What this covers: Loading 35mm film into a medium format camera — specifically a Zenza Bronica ETRSi with 75mm lens — and shooting it cross-format at the Roman walls of Silchester at dawn. Includes the technical setup, film choice, development notes, and the full series of thirteen frames from the session.
Film: Kentmere Pan 400 (35mm). Developer: Rodinal 1+25, stand developed for 11.5 minutes. Location: Calleva Atrebatum, Silchester, 5:30 AM.
There is a particular kind of creative restlessness that builds up after a long stretch of careful, considered work. The right film, the right developer, the right conditions, the right exposure — all of it controlled and deliberate. Eventually, something in you wants to introduce a variable you cannot fully predict and see what happens.
That is what led me to Silchester at half past five on a May morning, loaded with a roll of Kentmere Pan 400 — in 35mm format — inside the 120-format back of the Zenza Bronica ETRSi. The cross-format hack requires a pair of 35mm-to-120 adaptor spools, a willingness to wind carefully in the dark, and a reasonable tolerance for not quite knowing what the edges of your frame will look like until the negatives come out of the tank.
What it produces — sprocket holes exposed to light, cinematic frame edges, the 35mm image floating inside a gate built for a much larger format — is a look that digital cannot replicate and that standard film photography does not produce. It is not a technique for every session, but on the right morning in the right place it produces something genuinely unlike anything else.
How It Works — 35mm Film in a Medium Format Camera
The Bronica ETRSi is a 6×4.5cm medium format camera. It is designed to accept 120 roll film, which is approximately 60mm wide and has no perforations — the film is backed with opaque paper that protects it from light during loading and unloading. Standard 35mm film is narrower (approximately 35mm across) and has sprocket holes running along both edges, which are normally hidden inside the 35mm camera’s film gate.
When you load 35mm film into a medium format camera using adaptor spools, the narrower film sits centrally in the wider film gate. The medium format lens projects a much larger image circle than the 35mm frame requires, and the result is that the full width of the 35mm film — including both rows of sprocket holes — receives light. The image extends beyond where a standard 35mm camera would crop it, and the sprocket holes become visible in the final frame.
The practical process: the 35mm film is wound from its original canister onto a 120-compatible spool in complete darkness, then loaded into the Bronica back as you would load any roll of 120 film. Because 35mm film has no backing paper, you need to handle it carefully during loading to avoid fogging the edges. After shooting, the film is wound onto a second empty spool in darkness and then decanted back into a standard 35mm canister for development in a conventional developing tank.
Why Kentmere Pan 400
Kentmere Pan 400 is a practical choice for experimental work. It is affordable enough that a failed experiment does not sting financially, consistent enough in its behaviour that any unpredictability in the results comes from the technique rather than the film, and at ISO 400 it has enough speed to handle the low, soft light of a May dawn without requiring a pushed development on top of everything else the cross-format process is already introducing.
The grain structure of Kentmere Pan 400 suits this kind of work well. It is a classic-looking grain — not the smooth, refined structure of HP5 Plus or the crystalline sharpness of Tri-X, but an honest, tactile grain with a slightly warm mid-tonal character that sits well alongside the texture of ancient stone and the imperfect edges of a cross-format frame.
Development was stand development in Rodinal at 1+25 for 11.5 minutes — a method that uses minimal agitation (typically just the initial inversion to fill the tank, then leaving it undisturbed for the full time) and produces negatives with excellent tonal separation and retained shadow detail. Stand development is particularly suited to scenes with a wide tonal range — which a dawn landscape invariably provides — because the developer exhausts more quickly in the bright areas, automatically moderating highlight contrast while continuing to work in the shadows.
Calleva Atrebatum at Dawn
St Mary’s Church on the Roman wall at Silchester — Kentmere Pan 400 shot cross-format in the Bronica ETRSi. The sprocket holes visible at the frame edges are an intrinsic quality of the technique, not a defect.
Silchester is a place I return to repeatedly — it is central to the long-term Echoes of Calleva project and familiar enough that I know its rhythms across seasons and hours of the day. At 5:30 in the morning in May, the Roman wall is completely deserted. The early light comes in low and soft from the east, raking across the stone and picking up textures that the overhead light of midday flattens entirely. The birds are loud; everything else is quiet.
It is the right place for an analogue experiment. The location already exists in a kind of dialogue with time — walls that have stood since the second century, photographed on film chemistry that predates the digital age, using a camera system built in the 1970s. Adding a further layer of technical anachronism to that conversation felt appropriate rather than contrived.
The Roman wall at Calleva — the wide tonal range of dawn light handled well by stand development. The cross-format frame edge and sprocket holes give the image a quality closer to a contact print or test strip than a conventional negative.
Film Characteristics in Cross-Format Use
| Aspect | Details | Effect on Final Image |
|---|---|---|
| ISO Rating | 400 — rated at box speed | Adequate speed for dawn conditions without pushing |
| Grain structure | Classic medium grain, tactile character | Adds texture that suits stone and atmospheric subjects |
| Tonal range | Broad midtones, gentle highlights, deep shadows | Stand development extends shadow detail further |
| Contrast | Moderate — controllable in development | Stand development moderates highlight contrast automatically |
| Sprocket exposure | Visible along both frame edges | Cinematic, contact-print quality — a feature, not a flaw |
| Format quirk | 35mm film in 6×4.5cm gate | Wider field of view than standard 35mm; unique frame proportions |
| Development method | Rodinal 1+25, stand, 11.5 minutes | Enhanced tonal separation, retained shadow detail |
| Best use case | Moody landscapes, architecture, atmospheric early light | Rewards subjects with physical texture and tonal depth |
Can you really load 35mm film into a medium format camera?
Yes — with the right adaptors. The process involves winding the 35mm film from its canister onto a 120-compatible spool in complete darkness, loading it into the medium format back, shooting, then winding it onto a second empty spool and returning it to a 35mm canister for development. It requires a changing bag and some patience, but the mechanical process is straightforward once you have done it once. The results — with sprocket holes exposed and the full width of the 35mm film visible in the frame — are unlike anything standard 35mm or medium format shooting produces.
What adaptors do you need to shoot 35mm in a medium format camera?
You need two 35mm-to-120 adaptor spools — one to wind the film onto for loading, one to act as the take-up spool during shooting. These are available inexpensively from eBay and specialist film photography suppliers. Make sure you get the right size for your specific camera system — the Bronica ETRSi uses standard 120 spools, but other medium format systems may vary.
How many frames do you get when shooting 35mm in a medium format camera?
Fewer than with a standard 35mm camera, because the medium format film gate advances the film differently than a 35mm body does. On the Bronica ETRSi, which normally shoots 15 frames of 6×4.5cm on a roll of 120, a 36-exposure roll of 35mm film typically yields around 13 to 17 usable frames depending on how the film advance is set up. The frame count is less predictable than standard shooting — which suits the experimental nature of the technique.
What does the cross-format image look like?
The 35mm image sits centrally in the medium format gate, with the sprocket holes on both edges of the film exposed to light and visible in the final frame. The image area itself is standard 35mm proportions, but framed by the sprocket holes and backed by the larger negative area of the medium format film. The overall effect is reminiscent of a contact print or a test strip — cinematic in proportion, with a rawness to the edges that finished 35mm or medium format images do not have.
What film works best for cross-format shooting in a medium format camera?
ISO 400 films are the most practical starting point — fast enough to work in variable light without pushing, and with a grain character that suits the experimental aesthetic of the technique. Kentmere Pan 400 is a good choice for its affordability and consistent behaviour. Ilford HP5 Plus would also work well. Avoid very slow films — the technique introduces enough variables without adding the exposure constraints of ISO 25 or 50 into the mix.
What developer suits cross-format film development?
Stand development in Rodinal suits cross-format work particularly well. The minimal agitation and long development time produce negatives with excellent tonal separation and good shadow detail — which matters when the subject has a wide tonal range, as dawn landscapes invariably do. The 1+25 dilution used here is slightly more concentrated than the usual 1+50, which gives slightly more shadow density; a 1+50 dilution for a longer time would produce a similar result with slightly finer grain.
Is cross-format shooting compatible with the Zenza Bronica ETRSi?
Yes — the Bronica ETRSi works well for cross-format shooting because its interchangeable backs make loading and unloading in a changing bag practical, and its film advance mechanism advances the film a consistent distance per frame. The 75mm standard lens gives a field of view that suits landscape and architectural subjects in the cross-format configuration. Full details on the camera are in the Bronica ETRSi review.
This post is part of the Film Photography Hub — reviews, guides, and real-world observations from shooting and developing black and white film.
