I sell dried mushrooms and black fungus, which region and country needs more？
A simple lens consisting of a glass element can be used for image photography. However, all lenses suffer from deterioration due to focus errors known as aberrations. Lens manufacturers have had problems with camera design from the start. You are unable to remove aberrations. But clever designs almost make them disappear. Since there are seven main types of aberrations, a multi-element is required to mitigate them.
A modern camera lens consists of positive (convex) and negative (concave) lenses. Some are made of tough, dense glass. others are made of lower density glass. Some elements have an air gap. some are glued together. The cement must be transparent, non-yellowing and have a suitable refractive index. For most of the photo story, glue was made from the juice of the Canadian balsa tree. Today's lenses are cemented with a synthetic resin. The older cement is organic and acts as a culture medium that can support fungi and mildew. To overtake infected cemented lenses, you need to soak them in a suitable solvent. After separation, you need to cement again with an adhesive with the correct refractive index.
Such a task is daunting and likely to be unsuccessful unless the craftsman has an optical bench and special skills.
For all the following points: YMMV *, reservation trigger, no responsibility for advice, you decide if you try this at home. It may even work :-). Note that damage can be fatal and / or lethal (lens damage) occur. The best option is to consider the lens as depreciation. Anything you can do with the methods outlined below is a bonus.
Fungus in a lens becomes always worsen the picture but The degree of degradation may be invisible to mere mortals or render the lens completely unusable for all standards. Often, even a very visually significant lens flaw – such as a chip or a scratch – in a final image is not immediately obvious to a casual observer. Experts will usually be able to spot (or be able to say) that almost any defect is possible – mere mortals will not be able to tell if they are right :-)). In addition, the lens settings affect how much a particular error affects a particular image.
In some cases, the advice given under 1a and 1b will turn the results from generally unacceptable to generally acceptable. In other cases they will not. Only if you try, you can see how good a method is.
The best advice (but too late :-() is to never let it happen.Fungal grows only in humid conditions.Store the contact lenses in a well ventilated, dry place with desiccant pillows.
If it is in the lens, there are two options (apart from the disposal). While both may work, neither of them will work well.
1 (a) When ultraviolet light (ultraviolet light) is shone into the lens for an extended period of time, the fungus is "discouraged" by how well and how long it is uncertain. Keeping the lens with the shutter on a sunny window frame in a dry place for weeks to months completely open may give good results. Bring the lens back and tilt it so that the sun shines into the lens during sunny daytime periods. (Make sure the sun shines directly along or near the lens axis can focus the light on the endcap and melt it off – unlikely, but checkpoint and focus.) I tried this method with an extremely old Minolta 50mm f1: 1.4. manual lens and achieved tolerable results. I simply left the lens as above for many months and the next time I looked it turned out that the mold presence was significantly reduced.
1 (b) light from a germicidal A UV lamp (short wavelength) can be used instead of sunlight. This type of light can blind you or permanently damage your eyes if you look at them for a long time. This can lead to "arc eyes" – painful, but usually temporary inflammation of the eye. That does not mean that you should not use such lamps at all – they just need to be used with respect. These lights are available for many purposes from many sources and can be very cost effective.
Note that UV light "black light" is not suitable for this purpose. It is longer-wavelength and less biologically active.
Also note that the short-wave, high-energy UV (which is why you use it) of germicidal UV lamps will damage other materials such as some plastics and various other materials, including possibly parts of a plastic lens housing. This depends on material, distance, light energy and exposure time. YMMV, but caveat: You know you're using a tool with sharp, unguarded blades (even though you can not see them), and use it with care.
All this can prevent some people from UV sterilization lamps. If so, that's good. They are a great and useful tool, but not suitable for the use of careless or thoughtless people.
2 Disassemble and clean. If the lens is so damaged that it is unusable and the above procedure does not work well enough, the lens must be disassembled. If the lens is otherwise a "write-down" and you are mechanically competent, you may want to try it yourself. Assembling a lens capsule is considered an expert task, and realignment in assembly may require arcane knowledge, are still in business and cost money to use.
Fungus often attacks lens surface coatings and can etch the glass itself, so that the lens can be significantly or fatally affected independently. How much May / May / May is applied in your case is tbd. Some lens cleaners work very well. An aficionado and a good MTR test will probably tell you that something has happened, but the results can be very bearable in practice.
You can find articles on lens cleaning methods on the internet. I read a paper by Zeiss or Leitz in which it was suggested that cigarette ash is an excellent cleaning composition (!!!).
Added: Member 19602 has made this comment – since he has left and comments can also be added, I will add it to my answer.
On April 7, 2013, once member was said in 19602:
- I can tell you with absolute certainty that the Leitz recommendation is not a closed container with a desiccant but an area with constant air circulation. I used to be with Leitz Germany.