I haven’t had great luck with the used Canon EF 100-300mm f4.5-5.6 USM lens I bought a few months ago. Though, a lot of the problems so far are from not having enough light to try smaller apertures hand held. On this photo outing I was able to get out in the field early enough and brought along a tripod plus a wired cable release.
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Combining a brighter day with the Viltrox 0.71x EF to EOS M speedbooster adapter allowed me to really test things out. I was using the Canon EOS M5 for photos and the M50 for video. I walk around a snow covered state park to try out this combo so that I could better learn what the lens is capable of along with just enjoying photography, as usual.
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| One of the photos spots in the video. Tree bark texture is a great ever unique subject. |
Compared to a standard adapter, the Viltrox speedbooster uses an additional portion of the EF lens full-frame image circle and focuses it down into the APS-C format. With old EF lenses like this, it tends to improve quality of the resulting photos. At least in the center of the frame. The speedbooster adds its own set of optical flaws to the photos such as strong left and right edge vignetting along with blurring there due to the optical elements in the speedbooster. At the very least, this is what I’ve experienced so far with multiple film and early digital era EF lenses such as this 100-300mm, the 135mm f2.8 soft focus, 50mm f1.8, and the EF 85mm f1.8 lens.
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| An edited image with speedboosted settings of 131 mm, f-6.3, ISO 200, 1-160 s (speed boosted) |
The above image is one quick example of the lens. Toward the wider end you can expect better results than near 300mm. While the aperture says f.6.3 that’s taking into account the EXIF does use adjusted settings because the Viltrox adapter does apply it’s 0.71x modification automatically. The top portion of a full view and the bottom is a 100% crop toward the center of the image. Not too bad.
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| The image quality difference at 100% is visible here at the boosted 71mm (114mm) between two photos at f/5.6 and f/8. The smaller aperture has a lot more definition everywhere in the image. |
After this outing, I do think the lens is capable of producing decent images when the apertures is stopped down enough. The challenge comes with using something like f/8 at 200mm when I’m using a speedbooster. Using the normal adapter will make the situation worse. At least with the M5 and M50 camera bodies, going high ISO quickly makes the images a noisy mess.
From my limited use of a borrowed EF 75-300mm f/4-5.6 III USM Lens for volleyball photos, I think that design is overall better than this one optically. The negative of that design is that the manual focus ring moves when the lens is in autofocus mode, which makes it more awkward to use in practice.
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| A screen capture from the video. I’ve been trying to pick up litter after I finish with a photo outing to my local parks. |
Lately I’ve been finishing off my photo outing videos with a quick litter pick up session. This time it was pretty bad even though the snow should be hiding a lot of the trash. I don’t get what is with people that are so inconsiderate. The especially irritating thing about this outing was that there were large dumpsters within a short walk to the parking area. My goal here with including this topic in the video and on the site is to motivate fellow photographers, or frankly anyone that notices, to take a stand against people that do these things.
We have enough large problems as it is with how much humanity has taken over and re-purposed nature to our whims. We don’t need even more damage done by introducing harmful materials to the environment that turn into things create impossible to fix problems like micro plastics. There is no sifting the water and dirt to remove that.