Swap SRP lens underwater

[FuzzyNutz]

I might be making myself out to be an idiot right now, but why can't we do this? I've seen it posted more than several times that the SRP lenses can't be swapped underwater... why? Will anything bad happen? I guess the desiccant would be ruined, but what if you don't use desiccant and just let the lens fill with water? I have another camera where water gets in the space between the camera lens and housing lens, and the pictures come out perfect.

I ask because I'm excited to have a polarizing and red lens for my SRP, but now I'm bummed because people are saying they can't be swapped. I just don't see why not...

 

[JamesK]

If you do this, you will be defeating the purpose of the flat lens. By filling up the space in between the lenses with water, you essentially go back to a domed lens and your camera will not focus properly. The only thing I could suggest is getting a screw in UV filter that allows other filters to be screwed in to it. You could then screw off the outer lens and change it with another. This will however lead to vignetting of your video/picture.

 

[flareside]

You might check with B&H to see if the Ikelite 6441.32 will fit over the 55mm filter ring. You would have to notch it around the power button but that would at least make it removeable and certainly wouldn't have the vignetting of stacking filters.

 

[FuzzyNutz]

Ah ha! I see the light, thanks guys! I might have to look into some of the options you mentioned!

 

[paulw]

I really like my SRP lens but have the same issue, here is another answer: Backscatter Custom GoPro Underwater Housing Blur Fix Glass lens and Underwater Removable Filter Mount

 

[scubamarketing]

My allergies are making my head a little cloudy, but I'm not following the physics of this. I have an old Sea & Sea housing with a flat lens that allows for swappable lenses underwater and have never had focus issues with lenses or filters. Vignetting perhaps, but I'm not seeing how adding a lens on top of another lens would change it from a flat lens to a domed lens.

 

[JamesK]

OK, let me try to explain. With the SRP housing you have the original domed port lens, and then the adapter that allows a flat lens to be screwed in place. That flat lens can be clear or red depending on what you are using. If you remove that lens, then you only have the domed port. The Go Pro can not focus underwater with the domed port. If you then put another flat lens in place, theoretically you have another flat lens, however you have let water in between the domed port and the flat lens making the domed port the last lens before the water. This would be the same as simply holding up a piece of smooth glass or plastic in front of a domed port and calling it a flat lens. The air space in between the flat lens and the domed port, with the flat lens being the last thing before the water, is what allows the camera to focus.

I hope I explained the good enough.

 

[scubamarketing]

Thanks JamesK, I haven't seen the SRP housing in person so I didn't realize that's how it was designed. It makes perfect sense now, thanks again.

 

[JamesK]

No problem. Glad I could help.

 

[merxlin]

And just to be clear, you cannot swap "lenses" on any of the GoPro housings, only filters. AFAIK, there are no macro or wide angle (like you would need more wide angle) add-on lenses available yet.