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Message |
    
Rossjustin
Tinkerer
Username: Rossjustin
Post Number: 1
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 23, 2007 - 04:57 pm: | 
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I have two Carl Zeiss Jena lenses and both have little circles inside the body. I can see them when holding it up to the light. How bad is this?
Also the Biotar lens has marks where some body cleaned it with a not very nice rag. There are small swirls all the way around. Doesn't look like anything deep. Are these going to affect anything and are they removable. Thank you |
Nikos
Tinkerer
Username: Nikos
Post Number: 6
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 25, 2007 - 07:58 am: |
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Dust usually looks like dust. Most likely those little circles you see inside the body are air bubbles. They do not affect lens performance adversely and have been considered a hallmark of Jena (superior) glass.
The small swirls are "cleaning" marks. Actually they are scratches of the lens coating. Despite what some people say THEY ARE NOT REMOVABLE, unless you send the lens for recoating. If excessive, they may cause softness. They are the result of improper lens cleaning. By the way never clean your lenses until you are experienced enough to do so. When the time comes you will know.
Try to ignore them and see if you like the results. Lenses are made for taking pictures. If you like your photographs everything is fine.
I hope thie is of some help.
Nicholas |
Rossjustin
Tinkerer
Username: Rossjustin
Post Number: 2
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 27, 2007 - 01:00 pm: |
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That helps alot. I greatly appreciate the help. Justin |
Wideopeniris
Tinkerer
Username: Wideopeniris
Post Number: 2
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 06, 2007 - 07:30 am: |
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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. |
