Inon UWL-100

[MOliveira]

Hello,
I have some questions concerning wide angle wet lens.
I have a Inon UWL-100 and my plan is to add the respective dome in the future.

The question is: What are the practical differences between using the UWL-100 without dome and with dome?

Of course, the main one is the widest FOV (90º to +/-115º), but my concern is more about focusing and DOF.
If i´m not wrong the UWL-100 alone doesn´t produce a virtual image, but with dome I belive that are some limitations depending the use of macro mode.
I already read the INON Lens comparing document, but I would like to know any opinion from yours experience.

Thanks
Miguel Oliveira

[James]

I have been shooting the Inon 100 plus dome for several years. I do not use a macro setting. I have no issues with focus or close focus or anything like that. The camera behaves as normal other than it has a tremendous DOF and huge wide angle. I love the lens and dome combination. it is heavy and expensive.

Cameras that I have used it on are the Oly 5050, Canon 570, Canon S90.

James

[MOliveira]

Hi James,

As you can see on my other posts I have a Canon 590Is that have a 35mm equivalent widest zoom. So I belive, underwater, it gives me 88º with UWL-100 "solo", and around 115º with dome. Am I right?

In CFWA type of photo with dome, it is possible to focus around 5cm (2 inches) and infinity? using macro mode?
In Inon catalogue it´s writen that with dome I can focus from 0cm to 35cm on macro mode and from 35cm to infitity on normal mode.
But I belive that it could be more relative, because the virtual image bring the infinity (or distance objects) to few cm of the lens.

Do you have any experience about that?

Thanks
Miguel Oliveira

[James]

When the dome is installed the UWL100 becomes a semi-fisheye lens so straight diagonal FOV geometry calculations do not work strictly speaking but the DFOV you state seems reasonable, I measure about 126 degrees DFOV with my A570 and about 125 degrees with my S90. I am not saying those numbers are exact, just were what I measured from some informal pool shots.

http://www.bobatkins.com/photography/te ... _view.html

I have not felt the need to utilize a macro setting with the dome installed. I played around with it some but saw that some of my shots were blurred. Because I am not a big "macro guy" I may not be the best person to answer this question.

I should think that if you are wanting to place the dome right on a small critter and then shift the camera to macro and take a shot and compare it to the same shot in normal mode.

James

[scottg]

When taking wide-angle underwater photos you want to be behind a dome port if possible.

Behind a dome port, the camera will focus on a virtual image. Macro mode and non-macro mode usually have some overlap in their focal range, so either far work for farther away shots. I usually recommend to people that they use macro mode when shooting from behind a dome port.

I'd do quick some tests underwater to double-check which settings give the best results. One of my students has been getting great results with the FIX fisheye dome port, keeping the camera in macro mode.

I don't think you have to worry about DOF.

[MOliveira]

Thanks for your help.