Canon EF-S 18-135 mm f/3.5-5.6 IS STM
3. Build quality and image stabilization
In the photo below the tested lens is positioned between the Canon EF 24–105 mm f/3.5–5.6 IS STM and the Canon EF 35 mm f/2.0 IS USM.
 |
Please Support UsIf you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free. |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
The Canon EF-S 18–135 mm f/3.5–5.6 IS STM starts with a metal mount which surrounds protruding plastic element, which is characteristic for the EF-S mounts and a plastic ring with contacts and information that the lens was made in Taiwan. The rear element is 17 mm in diameter and it moves, being situated on the same level as the contacts at 18 mm and hiding at 135 mm inside the barrel about 4 cm deep. The interior of the tube is well darkened but in some places you can still spot electronic parts.
 |
The proper casing of the lens starts with an immobile ring and inscriptions: „EFS 18–135mm” and „IMAGE STABILIZER” along with the information about the minimum focusing distance which amounts to 0.39 of a meter. On the right side you see two switches controlling the focusing mechanism mode (AF/MF) and stabilization (STABILIZER ON/OFF). Next to them there is also a white square making the alignment with a camera easier and the LOCK switch which blocks the focal length scale at 18 mm.
 |
The next part is a zoom ring as wide as 41 mm. Most of it occupy comfortable rubber ribs and underneath you can find focal length markings at 18, 24, 35, 50, 85 and 135 mm. The ring itself moves smoothly and is properly damped.
Further on you see a manual focus ring 13 mm wide, completely covered by rubber armour with ribs. The ring has no marks and it works with an electronic relay. Running through all the distance scale takes a turn through an angle of about 180 degrees – still the value depends on the speed of the turn.
 |
The next part is an immobile ring with the Canon logo and behind it the proper tube ends. The front element is 53 mm in diameter and surrounded by an inscription stating the name and parameters of the lens; then you see a non-rotating filter thread, 67 mm in diameter and a hood mount. While you change the focal length the front element system extends on a homogeneous solid tube; during that operation the lens can get longer by almost 5 cm.
The optical construction of the Canon 18–135 mm IS STM consists of 16 elements positioned in 12 groups; one of them is made of UD (Ultra Low Dispersion) glass and one is GMo aspherical. Inside you can also find an aperture with seven blades which can be closed down to a value ranging from f/22 to f/36, depending on the focal length.
In this class of equipment Canon never spoil their customers with a rich accessory kit; accordingly you get only two caps with the lens in the box.
 |
Optical stabilization
The producer boasts of the image vibration reduction as efficient as 4 EV. Of course we didn’t hesitate to check that claim, taking several dozen photos at the 135 mm focal length with exposure times ranging from 1/160 to 1/2 of a second and the stabilization switched on and off. Then we determined the percentage of blurred photos at every shutter speed and presented it as a function of that speed, expressed in EV where the 0 EV point is an equivalent of 1/125 of a second. The graph below shows our results.
Like in the case of its predecessor, reaching the declared 4 EV is out of question but you get very solid 3 EV or minimally more. For this class of equipment it is a good result, deserving our praise.
