Rodenstock APO-Sironar W 300mm f/5.6

The Rodenstock Apo-Sironar-W 300mm f/5.6 is the longest focal length in the Apo-Sironar-W ("Wide image circle") series — Rodenstock's wide-coverage variant of the Apo-Sironar plasmat family. It is designed for 8×10 and larger formats where movement headroom (rise, fall, shift, tilt, swing) matters as much as base coverage. The 490 mm image circle at f/22 provides comfortable 8×10 coverage with substantial movements; coverage of 11×14 is tight (image circle barely exceeds the 457 mm diagonal); 16×20 and larger ULF formats exceed the lens's image circle and are not covered.^[1]

Of the three Apo-Sironar 300 mm variants Rodenstock manufactured (-N normal, -W wide, -S special), the -W is the choice when 8×10 architectural or studio work demands maximum movement headroom at this focal length.

The Apo-Sironar series and W designation

Rodenstock's Apo-Sironar is a family of apochromatic large-format plasmats covering most LF focal lengths from 100 mm through 480 mm. The series uses three letter suffixes that denote optical-design tradeoffs at the same focal length:

• -N (Normal) — the workhorse standard. Smaller image circle, lighter weight, smaller filter size. Optimized for 4×5 and 5×7 with some 8×10 coverage at modest movements.
• -W (Wide image circle) — larger image circle at the cost of more weight and larger filter size. Optimized for 8×10 and 11×14 with substantial movements.
• -S (Special) — peak optical correction within the family, often with similar coverage to -N. Apochromatic glass selection is more aggressive than -N or -W.

The 300 mm focal length is available in all three variants. The -W's distinguishing characteristic is its 490 mm image circle at f/22 — about 33 % larger than the -N's ~370 mm circle at the same focal length, with 80° angle of coverage rather than the -N's ~70°.

The 150 mm and 210 mm Apo-Sironar-W siblings serve the wider-angle slot in 8×10 and 11×14 kits; the 300 mm -W rounds out the kit as the normal-perspective lens.

Plasmat optical heritage

The Apo-Sironar family is built on the 6-element 4-group symmetric Plasmat design that has been the dominant general-purpose LF lens architecture since the 1890s. Apochromatic glass selection (low-dispersion crown / dense-flint pairs) reduces residual chromatic aberration to apochromatic levels — the third-colour correction that distinguishes apochromatic from merely-achromatic objectives.^[2]

The -W design preserves the symmetric Plasmat layout but selects glass elements and curvatures to extend the image circle without sacrificing the family's flat-field correction at the 300 mm focal length. The 80° angle of coverage is at the upper end of what Plasmat-derived designs achieve while maintaining usable corner sharpness; pushing past 80° in this design family generally requires a Biogon-derived or Topogon-derived layout instead.

Image circle and format coverage

• Image circle at f/22: 490 mm
• Angle of coverage: 80°

Format	Diagonal	Apo-Sironar-W 300 covers?	Movement headroom
4×5	162 mm	yes — vast	far in excess; oversize for the lens's intended formats
5×7	219 mm	yes	135 mm spare radius — generous
8×10	325 mm	yes	82 mm spare radius — substantial; full architectural-movement workflow
11×14	457 mm	yes (tight)	only ~17 mm spare radius — minimal movements
16×20	645 mm	no	image circle insufficient — corners cut off

The -W 300 is the 8×10 architectural / large-movement specialist's choice at this focal length. For 11×14 architectural workflow, look at longer focal lengths (the 360 -N covers 11×14 with movements, the 480 -N covers it generously). For 16×20, no 300 mm Apo-Sironar variant is sufficient.

Working notes

• Filter size 127 mm — among the largest LF filter sizes. 127 mm filters are expensive and limited in stock (warming filters, polarizers, ND grads). A 127→105 mm or 127→100 mm step-down ring plus the corresponding smaller filter is the practical workaround for most users; vignetting is not an issue at 8×10 even with the step-down.
• Weight 1610 g — heavy; one of the heaviest lenses in any large-format kit. Pair with a robust 8×10 camera (Sinar P2, Toyo 810M, Wista 8×10) and a heavy-duty tripod (Ries J600 / Gitzo 5-series equivalent).
• Mount: Copal 3 — the largest standard LF shutter, with top speed 1/125 s and X-flash sync at all speeds. Copal 3 is mechanically reliable but old enough now that a CLA before relying on it for important work is wise.
• Apochromatic correction — the -W is genuinely apochromatic, not just a marketing claim. Visible-spectrum colour separation is corrected to within a few microns at the focal plane; for high-end colour-reproduction or fine-detail B&W work this matters.
• Multi-coating — Rodenstock standard multi-coat. Flare resistance is excellent; the lens performs well in difficult lighting (back-lit, partial-sun, or with bright specular reflections at the edge of the frame).

Comparison: which 300 should I buy?

Variant	Image circle (f/22)	Angle of coverage	Filter size	Weight	Best for
Apo-Sironar-N 300 mm f/5.6	~370 mm	~70°	105 mm	~1010 g	4×5 and 5×7, modest 8×10 movements
Apo-Sironar-W 300 mm f/5.6	490 mm	80°	127 mm	1610 g	8×10 with substantial movements; tight 11×14
Apo-Sironar-S 300 mm f/5.6	~380 mm	~72°	105 mm	~1080 g	4×5 / 5×7 / 8×10 normal use; peak Apo-Sironar correction
Apo-Sironar-S 300 mm f/9	~380 mm	~72°	67 mm	~440 g	Lightweight backpacking 8×10 alternative

For most 8×10 photographers, the Apo-Sironar-S 300 mm f/9 is the practical choice — the dimmer max aperture is acceptable at this focal length (8×10 work is done from a tripod with the lens stopped down anyway), and the dramatic weight savings (~1170 g less than the -W) makes a real difference in field-kit weight. The -W comes into its own only when 11×14 coverage or maximal 8×10 movements are operationally required.

Compatible cameras

8×10 view cameras with Copal 3 lensboard support:

• Sinar 8×10 series (P, P2, F, X — all accept the Sinar 5×5" lensboard via Copal 3 mount)
• Toyo 810M / 810G
• Wista 8×10 field cameras
• Deardorff 8×10 (Copal 3 mount via flat lensboard)
• Various ULF cameras for 11×14 use (with awareness of the tight image-circle margin)

For field use, the lens's heavy weight and large filter size make the Apo-Sironar-W 300 mm a studio / architectural-survey specialist's tool more than a backpacking lens.

Related lenses

• Rodenstock Apo-Sironar-N 300mm f/5.6 — standard sibling; smaller image circle, lighter weight, smaller filter.
• Rodenstock Apo-Sironar-S 300mm f/5.6 — peak-correction sibling; -N-class coverage with more aggressive apochromatic glass.
• Rodenstock Apo-Sironar-S 300mm f/9 — lightweight backpacking alternative; same -S-class optics in a Copal 1 with f/9 max aperture.
• Rodenstock Apo-Sironar-W 210mm f/5.6 — wider sibling in the -W series; 8×10 wide-perspective slot.
• Rodenstock Apo-Sironar-W 150mm f/5.6 — widest -W; 8×10 wide-angle slot.
• Rodenstock Apo-Sironar-N 360mm f/6.8 — next focal length up; covers 11×14 with movements where the 300 -W is tight.