Reviews
Useful pack for reducing overall light entering the camera but the CPL filter is not as good.
This K&F Concept 4-Pack Filters is designed for the DJI Osmo Action 5 Pro action camera. Each of them replaces the original protective glass that is screwed onto the front of the camera by the manufacturer - You can see the red rubber ring that forms the seal and also acts to make the original protective glass very reluctant to start coming off.
The set of filters comprises of three neutral density (ND) filters and one circular polarising (CPL) filter.
The ND filters have densities that give factors of 8, 16 and 32 or, 3, 4 and 5 stops. They are coated so that you get minimal reflections and they have a purply-blue hue to the coatings. You can see in the photograph of its reflection that the front and back surfaces are flat and well aligned with each other.
The circularly polarising filter screws onto the camera in the same way as the other filters but being a polariser, you need to be able to adjust its angle of orientation and you do this by rotating the front section when it is screwed on. You can see in the photograph that the CPL filter has a little white arrow on it so that you can tell which way it is pointing.
However, if you hold the CPL filter so that it reflects a well defined light source, you will see that you get the front green reflection but the other reflection you get is offset laterally, indicating that the front and the back of the filter are not parallel. Additionally, I noticed that the reflection was uneven, indicating that it was not particularly flat either - this reducing the definition of the optical system as it blurs the image, reducing local contrast and generally reducing its quality whereas the ND filters did not show this.
This is a useful little set of lenses although a linearly polarising (LP) filter would have been a better choice as they werk a lot better than CPL filters and the camera doesn't seem to suffer from the exposure errors that LP filters gave some DSLRs that led to CPL filters becoming the norm several decades ago. Further, the quality of the CPL filter is not as good as the ND filters.
The set of filters comprises of three neutral density (ND) filters and one circular polarising (CPL) filter.
The ND filters have densities that give factors of 8, 16 and 32 or, 3, 4 and 5 stops. They are coated so that you get minimal reflections and they have a purply-blue hue to the coatings. You can see in the photograph of its reflection that the front and back surfaces are flat and well aligned with each other.
The circularly polarising filter screws onto the camera in the same way as the other filters but being a polariser, you need to be able to adjust its angle of orientation and you do this by rotating the front section when it is screwed on. You can see in the photograph that the CPL filter has a little white arrow on it so that you can tell which way it is pointing.
However, if you hold the CPL filter so that it reflects a well defined light source, you will see that you get the front green reflection but the other reflection you get is offset laterally, indicating that the front and the back of the filter are not parallel. Additionally, I noticed that the reflection was uneven, indicating that it was not particularly flat either - this reducing the definition of the optical system as it blurs the image, reducing local contrast and generally reducing its quality whereas the ND filters did not show this.
This is a useful little set of lenses although a linearly polarising (LP) filter would have been a better choice as they werk a lot better than CPL filters and the camera doesn't seem to suffer from the exposure errors that LP filters gave some DSLRs that led to CPL filters becoming the norm several decades ago. Further, the quality of the CPL filter is not as good as the ND filters.
23/11/2024