Lens adapters for GoPro?

[Charles W. Hull]

I'm looking for lens adapters to make the GoPro Hero less wide angle; less fish eye. Working with the 3D Hero, it seems to be quite capable with 3D. But the wide 127° FOV is very limiting; it sure would be nice to get it out to something like a 24mm equivalent lens. Does something like this exist? Or is there a lens/optical approach that might work?

[Wayne Reimer]

I'm sure that it would be possible to do, but I've never heard of anyone attempting it. I think the problem would arise in trying to find a lens small enough dimensionally to work, and still produce acceptable quality video.
I don't know if you could adapt a small lens from a point and shoot camera to it...I would expect there would be some severe vignetting at the very least.
It probably could be done, but I suspect the cost would be prohibitive, although it would be an interesting engineering exercise..

[Ian Newland]

The best solution is to replace the Gopro lens with a Sunlex lens. It's very easy i have one of my Gopros modified with this lens. External attachment lens don't work as Gopro has fixed focus.

YouTube - ‪Gopro lens modification - How to change lens to a sunex dsl355a-650-f2.8. No fisheye.‬‏

[Dustin Moore]

Originally Posted by Wayne Reimer

It probably could be done, but I suspect the cost would be prohibitive, although it would be an interesting engineering exercise..

The front end on the GoPro is probably a textbook fisheye and the main feature of a
fisheye is that the entrance pupil is in a vastly different place depending on what angle
the light is going into the system. There's a picture of this effect at
http://michel.thoby.free.fr/Fisheye_...eb-1200-EN.jpg

At any rate, when you design a lens attachment not only do you have to make sure that
all of the rays come to a sharp focus, you also have to make sure that they go through
the entrance pupil otherwise no light gets to the image.

It is difficult to make attachments even when the entrance pupil stays put, making an
attachment for a fisheye would be extremely difficult. Much better to rip the fisheye out
and stick in the lens you actually want.

If pulling lenses out of finished products isn't your idea of fun, I've had good success with the
de-fisheye plugin from NewBlueFX. Doesn't fix the fact that the gopro is a wide angle camera
but you can remap the fisheye-ness to be a bit more rectilinear at the cost of loosing some of
the wideness.

[Bill Thesken]

Here's a flat lens replacement for the water housing:

Flat Underwater Lens For GoPro Housing - Pursuit Diving

[Dustin Moore]

Was the first guy underwater? If so then he'll need that to stay on focus. Above
the water the flat lens replacement is mainly going to make things out of focus
(I think).

[Ian Newland]

No the flat will not put the GOPro out of focus above water (see my post in the other thread) The original domed glass housing lens is only a protective lens, however it does have a very slight magnifying effect to allow 720p mode extreme wide angle without vignetting on the housing, it does not effect focus.

[Charles W. Hull]

Originally Posted by Ian Newland

The best solution is to replace the Gopro lens with a Sunlex lens. It's very easy i have one of my Gopros modified with this lens. External attachment lens don't work as Gopro has fixed focus.

Thanks Ian, the Sunex lens looks like a good soultion!!

[Ian Newland]

Yep works well, make sure you put a little dab of hot glue or similar to stop the lens rotating out of focus. One thing he doesn't show you is the camera will no longer fit in the housing unless you remove the housing dome lens. I have made an extension tube to cover the extra lens length and a small flat lens cover is on the end of that so it is still waterproof. If waterproofing is not required, just leave the original dome off.

[Charles W. Hull]

Originally Posted by Ian Newland

Yep works well, make sure you put a little dab of hot glue or similar to stop the lens rotating out of focus. One thing he doesn't show you is the camera will no longer fit in the housing unless you remove the housing dome lens. I have made an extension tube to cover the extra lens length and a small flat lens cover is on the end of that so it is still waterproof. If waterproofing is not required, just leave the original dome off.

I did modify a 3D GpPro with the Sunex lenses. This makes for a very nice 3D setup. Thanks again for the tip Ian.

[Ian Newland]

You're welcome, glad it worked for you. Of course if you use a Sunex lens with a different Focal length (physically longer) it may not fit into the waterproof housing with the housing dome lens in place. I have made an extension to accommodate this, but if you stick to the original GoPro focal length then not an issue.

If WP is not required then just remove the dome and you still have the protective housing and mount attachments.

R