Nikon Lens Converters: Overview

General Information

Nikon manufactures five lens converters for modifying the focal length of the on-camera lens. The following image shows all five Nikon lens converters. On the first row, from left to right, are the 0.21x Fisheye Converter FC-E8, 0.63x Wide Angle Converter WC-E63 and 0.66x Wide Angle Converter WC-E24. On the second row, from left to right, are the 3x Tele Converter TC-E3ED and 2x Tele Converter TC-E2. Nikon also manufactures other converter lenses for the 5xxx series cameras.

All five Nikon lens converters

All of these converters are screwed on to the on-camera lens. Each lens has a "multiplier" (i.e., 0.21x, 0.63x, 0.66x, 2x and 3x). When a lens is used with the on-camera lens, the combined focal length is the product of the given multiplier and the focal length of the on-camera lens. Recall that the on-camera lens has focal length in the range of 38mm and 152mm (35mm equivalent). If the wide angle converter WC-E63 is used, the combined focal length is in the range of 24mm (=38mm×0.63) and 96mm (=152mm×0.63). The following table gives the range of the combined focal length of each converter. Note that vignetting will occur in the shorter end of the focal length when TC-E2 or TC-E3ED is used.

These lens converters are of type afocal. Parallel light rays entering an afocal lens are also parallel when they exit; however, the diameter of the exiting parallel light rays may be different from the diameter of the entering light rays. Thus, an afocal lens does not have focal length, or, its focal point is at infinity. As a result, afocal lens are only used for modifying focal lengths and other optical characteristics, and must be used with other prime lenses. This means afocal lens are not supposed to be used alone.

Because converters are attached to the on-camera lens creating combined lenses of modified focal lengths, the optical problems of the lens converter and the on-camera lens may be magnified by the combined lens. These include lens flare, ghost image, field curvature, aberration and so on. Please refer to On-Camera Lens Overview for the details.

Focal Lengths

As mentioned in previous section, the five lens converters and the on-camera lens cover focal lengths from 8mm to 456mm (35mm equivalent). The following table shows the focal length range and the corresponding lens converter. In general, if a focal length can be obtained with the on-camera lens, use the on-camera lens rather than a lens converter. For example, the focal length range of the WC-E63 overlaps with that of the on-camera lens (i.e., 38mm to 96mm). If the desired focal length is in this range, use the on-camera lens for better image quality even though WC-E24 and WC-E63 can also do the job. More precisely, use a lens converter only if the on-camera lens cannot reach the desired focal length.

Let us take a look at some actual images to learn the effect of these focal lengths. All of these images were taken at the same position with different focal lengths. We start with the widest possible focal length: the fisheye converter. The fisheye converter, at its shortest focal length (or widest angle of view), produces a circular image and covers more than 180 degree in all directions. However, fisheye converters is not rectilinear, which means straight lines become curves. Zooming in the on-camera lens until vignetting disappears, we have a full frame fisheye image that covers more than 100 degree horizontally. The corresponding focal length is approximately 15mm. If linear distortion is acceptable, the fisheye converter can be used as an ultra-wide lens!

Fisheye 8mm	Fisheye 15mm
Click on the image to see a larger one

The next range is 24mm to 38mm covered by WC-E24 or WC-E63. The most popular focal lengths in this range are 24mm, 28mm and 35mm. Since it is in general indistinguishable between 35mm and 38mm for most cases, we shall ignore 38mm and use 35mm as a substitute.

24mm	28mm	35mm
Click on the image to see a larger one

The next group of images are the standard (or normal) focal length 50mm and moderate telephoto 85mm, 100mm and 135mm. The on-camera lens is capable of taking photos in this range without using a converter.

50mm	85mm	100mm	135mm
Click on the image to see a larger one

The longest focal length of the on-camera lens is 152mm. Beyond this range, either TC-E2 or TC-E3ED must be used. The following images show the effect of 200mm, 300mm, 400mm and the longest 456mm.

200mm	300mm	400mm	456mm
Click on the image to see a larger one

Two Major Restrictions

The first and most serious restriction is that a mounted converter can block the flash sensor and sometimes the internal flash as well. Thus, the internal flash may not be used. Because the flash sensor is also blocked, external flashes may not be used either. The following image shows the flash sensor and the internal flash.

The following images illustrate the relative positions of the internal flash, the flash sensor and each converter lens. As you can see, there is sufficient space between the flash sensor and WC-E24 (and TC-E2). The other three converters have a large front element that may affect the sensitivity of the flash sensor. Additionally, even though the internal flash fires, the front portion of the converter tube will block the flash light.

FC-E8 Fisheye	WC-E24 Wide Angle	WC-E63 Wide Angle

TC-E2 Tele	TC-E3ED Tele

The above images also show another serious problem: viewfinder is blocked by every converter, which means you cannot use viewfinder for composition. Use LCD monitor instead.

The Use of Filters

The following table lists the thread size of each converter.

Here are two important notes:

1. Yes, the WC-E24 does have a filter thread. But, this thread is too shallow which makes the use of filter very difficult. Moreover, it will take two step-up rings to use any filter properly. The first one brings 48mm to some larger diameter, say 58mm, and the second one goes from this larger diameter to 72mm or even 77mm. Filter size less than 72mm will likely cause serious vignetting. Click here for more details.
2. Vignetting may occur if a filter, especially a polarizer, is mounted on a WC-E63. To test if a particular filter may cause vignetting, mount it on WC-E63 and take a photo with brighter background and smaller aperture (i.e., in the Aperture Priority mode). Note that you should use the image to judge the result rather than using the LCD monitor because the LCD monitor only covers 97% of the image and vignetting may occur in the unseen 3% area! Vignetting could become worse when a polarizer is mounted since polarizers are thicker than other type filters. Note that there are wide-angle filters and slim/thin wide-angle filters. The latter are specially made for wide angle lenses; however, they are more expansive. The following image shows the thickness difference between a slim wide-angle polarizer (4.5mm) and a conventional polarizer (8mm).

Slim wide-angle (left) and conventional polarizers (right)