If you wish to purchase the Sony RX0II c-mount adapter plate visit: https://strawhataerial.com/products/rx0ii-c-mount-lens-adapter-plate

What's the Point?

Converting the Sony RX0II to c-mount lenses opens up some serious cinematic possibilites. At 250g total weight, the RX0II paried with the Azure Photonics 6.5mm c-mount lens is a big step up in image quality compared to a GoPro, but does not sacrifice weight too much like a mirrorless camera. Whether you are an FPV pilot or a filmmaker, this mod will unleash the full potential of this incredible little camera. The issue with the stock Sony RX0II is its tiny f/4 aperture which doesn't let in a lot light, hampers the low light performance and dynamic range of the RX0II. In additon, it has a fixed focal length of 24mm (full-frame equivalent) which doesn't make it great for FPV use. You do have the option to use aftermarket 37mm filter mounts such as the PULUZ kit, and pair it with a 37mm wide angle lens adapter like the Beast Grip 0.6X , and this will increase the FOV and give you a great image, but the sharpness is lacking in the corners AND it still doesn't let in a lot of light through that f/4 fixed aperture. Converting to c-mount lenses opens up the floodgates to a whole host of possibilities for lens choices, some that let in waaaay more light and still provide a wide FOV without compromising on image sharpness.

How to Install

Installing this c-mount plate is relatively easy with the right tools and some patience. Follow my guide below to see if this project is something you can handle and of course, use it for when you decide to invest in this miniature cinema camera platform. The c-mount mod is much easier than putting together a naked Blackmagic camera and the procedure is 100% reversible, meaning if you decide to put your RX0II back together, this is still possible.

What Lenses to Use

Starting from least expensive to most, listed below are c-mount lenses that are 1) compatible with the 1" sensor of the RX0II 2) provide a wide FOV and 3) maintain sharpness across the entire image. Not to be confused with CS mount lenses, only c-mount will work because CS requires a back-plane focal distance so short that the lens will run into the sensor housing before focus is acheived.

1. Azure Photonics 6.5mm f1.4 2MP: (125g) This is my favorite lens because it is actually just as sharp as the 5MP verison below (at least on the Sony RX0II). In addition, it is still quite a fast lens and will let in a lot of light. The estimated FOV of this lens is 90-100 degrees horizontal and it is a bit wider than the 5MP version. The only issue with this one is it has color fringing (chromatic aberration) in high contrast areas such as tree branches against bright sky, but that is only noticeable when zooming into the footage 400%. If it really bothers you, you can also eliminate it with color editing in post. You can purchase this lens here: https://www.rmaelectronics.com/azure-photonics-azure-0614mlm/

2. Azure Photonics 6.5mm f2.0 5MP: (140g) This lens is almost twice as expesive as the 2MP verison, but the image quality is about the same surprisingly. It has a slightly narrower FOV and it may actually let in a little more light even though it is f/2.0 instead of f/1.4. I would recommend this lens only if the 2MP version is out of stock. Here's the link to purchase: https://www.rmaelectronics.com/azure-photonics-azure-06520ml5m/

3. Moritex 5mm F2.8 12MP: (150g) If you need a "no comprimises" kind of lens then this one is for you. There are actually some downsides though, but they are minor. It is a little on the heavy side at 150g and it's a bit longer and will protrude about 50mm out front. In addition, it does not have a filter thread so a slip-on ND filter will have to be fashioned. Despite that, this is a great lens option for those who want the best image quality possible. It has a very wide FOV like a GoPro, but it maintains sharpness at the edges with almost perfection, and there is no color fringing to speak of. It is made of quality glass and will let in tons of light. Of course, this image quality comes at a hefty price of $705 per lens. It is more difficult to get your hands on this one too because it is a machine vision lens. I purchased my sample from https://www.motionanalysisinc.com/.

Other Lenses: Feel free to research others lens options that I may have missed. If you find one, ask me about it in the comments below. Chances are I have already tested it and eliminated them as a candidate. BUT if you plan to use this c-mount kit for purposes outside FPV, then you are no longer restricted to the wide FOV spec. When looking at focal lengths of 12mm to 35mm, there a more options for c-mount lenses that cover 1" size sensors.

Camera Settings

Doing this mod is pointless if you are not taking full advantage of the Sony RX0II's image. To do this, a custom "Picture Profile" must be created that:

1. Reduces sharpness to a minimum
2. increases dynamic range
3. Balances colors for editing

The base Gamma setting for your picture profile should be Cine2 not S-log. The reason why is because the RX0II is only 8-bit depth and when using an S-log curve, although there is improved dynamic range, in post when spreading the lumetri values back out, the codec tends to break apart. Using the Cine2 gamma profile sets the image closer to the final product so the codec doesn't have to be stretched as far and better image fidelity is achieved. In additon, using the S-log gamma curve requires a minimum ISO of 1000 whcih introduces more noise. Please chime in below if you have tips on how to use S-log gamma with the RX0II while getting away with less noise and easier color grading, because I am still learning too!