If straight lines are paramount, then you'll be glad to hear that the distortion pattern is uniform across the frame, which should make corrections relatively straightforward to apply. This level of distortion should pose few issues, but may become apparently if straight lines are placed parallel to the edge of the frame, especially at 55mm. Visually uniform illumination is achieved one stop below maximum aperture throughout the zoom range.ĭistortion is well controlled, with Imatest detecting 1.39% barrel at 55mm at 0.824% pincushion at 250mm.
At 135mm the corners are 1.69 stops darker than the image centre. At 55mm the corners are 1.28 stops darker than the image centre at maximum aperture. It can be cured in software.Īpochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more.įalloff of illumination towards the corners of the frame is reasonably well controlled. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. These low levels of CA will be difficult to spot, even in large prints, or harsh crops from the edges of the to read our chartsĬhromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Simple.įor this review, the lens was tested on a Canon EOS 600D using Imatest.Ĭhromatic aberrations are well controlled throughout the zoom range, only just exceeding half a pixel width on a few occasions. The taller the column, the better the lens performance. The scale on the left side is an indication of actual image resolution. Averaging them out gives the red weighted column. The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Peak performance is achieved between f/8 and f/11 for this focal to read our charts At maximum aperture, sharpness in the centre of the frame is still outstanding and good towards the edges of the frame. Impressively, sharpness holds up very well at 250mm also. At this aperture, performance in the centre is still outstanding and sharpness towards the edges improves to very good levels. Peak sharpness across the frame is achieved at f/8 for this focal length. With the lens zoomed to 135mm, sharpness at maximum aperture remains very high in the centre of the frame and good sharpness towards the edges. Here sharpness is outstanding across the frame. Maximum performance is realised at f/5.6 for this focal length.
The image stabiliser takes just over a second to settle down properly, so it pays to pause a while to allow the system to catch up with your motion.Ĭanon EF-S 55-250mm f/4-5.6 IS STM PerformanceĪt maximum aperture and 55mm sharpness is already outstanding in the centre of the frame, with the clarity towards the edges of the frame being not too far behind. With care, sharp hand held images are possible around half the time at an impressive 1/25sec, which is roughly four stops slower than the usual rule of thumb for sharp images would allow. Focusing is performed internally, so the 58mm filter thread doesn't rotate, making this lens ideal for use with polarising and graduated filters.
55 250 stm 3.5 stops manual#
A small switch on the side of the lens allows switching between manual and autofocus quickly. The manual focusing ring is quite light to operate, but well enough damped to make applying fine adjustment a pleasure. Manual adjustments can be made in single focus mode once the lens has locked onto a target.
55 250 stm 3.5 stops full#
Unlike many of Canon's USM lenses, full time manual focus override is not possible, and manual focusing is performed by the focusing motor. The lens balances well with this camera, due to it only weighing around 375g and being relatively compact.Īutofocus is silent, swift and precise. As it is an EF-S lens, it can only be mounted on EF-S compatible Canon cameras, like the Canon EOS 600D used for testing. Just like the previous version of this lens, this lens is constructed from high quality plastics, including the lens mount.
55 250 stm 3.5 stops update#
This version is an update to the previous Canon 55-250mm IS II lens, adding Canon's new stepping motor technology, which promises smoother, quieter autofocus performance, which is especially suited to recording video.Ĭanon EF-S 55-250mm f/4-5.6 IS STM Handling and Features This telephoto zoom lens provides an angle of view equivalent to an 88-400mm used on a 35mm camera.
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