Is there a lens to put on the GoPro to reverse FishEye?

[stanleym7236]

That's not how light and optics works Jeroen3277.    Moving to an rectinear ultra wide angle lens would require multiple large diameter lens elements.   Could even be larger in diameter than the entrie size of the camera.   Cost, packaging, mounts, cases etc would all have to be redone.   If the present lens costs maybe 5-10 dollars or less, what you are proposing would cost more than the retail value of the whole camera besides the packaging. 

You could try some GoPro replacement lenses for prior GoPros to see if you can unscrew the present lens element and swap out the lens.  Ideally in a clean room or close to one.    Those give up the wide angle of the GoPro however.   

Really a true 2.7k in linear is an effective solution.   You can get the same in 4K with a lens swap to a much less wide lens.   

Looking forward to some videos from you showing the various lenses you try out, the lens swap process after you find a way not to harm the camera etc.   Might take a good part of a year to do so, am looking forward to hearing more.  

[jay-ell]

I've done lens swaps on my Hero 4 - when selecting a lens you have to make sure that the lwna is capable of resolving at 4k, alot of the lenses are only designed to focus images at standard or HD definitions and at 4k they are unsharp.  You need a lens capable of resolving at leats 8Mega Pixels.  The colour tuning on a GoPro is made using their own lenses, swapping out a lens for a different undistorted lens will have different ioptical qualities and can result in altering the colour of the resulting image.

Using software to defish an image is more than juist zooming in a bit

A fish eye image is taken and has a pin coushin distorthin applied to it which counteracts the curvature added by the fisheye lens.  The pincousion distortion pulls the corners out streatching the image out. This distorted image is then cropped back down to a 4k resolution, although the detail in the corners will be reduced.

Most action cameras have the fisheye distortion - it's part of the expected Action Camera look.

You can always look at other cameras such as the Firefly 8S 90 degree which has a 90 degree lens with less distortion, of course alot of the GoPro features are lacking in it.

[stanleym7236]

You can also do "linear" modes in your laptop/desktop.   For images at least you can get that linear look but with a wider angle.   However the look can change.   But you can avoid things like color shift, then again when editing it is normal to revise white balance and more.   I don't have a "linearizer" for video that goes as wide as I do for images, but there may be some out there.   Or the video frames can be run thru individually and made back into a movie afterwards.   

Really, GoPro delivered some very good options to us.   IF you use the camera as intended.  

If you want the wide angle with high resolution you want hypersmooth OFF and in-camera corrections off.   When you use hypersmooth and cropped and de-fishing modes they all reduce the wide angles and resolution of the stock lens.  

Those who have looked at the Osmo Pocket, that has a much narrower POV hence less fisheye / barrel distortions.   But it certainly has it's own limitations.