Here's a brief look at the Sony 135mm F/1.8 Carl Zeiss Sonnar lens.  Scroll down for the review. Lens SAL-135F18Z  Sony 135mm F/1.8 Box contents Front and rear caps, carrying pouch, hood and a users manual. Cost $1798 retail Build quality Very good Additional information New Carl Zeiss design for Sony. Specifications below   Optical configuration 11 elements in 8 groups Angle of view 18° full frame, 12° APS-C. Aperture 9 blades, circular Full frame and APS-C Yes, made for full frame.   APS-C equivalent, 202.5mm Depth of field and focus scales? Yes and yes Minimum focus, image plane to subject 28.3"  (720mm) Minimum focus, end of lens barrel to subject 21.5"  (546mm) Hard stop at infinity focus? No Length changes when focusing? No Focus ring turns in AF? No Filter size 77mm Filter ring rotates? No Distance encoder? Yes Max magnification 0.25x Min. F/stop F/22 Sony teleconverter compatible? No Dimensions W x L (my measurements) 3.46" x 4.53"   88mm x 115mm  Maximum  extended length (my measurements) 4.53"  (115mm)                                                       Weight bare (my scale) 35oz  (992g)  36.3oz (1029g) with caps, hood=5.7oz (162g) Requisite product shots. Mounted on Sony A700. Box contents with no box Side shot Front element Backside Sony X-ray view and MTF chart All testing done with the Sony A700, and Sony A900.  For full frame results, go to the bottom of the page.   For a better understanding of the terms and methods used for this review, go here.                      The Sony 135mm F/1.8 Carl Zeiss sonnar (made in Japan) lens is fast, expensive, and very heavy for its size.  It's aimed at advanced amateurs and professional photographers who shoot primarily in available light, hand-held conditions.  It would also make a good portrait lens which would help justify the cost.  This is an all new Carl Zeiss design, and not a re-badged Minolta.  Sony claims the use of two "ED" glass elements in the construction of the lens.  Box contents also include a metal hood, and a black vinyl-type carrying pouch.    Build quality is very good.  Fit and finish are indicative of other Carl Zeiss Sony lenses.  It has a satin (almost sparkly) black finish that matches the A900 better than the A700.  The lens has a focus distance window with ft and m in different colors along with DOF hash marks at F/22.  It also sports a focus hold button, which can be changed to DOF preview on certain Sony cameras.  My copy has a loose filter ring, but it has seen heavy use, and is still under warranty.   Focusing.  This lens has a long focus throw, but is fairly speedy, to about average from close-in to infinity using AF.  It's about the quietest screw-focus lens in the Sony lineup, but SSM would be welcome.  It focuses internally, so it doesn't extend out like the Carl Zeiss 85mm F/1.4, which focuses by extending the front. There's a little slop on the focus ring if you wiggle it in either manual or auto focus, that's no big deal though.  Manually, the focus ring is dampened a bit too much for my taste, but I don't use manual focus much anyways.  When going through the entire focus range, you'll need to twist your wrist about 120°, or 1/3 of a turn.  The focus ring doesn't turn in auto-focus mode.   The lens is multi-coated and resists flare and ghosting with average results, and similar to other primes in this range.  It comes with a metal hood with a ring of rubber around the end, and some fancy felt type lining inside.  It uses a ring of plastic to mount to the lens, and has no dot to show where to start the connection for mounting.  Don't lose the hood, or it'll cost you $150 to replace--and labeled by me as a Sony massive rip-off.     Filter size is 77mm.  Sharing this size in the Sony lineup are the 11-18mm, 70-200mm F/2.8, CZ 24-70mm F/2.8, 16-35mm F/2.8, and the 70-400mm G.   Normal filters, cause no additional vignetting on APS-C systems, but adds minor additional vignetting for full frame cameras at the widest apertures.   Coma None.    Color looks the same as other Sony lenses.    Bokeh is very smooth, even stopped down, but looks best wide open in my opinion.     Color fringing.   There is virtually no axial color fringing wide open, and very light lateral color fringing which occurs along the sides.  Check out the crops farther down to see what I'm talking about.  Overall, very good control and much better than the similar Sony 85mm F/1.4 CZ.   Random shots below.   Veiling glare and ghosts, F/5.6 Pesky green blob, F/5.6 Bokeh, F/1.8 Bokeh, F/2.2 Bokeh, F/2.8 Bokeh, F/4   The top left shot shows some average veiling glare and ghosts, use the hood and try to keep the sun out of the image.  The right shot shows the sun at an angle, with the camera held in the vertical position.  You can pick out a bright green blob.  With the sun centered, there isn't much of a problem.  Try to avoid images with the sun in the shot.  If you block the sun with your hand or hood when it's outside the image, there aren't any problems like you see above.  This lens is just barely average for controlling flare and ghosting.       The bottom crops show bokeh.  Out of focus highlights look very smooth wide open, and retain an even, circular look near F/4.  When out of focus highlights are in front of the subject, the bokeh isn't so good.   Distortion below.   Very light pincushion distortion.   Distortion is nearly non-existent.  If you like examining your pictures with a grid overlay, you'll see a very small amount of pincushion.  This lens shows the minor pincushion distortion at all focusing distances, unlike the Sony 85mm F/1.4, which changes distortion (pincushion to barrel) as the focusing distance changes.   Light fall-off.   F/1.8 F/2.2 Light fall-off or corner darkening is mild at F/1.8.  It blends well into the center of the image so it doesn't show in real life.  By F/2.2, it's gone     I wonder how sharp the corners are?            F/1.8           F/2.2          F/2.8           F/4          F/5.6           F/5.6, from center of image   These crops are from the extreme bottom right corner, and focused at infinity.  Things look good here at F/1.8, and real good past F/2.8.  In real shots, you'd be pleased as punch with the F/1.8 corners.  F/5.6 seems to be the maximum sharp aperture in the corners, so there's no need to stop down past that.  I threw in a center crop at F/5.6 to show you the difference between that shot and the F/5.6 corner shot.  I see no difference between the two crops.  Also note the nearly imperceptible lateral color fringing, which is far less than what shows up on the Sony 85mm F/1.4 CZ.     How sharp are the centers if the images are enlarged to a staggering size?            F/1.8           F/2.2          F/2.8           F/4          F/5.6           F/8          F/11           F/16 Center sample results.    Looking at the crops above, F/1.8 shows a little soft when compared to F/2.2, though F/1.8 is still plenty sharp for normal picture taking and enlargements.  The leaf-less twig at the right shows the most difference.  There's a tiny bit of veiling haze at F/1.8 visible along the top of the white wall at the bottom, but you really have to look for it, and at 100% on your screen.  Maximum sharpness seems to be in the area of F/4 to F/8, generally, only noticeable when taking pictures of test charts. This lens has a wide sharpness range between F/2.8-11.  There's no gain in sharpness by stopping down past F/5.6, though F/8-11 still looks good, but F/16 softens due to diffraction. The above crops were taken at dead center and focused at infinity.   Close focus sample.   Below, click to check out the close focus shot, a 100% cropped portion (307kb) of the full image.  The sample shot was taken with the Sony A 700 12.2mp camera.  The subject is a standard US stamp, 1"x 3/4" or 25.4mm x 19mm.  Also, note the macro shot was taken as close to the subject as focusing allowed; In this case, 21.5" or 546mm, measured from the front of the lens barrel to the subject.   Click for larger image, F/8, This maximum magnification shot is sharp, and has a good reproduction size of 0.25x.  There is little change in sharpness between F/4-11, but F/8 seemed the absolute sharpest at close focus, so use that aperture for test charts.     Full frame results using the Sony A900 below.   Check out the differences when using a film or full frame camera below.  I'm only pointing out the noticeable issues as compared to the APS-C bodies, so if I don't show it here, the results are not significantly different enough to warrant posting an additional set of images in this section.   Light fall-off             F/1.8           F/2.2          F/2.8           F/4   Light fall-off on a full frame camera is a little more noticeable as opposed to the APS-C crops shown earlier, but only at F/1.8, where it looks moderate.  It's mild at F/2.2, then nothing by F/2.8   Full image from A900 below.     The moderately dark corners are noticeable here, but it doesn't detract from the pretty orange, which is nearly overhead.  This shot was taken at F/1.8, 1/5000sec ISO 100!!  As always, don't shoot normal daylight scenes at F/1.8 unless you're looking for a super slim DOF.   Corner samples next.            F/1.8           F/2.2          F/2.8           F/4          F/5.6           F/5.6 from center of image   The corner performance is similar to the APS-C crops, which is good.  There isn't much difference in sharpness as you stop down, and they look nearly the same, except for light fall-off at F/1.8-2.2.  In the last row I show the difference between the corner shot at F/5.6, and the center shot at F/5.6.  I see virtually no difference as compared to the centers, super good full frame performance.  I see a very small amount of color fringing along the wall towards the bottom of the cropped image at F/4-5.6.  It doesn't show at larger apertures because of the darker corners.  These crops come from the extreme lower right corner.  Focused at infinity.   Distortion.   Mild pincushion distortion on A900   The distortion amount on a full frame system is about the same as the APS-C shot, showing a small amount of pincushion distortion.   Coma results with full frame  The Sony 135mm lens has no coma, even at F/1.8.   Comparison crops between the Sony CZ 135mm F/1.8 lens and the Sony 70-200mm F/2.8 G below.   Sony CZ 135mm @F/1.8 Sony 70-200mm @F/2.8 Sony CZ 135mm @F/2.8 Sony 70-200mm @F/2.8 Sony CZ 135mm @F/5.6 Sony 70-200mm @F/5.6 The Sony CZ 135mm does a great job (as expected) when directly compared to the Sony 70-200mm G zoom, set at 135mm.  The top row shows the 135mm at F/1.8, and it looks about the same as the zoom does at F/2.8.  The second row shows both lenses at F/2.8, and the 135mm is slightly sharper.  The bottom row shows the two at F/5.6, and at this point, they look about the same, which is no surprise.  All shots focused at infinity.       My final thoughts.    The Sony 135mm F/1.8 Carl Zeiss Sonnar is an expensive and fast telephoto lens.  It has a superb build quality, and feels very nice in the hand.  It would've been nice to have SSM focusing, though accuracy and speed are good, and it's fairly quiet as compared to the usual screw drive focusing system from Sony.  This lens is marketed at people wanting a medium telephoto lens for available light, hand-held use.  Portraiture work would be another legitimate use, justifying the cost.   As you saw in the center crops, the lens is darn sharp, with a (near) lack of spherical aberration, or haze, even at F/1.8.  Light fall-off is moderate using a full frame camera, though it diminishes greatly one stop down.  There's no coma, and the corners are almost as sharp as the centers.  Flare and ghosting seems average to just a little strong at times, but only when the sun is in the image. This lens performs about the same using APS-C or full frame coverage, very good news.   I really like this lens, and I'd greatly prefer it to the Sony 85mm F/1.4 CZ, generally due to the much better control of color fringing, and (in my opinion) a better focal range.  This is a solid lens all the way around, and if you have the cash, buy it, it's one of the very best Sony has to offer.