This question is in reference to magnifying my vision when sharpening saws. I use a pair of magnifying eyeglasses to sharpen saws. I don't know the magnifying power, but the focal length (distance from my eyes to the saw teeth is from 7" to 12". Within that range the teeth are sharp and well defined. Closer, or farther than that and the saw teeth get blurry.
I would like to buy one of the "Donegan OptiVisor Headband Magnifier". Donegan has a wide range of magnifications available. Each of the magnification levels specifies an associate focal length. Anywhere from 4" to 20" depending on the magnification.
My question is this: If I buy a Donegan 2x magnification head band with 10" focal length, and use this while wearing my magnifying glasses, with 7" to 12" focal clarity, will the overall focal length still be 10". Or do focal lengths of glasses plus lenses have some other factor to be considered?
Obviously my eyesight is not what it used to be. But anyway getting old has its benefits, I just don't remember what they are.
I would like to buy one of the "Donegan OptiVisor Headband Magnifier". Donegan has a wide range of magnifications available. Each of the magnification levels specifies an associate focal length. Anywhere from 4" to 20" depending on the magnification.
My question is this: If I buy a Donegan 2x magnification head band with 10" focal length, and use this while wearing my magnifying glasses, with 7" to 12" focal clarity, will the overall focal length still be 10". Or do focal lengths of glasses plus lenses have some other factor to be considered?
Obviously my eyesight is not what it used to be. But anyway getting old has its benefits, I just don't remember what they are.
Question about vision magnifiers
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