Fast, accurate focus is the hardest part of working with panoramic and large-format rigs in the field, especially if you’re scale-focusing or you don’t want to set up a ground glass every time. The Fotoman Auxiliary Rangefinder (aka ARF) drops into your accessory shoe and gives you quick, repeatable distance readings you can transfer straight to the lens. For landscape and pano work at f/11–f/22, it’s a small thing that removes a big hassle.
What it is
- Type: Optical split-image auxiliary rangefinder
- Mount: Standard accessory (cold) shoe
- Body: Machined aluminum, lightweight but durable
- Calibration: Tool-free (user adjustable in the field)
- Base length: 35 mm (distance between windows)
- Versions:
- Metric scale: 1 m → 20 m + ∞
- Imperial scale: 3.5 ft → 60 ft + ∞
Size & weight (measured)
- Dimensions: 62.5 × 35 × 23.5 mm
- Weight: 1.39 oz (negligible on a 6×12/6×17 setup)
Optical performance & view
The focusing patch is bright and crisp, which makes alignment easy in low-contrast scenes or harsh sun, situations where vintage units often look dim or hazy. You use it like any split-image RF: point at your subject, align the double image in the patch, read the distance index, then dial that distance on the lens.
Real-world setup
On my Horseman SW612, I park the ARF next to the viewfinder using two Voigtländer shoe adapters so I can frame with one eye and focus with the other without blocking access to the ARF. That bracket lives on the camera now; it’s genuinely convenient.
Accuracy check
I compared the ARF’s readings with a modern Leica D1 laser rangefinder. Results checked out—close enough that, once you’re stopped down for pano landscapes, depth of field comfortably covers any tiny error from the shorter base.
Calibration (no tools required)
Unlike vintage units that need a jeweler’s screwdriver (or a tech) when they drift, the Fotoman lets you dial alignment yourself in the field. If you work in changing temperatures, altitudes, or you travel a lot, this matters. It’s quick insurance for consistent focus.
The base-length trade-off
At 35 mm, the ARF’s base is shorter than long-base classics (e.g., a ~75 mm Leitz FOKOS). Longer base length = finer focusing discrimination, especially close-up and with fast lenses / razor-thin DOF. In a pure precision shoot-out, a long-base vintage RF wins on close-distance accuracy.
But: long-base vintage often means dim patches, haze, aging optics, and tool-based calibration. The Fotoman is modern, bright, and self-adjusting, and for f/11–f/22 field work from mid-distance to infinity, it’s absolutely accurate enough.
Pros
- Pocket-size, all-metal construction
- Tool-free calibration in seconds
- Bright focusing patch (beats many vintage units in sun/low contrast)
- Modern build: fewer issues with haze/dimming vs older RFs
- Quick, reliable distance readouts for large-format/pano workflows
Cons
- Shorter base (35 mm): less discriminating at close distances with fast lenses
- Not a laser: ultimate precision at very close range still favors a laser RF
- Price: around US $250, not cheap, but fair for a modern, serviceable unit
Best use-cases
- Panoramic landscape (6×12, 6×17) at f/11–f/22
- Mid-distance to infinity focusing where speed and repeatability matter
- Shooters who want modern brightness and self-calibration without the vintage headaches
Verdict
For large-format and panoramic field shooters who need a fast, dependable distance readout without hauling a ground glass every time, the Fotoman ARF is a smart, modern solution. It won’t replace a laser for close-up, ultra-thin-DOF work, and it’s not a long-base precision instrument, but in real pano-landscape use, it hits the sweet spot: light, rugged, bright, and easy.