# K&F Diffusion Filter HD Black 1/4 for 40.5mm lenses (model Kf01.1621)

**URL:** https://aio.lv/en/product--kf-sb8379--11878936
**Data updated:** 2026-03-09 20:44 (EET)
**Category:** Camera Filters
**Manufacturer:** K&F
**Manufacturer code:** SB8379
**EAN:** 6936069286601
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 50.49 €
**Prices and availability valid until:** 2026-07-29 23:59
**Price without VAT (21%):** 41.73 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--kf-sb8379--11878936

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 15.07.2026 | free |
| Pickup points | 20.07.2026 | 1.89 EUR |
| Courier delivery to door | 20.07.2026 | 4.99 EUR |

## Summary description

Diffusion (softening) filter K&F HD Black 1/4 designed for lenses with 40.5 mm thread. Provides light diffusion and softening of highlights while preserving overall contrast for portrait, wedding, and cinematic photography. Screw-mount optical filter for creative reduction of sharpness and halation effects, compatible with lenses accepting 40.5 mm filters.

## Long description

K&F Diffusion Filter HD Black 1/4 for 40.5mm lenses is a screw-mount optical filter designed to soften highlights and introduce gentle diffusion while maintaining overall image contrast. Engineered for lenses with a 40.5 mm filter thread, this HD diffusion filter produces controlled halation and a subtle reduction in micro-contrast to achieve a flattering look for skin tones and highlight rendition without excessive veil or loss of detail.
Advantages
The HD Black 1/4 diffusion element delivers smooth highlight bloom and reduced edge harshness while preserving midtone contrast and color fidelity. Its screw-in design ensures secure attachment to compatible 40.5 mm lenses and enables quick installation and removal. The optical construction minimizes unintended color shifts and maintains usable resolution for prints and digital delivery, making it suitable for both stills and motion work.
Suitable for
Portrait photography to soften skin texture and reduce specular highlights
Wedding and event photography where flattering highlight roll-off is desired
Cinematic and video production for controlled halation and organic highlight bloom
Editorial and lifestyle shoots that require a subtle vintage or film-like look
Key specifications
Filter type: diffusion / softening
Strength: 1/4 (subtle diffusion)
Mount type: screw-in (threaded)
Thread size: 40.5 mm
Optical finish: HD coating to reduce reflections and maintain color neutrality
Compatibility: designed for lenses accepting 40.5 mm front filters
How to use
Attach the filter to the front thread of a lens with a 40.5 mm filter mount by screwing it in until secure; avoid overtightening. Use the filter on open or moderate apertures to achieve the intended softening effect—wider apertures will emphasize diffusion on specular highlights while smaller apertures will retain more overall sharpness. Evaluate results on-camera and combine with slight exposure or white balance adjustments if necessary to maintain accurate skin tones.
Usage recommendations
For portrait and wedding work, position the subject so highlights fall within the frame to take advantage of the filter's controlled bloom. When shooting video, verify focus and preview on a calibrated monitor to ensure the diffusion level remains appropriate. Clean the filter surface with a microfiber cloth and lens-safe cleaner to avoid scratches; store in a protective case when not in use.

## FAQ

### How much does the K&F Diffusion Filter HD Black 1/4 for 40.5mm cost, and is it available for purchase?

The price is 50.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 10 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 15.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All K&F products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized K&F service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/11878936/67296610_large.webp