18.5mm f/1.8 evaluation the N1 system Fast Fifty

Started Dec 1, 2012 | Discussions thread
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Simon97 Senior Member • Posts: 2,453
18.5mm f/1.8 evaluation the N1 system Fast Fifty

I just received my new 18.5mm "normal" prime. Whenever I get a new lens I take some test shots on a chart and around the house (in and out) to get a feel for the optic and be sure it is performing correctly. Here is my evaluation:

The best news is that the lens is sharp wide open. Center is fantastic. Corners are not bad. There's light falloff towards the edges. The camera adjusts for this in jpeg, but you see it in raw. I can only guess the amount at 1 ~ 1.5 EV.

At f/2.8 there is a slight improvement to the center as there was little room to improve to begin with. In fact, I had to shoot raw to see the difference. The corners improve as does vignetting.

At f/4 the corners are crisp and falloff is gone.

Once you get beyond f/8, the image starts to blur due to diffraction. At f/11 the image needed help with sharpening in raw, the jpegs weren't so bad because the sharpening is already included.

I noticed a light amount of color fringing near the edge in raw. Not a big deal at all. Bright white (overexposed) objects next to dark objects showed light purple fringing.

The most annoying fault of the lens is the barrel distortion. It is moderate, about the same as the 10-30 at 10.

The lens is very light and more "plasticky" feeling than the kit zoom. The f-stop advantage gives the lens more opportunity for low light shooting (especially video) and DOF effects. I will probably miss the vibration reduction more in video shooting.

I have experience with many "fast 50" primes in film and DSLRs. They can be exquisitely sharp in the f/4 to f/5.6 range. This lens is no different except it performs better wide open where the fast 50s tend to be hazy. The fast 50s have less barrel distortion than this lens, OTOH.

I hope to post some pics soon. This lens is a sleeper. Get one!

 Simon97's gear list:Simon97's gear list
Canon G9 X Nikon 1 S1 Canon EOS Rebel SL2
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