Samsung 16mm f/2.4 i-Function NX
This compact ultra wide has a surprisingly large f/2.4 aperture for its diminutive size, how does it perform?
Samsung has a nice set of pancake lenses that all measure about 62x22mm, and this is the widest of them advertised at 16mm, with a very decent f/2.4 aperture. The closest pancake is probably the Sony 16mm f/2.8 Pancake for NEX, and even for SLR lenses there are very few dedicated wide angle primes for APS-C. The Pentax DA 15mm f/4 is a nice lens, and even though it is small it is almost twice as long and 1 and 1/2 stops smaller aperture.
The build quality of this lens is better than the other pancake lenses. Instead of having a plastic ring behind the focus ring, it is brushed aluminum. However, the rest of the construction is similar to the other pancake lenses.
The lens has 7 elements in 6 groups, with a 7 bladed diaphragm, with circular aperture opening. The minimum focus distance is good at 0.185 m (7.3 inches), but the lens is a light weight for a large aperture wide angle, weighing only 75 g (2.6 oz).
Comments on the Results
Uncorrected, this lens has fairly uniform performance across the frame on the test chart photographed at 1:53 magnification. Performance is okay wide open, but excellent across the frame from f/4. In its corrected state, the corners get a bit softer (due to the correction for the barrel distortion). The default sharpening settings might over-sharpen the center a bit. Remember anything in the blue region is somewhat meaningless on MTF20 as this is above the Nyquist frequency.
After lens correction there is no visible distortion, but the uncorrected RAW files have a massive 5% barrel distortion. I noticed very little field curvature on my chart at 1:53 magnification.
Lateral CA is acceptable, but visible. Oddly, the corrections don’t remove it. Longitudinal CA is noticeable wide open, but mostly disappears when stepping down.
Purple fringing is visible. It is mostly in the corners on the uncorrected images. It improves on stepping down, but is still visible.
Coma is very noticeable wide open, but disappears when stepping down the lens.
The lens is extremely resistant to flare. I found it difficult to get any sort of flare spots to appear.
Measured focal length corrected distortion is approximately 17.7 mm at 1:53 and 17.5 mm at infinity.
Measured focal length uncorrected distortion is approximately 15.5 mm at 1:61.
Pros and Cons
- Overall Performance
- Compact Size
- Visible Coma at f/2.4
- Corrected focal length closer to 18mm