Circular magnetic filters, CPL, ND, Mist and other photography filters

On the market, we find various magnetic circular filter systems. These systems share some characteristics and features, but most of them present design and usability issues. In this article, we will understand the main features to consider when purchasing a magnetic filter system, and which system meets these requirements and how. First, let’s briefly look at what magnetic circular filters are and the reasons they are among the most sought-after photography filters on the market.

Why have circular photography filters become magnetic?

Many of you are familiar with screw-in circular filters (ND, Polariser, etc.). Thanks to a rear thread, it is possible to screw a filter directly onto the front thread of the camera lens. By using the front thread of the same filter, we can continue mounting other filters in front of the first one.

The screw-in system, therefore mechanical, is very reliable and will remain the most traditional method for using filters on our lenses. However, there are a number of disadvantages to threading, including:

• The thread can seize if inserted incorrectly or after many uses
• Screwing and unscrewing to change a filter is slower and could potentially cause the filter to fall due to the awkward movement
• The presence of the thread requires a certain thickness for the filter, as it must be screwed in for a certain number of turns. The result is possible vignetting when using more than one filter
• In addition to possible vignetting, using more than one filter is inconvenient, as each must be screwed on top of the other, significantly increasing the time needed for use

For these reasons, and due to the growing demand to use more than one filter together, the idea was born to screw in just a first adapter ring (still using a thread to attach to the lens, of course) and then attach the subsequent filters through a magnetic coupling.

The magnet on the front of the adapter ring, also on both sides of all the JetMag Pro filters, allows for quick mounting and removal, a complete reduction in thickness, and great versatility of the entire system. Now, let’s explore the various features we need to know to ensure that our magnetic circular filter system is truly of high quality.

Magnetic circular filters: What you need to know

Like any product, the magnetic filter has a series of characteristics that distinguish low-quality, inexpensive products from well-designed ones that will not disappoint us in all usage situations. Let’s see what we need to consider.

Magnet strength

A magnetic attraction that is too weak, as one might easily guess, will make the system too fragile and prone to accidental falls. On the other hand, if the magnet is too strong, we will have difficulty separating the filters, the structure will be more easily scratched, and in the case of the polariser, it will be too difficult to rotate for the right polarisation.

Safety lock

Even a filter with a well-proportioned magnet can detach, such as in the case of bumps during transport. For this reason, it is advisable to have a safety lock. For example, in the NiSi JetMag Pro system, it is possible to rotate the filter into a position where a mechanical lock prevents detachment.

Variety of available filters

When we choose a system, we are also choosing a brand to partner with for future purchases. It is essential that the company decides to support the system with a wide variety of filters. In the case of the NiSi JetMag Pro, ND, CPL, UV, IR-cut, 4x Cross Screen (star effect), Mist, and Natural Night filters are available. Additionally, more filters will be released in the future, as the system is well supported by NiSi, which is a leader in the industry.

Optical quality and coating

Remember that when purchasing a magnetic circular filter system, we are placing a piece of glass between the photo and our lens. We must always ensure that we do not insert a lower quality glass compared to the one on our lens, rendering the designer’s work and our investment in a quality lens useless. Even in the case of an inexpensive lens, this glass will always be of higher quality than many cheap filters on the market. It is important to choose accessories made of optical glass with high-quality coatings. NiSi’s exclusive optical glass, multi-coatings, nano-coatings, and surface treatments are always among the most innovative on the market.

Ease of handling and separating

One of the main reasons for purchasing magnetic filters is their speed and ease of use. Unfortunately, many systems fall short in this regard. In fact, they are often constructed like screw-in filters, from which the threading has been removed and a magnet added, which is a significant mistake. A different mounting method requires a different way to handle the filters; for example, the NiSi JetMag Pro filters have small handles to allow for quick use. Additionally, the different colours of the handles make it easy to identify the filters and can be used as levers to separate them easily, providing a good grip and reducing the risk of dropping them.

Vignetting

The true Achille’s heel of magnetic filters is vignetting. The speed of mounting is an advantage when I can attach more than one at the same time. Unfortunately, many systems, despite allowing for multiple filters, vignette even with just two filters mounted together, and with wide-angle lenses, they can vignette with just one filter. The NiSi JetMag Pro filters have been tested at 15mm, and they show no mechanical vignetting with two filters. Other independent tests demonstrate that there is also no vignetting at 18mm with three filters. Of course, experiences may vary from lens to lens, but you can be assured that the NiSi system offers the least obstructive solution in terms of field of view obstruction.

Key features of the NiSi JetMag Pro filter system

Which magnetic filters to choose to get started?

The NiSi JetMag Pro System offers various purchase combinations, but first, let’s quickly review how the system works.

1. We use the JetMag Pro ring that matches the diameter of our lens (an 82mm ring for lenses with an 82mm diameter, a 77mm ring for lenses with a 77mm diameter, and so on).
2. Screw the JetMag Pro ring onto the front of the lens; now we can use all the magnetic filters from the NiSi JetMag Pro system.
3. If we want to secure the filters in place to prevent them from falling, we align the handle with the white mark found on the filter frame.

NiSi JetMag Pro magnetic filter kits

The Kits are definitely the recommended purchasing options, as they offer a good price compared to all the individual products and contain everything necessary for our photos. For those looking for a starter kit at a great price, we recommend the Custom Starter Bundle Kit, which allows you to choose 1 ND, the CPL, the rings (from 1 to 4), and includes lens caps and a complimentary caddy case. The Capture Kit with CPL and UV allows us to start with two excellent basic filters, while the Landscape ND Kit offers three ND filters (3, 6, and 10 stops) along with the CPL. Discover all the kits below or on the dedicated page.

Some tips for optimal use

1. We recommend using the CPL as the first filter, rotating it to the desired polarisation position, and then adding the other filters in front of it. This way, the polarisation is more comfortable, and it won’t be necessary to rotate everything together.
2. We advise locking the filters in the locking position (aligning the handle with the white line on the filter) only when storing the filters in the bag or when moving from one shooting location to another. During the shooting phase, especially when using a CPL, it is essential to keep the filters rotated to the desired polarisation position.
3. We recommend keeping the adapter ring always mounted, thanks to the option of using the provided cap to cover the lens. If you frequently use the CPL or another filter, you can comfortably leave it mounted as well, in the locked position and with the cap attached.

Videos for the JetMag Pro magnetic filter system