Review – Zunow WEX-075a Wide Angle Lens Adapter

Review

When I was approached by Scott Cantrell of Tapeworks Texas to review and assess the aspherical lens for the Sony PMW EX3 by Zunow, I was pleased to assist.  Scott and indeed all the personnel at Tapeworks, offer a higher level of customer attention than any of our other vendors.  This combined with their competitive pricing has made Tapeworks our first point of contact for equipment acquisition.

Now to the lens itself:

Basis of the test

As we have also been using the Fujinon XS8-4AS-XB8 wide-angle lens specifically designed for the EX3, it seemed this was the best comparison.  If it were to compare favourably to a task-specific design then this would give video professionals the best assessment.  The images were assembled on to a DVD, which is available at Tapeworks.

The images acquired were fractal for the most part with complex and varied texture and were shot in varying lighting conditions.  In addition, the test sequences chosen varied from close (1 meter) to mountainous areas at a range of a mile or two.  The full range of field of view and focus were captured.

Physical build

When I first opened the box for the Zunow I was struck by the fact that this is a very substantial piece of glass.  It is well made and possesses a simple and robust bayonet locking method for direct connection to the standard 1/2” Fujinon lens for the PMW EX3.  This is true example of the benefits of “keeping it simple”.   Mounting did require the removal of the protective UV filter that was installed on the Fujinon lens. There is little doubt that this adapter would provide a long period of service.

Due to the fact that it is aspherical and is meant to cover such a wide range, it is comparatively heavy.  The Fujinon XS8-4AS-XB8 is lighter than the WEX-075a Fujinon XS8-4AS-XB8 combination, however this does not preclude its use as a field adapter.   If it would be used for prolonged periods one may become a bit concerned about stresses to the lens mount on the camera.  This is most likely not an issue as the most likely use of this adapter, and indeed its benefit, is that it can be mounted only when required.  For those who feel the PMW-EX3 is too light and should feel more substantial, attach this adapter and you will have the weight your desire.  As an aside, as we will frequently trek into very remote areas carrying significant amounts of gear (often in hostile circumstances) the light and agile capability of the EX3 is welcome.  The WEX-075a is of course lighter than the Fujinon XS8-4AS-XB8 and much easier to place in backpacks, etc.

There is a distinct advantage to the approach of using a wide-angle adapter, as it does not involve the removal of the lens and therefore exposure to dust and the elements.  There are several times in the past when this would have been a most welcome part of the kit.  To prove the point, during the tests a few particles of dust inadvertently found their way on to the lens mount and are visible in shots of the sky.  We left these particles in the final images to make the point.

The lens hood that comes with the WEX-075a is roughly the same size as the Fujinon XS8-4AS-XB8 as would be expected.  Here again design simplicity was key with a straightforward slip on and tighten method of attachment being used.  The lens caps are of the slip-on type but are adequately snug.

Considering the value and price point of this lens and its greatest potential use for the field, I would like to have seen a more protective case rather than the nylon pouch that is provided.  For our purposes it will require more protection.

Image performance

A series of four tests were conducted to test the characteristics of the Zunow adapter against the Fujinon wide angle.  Each test was conducted with no Neutral Density on the first test during which the full range of the zoom function would be employed and then a subsequent identical test with a neutral density of 2 set on the PMW-EX3.

A variety of image surfaces were chosen in four separate lighting conditions.  Test Number Four was conducted with a strong backlit situation to attempt to force Chromatic aberration to be apparent.

In all tests the following characteristics were consistently observed:

The Zunow adapter provided a surprisingly sharp image especially when considering the large amount of glass being introduced into the image stream.  In some cases it would rival the purpose-built Fujinon lens.  On some images of relatively small objects in motion, the difference in clarity between the two lenses was difficult to distinguish (if at all).

Of course with a large aspherical adapter there is a tendency for distortion to form in the corners and depending on the degree of magnification, along the outer edges as well.  While the Fujinon lens held the clear advantage in this regard, the images made with the Zunow were still useful and the distortion hardly noticeable when the images were not being “zoomed”.  Corner distortion was also most apparent on those sections of the image, which were highly fractal.

As regards the equivalent focal lengths are concerned, the Fujinon actually allowed a wider angle of view whereas the Zunow enabled a closer focus when fully zoomed in to the subject.

A remarkable and distinct difference between the two lens arrangements was the narrower depth of field achieved by the Zunow adapter.  It was in fact a most pleasant surprise, which yielded some above average images.  This characteristic was naturally most noticeable when a narrow field of view was used and the Neutral density on the camera was set to 2.  The bokeh is acceptable and perfectly usable for a video lens.  It was certainly more dramatic than the Fujinon lens.  Therefore this could be used in certain circumstances when the use of a 35mm adapter is not available.

There was a difference between the two lenses in regards to contrast and colour representation.  The colour presented on the Fujinon was more vivid and the contrast more in keeping with the camera settings.  The characteristics of the Zunow however were well within adjustment tolerances both on the camera settings as well as in post-production.

Chromatic aberration was only apparent in several conditions and only in the outer extremes of the image, as one would expect.  It was however far better than was expected.

Summary

Some may feel that putting an adapter up against a dedicated design lens to be a bit unfair, however I would assume that at the price point, that would be the consideration most videographers would be making.   Therefore I felt it was important to see if such an adapter could serve the professional to an acceptable standard.  To me the answer is yes, under certain circumstances.  Indeed as previously mentioned, it would be extremely handy in the field and can be quickly applied when needed.  Certainly the unexpected benefit of a narrow depth of field provides a creative solution to many situations.

If one is aware of the potential shortfalls of using an adapter of this size, it can be of significant value.  In our case it will not replace the Fujinon lens but is being seriously considered for inclusion in our field kit.

Well done Zunow.

Review Provided By:
Philip E Hewitt
Seventh Victory
P O Box 1123
Qunicy, CA 95971

(( Disclaimer – Powered Production was not paid to post this review nor did we conduct the tests of the equipment, TapeWorksTexas is a friend of ours, and is who we choose as our vendor in the Houston, Texas area.))