Modifying c mount lens to run in mineral oil

Hello all,

I am an engineering student and I’m working on a project where I need to submerge a lens system and camera sensor in mineral oil. I have a c mount lens kit as well as a raspberry pi and its sensor. I’ve disassembled and reassembled two of the lenses under oil to fully fill them as well as immersed the sensor. the sensor and lens appear to work but I cant get them to focus. I know this is due to the fact that mineral oil has a far higher refractive index than air but I was hopeful with a large enough focal range I would be able to adjust the stock lens to adjust for the difference. any ideas on how to overcome this?

thank you,

As the mineral oil is nearly the same refractive index as some of the elements within the compound lens they will be almost ineffective at bending the light, hence the lack of focus ability.
If your project constraints allow, it would be better to seal the lens and sensor behind a flat window. So that the mineral oil interface happened at the sealed window and all the lens and sensor spaces are air-filled.

Thanks for your message. We will evaluate it. We are also constantly optimizing product design.