Full disclosure: I received this filter system at a significantly reduced cost in return for my unbiased review.

I just purchased a new Canon RF 100-400 lens that has pretty good glass but is not L quality. Although I have a good black and white CPL filter that matches this lens, I have never been very happy with the color cast. I have tried other K&F Concept lenses and was very impressed with the neutral color cast. So I decided to give this polarizer kit a try.

I really like the technology in this kit. This kit comes as a compact sandwich with machined metal caps front and back. All caps and filters are clearly marked with the filter size. There is a small storage bag to protect the filters and your other stuff when you throw them in your bag.

I previously tried another K & F filter and while I was very impressed with the glass, I was much less impressed with the machined aluminum frame. Unlike the previous filters, these attach easily to my lenses and don't bind. In practice, the knurling on the filters makes removal very easy and in the case of the CPL, the adjustment is very smooth. There is noticeable resistance, but no hint of binding or freedom of movement that you get with cheaper filters. The feel of this filter is quite nice.

The thin profile UV filter is MRC coated to reduce glare and improve cleaning. This filter produces virtually no color cast at all. When held up to a white background, I can't tell the difference between filtered and unfiltered white. I don't usually use UV filters because most of my lenses have better front elements than any filter I own, but with the RF100-400, I'll probably leave the UV filter on the lens since it doesn't have the same quality coatings as my other lenses.

The CPL is fairly thick, but not so thick that I will worry about vignetting since I use these mostly with medium to long telephoto lenses. All CPLs affect color to some degree. Depending on the polarization and angle of the sun, they usually darken the sky and change the color of the water, sometimes dramatically, so with a CPL it is difficult to determine what color cast may be present. Using the same test on a white background, I can see a slight cast against the adjacent white background that seems to have a somewhat brownish cast, but could simply be the result of light loss from the CPL. In test photos, I could not see any perceptible cast at all. It's close enough to neutral that I don't think it will have much effect on color correction in post.

All in all, really nice filters and pretty good value for the money. Recommended.

The pictures are clear and amazing, I love this camera, the black and white is amazing, color is vivid, I recommend this camera to all.

I chose the surveillance camera for outdoor use.

The total package comes with everything you need. Installation material is included. Everything is also included for wall mounting. Once everything is done, the app is installed.

Once the app is installed, you have to register. You also have to enter your e-mail address to receive the confirmation code.

The app is easy to understand. The camera records small video sequences when movements are made. It is also recorded more often, although you do not see any recognizable movement. Fortunately, this can be deleted again. The intercom works quite well so far.

The transmission during the day is crystal clear. But if the recording is not so good, the picture is shown only in black and white. At night, you can choose between color and black and white.

I chose the outdoor security camera.

The complete package comes with everything you need. Installation material is included. Everything is included for wall mounting. Once you've done everything, it's time to install the app.

Once the app is installed, you have to register. You also have to enter your e-mail address in order to receive the confirmation code.

The app is easy to understand. When there is movement, the camera records small video sequences. It is also often recorded, although you can't see any recognizable movement. Luckily it can be deleted. The intercom has worked quite well so far.

Transmission during the day is crystal clear. However, if the recording is not that good, the picture is only shown in black and white. At night you can choose between color and black and white.

K&F Concept 3G/4G Camera:
Fantastic image during the day and at night with white LED or IR. In addition, the camera can actually do without internet or power connection. Smooth operation when watching videos. Detected movements are communicated via push.
The software still has room for improvement

I got this solar surveillance camera for the house entrance because I don't have a wired power source there and of course it saved me work :)

What I like very much:
+ Design, camera is kept in a nice white, the solar -Panel has a matte finish.
+ Extremely easy setup, download the app, hold the QR code in front of the camera - done.
+ Selectable night vision function - either invisible infrared LEDs or white LEDs as visible headlights.
+ Push messages (identification of persons) incl. photo / video (storage selectable microSD card or cloud storage)
+ Thanks to built-in motors, the camera can also be swiveled from the cell phone.
+ Good camera image; SD or HD resolution selectable, depending on Internet bandwidth.
+ Good solar panel, fully charges the battery even in the current autumn sun.

What I don't like so much:
- The camera has an intercom function, but for me it had a relatively long delay and also a slight feedback, maybe this can be eliminated with a software update in the future. Since I personally didn't use this function, it still gets 5 stars.

The adapter fulfills its purpose and I am very satisfied with it. Only detaching the lenses is a bit cumbersome, but that's not a big problem. The aperture control also works without restrictions. It is important to mention here again that the adapter does not transfer the autofocus and you have to set it manually.

For me the camera is just big enough for all lenses, chargers and accessories. Nice color as in the picture. Sturdy backpack Really happy with it.