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Reciprocity

Rollei RPX 25 long exposures

What a metered time becomes on RPX 25, and the stops it adds — worked out from Rollei’s own data, never past it.

Form T-2

Your metered time

Rollei’s table: 2 s → 3 s, 10 s → 20 s, 20 s → 50 s, 50 s → 180 s

The maker’s reciprocity data ↗

Table 1

At a glance

Metered Expose for Added
1 s 1 s —
2 s 3 s +0.6 stops
4 s 6.8 s +0.8 stops
8 s 15 s +0.9 stops
15 s 34 s +1.2 stops
30 s 1 min 28 s +1.6 stops

Longer times are beyond the maker’s table and are not published.

Other films with reciprocity data

Other films with reciprocity data

The reciprocity calculator ›