1. Úvod
This manual provides instructions for the Viltrox PFU RBMH 20mm f/1.8 ASPH manual focus lens. This ultra-wide prime lens is designed for Nikon Z-mount mirrorless cameras, including models such as Z5, Z50, Z6, Z6 II, Z7, Z7 II, Z9, and Zfc. It offers a broad field of view and a bright f/1.8 maximum aperture, making it suitable for astrophotography, landscape, interior, and architectural photography.
The lens features an optical design with aspherical and low dispersion elements to reduce aberrations and an HD Nano multi-layer coating to minimize flare and ghosting. It is constructed from brass for durability and smooth operation.
Důležité bezpečnostní informace:
- Do not expose the lens to direct sunlight for extended periods, as this may damage the camera sensor or lens elements.
- Zabraňte pádu objektivu na zem nebo jeho vystavení silným nárazům.
- Chraňte objektiv před vodou a vlhkostí.
- Do not attempt to disassemble or repair the lens yourself. Contact authorized service personnel for assistance.
2. Nastavení
2.1 Obsah balení
Ověřte, zda jsou v balení přítomny všechny položky:
- Viltrox PFU RBMH 20mm f/1.8 ASPH Lens
- Krytka předního objektivu
- Zadní krytka objektivu
- Sluneční clona objektivu
- Pouzdro na objektiv
- Adaptérový kroužek filtru 82 mm
- Návod k použití (tento dokument)

Figure 2.1: Included accessories with the Viltrox 20mm f/1.8 lens.
2.2 Identifying Lens Parts
Familiarize yourself with the different parts of your Viltrox 20mm f/1.8 lens:

Figure 2.2: Key components of the Viltrox PFU RBMH 20mm f/1.8 ASPH lens.
- Lens Hood Position: Where the lens hood attaches.
- Lens Hood Index: Alignment mark for attaching the lens hood.
- Clonový kroužek: Used to manually set the lens aperture (f-stop).
- Zaostřovací kroužek: Used to manually adjust the focus.
- Depth of Field Rules: Markings indicating the depth of field at various apertures and focus distances.
- Mounting Index: Alignment mark for attaching the lens to the camera body.
2.3 Nasazení objektivu na fotoaparát
- Ujistěte se, že je fotoaparát vypnutý.
- Sejměte zadní krytku objektivu z objektivu a krytku těla z fotoaparátu.
- Align the mounting index mark on the lens with the corresponding mark on your camera's lens mount.
- Opatrně vložte objektiv do bajonetu fotoaparátu a otáčejte jím ve směru hodinových ručiček, dokud nezacvakne na místo. Netlačte na objektiv silou.
- To remove the lens, press the lens release button on your camera body and rotate the lens counter-clockwise until it detaches.

Figure 2.3: Viltrox 20mm f/1.8 lens properly mounted on a Nikon Z camera.
3. Provoz
3.1 Manuální ostření
Toto je objektiv s manuálním ostřením. Pro dosažení ostrého zaostření:
- Set your camera to manual focus (MF) mode.
- Podívejte se skrz viewfinder or use the camera's LCD screen.
- Rotate the focusing ring on the lens until your subject appears sharp. Utilize your camera's focus peaking or magnification assist features for precise focusing.
- The lens has a 148.5° focus throw, allowing for fine adjustments.
- The minimum focusing distance is 9.8 inches (0.25 meters).

Figure 3.1: The focusing ring and aperture ring on the Viltrox 20mm f/1.8 lens.
The engraved focus distance and depth of field scales on the lens barrel can assist with pre-focusing and hyperfocal distance techniques, especially useful for landscape and astrophotography.

Figure 3.2: The lens offers excellent close-up ability with a minimum shooting distance of 0.25m (9.84 inches).
3.2 Setting the Aperture
The lens features an aperture ring for manual control of the f-stop. Rotate the aperture ring to select your desired aperture value, ranging from f/1.8 to f/16. The bright f/1.8 maximum aperture is ideal for low-light conditions and creating shallow depth of field with pleasing bokeh, thanks to its 14-blade diaphragm.
3.3 Using the Lens Hood
The included lens hood helps to block stray light from entering the lens, reducing flare and ghosting, and provides some physical protection to the front element. To attach the lens hood, align its index mark with the lens hood index on the lens and rotate until it locks into place. To remove, reverse the process.

Figure 3.3: Lens with attached hood for flare reduction and protection.
3.4 Připevnění filtrů
The lens has an 82mm filter thread. An 82mm filter adapter ring is included to facilitate the attachment of screw-in filters. Screw the filter adapter ring onto the front of the lens, then attach your 82mm filter to the adapter ring.
4. Údržba
4.1 Čištění objektivu
- Prvky objektivu: Use a soft lens brush or a blower to remove dust. For smudges or fingerprints, use a clean microfiber lens cloth with a small amount of lens cleaning solution. Wipe gently in a circular motion from the center outwards. The HD Nano coating is water-resistant, but avoid excessive moisture.
- Tělo objektivu: Wipe the lens barrel with a soft, dry cloth. Do not use organic solvents like paint thinner or benzene.
- Always keep the front and rear lens caps on when the lens is not in use to protect the elements from dust and scratches.
4.2 Skladování
- Store the lens in a cool, dry, and well-ventilated place, away from direct sunlight and high humidity.
- If storing for an extended period, place it in a sealed container with desiccant packets to prevent mold and mildew growth.
- Avoid storing the lens with mothballs or chemicals that may emit volatile gases.
5. Řešení problémů
| Problém | Možná příčina | Řešení |
|---|---|---|
| Cannot attach lens to camera. | Nesprávné zarovnání nebo překážka. | Ensure the mounting index marks are aligned. Check for any debris on the lens mount or camera body. Do not force the lens. |
| Snímky jsou rozmazané/neostré. | Nesprávné manuální nastavení ostření. | Ensure camera is in MF mode. Carefully adjust the focusing ring. Use camera's focus peaking or magnification assist. |
| Excessive flare or ghosting in images. | Strong light source hitting the front element. | Attach the lens hood. Reposition to avoid direct light sources. |
| Dust or smudges on lens elements. | Exposure to environment, improper handling. | Clean lens elements as described in Section 4.1. |
6. Specifikace
| Funkce | Popis |
|---|---|
| Značka | VILTROX |
| Název modelu | PFU RBMH 20mm f/1.8 ASPH |
| Ohnisková vzdálenost | 20mm (30mm equivalent on DX-format cameras) |
| Maximální clona | f/1.8 |
| Minimální clona | f/16 |
| Držák objektivu | Nikon Z |
| Typ zaměření | Manuální ostření |
| Minimální zaostřovací vzdálenost | 0.25 m (9.8 palců) |
| Optický design | 12 elements in 9 groups (including 4 ED elements, 1 double-sided aspherical element, and 1 highly transparent element) |
| Čepele membrány | 14 (zaokrouhleno) |
| Velikost filtru | 82 mm |
| Povlak | HD Nano multi-layer coating (water-resistant) |
| Úhel View | 94 stupňů |
| Stavební materiál | Brass lens barrel |
7. Záruka a podpora
For detailed warranty information and customer support, please refer to the official VILTROX website or contact your local VILTROX distributor. Keep your purchase receipt as proof of purchase for warranty claims.
Oficiální obchod VILTROX: Oficiální obchod VILTROX na Amazonu





