T-mount to Nikon Z adapter compatibility

T-mount is the one entry in this matrix that is not really a camera mount at all. It is a lens-side interface — the M42 × 0.75 thread Tamron introduced in 1957 and standardised as T-2 in 1962 — with a fixed 55 mm spacing from the thread shoulder to the focal plane. The lens carries no bayonet of its own; it screws into a body-specific T-X adapter ring, and it is that ring which carries the camera mount. For a Nikon Z body you fit a T-Nikon-Z ring, and Nikon Z is the most accommodating destination in this whole matrix: its 16 mm flange is the shortest of any mount here, so the T-Nikon-Z ring is built as the longest tube, leaving a full 39.0 mm of clearance — the roomiest of any T-mount destination, with infinity focus never remotely in doubt. The Z mount's exceptionally wide 55 mm throat helps too, swallowing the bulky rear cells of a catadioptric lens without any risk of the optics fouling the ring. As always with T-mount, the optics sit at their designed 55 mm regardless of body, so the appeal is the one-lens-many-bodies economy: buy the glass once, swap the cheap ring when you change systems.

What you actually mount is all long glass, because that is what T-mount has always been for. The Vivitar 500 mm f/8 Mirror and the Samyang 800 mm f/8 Mirror MC are catadioptric (mirror) lenses, astonishingly compact for their reach because the light path folds back on itself, and the Soligor 400 mm f/6.3 Tele is a conventional refractive long lens. None autofocuses; all three were built as budget reach for wildlife, the Moon and the Sun. Nikon Z is a particularly apt home for that work, partly because of Nikon's long pedigree among astrophotographers — Nikkor glass and the F-mount were a fixture of film-era deep-sky imaging for decades — and partly because the Z bodies themselves are deliberately built for shooting in the dark. The Z6 II, Z7 II, Z8, Z9 and Zf carry a Starlight View mode that brightens the electronic viewfinder enough to compose framing in near-total darkness, and a Warm Display Color mode that shifts the screen to red to preserve your night vision at the eyepiece. A generic mechanical T-Nikon-Z ring from Fotodiox, K&F Concept or Gobe costs less than a memory card.

The verdict reads Mechanical · MF · no IS · Ap. ring, and every term is honest for this glass — with one nuance the badge cannot show. Focus is manual, set on the lens barrel and confirmed through the Z body's focus peaking and magnified live view, because there are no electrical contacts anywhere in a T-mount lens or its ring, so nothing passes EXIF, aperture commands or stabilisation data to the body. 'Ap. ring' is true of the refractive Soligor 400 mm f/6.3, which carries a real preset diaphragm — but it is not true of the two mirror lenses. A catadioptric design has no iris at all: the Vivitar 500 mm and Samyang 800 mm are fixed at f/8, so you control exposure with shutter, ISO and screw-in or rear drop-in ND filters, and you accept the signature ring-shaped 'donut' highlights a mirror lens renders out of focus.

Stabilisation is available on the bodies that have it, but you have to ask for it. Nikon's 5-axis in-body VR works with a fully manual lens once you register the focal length by hand in the 'Non-CPU lens data' menu — 500 mm for the Vivitar, 800 mm for the Samyang — after which sensor-shift engages, though at those lengths a monopod or tripod stays part of the kit. Mind which body you are on: the full-frame Z5, Z6, Z7, Z8, Z9 and Zf carry IBIS, while the DX bodies — the Z50, Z50 II, Zfc and Z30 — have none and lean entirely on support. Image circle is the easy part, because all three lenses cover full-frame, so they shoot clean on a full-frame Z6, Z7, Z8 or Z9, while a DX body reads the centre and applies Nikon's 1.5× crop — turning the Vivitar 500 mm into a 750 mm-equivalent and the Samyang 800 mm into a 1200 mm-equivalent reach monster on a body light enough to carry up a hill for lunar and wildlife work.

The honest summary: T-mount → Nikon Z is the budget-reach and amateur-astronomy route with the friendliest mechanics in the matrix, not a precision-AF or cine path. Fit a generic mechanical T-Nikon-Z ring — the roomiest clearance and widest throat of any T destination make it the easiest mechanical fit there is — focus by hand on the EVF (Starlight View earns its keep when you are framing a faint object in the dark), accept fixed f/8 and donut bokeh on the Vivitar 500 and Samyang 800 mirror lenses, reach for the Soligor 400's preset ring when you want a conventional rendering, and register the focal length in the Non-CPU lens data menu so VR helps at the long end on an IBIS body. And because T-mount is the de-facto standard for astronomy optics, the same T-Nikon-Z ring threads straight onto a telescope's focuser for prime-focus lunar, solar and deep-sky work — where Nikon's Starlight View and Warm Display Color make composing in the dark genuinely easier, so one inexpensive ring serves both your mirror lenses and your scope on the body you already own.