I found this filter to be a lot of fun and the price tag does not break the bank. It is made well with good quality glass. It threads on easily and the “streak” part rotates. I found the rotation to be spot on – not too tight and not loose or sloppy. The “streaks” to my eye emphasize the blue and green color ranges, but you do notice the effect in all colors. It just isn’t as emphasized in other colors. It does come with a case (always good for me as I carry gear regularly and need a way to protect it). I did do some pictures during the day with the filter, but found that I like more of the darker shots to highlight the effect. I did not notice vignetting, distortion, or unwelcome artifacts with the filter. I would recommend it, and I’m enjoying using it.

I used this with a 28-105mm f4 and a 50mm f1.8 both on my Lumix S5IIX. I really like the effect and I think the best use case is artistic portraits. Being able to smoothly rotate it is also nice. And it even rotates smoothly so that you can use it in a video if you want. That has a pretty trippy effect either to do a subtle flair shift or a full rotation. Some things to keep in mind are that you cannot really control the amount of flair. You might have some control with an ND filter, but that may be challenging since this mostly seems suited for night-time shoots. The other thing to keep in mind is that this is a blue streak filter, meaning that it will shift warm light sources to cool. You can see how this works in the pictures. See that the effect is most natural for the post light that is already cool.

Really enjoyed playing with this filter; the effect is pretty easy to see and I can think of a lot of creative applications!

Once the lens is screwed in place you can rotate it similar to a CPL to change the angle of the streaks.

I'm always happy to try a new (to me) filter effect with my camera, and this one is pretty neat. The filter is supplied in a shrink-wrapped box, accompanied by some individually packaged microfibre cleaning cloths. Inside the box, the filter comes with a hard case, with a secure surround that stops it from sliding around.

The filter has blue lines painted onto the glass, and a two part moving structure. The back screws on to the camera lens, whilst the front rotates, allowing the angle of the blue lines to be changed to optimise and change the angle of the streak effect. I ordered this in the 67mm size to fit together with a Lumix lens on my Panasonic S5IIXCE. The fit is good - I've not yet had an issue with this brand, and (amongst others) own several of their filters. The screw threads connect simply and without issue - although I did find doing this little fiddly before I realised that the front part of this filter rotates!

Having this filter installed doesn't, unlike some, alter the size of the lens cap needed, so the regular 67mm cap size can still be used with it.

The effect makes a single blue streak from one, small to middling sized bulb or light, and multiple streaks when there are more. I would have been happy with this if I had paid for it.

I sure wasn't expecting literal visible blue lines across the filter...but it does exactly what it says. Sharp image and bright blue streaks. It's a great way to stylize clips for music videos or films. Looking forward to having fun with this one!

I am an amateur photographer and in no way my opinion is professional. I have always been amazed by what filters can add to your photography game but cost made trying them a challenge.
This lens will give you that anamorphic blue lines of light that you see in movies, it is very subtle but beautiful . I don’t see any black crosses or distortions.
As for the price, it is reasonable.

I am using the &F Concept 82mm Blue Streak Lens Filter with my mirrorless camera. It works well to add a blue streak to specular highlights in an image. It functions like a starburst filter but generates the streak effect in blue. The filter can be rotated to position the angle of the streak as desired. The filter has a well-made feeling – both when screwing it onto my lens and when rotating the filter. Another bonus with K & F Concept products is they generally come with lens cleaning wipes – three were included with this filter.

This filter gives off an amazing look. Obviously it's hard to fake anamorphic but this gives off really convincing anamorphic light streaks. I love using it for concerts where there are a lot of point source lights. I also really like the yellow streak filter they have!

K&F has recently come up on the forefront of good value not overly expensive lens filters for cameras. I have a whole bunch of various K&F filters and they all are fantastic this blue streak lens filter lives up to previous K&F filters I have used. The construction is fantastic the quality of materials is great and the pictures that come out from the filter look even better. I like these filters so much I really don't have anything negative to say about them, they simply function as advertised every time you use it. K&F is a great company, and I highly recommend them.

I think this is a fun filter for music video projects and some creative and experimental shoots but this does NOT present that same natural flares from an anamorphic lens. So don't get this hoping to get that spherical lens to produce consistent flares like that of an anamorphic lens. What I do like about this is that you can get some really creative shots and looks by turning the filter element to have streaks run vertically, horizontally, and diagonally. Another cool thing is that if you pair these with an actual anamorphic lens, you can get some really fun and interesting effects. So it's great to have in your bag/kit, especially if you are in the realm of experimental and music video cinematography.