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Headband Visor Magnifier

I have a sharpening video with Bonnie and others in it some where. It will be in the last place I look and I haven’t started looking.

I use the optivisor. I use them over my prescription safety glasses that have about 36” focus.
I can use my my uvex face shield over them for turning finials and other details.

Rio Grand has them for about $45. They are light and comfortable.
https://www.riogrande.com/Product/Donegan-OptiVISOR-with-35X-Lens/113199
 
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Maybe "mageyes"? http://www.mageyes.com/default.htm
I lost mine for a while and bought the ones John linked to, they are similar to the Mageyes, the difference is the width of the lens. In the Donegan the lens is smaller width wise, not by much, but I was glad when the mageyes reappeared... I think both are good, I was just used to the slightly wider lens.
 
hockenbery said:
I have a sharpening video with Bonnie and others in it some where. It will be in the last place I look and I haven’t started looking.

I use the optivisor. I use them over my prescription safety glasses that have about 36” focus.
I can use my my uvex face shield over them for turning finials and other details.

Rio Grand has them for about $45. They are light and comfortable.
https://www.riogrande.com/Product/Donegan-OptiVISOR-with-35X-Lens/113199
Click to expand...

These Optivisors are very popular.......I also have some. One thing to consider, for anyone considering purchasing, is the focal length changes with the magnification you select. How close do you want your head to be to the work? I chose the 2.5x, which has a focal length of 8".

-----odie-----
 
I have a Donegan Optivisor that I've had for about 5 years. Many of these optivisors look almost the same...... Mine is 3.5x. Used it extensively when I was in pen production and still us it a lot today when doing fine detailing.
 
odie said:
One thing to consider, for anyone considering purchasing, is the focal length changes with the magnification you select.
Click to expand...

It's a very common misunderstanding and I'm picking at nits, but what you're referring to is actually the working distance ... the distance from the lens to the subject. The focal length is the length that a collimated beam of light passing through a lens focuses to a point. The magnification of a lens is a factor of how far it is from your eye ... and that, in turn, will affect the working distance.
 
Bill Boehme said:
It's a very common misunderstanding and I'm picking at nits, but what you're referring to is actually the working distance ... the distance from the lens to the subject. The focal length is the length that a collimated beam of light passing through a lens focuses to a point. The magnification of a lens is a factor of how far it is from your eye ... and that, in turn, will affect the working distance.
Click to expand...

Aye Bill.....

Is it not true, that increased magnification will mean both your eyes, and the lens itself will have to be closer to the subject, in order to see it clearly? Suppose point A is the subject, point B is the lens, and point C is your eyes. So.......if I get this right, then if the magnification increases, the distances AB, and AC will decrease to see clearly, but the distance BC remains a constant?

For our purposes here, someone interested in purchasing one of the optivisors, will have to base their decision on the type of work they do, the magnification they wish to have, and the distance their eyes, and lenses will be from the subject.

It does seem like picking nits.......but, I am attempting to have a more complete understanding. :D

-----odie-----
 
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odie said:
Aye Bill.....

Is it not true, that increased magnification will mean both your eyes, and the lens itself will have to be closer to the subject, in order to see it clearly? Suppose point A is the subject, point B is the lens, and point C is your eyes. So.......if I get this right, then if the magnification increases, the distances AB, and AC will decrease to see clearly, but the distance BC remains a constant?

For our purposes here, someone interested in purchasing one of the optivisors, will have to base their decision on the type of work they do, the magnification they wish to have, and the distance their eyes, and lenses will be from the subject.

It does seem like picking nits.......but, I am attempting to have a more complete understanding. :D

-----odie-----
Click to expand...

I think that what I was trying to say isn't what you thought I said. I was just saying what you were calling focal length is actually a term called "working distance" which is the distance from the objective lens to the subject while focal length is a fixed length characteristic of a lens that I defined earlier (I won't mention using a magnifying glass to focus sunlight to burn ants since none of us have ever done such a thing when we were kids, but that's a more down to earth definition :D) . The two distances aren't equal. You can think of the head mounted magnifier as being comparable to a multi-element fixed focal length camera lens where the magnifier is the objective element, eyeglasses would be an intermediate element, your eye lens would be the rear element, and the retina would be the sensor focal plane. The working distance from the objective element to the subject is affected by not only the magnifier, but also your glasses and your eye lens and the distance to the retina. Since these things vary from person to another, it means that the working distance also varies from one person to another. I noticed one of the ads mentioned focal length for different lenses in their magnifiers, but I have a feeling that they were really talking about working distance for an average person who doesn't wear glasses.

To respond to what you were asking, if it were possible to move the magnifier closer or further away from your eyes then you would change the magnification, but then it would be necessary to move closer or further from the subject to get things back in focus. This is exactly what macro photographers do. The focusing ring on the lens is used to change magnification and then focusing is done by moving the camera closer or further from the subject. Focus and magnification interact with each other. Another example in photography is that a photographer could use an "extension tube" (which is just a spacer) that goes between the camera body and lens. This allows the camera to be focused at a closer distance to the subject, but it also changes the magnification.
 
Not into the actual physics of magnification but I do know that a magnifying glass makes things look bigger! I stayed at a Holiday Inn Express once. OK.....I have a magnifying light that I used for building fishing rods and tying flies. I can focus it to bring things in clearer and magnified. Wouldn't be without it as I can look at my blank surfaces with a real big critical eye.
 
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I booted up the Bonnie Klein sharpening dvd and she appears to be wearing the Mag-Eyes visor. Mageyes.com. (It could be a different brand, but Mageyes is a relatively unique design, unlike the gray visors which are made by many manufacturers, including Optivisor and Baush&Lomb)
mageyes.jpg

As noted, they come in different magnifications, and if I recall correctly, come with 2 lenses that can easily be swapped. #2 (1.6X) and #4 (2.0X) are one set, and probably #5 (2.25X) and #7 (2.75X) are the other. Also, if I remember correctly, the 2.0X is "twice the magnification" and not necessarily the same thing as dime store reading glasses of 2.00.

As mentioned above, as the strength of magnification increases, the distance at which the object is in focus decreases. I can use Mageyes to tie tiny flies at a distance of 12 inches, and I can check for scratches in wood at 12 inches, but I couldn't turn on my lathe wearing that magnification.
 
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I bought something similar at Rockler Hardware several years ago except that they have a light shield over the lens. While it seems like a good idea, it was a poorly thought out design in which the shield hangs on the headband making it impossible to get them positioned correctly. The nice feature is that you can change magnification by flipping a second lens down over the first lens. There is a spring hinge at the top thst makes it easy to change magnification on the fly without needing to remove the magnifier. About the only thing that they are good for is removing splinters.
 
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