Just like most bobbies, you’ll require certain tools to repair or maintain the equipment that you use. I love repairing broken photography equipment, it helps save the planet and I save a lot of money along the way.
I’ll outline to you all the essential tools that you need for repairing lenses so that you don’t waste your time and most importantly, money on gear. Many people will give you the wrong advice on the internet, many from ignorant or arrogant personalities. This has resulted in many people, including me to botch my repairs when I was starting up. I’m neither ignorant nor arrogant, I’m a generous person with experiences to share so you won’t end up being a camera butcher.
Most of the tools that you’ll need can be bought in regular hardware stores. However, some are specialized and can only be bought in specialty stores or online. These are good investments, buy the best that you can afford but do not go overboard and buy something that is insanely expensive but of very limited use.
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Richard Haw's Classic Nikon Repair and Review 