Nikon compatibility weirdness - Nikon TC-16a teleconverter

About 4 years ago I purchased a Nikon TC-16a teleconverter with a manual focus Tokina 300mm f2.8 for use with my Nikon D2X for a little bird shooting.  The TC-16a is an interesting beast, it was designed in the late 1980s as Nikon had released few AF lenses, to give AF compatibility to their then current range of MF lenses.  It doesn't have full range for AF, but in practice, it works quite well.  You manually focus to approximately where the right subject distance and let the AF take care of the critical focus that is especially difficult to achieve with fast tele manual focus lenses.

When I first got it, the TC-16a worked like a dream with the D2X.  Recently, as I hadn't used it for quite a while and as I'd sold several of my MF tele lenses, I decided to sell it.  I pulled it out, put it on the D600 for a test run and.....nothing.  It wouldn't work.  It turns out that few Nikon SLRs, digital or film, have the right software and protocols to drive the TC16a.  Interestingly the contact pins are positioned quite differently to most lenses when viewed up closely too.  It just so happened the D2X was one of the few that could drive it.  

So I put it up for sale and hoped the potential buyer's camera would be compatible.  The first buyer came, and as soon as he pulled out his D600, I knew we were going to have trouble.  And so it was, the TC-16a refused to work.  However the guy still purchased!  It turns out that these are now quite rare, and a modification can be found to open up the protocol to other cameras.  His idea was to purchase for his Nikkor 300mm f2.8 Ai-S, which he could then use much more successfully than current.

Hibiscus - Nikon D2X with Tamron 90mm f2.8 macro

Hibiscus - Nikon D2X with Tamron 90mm f2.8 macro

Hibiscus - Nikon D2X with Tamron 90mm f2.8 macro

Hibiscus - Nikon D2X with Tamron 90mm f2.8 macro

Metabones 'Speed Booster' adapters and testing their Proof of Concept.

One of the more fascinating pieces of photography equipment to emerge are the Metabones 'Speed Booster' adapters that actually refocus an image from full frame to APS-C or mirrorless size sensors.  This gains 1 stop of aperture and promises a sharper image.  In actual fact they are like turning a teleconverter back to front, which make sense as you lose 1 stop of aperture on a 1.5x teleconverter.

So I decided to do my own test.  I reasoned that a Nikon TC-14a 1.4x teleconverter would be sufficient to replicate the effect, as reversed, the math is exactly the same as the Speed Booster adapter. (1/1.4 =0.714)  I also tried it with the 1.6x TC-16a, as shown in the photo below.

Firstly I got the Sony NEX 5n, held the teleconverter backwards to it and then put in front a Nikkor 45mm f2.8 GN pancake lens.  I quickly found I needed to add some length to the set up to gain correct focus, so I added in a Nikon PK-12 extension ring.  Even though it was a little tricky to hand hold, to my surprise it worked!  The shutter speed was higher than I predicted (suggesting a faster aperture) and the sharpness was good. Very cool!  The photo of the New Years card is how it came out the camera, with the lens set at f2.8.

The extension ring added a little too much base length, as it now won't focus on infinity, but allowed closer focus than usual.  As I was hand holding 3 separate components, I am sure the moved around a bit, and were not aligned properly, creating some shift in the picture like a shift lens does.

The $599 price tag is quite expensive, but I suspect Metabones will do quite well initially as there are no other adapters like it.  I am sure though that copies will come out and the price will come down.

Bird Watching with a 300mm f2.8

A couple years back I found an awesome deal on a manual focus Tokina 300mm f2.8, which I ended up purchasing.  It was quite the lens with a 114mm front element protector.

I then had a brainwave.  I set the lens on a tripod on inside on our dining room window and set up a bird feeder on the back deck.   As the lens had a trip mount, this allowed me to leave it up and take the camera off when I was using it for something else.

The lens was hooked up to a Nikon TC-16A teleconverter which has an AF element, allowing autofocus when using manual focus lenses – very nifty.  It won’t auto focus the full range of the lens, but if you get somewhat close using manual focus, the AF will look after the fine adjustment and takes out any guess work.

A 300mm f2.8 hooked up to a 1.6 teleconverter on a DX camera effectively gave 720mm at approx f4.5.  Pretty nice indeed.  All the photos are actual size (no cropping) and the bird feeder was approximately 5 meters from the camera.

Interestingly, with the seed we put in the bird feeder, it almost exclusively attracted cardinals, few other birds were interested.  The bright red one is the male, with female being more muted browns, with a dash of red-orange.