Olympus 7-14mm f2.8 Pro is a versatile high-quality wide-angle lens. However, its inability to attach filter limits the lens’ usefulness considerably. Fortunately, I ran into a team from STC Optics from Taiwan at a photo fair in Bangkok. They gave me a filter kit for Olympus 7-14mm f2.8 to test and review. After using this kit for two months in Thailand, I write my opinion of the filters and the filter adapter.

For my style of landscape photography, creativity is the most important factor. I like to travel to popular places and take pictures that are different from others. Of course, aesthetic and quality are important to my photos too. But there is no point in taking photos if I am simply seeing the world the same way as everyone else. Consequently, I evaluate photography equipment by their ability to provide me with creative freedom.

A temple in Ancient City park, Samut Prakan province
1.3 seconds, f10 using CPL and ND filter

STC Filters and Filter Adapter for Olympus 7-14mm f2.8

Before going further, please understand this is a sponsored review. STC Optical gave me the filters and the filter adapter in exchange for this review. In the box, I received one STC filter adapter and three STC filters. The filters are 105mm in size that matches with the adapter. They are UV, CPL and ND64 (6 stops) filters. Lastly, there is also a humongous 105mm lens cap.

105mm UV, CPL and ND64 filters with the adapter and lens cap
The adapter and the lens

Adapter’s Build Quality

When I hear of most filter adapters for an ultrawide-angle lens, I usually stay away. Most filter adapters are usually 3D printed home-made parts that are not durable. Additionally, I have to carry them and mount them on the lens every time I want to put on a filter. But this time is different. STC Optical filter adapter is very well designed and made of aluminum. There are two parts to the adapter. The first part is the 105mm filter adapter goes in from the front of the lens. It locks into the shape of the lens hood perfectly to prevent any wiggle. The second part is a ring that goes in from behind the lens that screws into the first part.

When equipped with the lens, the adapter is very secure and does not wiggle. The adapter felt like it was a part of the lens itself. I keep the adapter on the lens the entire time. Even after days of carrying in my messenger bag, the adapter stayed securely. I removed the adapter a few times. The adapter does not cause any scratch to the lens’s exterior body. However, I had to take the lens off the camera in order to put on or take off the filter adapter. That’s just a small inconvenience.

The adapter made the lens much bulkier due to the 105mm filter thread. However, it also acts as an improved lens hood that protects the actual lens’ hood. I leave the adapter on even when not using any filter. When attaching or removing a filter on the adapter, the back of the filter will touch the lens’ hood. The manual suggests that users loosen the adapter from the lens first before attaching or removing a filter. This is to prevent the lens’ hood from scratching the back of the filter.

A temple in Ancient City park, Samut Prakan province
1/160 Second, f8 using CPL filter

Filters’ Build Quality

The three 105mm filters seem very well made. What standouts is the dual surface coating of these STC filters. On most filters I use, only the front side has coating chemical. When cleaning these filters, only the front surface feels smooth. But when I clean the back surface, I can feel that it’s not as smooth. Because of the dual coatings, STC filters are very easy to clean on both sides. Additionally, the coatings are also antistatic (not attracting dust) and anti-liquid. Most of the times, I can quickly clean these filters easily using just an air blower.
The filter frames are very slim. If I mount one filter at a time, there is no vignette even at the 7mm angle of the lens.

Anti-liquid coating in action. Use a blower to quickly remove the droplets.

On the downside, because these filters are very slim, there is not much thread to mount the filters to the adapter. I often found a filter coming off of the adapter. So be careful. Interestingly, the CPL and ND filters have a rubber ring around them. I assume they are for weather sealing. However, these rings do block a part of the filters’ thread, making filter removal easy. Maybe that’s the point since most photographers don’t need CPL and ND filters all the time.

B+W UV filter next to STC Optical UV filter

Unlike BW filters, I never had a problem removing all three STC filters. This advantage cannot be overlooked. There were times when I cannot remove a BW filter in the field.

Sakunothayan Waterfall, Phitsanulok province
1/4 seconds, f7.1 with CPL and ND filter


Most of the times, I use filters for protection. I want to avoid cleaning a lens’ front element as much as possible. However, for this use case to be effective, the filters must not add any undesirable effects such as flare and reflection to images. After testing, I’m happy to say that all three filters add very little reflection when pointed to a strong light source. Most of the flares and reflections are already the characteristics of the Olympus 7-14mm f2.8 lens.

Here are some samples. The photos on the left do NOT use a filter.

For outdoor, I put on CPL filter to reduce surface reflection and increase color saturation of images. The CPL filter does its job reasonably well. Like the UV filter, it produces very little flare and reflection. Usually, I keep the CPL filter attached all the time unless I need extra light. Here are some photos with CPL filter.

Wat Phra Kaew in Ancient City park, Samut Prakan
1/25 second, f7.1 with CPL filter
A house in Ancient City park, Samut Prakan
1/50 second, f8 with CPL filter
A temple in Ancient City park, Samut Prakan
1/640 second, f6.3 with CPL filter

But the most creative use is the ND64 filter. When using a really wide-angle lens, I often have to get very close to the subject to achieve interesting composition. For example, I like to get very close to a waterfall with an ND filter to show the motion in the water. The problem is the water often splashes on to the lens. If I was using my other ND filter, this would be very hard to clean the water off. But with STC anti-liquid coating on the ND filter, I can easily blow the water away. This ND filter allows me to be creative without worry about cleaning too much.

ND64 filter is not too dark so I control the light by using the aperture. I often found myself using f10 or smaller aperture. This is not ideal for Micro Four Third camera sensor since the image sharpness is reduced. However, I can avoid this problem by choosing a time when the sun isn’t strong to take a picture.

Stacking Filters

The downside of the ND64 filter is its limited light reduction of only 6 stops. To me, this is not enough stop to create long exposure. I often use CPL and ND filters stacked together to get a total of 7 stops. I can see the filter ring at 7mm. But when I zoom to 10mm, the ring is not visible. For these STC filters, I did not notice any tangible loss of image quality when stacking.

Sakunothayan Waterfall
0.8 second, f8 with CPL and ND filter
My uncle in Sakunothayan Waterfall
1.3 seconds, f8 with CPL and ND filter

Here is a comparison of 7mm and 9mm when stacking filters. You have to zoom to 10mm to remove vignetting completely.



With the UV filter attached, I tried running water from a faucet toward the edges of the filter and the lens. The lens behind the filter is completely dry. The filter repels water very well. In the rain, these filters should be able to protect the lens reasonably well. Although the lens itself is weather-sealed, I like to avoid cleaning the front element from raindrops as much as possible. Again, these filters allow me to focus on creativity instead of worrying about my lens.

I was extremely impressed and went one step further by partially submerging the filters in a river. With an Olympus E-M5 II and the lens attached with CPL and ND filters stacked together, I submerged the camera about 1/3 of its height into the water. A bit of water got inside and made the lens’ front element wet. However, no water got in between the CPL and ND filters. I think the water got in from the adapter ring rather than the filter thread. The camera and lens are fine.

Lens Cap Problem

There is one minor detail on the 105mm lens cap I wish to improve. After using the filter for two months, I noticed several scratches on the edge of my CPL filter’s glass. These scratches are usually straight lines resembling the movement of the locking parts of the lens cap. I’m not 100% sure. I think removing and putting on lens cap could be the cause of these scratches. However, they are not deep and cause no visible effect on the photos.


– The adapter can permanently attach to the lens as an extra protection.
– The adapter fits the lens perfectly and does not move once installed.
– The filter and the adapter together are weather sealed.
– Filters produce very little reflection and flare.
– Filters are easy to clean in the field.
– Filters do not cause noticeable image degradation.
– Filters do not cause vignette at 7mm when using one at a time.
– Filters are circular rather than square. Possible to leave the filter on all the time. Does not need a special mount like Lee filters.
– The adapter adds extra size to the lens.
– Filters are 105mm in size. These are large and expensive.
– The lens cap can scratch the filter’s surface if not careful.

Wat Pho, Bangkok
1/2500 seconds, f7.1 with CPL Filter


Overall, I like the adapter and filters for Olympus 7-14mm f2.8. It’s very high quality and could easily be an official Olympus lens’ accessory. The only reservation I have against recommending this is its large size. Micro Four Third has the advantage its compactness. There are many other ultra-wide-angle lenses for Micro Four Third in the market that takes filter without needing an adapter. On the downside, they (Laowa 7.5mm f2.0 and Panasonic 8-18mm f2.8 – 4) do not offer all the features Olympus 7-14mm f2.8 has.

A temple in Ancient City park, Samut Prakan province
f/30 second, f14 using CPL filter

If you use Olympus 7-14mm f2.8 and want to use filters with it, this STC filter adapter is a solid choice. Comment if you have a question or want me to review something. Hope you enjoy the photos from Thailand!

Categories: Review


STC Filter Adapter Kit for Olympus 7-14mm f2.8 Review

Leave a Reply