Optical Filter – The All-Inclusive Buying and FAQ Guide

If you can’t find a good and a reliable optical filter = manufacturer, then you’re just in the right page! In today’s guide, we will go over a complete walkthrough of how you can get the best and highest quality color filter glass for your business!

Unlike other manufacturers, we here at SXET will never leave you wondering what your best choice could be! We’ll give you a complete take from top to bottom, so you know what to expect in finding your optical filter glass!

1. What is Optical Filter?
2. What Are the Two (2) Types of Optical Filters?
3. Where Do You Use Optical Filters?
4. Optical Bandpass Filters
5. What Does a Lens Filter Do?
6. How is an Optical Filter Glass Manufactured?
7. Is an Optical Filter Glass Necessary?
8. Do Lens Filters Affect Quality?
9. What Should You Look For in Optical Filters?
10. Can You Get Custom Shapes For Optical Filter Glass?
11. Long Pass Filter vs. Short Pass Filter
12. Where Can You Buy High Quality Color Filter Glass?

What is Optical Filter?

Optical filter is simply an instrument that’s used to transmit various wavelengths of light in a selective manner.

Figure 1 – An image of a plain and in-progress optical filter

In simpler and easier terms, they alter the light that passes through a particular unit, setting them based on the specific wavelength of light.

The importance of optical filters encompasses the traditional utilization of glass. As a matter of fact, the industries and sectors it’s used on is wide and vast.

What Are the Two (2) Types of Optical Filters?

Generally, there are two (2) types of optical filters: dichroic and absorptive.

Figure 2- Dichroic optical filter example

Both optical filter types are either made from glass or inorganic compounds and the difference of these two (2) are in terms of “how” they filter, not “what” they filter.

Figure 3 – Absorptive filter glass units in different sizes

Let’s briefly discuss what these types of optical filters are.

Dichroic Filters perform by reflecting a select type of wavelengths instead of absorbing them. The properties of these filters are what’s responsible for the reflecting of the light’s wavelengths. In the best sense, they’re used for shortpass applications.

Absorptive Filters, on the contrary, the properties of the filter is absorptive, meaning, it’s not technically reflected, but absorbed. This type of optical filter is the exact opposite of dichroic filters, which block out light.

Where Do You Use Optical Filters?

Figure 4 – You’ll be able to use and apply optical filter glass units in many different sectors

Since their main mission is to block out or “filter” the light passing through them, the usage of optical filters revolve around business sectors that has light as one of their most important variables. These include, but are not limited to:

• Photography sector
• Science/Research sector
• Medical industry
• Architectural and Engineering industry
• Commercial sector
• Theatrical production industry
• And many more!

Optical filters, especially the ones that we offer here at SXET are versatile to the extent that you can use it for many different business sectors and industries!

Optical Bandpass Filters

Optical bandpass filters are just another term for optical filter glass.

Figure 5 – Sample of optical bandpass filter with tint

However, bandpass filters are the type that’s more specific to what its function is because they refer to the wavelength range instead of the type of color or light.

They function by passing one a specific range of wavelength band, while allowing others. This selective procedure of filtering allows only a select wavelength to pass through, making it an effective instrument in microscopes, binoculars, and many others!

There are various types and kinds of optical bandpass filters, too! They include, but are not limited to:

• Standard Bypass Filters
• High-Transmitting Bandpass Filters
• Semi-Custom Bandpass Filters
• Hard-Coated Narrowband Filters
• Hard-Coated Broadband Filters

These types of optical bandpass filters are different based on their properties. So, you want to use them in accordance to how they are used and the effects they have.

What Does a Lens Filter Do?

Lens filters are optical filter glass units, they’re just specific to lenses. In simpler terms, lens filters help minimize glare, reflections, and the distribution of light on the surface of the lens.

Figure 6 – Different lens filters protect and secure the lenses, it develops it as well

Yes, we’re talking about camera lenses, smartphone lenses, as well as other types of lenses of gadgets. The effect of a lens filter is to improve, develop, and enhance the final look of an image after being taken.

Similar to optical bandpass filters, lens filters are also known to have many different types, some of which include a UV filter, a standard lens filter, and many more! You can also make use of lens filters to protect the surface or the main lens of your camera.

Other uses of it include protection of the eyeglasses, sunglasses, and other types of eyewear.

How is an Optical Filter Glass Manufactured?

The manufacturing process of optical filter glass units is rather simple and easy to understand. Many clients think that the method is difficult, but, in truth, it’s not!

Figure 7 – Plain and in different shapes for optical filter glass

Here’s a quick summary of how we here at SXET manufactures and produces color filter glass:

Step #1: Raw Material Sourcing

The first step in the manufacturing of optical filter is, of course, the sourcing or the gathering of raw materials that’ll be used for the process. Now, the materials that the manufacturer will find and source out will depend on the material you want your optical filter to have. As we mentioned above, you can use a wide variety of products to produce and manufacture color light filters.

Step #2: Softening/Heating

Next up would be the softening or the heating of the raw material. The softening process is done in order to make sure that the glass will be shaped and formed according to the clients’ wants and needs, it needs to be softened and heated at a particular temperature.

NOTE: The temperature needed will also depend on the material. Harder and stronger materials need higher temperatures, while those that are soft and easily molded can be retained at low and controlled temperatures.

Step #3: Pressing/Molding

When the glass material turns into a molten state, the next step that manufacturers do is they perform pressing and molding, to shape the glass product further. This procedure often requires specialized materials and equipment, not just regular components.

Oftentimes, glass-specific materials are used, and they’re usually sourced from a different supply chain.

Step #4: Annealing

Annealing is the process of cooling the shaped molten glass product in order for its properties to come out naturally. Similar to pressing and molding, annealing couldn’t be done in just a regular environment – it needs to be accomplished within an environment where sudden temperature changes wouldn’t negatively affect the glass product.

Step #5: Grinding

Grinding is one of the concluding steps of the optical filter glass supplication procedure. The reason why grinding is important is due to the fact that not all clients need pre-made shapes and forms of optical filters. The grinding process is what will differentiate their orders from other companies – and various types of special equipment are used for the grinding process, too.

Step #6: Polishing

Last, but most definitely not least is the polishing. This is the ultimatum of the optical filter manufacturing process. This is the step that would finalize the type and kind of color light filter you will get.

It is where the surface finishing method used will be dictated, as well as the polishing and the finalized form.

NOTE: While these may seem normal and common, not all optical filter glass manufacturers follow the same process. There are those that stand out and really try to differentiate the process they do.

Is an Optical Filter Glass Necessary?

Yes, optical filters are necessary because the result of the filtering isn’t just what you need to be looking at. In addition to it, it’s also important to mind the protective or the security layer that it will give the lens as well as the receiving end – which can be the device, the eyes (for eyewear), etc.

We mean to say that it’s an important tool or instrument, but it’s not required.

Do Lens Filters Affect Quality?

Some people, including those in the photography sector argue that cameras should never be used with lens filters for the reason that they tamper with quality. As a matter of fact, they say that using one is not effective in either absorbing or deflecting the wavelengths of the light that pass through.

But, is it true, though? Would color filter glass really affect the quality of the image when installed on top of a lens?

According to a particular in-depth study, the results have shown that the lens filter did not have any negative effects on the quality of the image (resolution). This is considering the fact that the filter is maintained and is kept clean and free from all types of impurities.

What Should You Look For in Optical Filters?

There are several things that you want to look out for in choosing or in deciding which optical filters you’re going to use.

Figure 8 – Look at the properties of the optical filter glass you’re going to purchase

The technical index or parameters that are the most searched for when it comes to these light filters include, but are not limited to:

Surface Accuracy

This is the deviation measurement between the intended shape versus the actual shape of the surface. A decent surface accuracy would be a figure that’s about 1/10 inches, which means that the plain surface of the filter is close or almost close to the intended shape.

Surface Quality

Of course, the quality of the filter’s surface should never be out of hand. You want a surface quality that’s about 0/0, 80/50, or even 40/20 to ensure that no negative effects or changes would happen when it’s latched or installed to the lens.

Material Used

Overall, the strength, durability, smoothness, and resistance of a color filter glass would take the properties of the raw material or the raw glass product that’s been used for it. Some of the most popular options for the material of optical filter glass include quartz glass, K9 glass, standard or float glass, B270, and BK7.

Optical Density

Optical density is the measurement of transmittance using an optical medium. In layman’s terms, it is the transparent material’s property to measure the speed at which the light passes through the material. You want the average optical density for your optical filters (OD2 to OD6). Anything higher than that could result in glaring.

Coating/Polishing

Last, but most definitely not least would be the coating or the surface finishing method done to the glass. There are many options you can choose from, but most companies and businesses look at the following options for the coating of their optical filters:

• Anti-Reflective (AR) coating
• Non-Glare or Anti-Glare (AG) coating
• Anti-Scratch or Anti-Smudge
• Tint or UV-Ray Protection
• Hard Coating

When shopping for your optical filters, it’s just right to take note of these properties to ensure that the final product would be crisp and all according to what you’re looking for.

Can You Get Custom Shapes For Optical Filter Glass?

Yes, many color light filter suppliers offer customizations for their products for the reason that not all clients and businesses require the same shapes and forms, properties, traits, characteristics, and more.

The market for custom optical filters is vast – you will never run out of options in doing so! All you need to do is submit a drawing or a draft of the specific optical filters you need, and the manufacturer should be the one to turn it into reality.

Long Pass Filter vs. Short Pass Filter

The most common and most talked about factor when it comes to optical filters is the difference between a long-pass filter and a short-pass filter. So, how do we differentiate the two (2)? Let’s start off by discussing what each of them are.

Long Pass Filters are specialized optical filters that transmit radiation that has long wavelengths, all the while blocking shorter ones. Short Pass Filters, on the other hand, are filters that block-long ones and allow short wavelengths.

They function opposite to what the other does. Similarly, they’re known and considered as edge filters, which refers to the rejection of larger or shorter wavelengths.

Where Can You Buy High Quality Color Filter Glass?

You will never run out of options in choosing the optical filter manufacturer to work with. There are manufacturers all around the world – from the busiest of the U.S., Canada, and the U.K., to the extremely cheap options from Chinese and other Asian manufacturers.

If you want quality partnered up with cheapness, then you should go and work with a Chinese color filter supplier. For many years, Chinese manufacturing companies have dominated the industry, even beating U.S. and U.K. suppliers!

The only challenge you’ll face when you decide to work with a Chinese manufacturing company would be the choice – it’s hard to compare because most manufacturers have similar traits and characteristics – not with us here at SXET!

Why Trust SXET With Your Optical Filter Glass?

SXET is known to be the best when it comes to the production of optical filters in various business sectors and industries. For more than a decade, we’ve manufactured the lens filters of the world’s most famous companies.

Through sheer determination, we built our reputation and was able to climb atop the industry’s ladder! Our comprehensive production procedure is one of the main advantages we have over other suppliers.

We perform deep and thorough inspections and checks of the optical filter glass units we produce before sending them to clients!

• Our experts and engineers perform inspections and assessments regularly
• All our optical filters are cleansed and disinfected via ultrasonic baths
• We utilize cutting-edge and state-of-the-art equipment for our products
• You can ask us for a free sample of the color filter glass you need

Whatever your location is and whatever business industry you may be in, you can definitely bank and count on us to produce the optical filter glass you need!

Never be worried about where you can get premium-quality lens filters because working with us will be the best decision you’ll make!

While we’re the best in optical filters, SXET’s overall skill isn’t limited to that. We can also be your go-to manufacturer if you need other products such as anti-glare (AG) glass, chemically strengthened glass, 3D tempered glass, keyboard glass, camera glass, and many more!

Get the Best Long Pass Filter Today!

Inquire about our products by leaving a message or by dialing our hotline and you will never be disappointed! From the quality, the ease of work, the speed–up to the customer service we offer, you won’t find another optical filter supplier as great as us!