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Legacy Lenses Discuss the use of older lenses, using adapters, from the Olympus OM system, Leica M and R-series, and the millions of others too.

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  #16  
Old 28th June 2016
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Re: Lens Fungus

They can certainly stop further development of fungus spots and remove the hyphae themselves (the body of the fungus itself) but obviously can't do anything about any existing damage to the glass or any coatings.

This is usually not any/much of a problem in general use, but in side light and flare-inducing conditions that very much doesn't apply.

I recommend shining a bright (e.g. LED) light through the lens and seeing what that looks like. I had an old 135mm Leitz that I inherited from my Dad serviced by a good specialist repairer and, while the mechanics are now superb, looking through at a light reveals a major snowstorm. I predict that yours will be the same, but would be pleased if it wasn't!
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  #17  
Old 28th June 2016
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Re: Lens Fungus

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Originally Posted by drmarkf View Post
I recommend shining a bright (e.g. LED) light through the lens and seeing what that looks like. I had an old 135mm Leitz that I inherited from my Dad serviced by a good specialist repairer and, while the mechanics are now superb, looking through at a light reveals a major snowstorm. I predict that yours will be the same, but would be pleased if it wasn't!
It always amuses me when I someone worries about a speck of dust in a lens. The front element of my 350mm would give them nightmares. I knew a bird photographer in the UK who discovered a crack an inch and a half long in the front element of his 600mm. He didn't know how long it had been cracked and continued using the lens.
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  #18  
Old 29th June 2016
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Re: Lens Fungus

Sure, and my Elmar is brilliantly sharp in general use, but flares when there's a bright source of light in the frame, whereas my contemporary, unfungussed 90mm f2.8 doesn't.

I'm not talking about the odd dust particle or titchy patch of mould on a small part of one element. This isn't rocket science!
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Panasonic 12-35, 15. Samyang 7.5 fisheye.
Assorted legacy lenses, plus a Fuji X70.
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  #19  
Old 29th June 2016
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Re: Lens Fungus

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...I recommend shining a bright (e.g. LED) light through the lens and seeing what that looks like!
I wouldn't recommend looking directly at collimated light, especially through a lens system.
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  #20  
Old 29th June 2016
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Re: Lens Fungus

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I wouldn't recommend looking directly at collimated light, especially through a lens system.
No, but shining torchlight through a lens is helpful for revealing and illuminating fungus and any other contamination. This is best seen by viewing the illuminated lens elements at an oblique angle.
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  #21  
Old 29th June 2016
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Re: Lens Fungus

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No, but shining torchlight through a lens is helpful for revealing and illuminating fungus and any other contamination. This is best seen by viewing the illuminated lens elements at an oblique angle.
Eyes are not 'designed' (ie have not evolved) to look at light, but to see with (reflected) light.

Normal incandescent light sources are better for the purpose (old style torchlight) and your recommendation for viewing oblquily is the best advise if you must look at a light source.

As for LEDs which emit in the near IR (such as those used for pointing) the retina can be damaged easily - no blink response, or reduced, and focused near perfectly on the retina.

I worked with equipment that emitted in near IR and apart from having to wear eye protection I had regular retinal scans - mainly for the benefit of the company, some suggested!
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  #22  
Old 29th June 2016
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Re: Lens Fungus

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Originally Posted by Ricoh View Post
Eyes are not 'designed' (ie have not evolved) to look at light, but to see with (reflected) light.

Normal incandescent light sources are better for the purpose (old style torchlight) and your recommendation for viewing oblquily is the best advise if you must look at a light source.

As for LEDs which emit in the near IR (such as those used for pointing) the retina can be damaged easily - no blink response, or reduced, and focused near perfectly on the retina.

I worked with equipment that emitted in near IR and apart from having to wear eye protection I had regular retinal scans - mainly for the benefit of the company, some suggested!
This is an interesting point. LED's emit a very narrow bandwidth of light, (it is an electrochemical reaction after all). I can imagine that LED's emitting near infra-red light could do a lot of damage before anyone realises.

White LED's try to cover the entire visible spectrum by using multiple chips, but most cheaper devices emit very little in the infra-red or near infra-red spectrum; hence their horrible colour rendition. Many cheaper devices also tend to emit of a lot of light in the green spectrum as the eye is most sensitive in this region.
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Old 29th June 2016
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Re: Lens Fungus

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Originally Posted by drmarkf View Post
Sure, and my Elmar is brilliantly sharp in general use, but flares when there's a bright source of light in the frame, whereas my contemporary, unfungussed 90mm f2.8 doesn't.

I'm not talking about the odd dust particle or titchy patch of mould on a small part of one element. This isn't rocket science!
I was referring to the suggestion of using a LED torch expecting a flurry of panic posts because there was a speck of dust in a lens. Of course, if you send another makers Luxury zoom off to be cleaned it can come back sharper because it was reassembled more accurately than it left the factory.
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