There is an optical reason why the ZTCs, and the Z lenses are better than DSLR lenes. The main driver is the shorter distance from the last element(s) of the lens to the sensor. At one point in my professional life as an astronomer with a focus on astronomical spectrographs, I had a bit of experience with lens design. It is MUCH easier to get good image quality over the sensor field of view with close final elements. One f/1.2, 300 mm aperture camera that we made had the last element 3 millimeters from the sensor which itself was 100x 100 mm CCD array. That lens was designed by a top professional lens designer.
Z Series Teleconverters vs F Series Teleconverters
- Thread starter Mark Garfinkel
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thanks for sharing. I was wondering if the diameter of the flange matters?
Part of the Z TC compatibility issue is the ‘it sticks out the front’ dimension and how that matches up with the rear elements in the lens I think….and making it work with physically shorter lenses with no rear clearance for the TC would affect the optical or physical design…plus realistically speaking TCs are more likely to be wanted with long lenses anyway.
For me…since my output is exclusively screen display…the 100-400 and both TCs are just fine. I can see slight differences in the images if I pixel peep with adjustment so the subject is the same size…but it is a ‘just different’ and not a ‘better/worse’ difference…and at normal display output size the differences aren’t there…so spending more $$ or carrying more weight makes little sense. I don’t use the 2.0 TC as much as the 1.4…but use the 1.4 more than the bare lens.
It could be a consequence of using larger elements toward to rear to make then lens more telecentric which field distortion. Less edge distortion appears to a characteristic of Z lenses compared to DSLR counter parts. The F mount has been around a long time; was there when I first started using Nikons in the mid 1980's. Nikon, as many optics manufactures, is very secretive on design details, but I imagine as they, and others, went mirrorless they took the opportunity for a new mount to take advantage of advances in optical design and manufacturing, which have been many. I have used Nikon DSLR 200/f2, 400/2.8 and 300/2.8 in my lab over the years and it would have been nice to have the optical prescription but that was a non-starter with NIkon. One reason I have stuck with Nikon as they lagged in mirrorless it that their glass has always been exceptional form my evaluations.
fcotterill
Well-known member
We discussed the question of why Z mount confers advantages to optical design. Here's a post in which I collated links and comparative diagrams.
Initial consensus suggested these design benefits were primarily for shorter focal lengths eg the two U Wide Zooms. These factors have likely also been leveraged in the designs of these Z Teleconverters.
Yet a couple of the newest Z telephotos have packaged a surprise or more, particularly the 400 f4.5S, which is so compact and light. In this prime, the Z mount appears to have enabled moving away from the more traditional telecentric design , see Thom Hogan's review
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Initial consensus suggested these design benefits were primarily for shorter focal lengths eg the two U Wide Zooms. These factors have likely also been leveraged in the designs of these Z Teleconverters.
Yet a couple of the newest Z telephotos have packaged a surprise or more, particularly the 400 f4.5S, which is so compact and light. In this prime, the Z mount appears to have enabled moving away from the more traditional telecentric design , see Thom Hogan's review
Does flange distance impact sharpness?
I recently asked the folks running Greys of Westminster YouTube channel via live chat about why the Z lenses are significantly sharper than f mount glass. They implied that the larger Z mount with the 16 mm flange distance as opposed to the 46 mm flange distance on the f mount is a big reason...
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John Navitsky
Well-known member
what i really appreciate is they have adopted a strategy of fully reworking their designed to take full advantage of the new mount.
when people are upset about the speed of lens releases, i always think that i'd much rather wait for them to do a fully reworked design rather than just to get a rewarmed product.