Why hasn't Nikon updated 1.7TC?

[eric_m4]

<p>Nikon replaced older versions of 1.4x and 2.0x Teleconverters but the 1.7x TC remains the same. Does anyone know if the 1.7x will be replaced with newer version? Wouldn't it make sense to upgrade the 1.7 model also?</p>

[ShunCheung]

<p>Nikon's TC-17E II is a much newer design than the TC-14E and TC-20E, versions 1 and 2. The original TC-14E and TC-20E were introduced way back in 1992 along with the AF-I lenses. Version 2 (2001) of those two teleconverters are really the same thing optically but the barrels have a wrinkle finish to match some of those AF-S lenses.</p>

<p>The TC-17E II (there is no version 1, as it starts with the "version 2" style wrinkle finish) was introduced over a decade later in 2004.</p>

<p>The TC-20E III (2009) and TC-14E III (2014) are true optical redesigns from the earlier 1992 versions, after two decades.</p>

<p>I am not sure there is a whole lot Nikon can do to improve the TC-17E II. Personally, I think it is mainly the 1.4x TCs that are useful. I lost too much light and there is too much optical degradation with the 1.7x and 2x TCs.</p>

<p>P.S. The TC-14E III is only fully compatible with G and E long teles, not earlier AF-I and AF-S lenses with an aperture ring.</p>

[ilkka_nissila]

<p>The TC-17E II (interestingly it is called II although it's the first version) was introduced in 2004, so it's 11 years old, roughly. The TC-14E II and TC-20E II were optically the identical to the TC-14E and TC-20E from year 1992, so the 1.7X is a 12 years newer design than the other two were (prior to their III updates). I suppose the 1.7x optical design is more current (than the TC-14x II and TC-20E II were) so there is perhaps less reason to update it. I recall that there is a patent for an aspherical version of the 1.7X, but Nikon hasn't brought such a converter to the market, at least not yet. </p>

[robert_bouknight1]

<p>The TC 17 I have works very well with my 70-200/f4 AFS VR to make a small, light setup for shooting in daylight.</p>

[alan_wilder1]

<p>I recently compared performance of the TC-17E II and T-20E III on my 300/4E PF shot wide open and saw virtually no difference. Optimally, the TC-17E should be paired with an f/2.8 lens to take full advantage of AF but works in a pinch on f/4 lenses in good light or center point AF focus. First the TC-17E III:</p><div></div>

[alan_wilder1]

<p>Now a 69% crop of the TC-17E</p><div></div>

[alan_wilder1]

<p>Now the TC-20E III full frame.</p><div></div>

[alan_wilder1]

<p>Lastly a crop of 58% of the TC-20E III. All shot were unprocessed in LR5 and shot wide open.</p><div></div>

[ShunCheung]

<p>Alan, I see your camera is a D750.</p>

<p>I have a few birds in flight images with the 300mm/f4 PF with a TC-17E II on a D7200. That combo can be pretty sharp. The main problem is that at max f6.7, AF is a bit of a challenge even under good light. Therefore, the sharpness problem mainly comes from focusing. With a moving subject, the keeper ratio is rather poor. Optically that combo is fine.</p>

<p>I still feel that these 1.7x and 2x TC are best on f2.8 fixed-focal-length lenses such as the 300mm/f2.8 and 400mm/f2.8. Of course, the 200mm/f2 is even better.</p>

<p>The 300mm PF was wide open to capture the following image. Hence it is f6.7 with the TC-17E II, 1/1600 sec and ISO 400 on the D7200.</p><div></div>

[alan_wilder1]

<p>Shun, we are in agreement that an f/2.8 lens would be optimal with the TC-17E to maintain fast AF function anywhere in the frame there are AF focus points, something practically required for BIF. My only point in the posts was to demonstrate IQ between the TC-17E II and TC-20E III were fairly close since the OP wanted to know why Nikon hasn't updated the TC-17E. Fortunately, at least the center AF point accurately focuses on lenses combos with effective aperture of f/8 or faster for more stationary subjects.</p>

[ShunCheung]

<p>Alan, I see a tiny bit of purple and green color fringing in your images. Those light-to-dark transition areas around the white window frame is challenging. I assume most of that is contributed by the 300mm PF lens as I have seen that myself, but part of it could be the teleconverters as well.</p>

<p>Other than that, what your and my experience tells us is that the 300mm/f4 PF is an excellent lens optically. Even wide open with the degradation of a 2x TC (or 1.7x TC), the quality is still quite decent. That means it has to be optically excellent to begin with.</p>

[alan_wilder1]

<p>I noticed the same fringing issue but it's small enough that a little LR5 de-fringe correction knocks it out as seen after the correction is applied on the TC-17E II combo.</p><div></div>