Inon WAL info

[fergyjohn]

G'day

Just tested my new WAL above water, YUK. All the straight line edges appear curved, is this normal, will the same thing appear with my underwater shots, or is there some things I need to Know.

Your valuable advice is sought.

 

[justin-branam]

in my experience with the sea and sea 16mm wide angle there is a bit of "curvage" on the edges. i believe almost all wide angle lenses will do this. BTW. if you are unhappy with it and want to sell it, let me know.

 

[Dee]

That curved edge thing is called the pincushion effect. Some WA lenses are worse than others. Some like the distortion as an artsy effect, but I'm with you...I don't like it. Someone else can tell you for sure and explain the why's but I've seen the worst distortion from the lenses that say they can be used both above and beloe the water. Underwater, my S&S WAL doesn't produce the distortion you're seeing.

 

[Gilligan]

I just recently started using my Inon WAL so it's a little early to tell on that. I think it depends on the shot.
This one looks normal.
This one may be a little out of proportion on the left and right as compared to looking down the center.

BTW - You may want to mark your housing lens port ring and your housing so as to be able to easily tell if you are accidentally unscrewing the housing ring along with the WAL.

 

[ssra30]

You will find that you get barrel distortion (or what Dee called pincushion effect) to be a lot more significant when you use the WAL on land. On land, the WAL will give you about 130 degree field of vision. Underwater, you only get about 90+ degree field of vision but also less barrel distortion. I find Inon WAL to be pretty good and like it a lot for underwater use. If you add the Inon domeport which will give you 130 degree field of vision underwater, you will get more of this barrel distortion/fisheye lens effect to a certain extent.

 

[slowhands]

You will find that you get barrel distortion (or what Dee called pincushion effect) to be a lot more significant when you use the WAL on land. On land, the WAL will give you about 130 degree field of vision. Underwater, you only get about 90+ degree field of vision but also less barrel distortion. I find Inon WAL to be pretty good and like it a lot for underwater use. If you add the Inon domeport which will give you 130 degree field of vision underwater, you will get more of this barrel distortion/fisheye lens effect to a certain extent.

This distortion is inevitable with very wide angle lenses. For natural objects underwater, it usually does not matter because there are no straight lines. For wrecks or ruins, it's bad. There is a software program called PanoTools that will correct it. See the following for details:

http://www.splashdowndivers.com/photo_gallery/underwater_photography/image_processing_wide_angle.htm

 

[BadFish]

BTW - You may want to mark your housing lens port ring and your housing so as to be able to easily tell if you are accidentally unscrewing the housing ring along with the WAL.

Oh!!!! very good Tip Gilligan.... Thanks

 

[Aardal]

Oh!!!! very good Tip Gilligan.... Thanks

Ditto...

Something I hadn't thought of.....duh! Thanks Gilligan.

 

[Gilligan]

Your welcome. That's what retired folks do with their time.

 

[fergyjohn]

Thankyou all for your comments, will try it out in a fortnights time, have a little club trip on.