Optics - The Essential Basic Tools of Watchmaking
Watch movements and parts can be tiny, even more so in female watches. Even with 20-20 vision you're still going to struggle to visually see what you're doing especially when it comes to the more delicate tasks like inspecting small parts for wear or damage and oiling.
The magnification of each of the following optical options is defined by a number followed by an X. For example if you have a loupe with 3x magnification it should make the object appear three times its actual size, though you should note that the larger the magnification the smaller the viewing field:
Magnification: 10x - eye to object: 1" inch (25mm)
Magnification: 6.7x - eye to object: 1½" inch (38mm)
Magnification: 5x - eye to object: 2" inch (51mm)
Magnification: 4x - eye to object: 2½" inch (64mm)
Magnification: 3.3x - eye to object: 3" inch (76mm)
Magnification: 2.8x - eye to object: 3½" inch (89mm)
Magnification: 2.5x - eye to object: 4" inch (102mm)
It is recommended that all watchmakers should have access to a 3.5x to 5x magnification for everyday use and 10x magnification for inspection work, specifically jewel holes and balance staffs. The quality of the lens will determine how strained your eye(s) will become over prolonged use and glass lenses tend to be better quality than plastic lenses.
There are a few optical options available to a watchmaker (all of which will be available in multiple magnification levels) which I have outlined below:
The most basic option and one which some people will have lying around anyway, a quick, easy and cheap option to begin with. The biggest drawback is that if it doesn't have a stand it will need to be held therefore only leaving one hand to work on your movement which is not ideal. I mostly find I need both hands available to work on a movement, my left hand to hold on to or steady the movement and my right hand to use the required tool. Magnifiers on a stand are better options but they will need to be moved as you move around the movement and may get in the way.
Basic Variety = around £4
Go for a cheap option.
Sometimes also referred to as an Eyeglass, this is the go to optical tool for most watchmakers. It can easily be held in place by your eye and allows both hands to be free. It also means you can quickly switch between different magnification options as required without too much fuss.
These come in a variety of options from a single plastic lens to a high end double glass lens and metal frame.
I've purchased a few of different loupes so far trying to find the best one for me. One issue i had with my original loupe was that it would often steam up and require me to stop what I was doing to wipe the glass. One solution for this is to drill a hole in the top and bottom of the loupe to allow airflow, alternatively you can purchase a loupe like the photo example with a pre-cut hole in the top and bottom. Strangely these types of loupes are sold as having the benefit of allowing light in to help improve the visuals and do not mention the steaming issue which me and numerous other watchmakers I know have experienced.
Basic Variety = around £4
Branded Variety = up to £100
It's worth splashing the cash for a quality branded loupe from Bausch & Lomb, Bergeon or Horotec. I suggest you purchase two loupes, 5x loupe and a 10x loupe to cover all bases. I currently use the Bergeon 2611-TN No.4 (2.5x) and Bergeon 2611-TN No.1.5 (6.7x) loupes as i don't like being as close to the movement.
As an additional accessory to a loupe you can also buy a holder which is in effect a metal coil which allows the loupe to be help in place on your eye without the need to crunch your eye. It also allows the loupe to hang around your neck out of the way while not in use. These are adjustable to any loupe.
This is an essential addition if like me you wear glasses and can even work on top of your glasses although the loupe is more prone to move around.
Basic Variety = around £2-5
Go for a cheap option, although i use the Bergeon 5641 Loupe Holder pictured above.
Clip On Loupe
A better solution for those who wear glasses like I do is to purchase a clip on loupe. This is in effect a loupe with a clip that allows you to clip it on to the frame of your glasses and then flip the loupe up and down as needed.
I've also purchase some of these types of loupes and found them great, but perhaps due to the cheapness of the loupes and/or my badly fitted glasses, I found that the extra weight of the loupe on my glasses made them slide down my nose too frequently which became annoying and made these loupes more of a hindrance than a help.
Basic Variety = around £4
Branded Variety = up to £70
It's worth splashing the cash for a quality branded clip on loupe from Bergeon or Horotec. Again I suggest you purchase two clip on loupes, 5x loupe and a 10x loupe to cover all bases.
It is generally suggested that you should keep both eyes open when using a loupe, as it is less tiring and speeds up transition to unaided vision.
Head Band Magnifier
Another quite popular option is a head band magnifier. This is basically a head band that fits comfortably around your head with a visor attached to the front. They are made from a lightweight plastic that can be adjusted to fit any size head.
They have the added benefit of a much wider viewing angle as both eyes are magnified and can be worn on top of your standard glasses if required. The actual visor itself can be flipped up when not required and the lenses are interchangeable. One of their biggest advantages is that they allow you to work at a greater distance from the work.
I've never tried this option myself as yet, would love to be able to test it out for a week to see if it suits me before I commit to buy one.
Basic Variety = around £8
Branded Variety = £50-90
It's worth splashing the cash for a quality branded head band magnifier from Bergeon or Donegan. The Donegan Optivisor range seems to be the most popular among watchmakers.
Offering sharp, crystal clear stereo images and great flexibility, a microscope is the perfect inspection tool for any watchmaker if your bench space allows.
A microscope gives a very large zoom magnification range and large working distance (8 inches), also a number of microscopes include an articulating arm and an LED ring light to provide bright, even and cool illumination.
Basic Variety = around £200
Branded Variety = around £900
It's worth splashing the cash for a quality branded microscope from AmScope which are available in multiple variations including with boom stand.
I'm short sighted so my current tool of choice here is the traditional loupe with the pre-cut holes for light/ventilation with a holder and I tend to switch between this and my glasses depending on whether I am doing close-up work or not. Definitely not the most efficient setup for me but it suits my requirements for now.
If you think I've missed anything or have anything to add, please comment below.