Photo Jottings

Here’s a brief look at the Sony NEX 18-55mm F/3.5-5.6 zoom lens.  Scroll down for the main review.

Requisite product shots.

Front element

Backside mount

NEX 5 with 18-55mm lens and included hood

Fully drawn in

Fully extended

X-ray view and MTF chart

Only the Sony NEX 5 was used for this review.

For a better understanding of terms and methods used in this review, go here.

The zoom action is smooth and dampened properly in my opinion, and holds its position well, so there is no zoom creep.  Focal length index marks come at 18mm, 24mm, 28mm, 35mm, and 55mm, and the EXIF data matches those lengths.  As a side note; this lens shows EXIF data for every focal length possible, everything between 18-55mm!

In the box: Sony says it comes with front and rear caps, a hood, and an owner’s manual.

Focusing.  This lens auto-focuses quickly, mostly accurately—and without a peep.  It’s much smoother and quieter than the loud and obnoxious focusing Sony 18-55mm SAM lens.  The front filter ring doesn’t turn when focusing, so your polarizers and grads will work great.  Added later—focusing using multi-area has about a ten percent miss rate for some reason.  I’ve used spot and center (but not nearly as much as multi) without any problems.

Lens flare/ghosting.  Above average control for a telephoto zoom by today’s standards, and similar in performance to the 18-55mm SAM kit lens.

Color fringing (CA).  Below average control at the wide end where you’ll see plenty of red and cyan along the sides of the image, at all apertures.  The long end has excellent control of lateral color fringing, with almost none visible.

Bokeh.  Rather harsh overall, especially at the wide end, but is somewhat smooth as you near 55mm.  Look below for sample crops.

Color.   Same as other Minolta AF lenses.

Close up filter.  N/A

Coma.  Very minor coma at the widest focal lengths and largest aperture in the extreme corners.  One stop down eliminates coma.

Regular filters cause no additional light fall-off when the aperture is fully open at either end of the focal length.

Filter size is 49mm.  This size is not widely used by Sony, but is commonly available.  Current Sony lenses that use this size are the 30mm F/2.8 macro and 28mm F/2.8.

Distortion.  You’ll notice strong barrel distortion at 18mm, becoming flat around 22mm, then turning to moderate pincushion distortion at 55mm.  Close focus through infinity focus seems to show about the same amount of distortion.  Check out the cropped samples below.

Distortion examples directly below.

18mm, strong barrel distortion

55mm, moderate pincushion distortion.

 

Aperture/focal length guide.

 

Focal length numbers carry through between apertures, which is normal.  Interestingly, the 18-55mm lens has focal length EXIF data recorded for every number, 18 through 55.

 

Bokeh is harsh at 18mm, producing a noticeable ring around highlights, that’s typical for kit lenses.  Towards the long end, the out of focus background highlights are rendered a little smoother.  Crops are from the center of the image, about 10′ to 20′ (3m-6m) behind the focus point.

 

 

Coma is only barely visible in this 100% corner crop at 18mm, and then only when using the largest aperture.

 

 

Ghosting control is very good, and these images show very little in the way of colored dots or blurred circles.  I see just a few spots (middle of palm trees) in the 18mm, F/5.6 vertical image, bottom right, and a minor smudge at 36mm, F/5.6, (no hood was used), top right, which is just off to the left of the image.  Using my hand to shade the lens would’ve eliminated that smudge.

 

Light fall-off or corner shading is very light at both ends, and really isn’t noticeable in actual images.  Regular filters don’t cause any additional light fall-off at either end, or when using a wide aperture.

Center sharpness.

Below are crops from the image centers at 18mm.

Center sharpness is very good even with the lens wide open.  I think F/5.6-8 is probably the optimal aperture in the centers at this focal length.  Diffraction causes softening at F/11.  The fuzzy stuff under the cactus is a spider web.

 

At the mid-section, sharpness is best at F/5.6-8, and there is a noticeable change in sharpness as you stop down.  Diffraction sets in at F/11.

 

Below are the corners at 18mm.

 

Again, the F/5.6-8 crops look pretty good, especially for the extreme corners.  Some light fall-off is visible in the corners when the crops are presented like this, that’s why they’re a little darker than the center crops.  This particular image crop doesn’t show the color fringing that takes place at the wide end, look below for a good example.

18mm, F/8 extreme left side at middle of image

Here’s the rather strong color fringing I was talking about at the top of the page.  This image crop was taken from the extreme left side at 18mm, F/8.  You’ll see the red and cyan fringing along the tree trunk at middle left, and the rocks at the bottom.

Center sharpness at 55mm.

Below are crops from the image centers at 55mm.

Center sharpness at full telephoto is just a hair soft at F/5.6, (mostly noticeable in the tree limbs on the upper right side), but closing the aperture to F/8 sharpens things up nicely.

 

At the mid-section, things look very similar to the center crops.

 

Below are the corners at 55mm.

 

The extreme corners are soft, with low contrast, and need an aperture adjustment to sharpen them up.  Fortunately, just a stop down and things look much better.  All crops in each section have the same exposure values.

Let’s check out the macro capabilities of this lens.

As close as you can get. F/8. click for larger image

 

 

Now for the conclusion.

 

This kit zoom lens turned in a pretty good performance overall, and works best at F/5.6-8, which is good news too.  The long end has some good qualities, like smooth bokeh or background highlight blur, lack of color fringing, and very good overall sharpness, although a little soft at F/5.6 in the extreme corners.  The wide end is very sharp in the centers and mid-section, but the extreme corners need to be stopped down; and of course don’t forget the strong color fringing and distortion that occurs at and near 18mm.  There is a slight lack of contrast with the lens towards the long end, (noticeable in the macro shot), but that’s normal for an inexpensive kit type lens, you can’t have everything.  None of these things are a big deal unless you stare at your images all day blown way up on your computer screen, or have a high megapixel camera like the NEX-7.

 

This lens is similar in optical performance to the Sony 18-55mm A-mount lens, but there are some noticeable differences other than optical qualities, like the fact that this NEX e-mount lens is built much better, and is smoother when zooming and manually focusing.  Also, the NEX 18-55mm silent, and pretty fast focusing motor is light years ahead of Sony’s poorly implemented SAM focusing system, just be aware of the focusing issue as mentioned at the top.  Bottom line; check your shots using the LCD!

 

The NEX e-mount 18-55mm makes a good lens to keep permanently on your NEX camera (unless you have the NEX-7), it’s not so big and heavy to become burdensome, and just small and light enough to be pocket-able, well, maybe not your jeans pocket, but a jacket pocket definitely!