55mm Cool Tone Soft Focus 1/4 Filter, Cinematic Blue Mist Glow Lens Filter for Portrait & Night Video, Highlights Cool Blue Tones, Reduce Contrast - Nano-Xcel Series

My K&F Cool Diffusion Filter features an 82mm thread size. As with several recent K&F products I use, it feels like a more premium product. This starts with the premium hard plastic case that unscrews, which is a massive upgrade over a cheap plastic clamshell design. The case has some integrated rubber padding on the inside to stop the filter from sliding around, and they also include a microfiber cleaning cloth. The threads on the filter itself are excellently machined, allowing it to screw onto my lenses smoothly without the need for a filter wrench. It contains no moving filter elements, and you can comfortably use your original lens cap directly on top of the filter without needing to remove it first.
Cool diffusion filters work by scattering light and softening the overall image. This K&F filter is a 1/4 strength variant, so it visibly softens the image without destroying the inherent sharpness and quality of your camera equipment. It introduces a wonderfully dreamy, soft glow to photos and video footage, whilst noticeably smoothing out skin tones directly in-camera for portrait work. It also creates a pleasing halo effect around direct light sources. The filter tint does slightly reduce the light hitting your sensor, requiring a fractionally longer exposure, but it is not a dedicated ND filter, so the difference is not drastic.
Crucially, it is a remarkably thin filter, and it did not vignette my images even when tested on a wide 15-35mm lens.
Off the camera, you can see a distinct blue tint on the glass itself. In your images, the practical effect behaves similarly to manually increasing the white balance temperature to a cooler setting. If you are shooting video, this could be highly effective in clinical or futuristic spaces to enhance the overall atmosphere. I suspect it will add an incredibly interesting effect during the winter months, though sadly it is peak summer whilst I am testing it. Even when testing it under harsh summer sunlight, I did not experience any unwanted lens flaring.

I’ve used a few K&F filters before and this one doesn’t disappoint. The 1/4 cool diffusion effect adds a subtle cinematic glow to highlights without making the image look overly soft. It takes the digital edge off footage nicely while still keeping plenty of detail.

The filter feels well made, with a solid metal frame that screws on smoothly. The glass is clean and the coatings seem to do a good job of reducing reflections and making it easy to wipe fingerprints away.

The slight cool tone can look really nice for moody outdoor shots or evening scenes, although it won’t suit every situation. If you’re after a gentle film-like look rather than an over-the-top effect, this is a great choice and offers excellent value for the quality.

I got the 82mm version of this so I can fit it to my larger lenses and use step down to fit smaller ones. The filter is very well constructed, and I like the new design to the K&F filter cases that holds the filter in it securely so it doesn't rattle.
I'm impressed with the optical clarity of this. It's distortion free. The creative effect of the cool blue misty look is excellent, and really works well on both photos and videos. It's not the cheapest filter, but for high quality optics and a large filter size, this is really good value for money from a known brand K&F. I'd recommend this to all photographers even if they are amateurs or professional.

Je suis un photographe depuis au moins deux décennies et je crois énormément en certains filtres contrairement à d'autres photographes qui relaient sur des effets ajoutés en post-production. Je préfère produire les effets directement dans l'objectif pour ma part car je trouve que ça permet des résultats plus précis et moins dégradés.

Voici ce qui ressort de mon évaluation :

- La qualité du verre me semble être très bonne. Je ne perds pas trop au niveau de l'exposition lorsque je l'utilise et je n'ai pas observé de reflets anormaux ou d'aberrations chromatiques liées au filtre. Il n'y a pas de perte de détails apparente non plus sur mes clichés en les comparant. Ce sont les indicateurs habituels que j'utilise pour déterminer si le filtre est bon.

- C'était bien emballé et c'est arrivé avec un petit boitier rond pratique pour stocker un filtre sécuritairement.

- Au plan de la qualité , vous pouvez observer sur mes photos un effet légèrement fantomatique autour des zones plus lumineuses. Dans les films, les scènes de rêve sont souvent représentées en utilisant ce genre de filtres. Je trouve le résultat vraiment intéressant.

-Je constate que la colorimétrie est parfois plus simple à faire. Ça semble étendre juste un peu plus la lumière sans perdre de détails et donc les zones de surexpositions sont rares sur mes clichés. J'ai trouvé ça vraiment facile d'éditer mes clichés pris en fichiers RAW 14 bits.

Côté plus négatif :

- Ce filtre est très portable mais il est mince et son filetage est délicat donc il faut s'assurer qu'on est bien placé lorsqu'on le serre sinon , ça peut coincer. Ça a failli m'arriver donc je suggère aux gens qui l'achètent de prendre le temps de l'installer. Une fois que je me suis habitué, j'ai pu le visser et le dévisser sans issue. Je ne retire pas de points pour ça parce que c'est le propre de ce genre de filtres qui sont faits très minces et ils le sont surtout pour qu'on puisse les associer à d'autres filtres, ce en rallongeant le moins possible la longueur de la lentille.

En conclusion :

J'adore ce filtre là et j'espère pouvoir en tester d'autres de ce genre pour créer des effets directement dans l'objectif de ma caméra. Si je mets en perspective le prix de vente affiché qui est de 149,99$ au moment de cette évaluation , je dois dire que selon moi ça le vaut. Ça n'est pas un filtre qu'on laisse sur sa caméra presque en tout temps comme un filtre polarisant ou un filtre UV mais pour certaines scènes précises , je trouve que ça n'a pas d'égal.

Je le recommande surtout aux professionnels mais aussi aux enthousiastes et au débutants qui veulent apprendre.

I'm very impressed with the K&F Concept 67mm Cool Diffusion Lens Filter, it's part of their NANO-X series.

The knurled edge makes it easier to hold while putting it on your camera lens and also helps with the removal process when you're done. It has a matte black finish to reduce glare from sunlight and studio lighting. It comes in a cool plastic case with rubber rings to hold it in place during transport so it won't bounce around and get scratched or damaged, very clever. A Microfiber Cleaning Cloth is included in the box.

Cool Diffusion filters are primarily used to introduce two effects to photos or videos. First, it diffuses light which helps to soften the image, reduce contrast and create a more cinematic look. Second, it shifts the color tone away from yellow and orange and makes it appear more bluish or colder. This filter handles both of these tasks very well and retains good clarity and sharpness. It creates an interesting mood and style, making this a worthwhile piece if you do portrait photography or like to VLOG and want to stand out and add a dreamlike glow to your projects.

In summary, this K&F Cool Diffusion lens filter is high quality and comes with a one year warranty that's backed up by a well-respected company. It's easy to recommend this one!

I’ve come to like K&F Concept products and have a few other filters from this line. The build and packaging of the filters is nice and definitely feels worth the money. The optics on their filters are usually pretty good as well- not top of the line but definitely more than acceptable for their price point- and this one seems to fit that.

The 1/4 most blooms highlights and reduces some of that “digital feel”. 1/4 is pretty soft and not super subtle- which is absolutely fine and can look awesome when you want it but if you want something to subtly bloom the highlights check out a 1/8.

The blue coating cools your image, but I think I will need to do some deeper tests on this for subtly because from my initial tests it seems very close to the same effect of just reducing your white balance by 1000k. This seems backed up by their product page saying not to use the filter in auto white balance or you won’t really notice that effect. I can see some uses where you might want a filter instead of just adjusting white balance (especially shooting film or something)… again, there may be some more subtleties I am currently missing.

However, with all that said, the filter does exactly as it advertises so if you’re in need of these 2 features then this will fill that need.

I recently took a photography class and filters like this were discussed as a great way to add a more cinematic look straight out of the camera. This K&F Concept filter does exactly that by giving bright light sources a subtle, cool-toned glow without making the entire image look soft or blurry. Street lights, headlights, reflections, and other highlights take on a much more pleasing appearance, especially during night photography and video work. I also noticed that it helps smooth out skin highlights in portraits while still maintaining good overall detail. The optical quality is excellent, with very little impact on sharpness compared to some lower-quality diffusion filters. The coatings do a good job resisting fingerprints and make cleaning much easier after a shoot. The included cleaning cloth is a nice bonus and useful for keeping the filter spotless in the field. Overall, this is a high-quality creative filter that adds a professional cinematic touch to photos and video without overdoing the effect.

This filter makes every shot look like a dream. Attaching the glass to the lens was simple and it fits perfectly without any issues. The soft glow on street lights at night is exactly the vibe that was missing from my photos. It smooths out skin tones in a way that feels very natural and not fake at all. Sharpness remains totally intact even with the mist effect added to the scene. Carrying this around is easy because the coating keeps it clean and fingerprint free. Serious work went into this because it feels sturdy and solid in the hand. That little cloth included in the box is a nice bonus for keeping things smudge free while shooting. Every video clip feels much more professional with that subtle blueish tint in the highlights. Testing this out on cityscapes was fun and the results look stunning!

This company makes some tremendously good quality very good value optical products. I have purchased them for a number of times over the years and swear by their quality. All the products I make are quite well-made and extremely well package. The filter itself comes in a beautiful case that protects the filter itself. Theyve ingenuously created a ridged area that keeps the filter from bouncing around inside the case itself. V it’s remarkable the impact that this filter has on basic images very good quality, softening, and smoothing filter.