I made a number of comparisons with the Olympus f1.8 Fisheye and Samyang 7.5mm Fisheye both inside and out to evaluate their quality. I’ll start with an outdoor comparison taken from Brighton Pier, with the camera tilted so the natural horizon stretches from corner to corner, ensuring plenty of fine details in the hardest areas for the lenses to render sharply.
I shot the scene with both lenses at every aperture setting using an Olympus OMD EM1 and made a series of crops from the corner and center, indicated by the red rectangles here. I’ve presented these crops below at 100%, starting with the Olympus 8mm at f1.8, f2, f2.8 and f4. These are all JPEGs out of camera.
As you can see above, the Olympus 8mm f1.8 Fisheye delivers excellent quality even when the aperture is wide-open. There’s loads of fine detail in the middle and corners of the frame and very little benefit in sharpness when closing the aperture. You will however notice darkening in the corners at the maximum aperture and f2, due to vignetting. This is however easily corrected in software, and is also effectively eliminated once the aperture is closed to f2.8 or smaller. So for the best results out of camera, I’d try to shoot at f2.8 to f4, but I certainly wouldn’t be concerned by shooting this lens at its maximum aperture.
Now for a comparison with the Samyang lens. Here’s the Olympus 8mm f1.8 Fisheye at f4 again, followed by the Samyang 7.5mm f3.5 Fisheye closed a tad to f4. Note the brightness of the scene changed a little here, so try to look beyond the brightness and concentrate on the detail. Also note the Samyang crops show a slightly larger area due to its slightly shorter focal length.
In the comparison above, the cheaper Samyang impressively manages to keep up with the premium Olympus Fisheye in terms of detail in the corners and center – and lest we forget, the aperture of the Samyang lens has only been closed a fraction from its maximum, whereas the Olympus has been closed by over two stops, so is well into its comfort zone. The Samyang is darker in the corners, which interestingly continues throughout the aperture range. Maybe this is a type of vignetting that won’t go reduced optically, although it’s accentuated here by slightly dimmer conditions, and again it’s something that’s easily boosted in post.
For my second comparison I went indoors to the most excellent GAK store in Brighton, which is one of the biggest and friendliest guitar shops I’ve ever visited, not to mention one of the most beautiful too!
A large wall of guitars made a perfect subject for an interior comparison, and as above I shot it with both lenses at every aperture setting and made a series of crops from the corner and center, indicated by the red rectangles on the full view here.
I’ve presented these crops below at 100%, starting with the Olympus 8mm at f1.8 and f4, then followed by the Samyang closed a tiny amount to f4. These are all JPEGs out of camera.
As before there’s a high degree of detail across the frame of the Olympus samples, even when the aperture is wide-open, and as before very little detriment to overall sharpness at f1.8. What is apparent again though is the vignetting when the aperture is wide open, darkening the corners of the frame. In this example it was again effectively eliminated by closing the aperture by roughly one stop to f2.8. At f2.8 to f4, the ultimate detail also becomes fractionally sharper, so again these are my preferred apertures for shooting with the lens, although again there’s little to put me off shooting wide-open if the conditions demanded it.
Here’s the Olympus at f4 again, followed by the Samyang closed a fraction to the same f4 aperture.
In the comparison above, the Samyang again punches above its weight, delivering roughly the same detail in the corners – albeit with a little darkening – and a slightly crisper result in the middle, although this could be down to having a flatter field or the Olympus making a slight focusing error. Either way, the Samyang can certainly keep-up in terms of sharpness which is impressive for its size and price.
If you’d like to see more examples of the Olympus in action, check out my Olympus 8mm f1.8 Fisheye sample images, or skip back to my verdict!