KonicaImpresa 50

Konica Impresa 50 was an ISO 50 professional color negative film made by Konica for C-41 processing, sold in 135 and 120 [1]. Its datasheet claims the highest level of granularity and sharpness of any color print film then available [1]. Konica Minolta closed its color film division in March 2007 [5], so the film now exists only as expired stock.

Look and color

Little has been published about the color, and the detailed accounts describe rolls that were long past their date.

• Konica’s claim. The datasheet speaks of “Simulated Spectral Foundation Technology” that captures subtle tones with fidelity, and of extremely fine shadings of color [1]. It says nothing about saturation.
• Restrained, according to one review. A 2016 review of 15-year-old rolls found saturation “not the hallmark” of the film, though some frames showed good color fidelity [2]. A search summary of forum posts, which we could not open, adds that blues, cyans and greens look clean and “liquid”, and yellows and oranges weak. We treat that as unverified.
• High, according to another summary. A summary of an ePHOTOzine article, also unread, reportedly calls the saturation high for a low-contrast film. The sources contradict each other, and the Grain Archive style takes a sustained saturation, not as strong as Kodak Ektar’s [7].
• Cool cast. The same 2016 review found a strong shift toward cooler tones [2]. Whether the cause is the film, the light, the age of the roll or the printing is not established.
• Expired rolls. Rolls sold today are far past their date. A photographer who shot an expired roll saw uneven quality between frames and occasional unexplained discoloration [3].

Tonality

• Curve. On the datasheet’s characteristic curves (Status M densities), the three layers run as nearly parallel straight lines between log H −1.5 and +0.5. We read slopes of about 0.7 (blue), 0.6 (green) and 0.55 (red). The toe is short. Red and green curve slightly toward +0.5, while blue stays straight (our reading of the graph). Middle gray is not marked, so the shoulder cannot be placed in stops [1].
• Contrast. The datasheet promises “delicate contrast” without a figure [1]. Reviews say low: a photographer calls the film low-contrast and “dreamy”, as the maker marketed it [3], and another found thin negatives and a lack of contrast [2]. Both handled expired rolls that had lost speed, so they do not prove how fresh film behaved.
• Speed. The photographer of the Flickr set found the expired roll behaving like ISO 25 to 32 and asking for a lot of light [3].
• Long and short exposures. No correction is needed from 1/10,000 s to 1 s, and +½ stop at 10 s with no filter [1].
• Light sources. It is balanced for daylight, electronic flash and blue flash bulbs. Konica lists ISO 16 with an 80B filter under 3400 K photolamps and ISO 12 with an 80A under 3200 K tungsten [1].

Grain and sharpness

• No grain figure. The datasheet gives neither an RMS granularity nor a Print Grain Index, so the grain cannot be compared with other films’ numbers. It only claims the highest granularity and sharpness level among color print films then on sale [1].
• Resolving power. 63 lines/mm at test-object contrast 1.6:1 and 160 lines/mm at 1000:1 [1]. Konica’s faster Centuria Super 400 sheet gives 50 and 100 lines/mm [6]. Konica also publishes a modulation transfer curve for Impresa 50.
• Expired rolls. The 2016 review calls fine grain the film’s main selling point and says it held up after aging [2]. The Flickr photographer saw considerable grain in the shadows of an expired roll [3]. The style follows the datasheet claim: very fine grain.

Spectral sensitivity

The blue-sensitive layer rises to a broad hump around 450 nm and falls steeply past 460 nm, the green layer peaks near 551 nm, and the red layer forms a wide plateau centered near 620 nm. Blue and green cross near 484 nm, green and red near 571 nm, and the green and red curves overlap widely [1]. The Grain Archive style is not computed from these curves.

Names, status and history

• Name. The datasheet calls it Konica Color Impresa 50 Professional [1]. Camera-wiki spells it “Impressa” in its list of Konica color negative films [4]; we found no separate product under that name.
• Introduction. A 2016 review says it appeared in the late 1990s [2]. The datasheet is undated and we found no manufacturer announcement.
• End of production. Konica Minolta closed its color film, color paper and minilab divisions in March 2007 [5]. Camera-wiki notes that DNP took over the Odawara factory in 2006 and relaunched only the Centuria brand, dropped two years later [4]. We found no page giving a date for the last Impresa 50 batch. A search summary mentioned May 2014, without a source we could check, so we do not use it.
• Today. Only expired stock remains. Konica advised keeping unused film in a cool, dry place, below 10 °C [1].