| Author | Message | ||
     Wideopeniris Tinkerer Username: Wideopeniris Post Number: 2 Registered: 08-2007 Rating: N/A |
Depends on what you mean by circles. Some lens fungus will show as a circle surrounding a central spot - the fungus (contrary to popular beleif) feeds on dust particles - this food source is quickly exhausted and often a ring of 1-2mm diameter is as far as it gets. It depends on the type of fungus. Some fungus marks are like spiders webs or star shapes but these are mycelium growing types. A common source of getting fungal haze or spots is incorrect cleaning. Some people will spray water based cleaning fluid on their lens elements - this leaks into the body of the lens and creates a nice damp semi sealed environment ideal for fungii. Always apply cleaner sparingly to the cloth and wipe your lens with it, not the other way around. The swirls are on the outer coating caused by rubbing with a contaminated cloth or not blowing sand or other hard particles off the lens before wiping. Use a blower and gentle brush to remove debris before wiping away smears and fingerprints. The effect of bubbles, small fungus marks and cleaning mark to the photographic peformance are the same. Some off axis light is scattered by these defects and causes a degradation in the image contrast (filling in shadows with scattered light). If the proportion of the light going through the lens being scattered is small then the effect may not be noticable or be only noticable on high contrast scenes with black and white film or in the shadows of digital pics. If you do have fungus spots then there is only a small chance they can be cleaned. The fungal by-products are often acids that etch coatings and glass surfaces. Some moulds can be removed sucessfully. Its a matter of chance and requires full disassembly of the lens. Often not worth the cost. What Nikos says is correct - shoot some frames, see if you like them.Compare with another lens to check contrast. Good luck, Kevin. |