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| On-camera lens @ 38mm | Wide angle @ 38mm | Wide angle @ 25mm |
| Click on the photo to see a larger one | ||
On this page, we shall take a look at the image quality of Nikon 0.66x Wide Angle Converter WC-E24 and Nikon 2x Tele Converter TC-E2. Rather than counting the number of lines the lens can resolve, I prefer to take a field test. In what follows, we shall do the wide angle converter first, followed by the tele converter. The test camera is a Nikon 950 set to NORMAL, the default shooting mode.
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| On-camera lens @ 38mm | Wide angle @ 38mm | Wide angle @ 25mm |
| Click on the photo to see a larger one | ||
The following shows the center parts of each image. All images are simply cut off from the original, and untouched. In terms of resolution, the on-camera lens and the wide angle converter are about the same; however, the wide angle converter causes some loss of contrast. When the wide angle lens is zoomed all the way out, both resolution and contrast become lower, but not by very much.
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| On-camera lens @ 38mm | Wide angle @ 38mm | Wide angle @ 25mm |
| Click on the photo to see a larger one | ||
Now let us look at the corner part. The following images are direct cropped and untouched part of the upper-left corner of each original image. Again, the one taken with the wide angle converter is slightly inferior to that of the on-camera lens. Image definition and contrast are better with the on-camera lens. Can we conclude that the wide angle converter is slightly interior to the on-camera? Not yet.
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| On-camera lens @ 38mm | Wide angle @ 38mm | Wide angle @ 25mm |
| Click on the photo to see a larger one | ||
When the on-camera lens zooms to a position so that the combined focal length of the wide angle and on-camera lens is approximately 38mm, the image is only part of the total coverage of the wide angle lens as shown above. Hence, the middle image above is still near to the center as shown below. To understand the real image quality, the upper-left corner is cropped and untouched as shown in the right image above. This image clearly shows that the image definition is so soft that tree leaves are blurred and that contrast is low. Therefore, the quality of the wide angle lens at the upper-left corner is not good compared against that of the on-camera lens.
The following shows the images at the upper-right corner. They exhibit essentially the same result. In conclusion, the wide angle converter WC-E24 is slightly interior to the on-camera lens in the center, but exhibits a softer image than the on-camera lens in the corners.
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| On-camera lens @ 38mm | Wide angle @ 38mm | Wide angle @ 25mm |
| Click on the photo to see a larger one | ||
The left image below was taken by zooming all the way in (i.e., focal length 115mm, 35mm equivalent), while the right image was taken with the TC-E2 tele converter by setting the on-camera zoom lens so that the image size is approximately identical to the left one. Note that both images were taken using the smallest possible aperture. A first impression is that the tele converter and on-camera lens combination provides higher contrast than the on-camera alone does. As a result, I feel that the tele converter produces a "sharper" image.
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| On-camera lens @ 115mm | Tele converter @ 115mm |
| Click on the photo to see a larger one | |
The following two images are the center parts of the above corresponding ones. They are cropped and untouched. As you can see, the color/tone in both images are different, and, again, the one taken with the tele converter has high contrast. This can be seen with the small decal near the lower-right corner, and the small leaves at the center. Moreover, the tiles in the shadow are sharper in the right image!
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| On-camera lens @ 115mm | Tele converter @ 115mm |
| Click on the photo to see a larger one | |
Let us take a look at the image quality at corners. The first two are cropped from the upper-left corner, while the last two are from the upper-right corner. Again, the on-camera lens at 115mm is softer and has less contrast, although both images are softer than those at the center. The other two images share the same results.
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| 115mm | Tele converter @ 115mm | 115mm | Tele converter @ 115mm |
| Upper-left corner | Upper-right corner | ||
| Click on the photo to see a larger one | |||
Does the tele converter and on-camera combination have a better image quality than the on-camera lens at focal length 115mm? Judged by the above images, this is the case. But, everyone knows that adding glasses to a lens reduces image quality. Even worse, we are not adding a glass, but adding a converter! Here is a possible answer. Although some zoom lens have their best image quality in the middle, most zoom lens have better quality in the shorter end than the longer end. In this case, the image quality at 38mm is better than that at 115mm. The combined focal length 115mm of the tele converter and the on-camera lens is about 1/4 from the wide end of the on-camera lens. See Nikon 2x Tele Converter TC-E2 for the details. Thus, the on-camera lens is at its prime focal length range. Even though adding a tele converter that could reduce the image quality, the combined result is still better than the worse quality of the on-camera lens. Note that this conclusion is derived from only one focal length, 115mm, it may not apply to the whole range of available focal lengths.