Problem with Inon UWL-100 WA Conversion Lens

[greenpants]

Guys,
I have a Canon G9, Ike housing and a Inon UWL-100 Wide Angle conversion lens.

The problem is that I am getting is a lot of softening around the edges. I understand I need to zoom in a little to prevent vingetting, and i am. Even when zooming in a lot for wide angle close focus shots I still get an unacceptable amount of softening.

See:


Am I doing something wrong?
Is this degree of softening normal?
Have I got a faulty lens?

Help!!

thanks
Dan

[Cussy]

Dan,
Do you get this affect out of the water too?
Rob

PS I had some softening with an Epoque add on lens, nothing like this though

[greenpants]

I don't think so....I'll try it later.

cheers
Dan

[David P]

Although I've only done a handful of crude tests I most certainly don't see anything on this scale with a UWL-105 on a Fuji F30 - I'll see if any of my few samples are useful this evening.

[Cussy]

Reason I ask is it will rule out a number of things. I often got weird effects when air got trapped between the lens and the housing. This area acted like a lens and distorted things. If all surfaces are clean and this doesn't happen topside then you know it isn't your camera or the lens.

Also not sure how this lens attaches to your particular camera. If it has a separate mount then you have to be careful that the optics of the camera are directly down the centre of the lens - it has to be perfectly in line otherwise you get awful distortion. This can be obvious if the distortion is asymmetric.

You can buy quite expensive filters to get this effect! What it does remind me of is an article I read where it suggested smearing vaseline on a plain filter, this gave a similar effect to what you're seeing, although a lot more extreme.
Rob

[greenpants]

Originally Posted by Cussy

Reason I ask is it will rule out a number of things. I often got weird effects when air got trapped between the lens and the housing. This area acted like a lens and distorted things. If all surfaces are clean and this doesn't happen topside then you know it isn't your camera or the lens.

Also not sure how this lens attaches to your particular camera. If it has a separate mount then you have to be careful that the optics of the camera are directly down the centre of the lens - it has to be perfectly in line otherwise you get awful distortion. This can be obvious if the distortion is asymmetric.

You can buy quite expensive filters to get this effect! What it does remind me of is an article I read where it suggested smearing vaseline on a plain filter, this gave a similar effect to what you're seeing, although a lot more extreme.
Rob

Rob,
I made sure there was no trapped air during the dive by removing the lens underwater. The lens screws in directly into the Ikelite short port and is very secure.

Definatley no vaseline involved

cheers
Dan

[Mike Ward]

Does the Ikelite converter ring detach from the housing? Is that mis-aligned?

One other thought - I seem to remember the reason you need to zoom the camera in a touch is because the lens is mounted pretty far forward, quite a way from the camera lens? Maybe that's it?

[greenpants]

Originally Posted by Mike Ward

Does the Ikelite converter ring detach from the housing? Is that mis-aligned?

One other thought - I seem to remember the reason you need to zoom the camera in a touch is because the lens is mounted pretty far forward, quite a way from the camera lens? Maybe that's it?

Mike,
Thanks for your reply, there is no adaptor the lens screws directly onto the port of the housing. I'm very sure there is no alignment issue.

The port is a special shorter version specifically for use with WA conversion lens's, so I'm sure the distance isn't an issue.

thanks
Dan

[Cussy]

Dan,
Sorry Mike and I are asking stupid questions, we appreciate you've probably tried the obvious already.

But I think you've got at least one answer - this isn't normal.
Rob

[Mike Ward]

Yup, sorry for the stupid questions, but as Cussy says, not normal. Get it changed?