Sunday, November 1, 2009
Vivitar Series 1 90mm 1:1 Macro Extender Comparison
I was curious whether or not there was a difference between the Vivitar and Tokina 1:1 Macro extenders for the Vivitar Series 1 90mm. So...
In anticipation of getting the famed Vivitar 90mm "Bokina", I came across (and quickly bought) a Tokina branded 1:1 extender originally made for the Tokina 90mm AT-X version of this lens. These lenses achieve only a 1:2 reproduction ratio on their own and were consequently designed with a paired 3-element extender for 1:2-1:1 reproduction. Finding these extenders sold alone is rare, and even more scarce in Nikon AI mount.
The article posted here claims the extender is a 3-element optic designed to minimize aberrations within the "difficult" 1:2-1.1 ratio. "A concept borrowed from astronomical optics".
As often seems to be the case, shortly after discovering this vivitar 90mm/tokina macro extender combo, a vivitar 90mm with macro extender appeared on the "in-transit" section of KEH's website. Well of course, I had to request a notification when it became available. KEH often has items, such as this listed at a book value. For a lens with more of a "cult" following this typically means prices well below those paid on auction sites. $150 in Bargain condition. Another policy of KEH is severely underrating lenses. My guess for this would be it is a result of a good number of returns due to very meticulous natured photographers scrutinizing every facet of their equipment and considering the slightest cosmetic defect less than EX condition. Placing anything that is essentially not "mint" in the "bargain" section frees KEH from a lot of misery! ANYWAY, I received the lens and other than minor dust inside the glass, which does not affect the image quality and is expected of a lens 30+ years old, it is in immaculate condition.
Above is the lens I received, "Bargain condition" indeed!
The Vivitar branded macro extender with built-in rotating tripod mount.
Now owning both macro extenders, I began analyzing the various physical differences and wondered whether there was any optical performance difference. While the Vivitar lens and extender were produced in the 70's (still by Tokina), the Tokina AT-X version wasn't manufactured until the 80's. Although the optical formula did not change, it does appear some differences in coatings did occur.
Right off the bat, the two extenders can easily be differentiated by Vivitar's prominent built-in rotating tripod mount. Also, the Vivitar version has a glossy, reflective black sheen matching that of the Vivitar 90mm lens. The Tokina on the other hand, has more of a brushed, flat black finish with a rubber grip. In terms of build quality, the Vivitar feels like a rock, solid and heavy. The Tokina feels tinny, clanks, and is considerably lighter. I really love the tripod mount since this lens can get rather long as it gets cranked out there. Also, the ease of rotating the camera from this mount is unmatched. Overall, the Vivitar just feels more engineered. Optically we can easily see the hue difference in the two coatings, as the Tokina takes on a vivid red cast while the Vivitar maintains a more subtle gold.
I went for a walk at my new favorite park and ended up down by the recently flooded creek. I found a perfect littly clam shell half buried in the sand. I set up a tripod and used the timer function to take an image at each aperture. I used the same 90mm lens with both extenders.
**I have updated my thoughts on this test since its initial release**
OK, so in the end, the results are not extremely ground-breaking but still enough to fulfill my curiosity! The extenders produced virtually identical images at each aperture. However, for the pixel peeper, there may appear to be a couple differences. It appears as if (at least in these wide-open samples), the Vivitar produces a slight bit more color fringing than the Tokina branded extender but it a hair sharper. Now initially, I just noticed the color fringing and labeled that as the only key difference. However, after discussing this with my girlfriend, she pointed out she though the Vivitar looked sharper. Looking closer, as well as at other aperture samples, she's right. The Vivitar branded extender does produce slightly sharper images (at least between the two extenders I have, more on this later) Below is a side-by-side of the extenders shot at f/2.5 and an extreme close-up demonstrating the color fringing evident. Also, it is fairly easy to see based on the texture of the shell and in the grains of sand, the difference in sharpness. In analyzing the plane of focus, both shots appear to be in very close proximity if not just about exact. The camera did not move and I did everything in my power to merely switch out the converter. The lens remained cranked all the way out to 1:1. Take a look and see what you think!
Again, this is only fodder for pixel peepers, but hey, it's something I wanted to know! Understand also, these results are based on tests from a single sample of each extender. Not every sample produces the exact same results and the extremely minor difference in the two extenders may merely be a result of leniency in factory standards (even between months of production). That is, not all Tokina extenders or Vivitar extenders may behave this way. It would take some testing on a random group of samples over the course of production from each to really by exact. So if you have one, send it to me, haha!
So perhaps this test is a little extreme. With either the Tokina or Vivitar, I don't believe you will notice much difference in almost all cases. I find the build quality, addition of the rotating tripod collar, and the added sharpness (by a hair) to outweigh the extremely minor difference in image quality between the two extenders. Honestly, the solid feel of the Vivitar alone is enough to sell me on it. Given the choice, while being sharper, though it appears to produce more color fringing (barely), I would choose the Vivitar branded extender.