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![](2025-12-10-15-24-28.png)
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+## lens and oil
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+How mineral oil affects lens materials
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+
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+### ● Glass elements
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+Mineral oil **does not damage glass**. No dissolving or warping.
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+
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+### ● Optical coatings (multi-coatings)
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+Mineral oil does **not chemically attack coatings**, but it can leave an **oil film**.
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+This causes:
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+- lower contrast
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+- foggy look
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+- ghosting
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+
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+### ● Optical glue (UV glue / epoxy glue)
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+Most lens groups use **epoxy-based optical cement**.
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+- Short-term contact: usually **safe**
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+- Long-term soaking: may **soften**, **yellow**, or **release stress**
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+
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+### ● Plastic parts (ABS, PC, nylon)
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+Usually **stable** in mineral oil.
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+Some plastics may swell after many months.
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+
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+
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+## lens tuning
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+
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+![](2025-12-10-19-40-21.png)
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+
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+### Six keys to maintain clarity after oil immersion
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+
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+- Use oil with a consistent, stable refractive index
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+- Avoid any trapped air bubbles
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+- Ensure every lens surface is completely clean
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+- Lens elements must not be decentered or loose
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+- Use oil that stays clear long-term (no discoloration or precipitation)
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+- Re-focus after oiling to restore optimal imaging
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+
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+🔹 Step 3: Loosen M12 lens lock
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+
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+Most M12 lenses have a locking ring / small set screw.
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+
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+Loosen just enough to rotate the lens for focus adjustment.
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+
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+Keep the lens barrel supported.
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+
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+🔹 Step 4: Adjust focus
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+
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+Rotate the lens barrel slowly while observing the live camera feed.
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+
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+Look for the sharpest image on your test target.
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+Zoom in on the LCD or PC and check multiple points (center + edges).
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+
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+Fine-tune until center and corners are acceptably sharp.
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+
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+Note: Oil can slightly change corner distortion, so prioritize center sharpness.
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+🔹 Step 5: Lock the lens
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+Tighten the M12 locking ring or set screw after final focus.
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+Avoid over-tightening (plastic threads may strip).
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+Make sure the lens does not move after locking.
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## camera lens
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