Sony DT 18-135mm F3.5-5.6 SAM A-mount lens review by QuietOC
|QuietOC#25496 date: Feb-19-2016|
flare control: 4
|ownership:||I own this lens|
|compared to:||Sony DT 16-50 F2.8 SSM|
Sony CZ 16-80 F3.5-4.5 DT
Sony DT 16-105 F3.5-5.6
Sony DT 18-55 F3.5-5.6 SAM I/II
Sony DT 18-70 F3.5-5.6
Sony DT 18-200 F3.5-6.3
Minolta AF 24-50 F4
Minolta AF 24-85 F3.5-4.5/RS
Minolta AF 24-105 F3.5-4.5 D
Minolta AF 28-85 F3.5-4.5
Minolta AF 28-105 F3.5-4.5/RS
Minolta AF 28-135 F4-4.5
Minolta AF 35-70 F4
Minolta AF 35-105 F3.5-4.5/New
Sigma AF 28-105 F2.8-4
Sigma AF 35-135 F3.5-4.5
Tamron SP 17-50 F2.8
|price paid:||91 USD (used)|
7.5x zoom range
Center sharpness and contrast
Slow but accurate AF
Image quality near 43 mm
|negative:||Noticeable focus shifting with any zoom action|
Very mushy corners at 24 mm
Rear focus control
Clutch vagueness in MF control
Somewhat heavy and inconsistent zoom action
CA at long end
Decentered, mushy bottom left corner
Imperfect Lens Compensation
|comment:||This is currently the cheapest APS-C normal kit lens after the 18-55 SAM II, though it has mostly been slightly more than the older, screw-drive Sony DT 16-105 on the used market. It is the same basic size as the 16-105, 28-105, and 35-105 but even lighter than the 16-80. It shares some a similar reach and uncommon rear focus with the 1985 Minolta AF 28-135 f/4-4.5.|
This is the only focus motor lens I have which responds to the AF/MF switch on the camera body, but it also has a redundant AF/MF switch on the lens. Both switches have to be switched to AF for AF to function. The AF switch on the barrel is also a different shape and operates in a perpendicular direction to the ones on other SAM lenses.
The manual focus control ring is at the back of the lens like the Minolta AF 28-135 f/4-4.5. Also like that lens the focus grip is pretty narrow. The full-time manual focus control uses clutches somewhat like the 16-80, 16-105, 24-105 and Tamron 60 F2 Macro and has a similar vagueness and play as those lenses. There is slightly more feedback than the Tamron, but precise adjustments are nearly impossible.
The SAM AF noises are high pitched and annoying in a quiet room. The SAM is nowhere near as quiet as the motor in the Tamron 60 F2, but in a typically noisy environment the squeaks aren't very noticeable.
Image quality varies over the zoom range. It is weakest at short normal focal lengths. For example the corners at 30 mm are worse than the corners at 135 mm. A good portion of the frame is soft at 24mm, but edge-to-edge sharpness is very good from around 35 to 50 mm with the best performance midway between those focal lengths. The focus plane at 18 mm is also quite flat, but there is a large amount of barrel distortion at that focal length. The image quality remains good past 50 mm, but some moderate lateral CA becomes visible.
This copy seems to be somewhat decentered with the bottom left corner mushy while the opposite corner is very good. Even on the low resolution A58 rear display the lens defocuses noticeably with any movement of the zoom control. The focus also shifts consistently in one direction with zoom. Both of these focus shifting traits make the lens a poor choice for video recording. The focal length also decreases significantly at close focus.
The somewhat long 450 mm minimum focal distance is a drawback compared to the standard 18-55 kit lenses (250 mm). Contrary to the review below, the older 16-105 lens focuses closer (400 mm) as does the 16-80CZ (350 mm).
Overall it is a nice kit lens with good reach and very good image quality in the middle of its range.
Test chart comparison with Carl Zeiss 16-80 and Sony DT 18-135 SAM.