Japan Camera Grades

By Yu Kanke · Japan Camera Grades · Last verified 2026-10-28

The Japanese Fault Glossary

Twelve words that appear in Japanese used-camera listings — and what each one actually costs you.

Last verified: 2026-10-28.

Japanese shops put the real information in a free-text comment field, not in the grade. The grade tells you about cosmetics; the comment tells you about condition. These are the terms that decide whether a lens or body is worth importing.

The four shops compared in our grading article (Kitamura, Fujiya, Map Camera, RE Camera) all use this vocabulary, but they do not define every term, and the same word can carry different severity depending on where you buy.

1. カビ — fungus

Filamentary growth on lens elements or coating. Shows in a listing as "カビあり" (fungus present) or "カビ無し" (none) and, at good shops, which element.

Fungus etches coating as it grows. Surface fungus on a front element is often cleanable; fungus between cemented elements usually is not. For resale, assume the coating has been affected unless a repair invoice says otherwise.

2. クモリ — haze

A milky film, usually evaporated lubricant from the aperture or helicoid, condensing on inner glass. Listing: "クモリあり".

Separate from fungus. Haze reduces contrast and flare resistance but is frequently removable by a repair shop because it sits on the surface of an inner element. A hazy lens can be a good buy if the price reflects a service.

3. バルサム切れ — balsam separation

The cement layer between two cemented elements is failing. It appears as an oily sheen or rainbow patch, usually at the edge. Listing: "バルサム切れ".

This is the most expensive of the glass problems: it requires separating, recementing and re-centering. Treat it as a parts lens unless the model is rare and you have a repairer.

4. チリ・ホコリ — dust

Normal. Almost every used lens has some. Only worth pricing in when it is visible in the image at small apertures, which sellers rarely test for.

5. 絞り羽根の油 — oil on the aperture blades

Oil migrates onto the diaphragm from the helicoid grease. Listing: "絞り羽根に油".

The blades become slow or sticky, and exposure drifts at small apertures. On manual lenses this is a standard service; on autofocus lenses it means disassembly.

6. ヘリコイド固着 — stiff or seized focus helicoid

Old grease hardens. The focus ring becomes stiff, uneven, or immovable. Listing: "ヘリコイド固い" or "ピントリング重い".

A stiff ring is a service item. A seized one on a lens with a complex floating-element group is a bigger job. Ask whether the ring moves at all.

7. モルト劣化 — deteriorated light-seal foam

The foam seals around the film door and mirror box degrade into a sticky paste. Listing: "モルト劣化" or "モルト要交換".

Cheap to replace as a part, but the sticky residue can transfer to the mirror and shutter. On a body that has sat unused, always assume replacement is needed.

8. ミラー腐食 — desilvering on the mirror

The reflective coating on the edge of the mirror lifts. Listing: "ミラー腐食".

Cosmetic to the finder image, not to the photograph (the mirror is out of the light path at exposure). It does affect resale value on collector models and is a negotiation point, not a dealbreaker.

9. プリズム腐食 — desilvering in the prism

The same failure inside the pentaprism, usually from foam contact. Listing: "プリズム腐食".

Shows as a dark or discoloured patch in the viewfinder. Again, not in the image path, but repairs are uneconomic on most models.

10. 幕切れ・シャッターのタルミ — shutter capping / curtain drag

The two shutter curtains travel unevenly at high speeds, causing a dark band on one side of the frame. Listing: "シャッター要調整" or "幕切れ".

Easy to miss because it only appears at fast speeds. Ask for test shots at 1/1000 and 1/500, or assume a service is needed on any mechanical body that has not been used recently.

11. 露出計の誤差 — meter error

The meter reads high or low. Often caused by wrong battery voltage (mercury cells replaced by alkaline) or a degraded CdS cell. Listing: "露出計動作不良" or "露出計±1EV".

On mechanical bodies the meter is a convenience, not the camera. On electronic bodies it may indicate a deeper fault.

12. 電池ボックスの腐食 — battery corrosion

Leaked cells have attacked the contacts, and often the circuit board. Listing: "電池ボックス腐食".

The single most common reason a cheap electronic body is cheap. Surface corrosion on the contacts is fixable; corrosion that has reached the board usually is not.

How to use this list

  1. Read the comment field before the grade. Grade is cosmetics; these twelve terms are condition.
  2. Separate cleanable from terminal. Haze, dust, oil and foam are usually service items. Balsam separation, prism desilvering and board-level corrosion are not.
  3. Ask for the specific term. Japanese sellers answer direct questions well. "レンズ内にカビ・クモリ・バルサム切れはありますか" gets a real answer; "is it in good condition" does not.
  4. Price the service, not the defect. A hazy 50mm at the right price is a better purchase than a clean one at the wrong price — but only if you know a repairer.

Sources

Definitions describe how the terms are used in Japanese retail listings. Severity and repair cost vary by model and by shop. Verify on the individual listing.