Wide angle lens options

[mkhilario]

the fantasea bigeyes are not conventional wet lenses per se. They are refractive domes designed to be used on a flat port to restore original dry FOV, not increase it. At 67mm diameter mount I think it may work without vignetting. Edge distortion and sharpness when used with as wide a lens as the gopro may be an issue though.

 

[Interceptor121]

Not sure what flareside was going on about as you can't use a lens designed for a flat port on a gopro?!?

I did some pool tests with the Hero2 as I wanted to figure out myself what the fov was so I compared it to my Panasonic LX7

I took two shots from the same point on a tripod against the pool wall

This is the LX7 with the Nauticam Wet mate (84 diagonal fov) number of pool tiles 14.5



This is the hero2 number of pool tiles 17



This is the LX7 with the UWL-H100 19 tiles



Doing a bit of extrapolation the Hero2 that has 170 on land has about 90-92 diagonal in water that is around 82 fov horizontal

I have looked at gopro2 vs gopro3 fov comparison and they are identical, I also looked at some side to side video with the hero3 and the Sony Rx100 and the same inon lens and you can see the Inon lens on a 28mm equivalent camera is wider

You can also see the amount of distortion of the gopro in the corners, that explains the blur you get in water that sometimes people confuse with housing fogging but it is just the lens being what it is

 

[mkhilario]

Well, I don't think anyone would suggest using a inon 165, or any other wet lens on a gopro. The underwater comparison shots are interesting, tha ks for posting. As I said, fantasea big eyes are refractive wet domes, not lenses per se. The link is on my first post.

 

[Interceptor121]

I know the fantasea the nauticam wetmate I have is similar actually better with 67mm thread however if you try putting it on you can see the frame
I think 90-92 diagonal fov is fine for most situations fisheye lenses in water are really only for stills not for video

 

[flareside]

Interceptor, I understand what you are saying but interpolating from an assumed value only makes your final answer as good as the initial assumption. That assumption being that the LX7 with the UWL-100 provides a 100 degree view which will not be the case as the lens was designed long before 24mm lenses became common. If you could provide camera distance from the wall and length of the wall tiles it would be far more helpful in determining the actual underwater FOV.

 

[Interceptor121]

The lens is designed to 100 degrees with a 28mm equivalent camera the LX7 was zoomed at 28mm so exactly as it needs to be for the lens to reach 100 degrees
Declared values are diagonal but I only measured horizontal as am counting pool tiles
I worked out that the values from inon are pretty much spot on to the point that they are likely more accurate than an empirical system to count tiles
Once you do that you can calculate what the gopro does quite easily with a certain degree of confidence
And in any case that was just to show that the gopro is narrower than a 100 diagonal lens and wider than an 84 diagonal lens so still quite wide but not as wide as a compact camera with a wet lens on
As the gopro has a non rectilinear lens behind a flat port in water it is not possible to a calculate upfront what reduction of fov you will have
As it stands the gopro looks around 80 horizontal that is 90ish diagonal

 

[ronscuba]

For video of wrecks and people the GoPro lens works well. Curious, other than that, what are people shooting video of that they want a lens covering more than 90 degrees ? It might sound funny, but I think a narrower lens would make the GoPro more versatile for shooting UW video of marine life.

 

[mkhilario]

Well here it is. A swiss made, purpose built gopro housing with dome port:

Subspace Pictures, Preobjectif Gopro

USD 260-

Interesting..

 

[Interceptor121]

For video of wrecks and people the GoPro lens works well. Curious, other than that, what are people shooting video of that they want a lens covering more than 90 degrees ? It might sound funny, but I think a narrower lens would make the GoPro more versatile for shooting UW video of marine life.

I don't understand that either. Once you have a fisheye lens you then run into the issue that you can't light the whole frame as with video light you don't cover more than 120 degrees best case.

In video terms a wide lens is 80-90 degrees diagonal or 75-80 horizontal, many operators have captured fine wide angle with this nobody needed a fisheye. I believe the only lens at 120 is the fathom but that is when you need to have a close up shot of a grey whale

On the contrary if the GoPro had a controllable zoom even inside the lens that would be useful as shooting always mid and wide is a strong limitation

---------- Post added May 9th, 2013 at 02:46 PM ----------

Interceptor, I understand what you are saying but interpolating from an assumed value only makes your final answer as good as the initial assumption. That assumption being that the LX7 with the UWL-100 provides a 100 degree view which will not be the case as the lens was designed long before 24mm lenses became common. If you could provide camera distance from the wall and length of the wall tiles it would be far more helpful in determining the actual underwater FOV.

Also I have the UWL-H100 lens designed for 28mm cameras that actually does not vignette even at 24mm on smaller lenses. I think you refer to the older UWL-100 for 35mm cameras

 

[flareside]

--------- Post added May 9th, 2013 at 02:46 PM ----------

Also I have the UWL-H100 lens designed for 28mm cameras that actually does not vignette even at 24mm on smaller lenses. I think you refer to the older UWL-100 for 35mm cameras

Issue was not vignetting but FOV based on zoom range and you already answered that question.