Saturday, May 17, 2014

The Vivitar 2x Macro Focusing Teleconverter: More Than A Gimmick


I came across this Vivitar 2x Macro Teleconverter in the local camera shop years back and thought it looked pretty interesting. Against my usual judgement, and because I needed to spend a few extra dollars to get a deal on something else, I picked it up. It was only recently I began playing with it and upon discovering it's very capable nature, I did some web crawling and found it has quite a following (and for good reason it seems). So I figured, what better way to see what it's capable of, than compare it to a couple of my favorite manual focus macro lenses? The Kiron 105mm and the Tokina 90mm (Vivitar Series 1 90mm could be also considered as they are optically very similar).

I have not used a ton of optical adapters in my life. This is due, in part, to a commonly held photographic tenant that says: adapters, teleconverters, or any optics placed between your lens and the camera will degrade image quality. If you are unfamiliar with this concept, consider this: Prime lenses, lenses with a single focal length, are designed for a fixed angle of view (e.g. what you will see in the frame). And to this day, no lens exists that is devoid of all optical aberrations. These greatest lenses we have still have aberrations, albeit far less prominent than their average counterparts. To complicate things, consider the zoom lens. Zoom lenses introduce new problems because now we are attempting to do the same thing as mentioned above, across a range of focal lengths, which inevitable taxes the design even further. Inevitably, we find more aberrations in zooms (Though again, there exist some AMAZING zoom lenses, that is to say, the output still looks amazing for printing and even enlargement, so we are still speaking in relativities). Now consider the adapter, be it a teleconverter or macro adapter, or what have you. This optic, especially those from third party manufacturers, attempts to accept the image coming from a range of optics (designed by different companies), and manipulate it (increase magnification, etc.). The adapter must do this despite already present aberrations from the primary lens AND try not introducing too many more aberrations. Because of the introduction of more glass into the formula, we already lose some light (stops). Tell me that's not a tall order.

But, as I say, keep in mind, the relativity of this concept. All lenses have aberrations. And yet, everyday we make and see amazing imagery coming from these lenses. The key is understanding each lens' strengths and weaknesses and using them appropriately. And thus, we come to the point of why I bother pixel-peeping and writing. It is quite simply, to answer the next, and more oft asked questions, 'How much is the image degraded? Does the optic enable me to capture something I would otherwise not have been able to record, and with acceptable enough quality to match my desired output?" This answer will inevitably be different for everyone and again, I stress, the whole purpose I write is to share my findings, and let you decide (though I obviously throw in my 2 cents!).

Setting the Stage



Recently, my wife asked me to photograph jewelry she made, to begin listing it on etsy. I decided on a backyard shoot, in the grass. I naturally grabbed a beer first (given the weather, a New Belgium's Summer Helles seemed appropriate!), my favorite macro lens, the Tokina 90mm f/2.5 and begun making images. I had also recently been conceptualizing a post about this Vivitar Macro Adapter and realized this would also be the perfect opportunity to explore the adapter's capabilities. After completing the 'job', the day was simply too gorgeous to go inside and I began tinkering (montage to the day pictured above). Using a piece of her jewelry as my subject, I grabbed my Kiron 105mm f/2.8, the Tokina 90mm f/2.5, and the Vivitar 2x Macro Focusing Teleconverter which I attached to my Nikon Series E 50mm f/1.8.


Also, I have begun using a GGS Swivi LCD Viewfinder to achieve critical focus. I cannot recommend one of these more! For me, it functions in several ways: Most importantly, I found I was having trouble achieving pin-point accuracy of focus, especially when using larger apertures (shallow DoF). This finder enables me to use the live view mode, zoom into my images to find precisely where my focal plane is, in my frame, even in bright sunlight. I will likely be reviewing this further in the future.

Specifications
Source: The teleconverter's user's manual.

Optical Construction: 7 elements, 5 groups
Coating: Multi-coated for increased light transmission
Diaphragm Coupling: Fully automatic
Weight: 282g (10 oz)
Length: 44.2mm (1.74")
Max. Barrel Diameter: 66.1mm (2.6")

Manufacturer: It seems to be suspected that Kenko-Tokina was the producer of this optic, and a few variations in branding have been reported, though all seem to be the same 7-element optical formula.
Other Brandings: Teleplus, Panagor

As a 2x teleconverter, this optic doubles your focal length and reduces light transmission by 2 stops. So in the case of this article, my Nikon Series E 50mm f/1.8 becomes a 100mm f/3.5. Macro reproduction can achieve 1:1 with this teleconverter.

Build and Handling

This little adapter feels solid in the hands, and the focusing helicoid turns smooth as butter. It appropriately harkens back to the solid lens builds of it's day. Overall, it is a pleasure to use.

Disclaimer

I want to emphasize that this article is about my experience with this optic. As with any optic, so many factors can contribute to skewed results. Consider that element is amplified ten-fold with the Vivitar Macro Teleconverter since it is an adapter, to be used in conjunction with so many other lenses. Someone using a different lens (than the Nikon Series E 50/1.8) will likely have a completely different set of results. That is, in some ways, the exciting nature of the optic. Experimentation!

Comparison

The following is the full frame I opted to use to do my comparison. I found a busy log, and place the shiny bracelet on it. It is, indeed, a cluttered shot (and this is the point). For me, the frame was about finding a frame that contained depth, lots of detail, and a range of highlights and lowlights. There will be some differences in lighting as the sun did pass behind some clouds now and again, and because of the varying focal lengths, the magnification of the subject within the frame will shift slightly (though they are pretty close). Also, I noticed the focal plane is shifted ever so slightly between images, though it shouldn't be difficult to see where focus is and assess accordingly. The full image is reduced resolution, but all crops are 100%.


Full Image


Wide Open Crop (Near Center)


Wide Open Crop (Off Center)


Crop @ f/5.6, f/5.6, and f/7.1 (Near Center)


Crop @ f/5.6, f/5.6, and f/7.1 (Off Center)

For this comparison, I only posted the results wide open, and then stopped down 2 stops to summarize my findings as I look at the results with all apertures. Wide open, using the Series E 50mm, the image quality suffers from some massive issues. It looks downright terrible (to me). Significant chromatic aberration is evident, some serious coma is occurring out at the edges, the bokeh is awful, sharpness across the frame is laughable. It's poor. But, no kidding, as soon as I stopped the lenses down to f/4 (and effectively f/5 for the Vivitar), the Vivitar quickly began falling in line. And by stopping down 2 stops, to f/5.6 (and f/7.1 effectively for the Vivitar), we can see the teleconverter/50mm combo becoming an actual contender, or at least an optic worthy of comparing.

Here is another impromptu comparison between an image I made, of a little bug on a leaf, first with the Tokina 90mm and then with the Vivitar/50mm combo. The framing is different, the plane of focus is slightly different, but again, consider it for what it is.


Bug on a Leaf
Tokina 90/2.5 (1/400 @ f/5.6)


Bug on a Leaf (crop)
Tokina 90/2.5 (1/400 @ f/5.6)


Bug on a Leaf
Nikon Series E 50mm and Vivitar 2x Macro Focusing TC (1/320 @ f/10 effectively)


Bug on a Leaf (crop)
Nikon Series E 50mm and Vivitar 2x Macro Focusing TC (1/320 @ f/10 effectively)


Conclusion

Clearly the Vivitar 2x Macro TC is capable of producing some impressive macro results, technically speaking. I mean, for a TC I am very impressed and pleased to own it. I love the concept of experimentation and will definitely be trying it with my other lenses.

But where I find issue with this TC is simply it's lack of robustness. In order to get solid results, many variables must be accounted for. The user must have a proven lens to mate with the teleconverter. He or she will likely need to stop the lens down a bit to achieve significant results which means losing even more light than the 2 stops this 7-element TC already absconds with. So any f/1.8 or f/2.8, which becomes an f/3.5 or f/4 just by attaching the adapter, becomes an f/7.1 or f/8 once stopped down to the sweeter spot. That means we need to have a fairly well illuminated subject to be able to capture sharp images devoid of any camera shake (and the use of a tripod becomes all the more important, which isn't necessarily convenient).

I bought this TC for something like $30. I bought my Nikon Series E 50/1.8 for nearer $40. Glancing on eBay, I see many of these TCs for sale, for around $40+. So consider, we achieved the image quality above for ~$70.  In my experience, I have found plenty of macro lenses for around this price. Heck, an old Nikkor 55mm f/3.5 would run you the same price as the adapter sometimes. The occasional Vivitar 90mm f/2.5 (Komine made version) will go for between $75-150. The point I am making is, you can find a dedicated macro lens that will likely outperform this adapter (plus whatever you stick it to) for around the same price or slightly more (or less if you really find a deal!).

BUT, all that said, should you happen into one of these, for the right price, let it not be said, it is a poor optic. Quite the contrary, this little TC can enable you to capture some very beautiful, high-magnification images.

Other Sample Images


Dandelion
Nikon Series E 50mm with Vivitar 2x Macro Focusing TC @ effectively f/7.1


Dandelion (crop)
For fun, I threw the Tokina 90mm f/2.5 with it's matched macro extender on the Vivitar Macro Teleconverter and in conjunction with an off-camera SB-600, captured a few images of this little jumping spider that appeared on my windowsill.


Jumping Spider (cropped)
Tokina 90/2.5 with 1:1 Extender and Vivitar 2x Macro Focusing TC @ effectively f/22 (-3 stops)

The image above is a crop, has some post-processing applied and some sharpening because of it has been resized down using the 'bi-cubic sharper' setting in PS. Still, after using both the Tokina 90mm macro extender and the Vivitar Macro Teleconverter, I was able to really get in tight (while still maintaining 8-10" of working distance, with this jumping spider. As can be seen, chromatic aberration is present but I am still very impressed.

Resources

Pentax Forums thread with a good amount of user input on this TC:
http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/27163-vivitar-2x-macro-focusing-tele-converter-definitive-thread.html

The Chens blog - write up with User Manual!
http://mailch.blogspot.com/2012/08/the-users-review-vivitar-2x-macro.html

Another User's Write-up
http://www.nicobastone.com/Vivitar_2x_Macro-Focusing_Teleconverter.htm

Manual Focus Lenses forum post
http://forum.mflenses.com/vivitar-2x-macro-focusing-teleconverter-t40765.html



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