K&F ¼ Black Diffusion Filter
This was my first hands-on use of this K&F Concept 1/4 Black Diffusion filter. I had seen some reviewers who thought the 1/4 strength filter might provide too much diffusion. I disagree - I think the amount hits the sweet spot for skin softening and contrast diffusion. In my opinion, it produces an in-camera effect similar to a mild glow effect that can be achieved in post processing. I shot my volunteer subject in early evening. First, I positioned her in the shadow of a large tree but in a spot where the sun was falling on the back of her head. I shot wide open on my Tamron 24-70 mm f/2.8 G2 attached to my Nikon D500.
There was some skin softening and lessening of contrast on the subject's face, but the effect is most keenly seen in the out of focus areas, particularly in the upper right, toward the sun. The tone seems a bit warmer there and I think this filter would make an excellent starting point for light and airy backlit portraits. In the second example, I switched places with her and shot her front lit. In this example, the skin softening and contrast reduction was greater. Comparing the white line drawing on her shirt will give you the greatest example of how much softening is occurring.

I am very pleased with the performance of this filter. It is nice to have a tool in the kit for those clients who want softer portraits. I shoot a lot of outdoor portraits, and this will be something I will try with maternity and engagement sessions. I will also be using this for head shot situations where I know going in that I will need skin softening. I am not ready to say I will use it for all the shots in those situations – I am a belt/suspenders type of person – but certainly will incorporate on some. I do have a couples session coming up later today and I am looking forward to trying this out with off-camera flash. I will post those results as an edit.

I am as impressed with the craftsmanship as I am with the performance. The filter comes with a threaded metal faceplate. After screwing the filter onto the lens, the faceplate unscrews from the filter. This keeps the filter protected from dust, scratches, smudges while in storage and while handling prior to attaching to the lens.