Arducam2.8-12mm Varifocal C-Mount Lens for Raspberry Pi HQ Camera, with C-CS Adapter, Industrial Telephoto Lens

1. The TELE-WIDE ring is mislabeled! TELE expands the viewing angle, and WIDE shrinks it!UPDATE: I received a kind letter from customer service, who offered several options to resolve the issue. It seems I was among the few customers (or even the only ones) who had the wrong zoom ring.2. You cannot focus the image in the entire TELE range.UPDATE: Turns out it's not a fault with the ARDUCAM lens, but with the IFWATER camera body. The distance between the lens seat and the sensor surface was neither 17.53 mm (which is standard for a C lens) nor 12.53 mm (CS lens), but around 14.5 mm, which made it impossible to focus properly. So I have to update the review for IFWATER camera too.

I really like this lens. It's a great multi-purpose lens for c-mount cameras. Very wide FOV when zoomed out and decent telephoto when zoomed in.This lens does NOT have an IR-Cut filter and will show red infrared fringes when used on cameras without an IR-Cut filter. You can see this in Jim G's review photo. I don't think an IR filter can be adapted to this as the focusing element extends past the mounting threads on the back of the lens. You would need a camera with built-in IR-Cut filter.

When not in focus, there are a lot of lens imperfections may be visible: scratches, chips or dust that may affect the result. It's not noticeable from the outside and looks like there are internal defects. I ordered two lenses, both had this problem. Had to return them. For $65 I expected better quality.Also, zoom control label is not correct. When turning towards "wide", the picture gets closer; when turning towards "tele", the picture gets wider. Very confusing.

I decided to give this a shot even with the other negative reviews, but was highly disappointed. Everything is heavily tinted purple using this lens. The clarity is also not what you'd expect, even testing at different ranges from wide to tele. The focus is touchy as is common with this type of lens, but it still isn't near as clear as the cheap stock lens I have.

This lens combines extremely poor quality with extremely challenging operation. The chromatic aberration on this lens is the worst I have ever seen. It's not purple fringing, it's a purple border! Operation of the lens is difficult. Controls are not well labeled. I have no idea which way the zoom works. And is "near-far" a reference to focus or zooming? For this price in a small lens, I was getting at least decent quality. Nope. Returned.

This is for the 2.8-12mm varifocal lens. It's okay as a wide angle lens. However, it cannot focus on anything if you zoom in more than a little bit. This is complete trash and unusable as anything other than a fixed focal length lens.

All pictures in the product page for the 2.8-12mm show a IR filtered lens, The one they sent me IS NOT filtered. Since the back part of the lens does move, is also very difficult to glue an IR filter glass in place. I'll keep it since it seems well constructed and it may work for some night uses, but let's be clear: pictures and product should match.

The lens works great and operate nicely. I don't have the materials to test the claims.