I have plenty of lenses and most have 77m filters on them. But there are a couple that evaded protection as I believe less is better.

Anyway I thought I would give the K&F a try.

Overall and first impressions are generally good. The filter comes well protected in a stiff nylon case. This does not have any recycling marks on it and experience tells me that once a filter is on a lens it stays there. So a black mark there for recyclability.

Back to good points, the lens mount is matt black, the best example I have ever seen, very 'lumpy' and glare resistant. The thread is excellently cut with no sharp or rough edges. The outer rim is ribbed in several places making the filter easy to grip should you ever need to remove it. The mount is exceptionally shallow which again is a plus point minimising the risk of unwanted vignetting. I couldn't detect any deterioration in optical quality or increased flaring from the glass. Unusually the filter arrives with a lens cap, this is a copy of the Nikon 'pinch' design but the Nikon one works better.

A fine piece of kit.

K&F Concept has become a go-to brand for quality yet affordable gear for photographers, and this filter lives up to those expectations. The build quality is impressive for the price. It comes in a plastic storage box with a solid lens cap, a lens cap tether, and a cleaning cloth, all for under $16.

The primary need for a UV filter is to protect your expensive lenses from dust, dirt, scratches, and potential damage, while also cutting down on the blues a little. While this filter from K&F is their basic UV model, it does the job well. It's not waterproof or scratch-resistant, which explains the lower price. They offer more expensive options like their Nano-X series, but those come at a higher cost.

Cheap filters can often cause flaring or ghosting in your images when there's a strong light source and can also affect autofocus and image sharpness. However, I haven't noticed any of those issues with this filter. The clarity of the glass seems excellent, and my shots remain crisp and clear.

The ultra-slim design of this filter ensures there's no vignetting, even when used with wide-angle lenses, which is a plus for landscape photographers like myself. The included lens cap is also a nice touch; it snaps on securely and feels better than the ones that came with the lens.

Overall, this is a solid choice for photographers looking to protect their gear without breaking the bank. It combines quality, affordability, and reliability, making it a valuable addition to any camera bag.

This is a really nice little kit, and exactly what I needed. Somewhere along the line, I lost the lens cap for my Canon prime lens, plus I really wanted a simple UV/haze filter for it. This package worked great, and I'm happy with the quality and clarity of the filter.
I am sure there are more serious photographers out there who could find fault with the filter (perhaps bragging about one 10x the price), but I could detect no visual artifacts or issues with it.

I like it, I think it works well, and it can be stacked with other screw on filters

I have used this filter on one of my 77mm lenses with good results.
Likes:
- The filter causes no apparent loss to image quality or contrast.
- The filter screws on the lens smoothly. The added texture on the filter edge makes it easy to put on and remove.
- It comes with a lens cap and case. My OEM lens cap fits on the filter as well.
- The filter is selling for $15.99USD as of this review and that is a very good price for glass of this quality.

Especially when going on location shoots, I like having a UV filter on the lens. The extra piece of mind that your lens has an extra layer protecting the front element is invaluable. The main thing to watch out for with them is a decrease in image quality or sharpness, unwanted haze or flares, and other subtle optical effects. Luckily, this one doesn't produce any of those issues to any noticeable extent. I have purchased other K&F Concept filters and all of them have been satisfactory quality.

Bought these for a lens I ended up returning, but worked great for the one day I used it.

These filters seem fine for the basic cover-your-lens protection job that most people need. They cost much less than the more known brands. For my purposes, and I've been using pro grade gear for years, they work fine.

I was very pleasantly surprised that the product works exactly as described. I always have it with me, just like my camera, and use it almost every day.
And instead of buying several D-filters with different thicknesses, it's better to buy this one here, which can be individually adjusted. Absolute purchase recommendation

While I can’t measure whether this filter is reducing the UV content entering the lens I can say that it is clear does not decrease the light passing through it as the camera exposure values don’t change with or without the filter fitted, is well made and a reasonable price. So I’m happy with this product and would buy it again.