   In the box: the lens, front and rear caps, a petal type plastic hood, a carrying bag and owner's manual.    Focusing.  This lens auto-focuses almost silently.  Focusing seems quite accurate at all focal lengths, and reasonable quick in good light.  The front filter ring doesn't turn when focusing, so your polarizers and grads will work great.           Requisite product shots. Front Fully extended Back Sony Carl Zeiss 16-80mm on left, Panasonic 12-35mm on right Panasonic MTF graph Panasonic x-ray view       General information and specifications.   Lens Panasonic Lumix X Vario 12-35mm F/2.8   Model number H-HS12035 Box contents Front and rear caps, carrying bag, and a user's manual.  Cost $1144 retail as of 1/2013. Build quality Good to very good. Additional information Marketing fluff; Nano surface coating, and 'HD' video support. Specifications   Optical configuration 14 elements in 9 groups Angle of view 84°-34°  Aperture 7 blades, curved Formats Micro 4/3 only.  With a crop factor of 2x the coverage equals 24-70mm in 135 film format. Depth of field and focus scales? Nothing. Min. focus distance, image plane to subject @ max reproduction ratio About 9.5"  (241mm) Min. focus distance, end of lens barrel to subject @ max. reproduction ratio About 4.75"  (121mm) Hard stop at infinity focus? No Length changes when focusing? No Focus ring turns in AF? No Filter size 58mm Filter ring rotates? No Distance encoder? Yes   Max magnification 0.17x, or 0.34x (1:2.9) with crop factor. Min. F/stop F/22 Factory teleconverter compatible? N/A Length changes when zooming? Yes Dimensions WxL  (my measurements) 2.6" x 2.9"   67mm x 74mm.  Widest at zoom ring. Maximum  extended length (my measurements) 3.8"  (96.5mm)  longest at 35mm.                                      Weight bare (my scale) 10.6oz  (301g)      Optical qualities summary.   Lens flare/ghosting.  Some large but dull ghosts appear when super bright light sources are close to, or inside the frame.  I see mostly magenta smudges with green arcs and arrows, samples below. Color fringing (CA).  Very good control at the long end, average control at the short end. You'll see some magenta and cyan along high contrast edges along the sides of the image, see sample below.        Bokeh.  'busy' at all focal lengths and longer focusing distances when the lens is at F/2.8, getting slightly smoother as you stop down.   Color.   Neutral.    Close up filter.  N/A.      Coma.  None that matters.   Regular filters cause no additional light fall-off.   Filter size is 58mm.  This small filter size is common for larger 4/3 lenses.   Distortion.  very low when shooting jpegs.  RAW shooters will see heavy barrel distortion at 12mm, but it corrects pretty well in post.  Check out the cropped samples below.   12mm, corrected Jpeg, slight barrel distortion 12mm, uncorrected from RAW file 18mm, corrected Jpeg, straight. 18mm, uncorrected from RAW file. 35mm, corrected Jpeg, moderate pincushion 35mm, uncorrected from RAW file, no difference.   Distortion is very strong in uncorrected images like RAW at 12mm, but straightens out quickly as you zoom out.  There is very little in-camera distortion correction going on past 20mm.  Just for clarity, the 'corrected' version is what comes out of the camera when saving images as jpegs.  The RAW distortion at 12mm is correctable in most image editing programs because of the relatively simple curve, although a slight 'bump' in the middle remains.     Light fall-off.              12mm F/2.8              12mm F/4            35mm F/2.8              35mm F/4   Light fall-off is not much of an issue at any focal length.  Oddly, Uncorrected files show almost the same signature as the corrected files.  At F/4, there is no issue with light fall off, or at F/2.8 if you stay slightly away from the ends of the zoom.  No additional light fall-off problems with the use of regular filters.     Flare and ghosting.              12mm F/5.6              21mm F/5.6   The Panasonic 12-35mm lens produces a typical amount of ghosting, with magenta and green noticeable when the sun is close to, or inside the frame.  I did on a few occasions see a huge magenta blob in the frame when the sun was just outside the frame at the middle top; odd!  Contrast is decent to good at all focal lengths, even when the sun is inside the image.     Bokeh samples.              12mm F/2.8              12mm F/4            35mm F/2.8              35mm F/4   Bokeh looks a little 'busy' at all focal lengths when the lens is wide open. I see outlines and center dots, especially noticeable at large viewing sizes.  Stopping down to F/4 or beyond smooths out the blur and makes it look better, but depth of field is huge at 12mm, so you're only likely to get noticeable highlight blur at longer focal lengths.  Bokeh is the character of out of focus highlights, and not simply how far out of focus the background is.     Bokeh at close focusing distances     Bokeh looks very smooth when you focus on something close and your background is close too, all lenses will show this to some extent.       Color fringing.     Lateral color fringing (which occurs along the sides of the image and does not go away by stopping down the aperture) is noticeable at the short end of the lens, but is not noticeable at all on the long end.  I see moderate amounts of magenta along the cactus (weird how it disappears in small sections), and some cyan (light blue) along the mountain ridge-line.  The sample was taken from the middle of the right side of the image, at the last 700 pixels.  Panasonic camera owners will not need to worry about color fringing as the camera will eliminate it when shooting jpegs.  As of this review Olympus has not yet incorporated this into its 4/3 products, that will change soon.       Let's check out the close focus capabilities of this lens. Check out the 100% cropped portion of the full image.  The sample shot was taken with the Olympus E-5M 16mp camera, so don't compare it to others that were taken with 12 or 24mp cameras.  The subject is a standard US stamp, 0.87"x 1.0" or 22mm x 25mm.  Also, note the shot was taken as close to the subject as focusing allowed; in this case a very short 4.75" (121mm), measured from the front of the lens barrel to the subject.     This lens has a good reproduction size of 0.34x, (1:2.9) in 135 film format, and it produced a sharp close focus shot at F/8.  As a side note; the "1996" on the bottom left of the stamp measures a mere 1mm wide.   As close as you can get. F/8. click for larger image     Conclusion.   The Panasonic X Vario 12-35mm F/2.8 is a medium zoom lens with the same coverage as a full frame 24-70mm lens, however being that it's a micro 4/3 lens, it's much smaller, lighter, and less expensive than a full frame lens.  Overall, the Panasonic turned in a very good review, so let's look at the good points, the not-so-good points, and the inevitable version II wish list.   As I've stated several times, this lens is quite small and light-weight for a mid-range F/2.8 zoom, it's not really that much larger than a standard kit lens for an APS-C camera, and is actually smaller than a full frame kit lens!  The lens feels very solid in the hand, and is balanced reasonable well on larger micro 4/3 cameras, like the Olympus E-M5 used for this review.   Optically, the lens is best at the short end, from about 12mm to 15mm, where the centers and mid-sections are extremely sharp, even wide open, but do respond to stopping down to F/4, where the sides show increased resolution.  The rest of the zoom range is equally sharp in the centers and mid-sections, but the sides do suffer from resolution and contrast, especially as you near 35mm.   Color fringing is not problematic once you leave the wide end, and even so, it's correctable in most image editing software if you shoot in RAW.  Ghosting control is average with the usual green and magenta blobs and arcs, and seems to be about the same at all focal lengths.  Flare control is average to good, with the contrast holding up well at all focal lengths even with the sun inside the image.   Distortion is not an issue at all when shooting in jpegs, but 12mm barrel distortion is strong when saving as RAW, but again, it's a relatively easy fix in post.     Close focus quality is very good as long as you focus correctly, and stop down to F/8 for flat copy work such as my stamp shot.   My wish list for version II would be to improve the sides of the image at longer focal lengths, the current quality is slightly disappointing.  Adding a couple of focus hold buttons would be nice too.  Also, the (early 2013) retail price is a little high for such a small lens, however, the quality at the short end is stellar, and that alone may be worth the price.   Finally, don't overlook the low-light (hand held street shooting) capabilities of the Panasonic 12-35mm F/2.8 lens for video or still work, it's almost perfect as the quality is very high at F/2.8-4 through most of the frame, and that allows you to keep the ISOs down for cleaner shots.

Sample crops from the centers, mid-sections and corners.   12mm.               Center           Mid-section              Corner F/2.8 F/4 F/5.6 F/8 F/11   20mm.               Center           Mid-section              Corner F/2.8 F/4 F/5.6 F/8 F/11   35mm.               Center           Mid-section              Corner F/2.8 F/4 F/5.6 F/8 F/11   At the short end, the entire frame is quite sharp at F/2.8, but the mid sections and corners get a little sharper at F/4, there is no more sharpness gain by stopping down the aperture---that's cool!  In the middle of the zoom range, (20mm) the centers and mid sections are sharp from F/2.8 to F/8, but the sides are a little soft, and don't seem to respond much by closing the aperture; however, this is still very good performance overall.  At the long end, (35mm) the centers and mid sections are very sharp wide open, with the sides a little mushy at F/2.8, with only marginal gains from stopping down the aperture.  Contrast is excellent in the centers and mid sections at all zoom lengths, but is lacking along the sides as you zoom out.  This lens is extremely impressive at the wide end, and very good as you zoom out, with the sides being the only issue keeping the lens from being a dream come true.  All focusing distances were at or near infinity using manual focus and focus bracketing.   That's it for the review, if you'd like to help out the site, please visit B&H Photo if you're thinking of purchasing the Panasonic 12-35mm F/2.8 micro 4/3 lens.