Phase One 150mm AF f/2.8 IF

The Phase One 150mm AF f/2.8 IF is a 150mm prime short telephoto lens with a maximum aperture of f/2.8, internal focusing, and autofocus, built for the Phase One / Mamiya 645 mount system.

Key Specifications

• Focal length: 150mm (prime)
• Lens type: Short telephoto
• Maximum aperture: f/2.8
• Autofocus: Yes
• Internal focusing: Yes — the barrel does not extend during focus
• Mount: Phase One / Mamiya 645
• Prime or zoom: Prime
• Recommended use: Portrait, sports

What makes the Phase One 150mm AF f/2.8 IF special?

Among the 150mm options available for the medium format Phase One / Mamiya 645 ecosystem, the f/2.8 aperture is a serious differentiator. The internal focusing design means the lens stays the same physical length throughout the focus range — a practical advantage when you're working in the field and don't want a shifting center of gravity or accidental hood collisions. Autofocus makes it genuinely usable for editorial portraits and even faster-paced shooting scenarios where manual focus would cost you the moment.

Competing 150mm options in this mount, including the 150mm f/3.5 Blue Ring variant, trade that one-stop of light for a slightly longer effective working distance and high-sync shutter compatibility — useful in studio flash work. If you shoot primarily with available light or need subject separation at maximum blur, the f/2.8 aperture gives you a clear edge. On a medium format sensor, bokeh at 150mm f/2.8 is dramatically shallower than what you'd get from a 35mm full-frame equivalent, making this a go-to portrait focal length for photographers who want that unmistakable medium format rendering.

Phase One has built this lens for long-term professional use, and that shows in the optical and mechanical construction. Corner-to-corner sharpness wide open is a consistent finding in forum discussions and real-world reviews — a claim that matters a lot on large medium format sensors where edge softness is immediately visible in final files.

Who is the Phase One 150mm AF f/2.8 IF for?

Portrait photographers working on medium format will find this focal length and aperture combination hard to beat. At 150mm on a 645 sensor, you get natural subject compression, flattering perspective for headshots and three-quarter shots, and enough working distance to stay out of your subject's personal space. The f/2.8 aperture keeps you shooting confidently in lower light — indoors, late afternoon, overcast days — without forcing you up to high ISO.

Editorial and commercial photographers who occasionally need to track movement — a walking model, an athlete mid-action, a candid moment — will appreciate the autofocus. It's not a sports telephoto in the conventional sense, but for controlled sports portraits or dynamic editorial sessions it holds up.

If you're already shooting with a Phase One body like the XF or an older AF body paired with an IQ back, this lens slots directly into your existing system. It's also worth knowing if you're building out a used kit: the 150mm focal length pairs naturally with a wider prime like the Mamiya 80mm f/2.8 for a two-lens portrait setup that covers

Buying a used Phase One 150mm AF f/2.8 IF

Buying a used Phase One lens is a smart move — these are professional tools built to last, and a well-maintained copy will perform identically to a new one. That said, there are a few things worth checking. Internal focusing lenses like this one have more moving glass groups, so confirm that autofocus cycles smoothly and quietly with no hunting or hesitation. Look for any signs of impact to the rear element or mount contacts, as medium format lens mounts take more stress than 35mm equivalents.

Cosmetic wear — light handling marks, minor barrel scuffs — is normal on a professional-grade lens that has seen regular use and doesn't affect optical performance. What you want to avoid is decentering (uneven sharpness across the frame) or haze inside the elements, both of which are visible in test shots.

Every pre-owned Phase One 150mm AF f/2.8 IF sold through Camera-tweedehands.nl is professionally inspected, individually photographed, and comes with a minimum 12 months warranty. The actual warranty period is shown on the variant listing. Returns are accepted within 14 days.