On June 17th, 2014 Canon announced the telephoto zoom, the 55-200mm for the EOS-M system, giving the EOS M system an up to 300mm equivalent focal length zoom.
The EF-M 55-200mm f/4.5-6.3 IS STM is a telephoto zoom lens for Canon's EOS M mirrorless camera system. It includes optical image stabilization with a claimed 3.5 stop benefit and uses a stepper motor which allows silent autofocusing, even during movie recording. The lens offers a zoom range equivalent to 88-320mm.
Overall it's product highlights include;
- EF-M Mount Lens/APS-C Format
- 88-320mm (35mm Equivalent)
- Aperture Range: f/4.5 to f/32
- One UD Element & One Aspherical Element
- STM Stepping AF Motor
- Full-Time Manual Focus Override
- Optical Image Stabilizer
- Rounded 7-Blade Diaphragm
|CIPA IS rating
||1 UD, 1 aspherical element
||STM Stepper motor
|Full time manual
The EF-M 55-200mm is composed mainly of plastic for the exterior and interior, and also the mount. Even though it is made up of plastic, it feels sturdy and well built to use. There is very little wobble and play as you extend the barrel, and the mechanisms move smoothly.
The STM motor used in this lens is a lead screw STM motor and offers fast AF.
The manual focus adjustment is focus by wire, with a small manual focus ring at the end of the lens. Focus by wire means that electronically the lens detects if you are spinning the focus wheel and moves the lens accordingly. As you move the wheel faster or slower, will depend on how quickly the focus adjustment occurs. Many people dislike this focus method because it lacks the tactile feel and consistency that you get with mechanically coupled focus rings.
The EF-M 55-200 is a relatively complex lens given its size and weight, consisting of 17 elements in 10 groupings featuring one UD (ultra-low dispersion) and one aspheric element.
The EF-M 55-200mm starts off at F4.5 and slowly moves towards maximum minimum aperture at 165mm, where it reaches F6.3 and continues at F6.3 until end of the zoom range, 200mm
Zoom Aperture Comparison
At this current time, there is only one other telephoto lens for the EF-M system, the 18-150mm. The 55-200mm is considerably faster across the much of the shared zoom range.
Summary - MTF
The MTF (or Modulation Transfer Function) provides a way to measure lens performance. Atypically this is computer generated based upon models, the lone exception being Zeiss that shows their MTF’s based upon a production lens sample.
For a detailed explanation of MTF and specifically how Canon shows their charts, refer to the article in Canon’s Digital Learning Center here.
Reading MTF Charts
The charts for the EF-M 55-200 suggest good performance at 55mm, better as you stop down the lens and the lens tails off towards 200mm, requiring you to stop down to at least F8 for good performance.
From the color test images, we can see that at 55mm and as we go upwards, the resolution seems to fall off. It seems like our sample fares worse than it should at 200mm.
Stopping down the lens is necessary, and this may make the lens unnecessarily dark needing at least F/8 to F/11 at 200mm to achieve good sharpness.
Canon’s DPP and some of Canon’s later camera bodies contain DLO, Digital Lens Optimizer, which can be used to correct various aberrations with any of the supported cameras and lens combinations. All the EF-M lenses have DLO “configurations” allowing you to further improve the characteristics of the lens. Using DLO with this EOS-M lens is highly recommended as it clears up a lot of aberrations and the resultant images are excellent. As you can see from our DLO samples below it sharpens up this lens considerably removing all traces of CA especially at 200mm. Since at 200mm you are also shooting at a maximum aperture of F6.3, DLO also assists in removing the effects of diffraction that are present by default at 200mm.
If you are interested in learning more about DLO, Canon has a DLO mini-website, located at https://global.canon/en/imaging/dlo/
Sharpening for non DLO images is set at USM Strength 2 Fineness 2 and Threshold 1 and for DLO images, USM Strength 1 Fineness 2 Threshold 1 with DLO strength set to 50.
We tested this lens on a full spectrum modified Canon M5. The conversion was done by Kolari Vision, who in our opinion, one of the leading vendors of infrared modified cameras and filters.
Converting your camera allows it to be more sensitive to infrared wavelengths, that are normally reduced by your sensor’s IR/UV cut filter. IR conversion removes that cut filter, and replaces it with an infrared filter, or in the case of full spectrum, clear glass. This allows the camera to be far more sensitive to various wavelengths that normally a camera is not. Because normally cameras are not sensitive to these wavelengths, lenses are also not designed around these wavelengths. Various problems may occur with complex lens designs, including hotspots (a center area of the lens brighter than the peripheral, more noticeable as you stop down the lens) and wavelength smearing which atypically shows up as a loss of resolution in the periphery of the lens. Lenses are also more prone to flare.
Each test is performed using Kolari Vision slim PRO anti-reflective infrared filters, which we find to show the best characteristics and contrast of any filters we have tried. They also have Teflon coated filter threads which we find to be extremely useful when we are swapping filters frequently during testing. While any filters will show an adequate final image, since each photo you are taking with a converted camera has a filter, we recommend using the highest of quality filters that you can afford.
Infrared performance is good across the board, requiring little stopping down to achieve the best this lens can do on a converted camera.
As with color performance, as you increase the focal length, you also decrease the resolution and need to stop down further.
There are no visible hotspots or smearing associated with IR with this lens.
We did discover one fatal flaw that may affect you with IR photography and this lens. During our hotspot testing, it was quickly discovered that there is an internal IR LED inside the camera that causes an extreme IR light leak during longer exposures.
As an example, this is a 30 second exposure, with the lens cap ON.
This lens is unsuitable for long exposure IR photography.
Vignetting isn't much of an issue with the EF-M 55-200mm, however, it shows moderately more vignetting at 200mm than at 55mm.
Given the size and price of the EF-M 55-200 it's a good performer, however, you have to work at bringing out the best you can with this lens by carefully stopping down and testing your copy to see how it fares at 200mm. Its infrared performance is good, with the notable exception of long exposure IR photography. There are no visible problems on a converted camera body with normal exposures. Overall, we find that DLO sharpens up this lens considerably at the long end, removing aberrations successfully and rendering a pleasant image.