Panasonic published an text (google translated here) from Panasonic engineer who developed the now 14 year old Leica DG Vario-Elmarit 35-100mm f/2.8 lens. Several highly interesting engineering details and design choices stand out:

1. The “99.9mm” Obsession & Coincidence
The Target: When designing the lens, the team faced the classic battle of performance versus size. After building multiple mockups t[3][4]o test ergonomics on actual camera bodies, they strictly targeted a total length of “less than 100mm.”
The Result: They squeezed the final length down to exactly 99.9mm.
A strange Coincidence: Matsumura points out a quirky design coincidence—the full-frame LUMIX S 24-60mm F2.8 (released in 2025, over a decade after the original 35-100mm design) also ended up measuring exactly 99.9mm in overall length.

2. The High-Risk (+)(-)(+)(-) Optical Formula
To make sure the lens stayed compact and robust, the designers utilized an inner zoom mechanism (the lens barrel does not physically extend when zooming).
Within that framework, they selected a positive-negative-positive-negative alternating lens group layout. This alternating setup makes it incredibly easy to bend light significantly, allowing for massive miniaturization.
The Catch: This layout is highly sensitive to mounting alignment and component precision during mass production. To prevent degrading optical performance, Panasonic had to significantly elevate the component machining and inspection precision in their factories to handle the tight tolerances.

3. Calculating “Refractive Power Per Unit Weight”
To maximize autofocus and optical image stabilization (O.I.S.) speeds, the moving elements needed to be as light as possible. Lighter glass meant they could use smaller, lighter drive motors.
To achieve this, the designers actually compiled a specialized index table comparing refractive power per unit weight for different glass materials.
Furthermore, they applied the alternating convex/concave element philosophy even to the focus and stabilization groups to shave off every possible fraction of a gram.

4. A Dual Personality for Bokeh and Sharpness
Lenses often struggle to balance clinical sharpness open-wide with pleasing, soft backgrounds. Panasonic engineered this lens to behave differently depending on subject distance:
Distant Shots: Spherical aberration is corrected to almost zero, ensuring maximum sharpness and high-contrast rendering at infinity.
Close-up/Portrait Shots: The design intentionally allows for mild spherical aberration at close distances. This slightly softens the focus plane and creates background bokeh that is bright in the center and gradually darkens toward the edges—avoiding harsh, distracting “double-line” bokeh.

5. Combatting the 40% Lens Hood Problem
To ensure strong resistance to backlighting, a telephoto zoom typically requires a very long lens hood. On this highly compact lens, the lens hood takes up roughly 40% of the entire footprint, which impacts its travel-friendly design.
To make sure photographers could shoot clearly even without the bulky hood, the LEICA DG renewal added a brand-new internal light-shielding material inside the barrel alongside its premium nano-surface coatings to absorb stray reflections.

6. Destigmatizing Telephoto “Street snaps”
The developer actively champions using this top-tier telephoto lens for casual, daily street snapshot photography. Since the inner zoom means the lens doesn’t physically expand when zooming, it does not resemble a conspicuous, intimidating “bazooka” lens, allowing photographers to capture natural portraits and compressed street compositions discreetly.

Om System invited a bunch of influencers to a trip in Nambia. In this video you can see MFN report about that cool trip.

Aperture Explained in 2 Minutes | OM Snapshots

Today deals at Amazon, BHphoto, Adorama, Amazon DE, Amazon UK, Amazon FR, Amazon IT, FotoErhardt DE, FotoKoch DE.
Finding Calm When the Conditions Fail OM-1 MKII (Guido Van De Water)
Tips for photographing bears (Emilie Talpin Photography)
A Beginner’s Guide to Wedding Photography (Explora).
ssembling Your Portfolio as a Photographer (42West).

Plenty of news on the facebook OMD group, Panasonic FF and the GH5 group.
I kindly invite you all to follow me on Youtube, Instagram, Threads for more broader camera talk.

I Didn’t Expect to Feel This Way About Micro Four Thirds

Today deals at Amazon, BHphoto, Adorama, Amazon DE, Amazon UK, Amazon FR, Amazon IT, FotoErhardt DE, FotoKoch DE.
Can You REALLY Tell the Difference? Sony A7 IV vs OM-1 (Maurice Mercado)
How to Photograph the Fast Flying Little Tern in Flight with the OM-1 Mk2 and the 150-400mm Lens (Mike Lane)
Wildlife Photography Composition Guide (Explora).
How To Master Spring Lighting as a Photographer (42West).

Plenty of news on the facebook OMD group, Panasonic FF and the GH5 group.
I kindly invite you all to follow me on Youtube, Instagram, Threads for more broader camera talk.

Wandrd just launched their new magnetic Camera Strap on Kickstarter (Click here). Check out the project page to see all the new innovative features!