Articles

A banded jawfish protects his babies in his mouth: With the Sony 100mm macro lens, every single eyeball of the soon-to-be-born offspring are visible (Sony a7R Mark III, Sony 100mm f/2.8 Macro GM OSS, f/16, 1/160s, ISO 100)
 

The new Sony FE 100mm f/2.8 Macro GM OSS lens enters an already mature ecosystem of underwater macro photography equipment. High-resolution sensors, sophisticated autofocus systems, and the widespread adoption of wet optics have collectively narrowed the gap between what is technically possible and what is practically achievable in the water. Against this backdrop, expectations for any new macro lens should be tempered: True revolutions are rare, and refinements increasingly arrive in subtle increments.

In that context, the Sony FE 100mm f/2.8 Macro GM OSS lens is better than its venerable predecessor—the Sony FE 90mm f/2.8 Macro G OSS—in nearly every measurable way. It is sharper, more refined in rendering, and (marginally) more confident in autofocus performance. Yet it is not a lens that suddenly enables images that were previously impossible. With modern wet optics and solid technique, the long-standing 90mm f/2.8 Macro remains fully capable of producing images that are indistinguishable in real-world use.

Where the 100mm f/2.8 Macro does meaningfully distinguish itself, however, is in its compatibility with teleconverters. This single addition expands the system’s flexibility in a way that feels genuinely relevant to contemporary underwater macro workflows.
 

An exceptionally alien and almost transparent glass squid found in the Gulf Stream. At nearly seven inches in length, the addition of a Nauticam MFO-3 means you can still be in an ideal position for larger macro subjects (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Nauticam MFO-3, f/11, 1/160s, ISO 250)

Build, Handling, and Autofocus

From a handling perspective, the 100mm f/2.8 Macro reflects Sony’s current design language. Build quality is excellent, with improved coatings and a refined control layout that translates cleanly into underwater housings. The lens is surprisingly lightweight and balances well behind a macro port.

Autofocus performance is improved over the 90mm, though not dramatically so. Focus acquisition felt marginally faster and more confident, particularly for low-contrast subjects, like on blackwater dives using red focus lights. That said, underwater macro remains a discipline where subject movement and focus light positioning often dominate autofocus performance far more than small generational gains in lens motors. The improvement is real, but subtle enough that it would be difficult to identify without files side by side.

As with most lenses used underwater, ergonomics matter far less once the lens lives permanently behind a port. What does matter is the number of physical controls on the barrel. These include a focus limiter, OSS switch, AF/MF controls, and a programmable focus-hold (“A”) button. In practice, most underwater shooters will ignore, tape over, or disable nearly all of these. I typically switch off OSS for strobe-lit macro work, and the focus-hold button is inaccessible in a housing.

The most critical control to be aware of is the push-pull focus ring clutch, a holdover from the 90mm f/2.8 Macro. Unfortunately, this physical clutch can easily be bumped into full manual focus before a dive, which can effectively ruin a macro dive if no manual focus gear is installed. Fortunately, there is a simple physical workaround: Placing a small O-ring behind the clutch prevents it from actuating. An old Nauticam N85 port O-ring fits perfectly and provides a reliable, non-permanent fix.
 

Top: The Nauticam N100 Macro Port 125, mated with an Isaac Szabo 18mm extension ring, mounted on my Nauticam NA-A7III housing, is a perfect fit for the Sony 100mm f/2.8 Macro with the Sony 1.4x Teleconverter. Bottom: My physical button settings: AF/MF set to AF, Full Time DMF set to OFF, Focus range set to Full, OSS set to OFF, and IRIS LOCK set to A (very important so your camera body controls the aperture instead of the aperture ring on the lens). Also shown is how an O-ring can be placed in the groove in order to disable the deadly focus clutch

Optical Performance: Better, but by Degrees

Optically, the 100mm f/2.8 Macro is clearly the superior lens. Center sharpness is excellent, edge performance is improved, and contrast is slightly higher across the frame. On high-resolution bodies, particularly those exceeding 40 megapixels, these gains are measurable at the pixel level.

In practice, however, appreciating the difference requires deliberate scrutiny. Once water, strobes, and subject behavior enter the equation, the gap between the 100mm f/2.8 Macro and the 90mm f/2.8 Macro narrows considerably. It takes genuine pixel-peeping to identify consistent advantages in real underwater images. This is not a criticism of the lens, but rather a reflection of how optimized underwater macro systems have already become.
 

Getting a portrait of a 10mm-long bumblebee shrimp is no problem for the 100mm f/2.8 Macro. With a native lens magnification of 1.4x, powerful magnifiers like the Nauticam SMC-2 perform even better (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Nauticam SMC-2, f/16, 1/100s, ISO 100)

Wet Optics Compatibility: The Modern Baseline

Like its predecessor, the 100mm f/2.8 Macro integrates seamlessly with the wet optics that now define macro photography underwater. Testing confirmed clean compatibility with commonly used diopters, including high-power options.

Paired with optics such as the Nauticam MFO-3, the lens delivers a wide, distortion-free field suitable for larger macro subjects, with no meaningful edge degradation. Higher-magnification optics such as the Nauticam SMC-1, SMC-2, and equivalent diopters perform as expected, reinforcing that the 100mm f/2.8 Macro slots directly into existing systems rather than demanding a rethinking of modern macro photographers’ systems.
 

A larval pomfret rides on a larval sea cucumber for safety in the open ocean during a blackwater dive in the Gulf Stream off Florida: Blackwater subjects can be notoriously difficult on autofocus systems, particularly when paired with longer focal length macros—not so with the 100mm f/2.8 Macro (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Nauticam SMC-3, f/18, 1/160s, ISO 200)

Teleconverter Compatibility: A Genuine Bright Spot

The most consequential addition with the 100mm f/2.8 Macro is its compatibility with teleconverters, a long-anticipated feature that meaningfully expands the lens’ usefulness underwater. Sony officially supports both the 1.4x and 2.0x teleconverters—a first for the company’s macro lineup.

At its native configuration, the 100mm f/2.8 Macro offers 1.4:1 reproduction, exceeding life-size magnification without diopters. With the Sony 1.4x teleconverter installed, effective magnification increases to approximately 2.0:1 before any wet optics are added. Sony’s 2.0x teleconverter pushes this further, approaching roughly 2.8:1 magnification, albeit with increased light loss.
 

A predatory pelagic nudibranch snacks on an unsuspecting jelly: The ability to use teleconverters is a massive advantage of the Sony 100mm f/2.8 Macro over other mirrorless macro lenses on the market (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Sony 1.4x Teleconverter, Nauticam MFO-1, f/18, 1/160s, ISO 100)
 

Equally important is how the teleconverter alters the system’s working distance. By effectively shifting the focus range outward, the teleconverter pairs exceptionally well with modern wet optics. When combined with lenses such as the Nauticam SMC-3 or MFO-1, the increased working distance translates into a more forgiving shooting envelope, improved strobe placement, and reduced risk of disturbing sensitive subjects when you want to catch the rare behavior.

Notably, even with a teleconverter mounted, lower-power optics such as the MFO-3 remain highly usable. This preserves the flexibility to step back and frame slightly larger subjects without removing the converter mid-dive. In practice, this allows a single configuration to span traditional macro through extreme macro within one dive, a level of versatility that was previously more cumbersome to achieve.

These teleconverters introduce some predictable trade-offs that include modest light loss and increased system length, though these are largely mitigated underwater. Strobes dominate exposure, and port extensions are already a routine consideration in macro systems. The popular 1.4x teleconverter requires a port extension of about 18mm and the 2x teleconverter requires 43mm of extension.
 

Even with the teleconverter installed, wet optics like the Nauticam MFO-3 can restore a useful, wider view. This colonial tunicate was nearly a foot long—big for any macro lens—but this flexible combo could achieve sharp results and fit the entire animal in frame (Sony a7R III, Sony FE 100mm f/2.8 Macro GM OSS, Sony 1.4x Teleconverter, Nauticam MFO-3, f/16, 1/160s, ISO 400)

Sony 90mm vs 100mm: Skill Still Matters More Than Hardware

Comparing the 90mm f/2.8 Macro and 100mm f/2.8 Macro in isolation risks missing the larger point. In capable hands, both lenses are capable of producing images that are functionally the same on social media or in print. The difference between results is far smaller than the difference between an experienced macro photographer and a developing one.

The 100mm f/2.8 Macro offers refinement, not reinvention. It rewards photographers who are already operating near the technical ceiling of their systems, but it does not invalidate the 90mm, nor does it suddenly unlock images that could not previously be achieved.
 

A shallow depth of field image of a squat urchin shrimp: The existence of the 100mm f/2.8 Macro does not mean older lenses like the 90mm f/2.8 Macro are obsolete; it simply provides a better all around option but does not revolutionize the underwater macro game—except perhaps with regards to teleconverters (Sony a7R Mark III, Sony FE 90mm f/2.8 Macro G OSS lens, f/13, 1/160s, ISO 100)

Cost, Port Systems, and Opportunity Cost

Price is the most significant negative against the 100mm f/2.8 Macro. The cost of the lens itself is substantial, and it often necessitates new ports, extensions, and gearing. Most underwater photographers are looking at an “all in” cost exceeding $2,000. These additional expenses represent a real opportunity cost.

For many photographers, the same investment could fund upgraded lighting, additional wet optics, or increased dive time, all of which often yield more immediate improvements in image quality. This consideration is particularly relevant for shooters who have not yet fully optimized their existing systems. If you are deciding between upgrading your 90mm f/2.8 Macro or going on a photo workshop, I would choose the photo workshop.
 

Out with the old and in with the new: The size difference between the Nauticam port for the old 90mm f/2.8 Macro (right) and the port for the new 100mm f/2.8 Macro (left)

Who Should Consider This Lens

The Sony 100mm f/2.8 Macro is best suited for photographers who:

• are already operating high-resolution camera bodies;

• have optimized lighting and wet-optic setups;

• value incremental improvements in sharpness and handling;

• intend to leverage teleconverter compatibility for extended macro flexibility.

It is a less compelling prospect for photographers still refining foundational macro technique or those expecting a dramatic leap in creative capability.
 

The Sony 1.4x teleconverter is a powerful tool for extending the range of the lens, all while maintaining acceptable depth of field like this double portrait of a pelagic seahorse and its driftfish roommate (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Sony 1.4x Teleconverter, f/14, 1/160s, ISO 400)

Final Thoughts

The Sony FE 100mm f/2.8 Macro GM OSS is the company’s best macro lens to date. It improves upon the Sony FE 90mm f/2.8 Macro G OSS in nearly every technical respect and integrates seamlessly into modern underwater macro systems. Its true standout feature is teleconverter compatibility, which meaningfully expands magnification and working-distance options in a way that aligns perfectly with today’s wet-optics focused systems.

That said, this is an evolution toward perfection, not a revolution. With skill and modern wet optics, the 90mm f/2.8 Macro remains fully capable of producing exceptional results. The 100mm f/2.8 Macro refines what is already possible, and for photographers chasing the ultimate technical ceiling, it delivers. Whether those refinements justify the cost will depend entirely on where a photographer sits in their system, their technique, and their priorities.
 

A mother Phronima has given birth to many, many, many babies, captured in blistering detail with the 100mm f/2.8 Macro lens (Sony a7R Mark III, Sony FE 100mm f/2.8 Macro GM OSS, Nauticam MFO-1, f/11, 1/160s, ISO 400)
 

To see more of Gabe’s work, please give him a follow on Instagram, visit his website, or perhaps join him for a dive in Florida at the Blue Heron Bridge.
 

Sony FE 100mm f/2.8 Macro

When purchasing underwater photography equipment like the products mentioned in this article, please support DPG by supporting our retail partner—Backscatter.com