## Samyang 85 mm f/1.4 Aspherical IF

## 5. Chromatic aberration

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Here we can really praise the Samyang for its method of correcting chromatic aberration. At the edges of both the DX and the FX matrices the degree of aberration is minimal and goes unnoticed.

One point must be explained: discerning readers may be surprised to note that the aberration on the smaller D200 matrix is greater than the full frame D3x. This is due to our chosen unit of measurement. If we gave the aberration in pixels, it would be greater on the D3x. The difficulty in expressing aberration in pixels is that it wrongs cameras with smaller cells. Our method is to give the percentage value obtained by dividing the degree of aberration in pixels by the frame dimensions also expressed in pixels. This resolves the problem of pixel size, although it means that the measurements on the full frame are divided by a larger number, giving a lower percentage value, as seen on the graph.

And this is not without sense, even though it might seem so at first glance. The percentage value means we can forget about pixel size, but also allows us to see the problem as a whole. It tells us that the aberration will disturb us when we look at the whole picture, but not when we look at a 1:1 magification. Thus, when looking at 1:1 the aberration on the D3x appears greater than that on the D200. When we bring up the whole picture on the screen, it will be harder to see on the full frame, and this is what our graph indicates.