Wide Angle Options for the 10bar LX3 housing

[Nemrod]

OK Nemrod, I pulled the trigger and went with the UWL-04 to test this thing out. It should be here in a week or so. When it comes in I'll take it to the fish tanks to get some test shots. The $400 was much easier to swallow than the $700-800.

Thanks again,
Patrick

Hey, well, uh, OK, I was wanting you to do a little more checking into it but, congrats, please let me know how it works. I am very excited for you that it will do good for you.

N

 

[flounderer]

You have given me the best options to date and I've been checking for a little while. The UWL-04 seems to be a safe option to test out. There is very little information out there on the 10bar housings so if I'm going to decide on something I have to bite the bullet and try it out. Scotts page has the only actual info on the housing I've seen but I want a cheaper options. This lens fits the bill so the bullet has been bitten.

 

[flounderer]

I have the UWL-04 and I hope I can explain this without having to take pictures. There is some vignetting which I expected. It's mostly that the glare shield is visible more than the black corners. I have to zoom 1/4 in to remove it. At the zoomed level the field of view is nearly the same as without the lens (flat port). I know this will change underwater but how much? Will the domes FOV stay the same below water as above water while the flat will lose some FOV? Once I get the lens wet I can't return it. I hate to ask such a "speculatory" type question but I want to put it out there before splashing the rig.

Thanks again
Pat

 

[Nemrod]

I have the UWL-04 and I hope I can explain this without having to take pictures. There is some vignetting which I expected. It's mostly that the glare shield is visible more than the black corners. I have to zoom 1/4 in to remove it. At the zoomed level the field of view is nearly the same as without the lens (flat port). I know this will change underwater but how much? Will the domes FOV stay the same below water as above water while the flat will lose some FOV? Once I get the lens wet I can't return it. I hate to ask such a "speculatory" type question but I want to put it out there before splashing the rig.

Thanks again
Pat

The FOV you see above the water with the flat port is reduced by 25% underwater. However, the domed lens will remain the same, actually, since it is a corrected underwater lens, it may get wider.

I am pretty sure the pics on Scott's site are cropped to 16:9 and I imagine what you will need to do with any wide angle lens on your camera, is crop the c---p out of them. That is what I was saying in my post #2. This is what I was concerned about.

But, to make you feel better, my Inon 165 does the same thing on the surface. But the full FOV you see on the surface is preserved. I think it will give you the best you can get underwater, crop it 4X6 or 16:9.

Can you give me a picture of the rear of your new lens--I need to see something there. Also, what is the clear diameter of the rear element of the UL-04 and the front element of your LX3?

N

 

[flounderer]

The diameter of the clear area on the rear of the UWL-04 is 38mm, on the camera 22mm.

 

[Nemrod]

The rear element of the Inon 100WAL is about 43mm diameter. I don't really know if that would help anything or not. Imagine looking through a straw, as you move the straw closer to your eye the FOV through the straw increases, likewise, at any given distance from your eye, if you increase the diameter of the straw you will see a wider FOV through the straw. However, a lens system is not hollow like the straw, the light path is bent by the lenses so my simplistic analogy is not ironclad.

The diagonal FOV of a 24mm lens (35mm equiv.) underwater using the magnification factor of 1.3 is 69.5 degrees. On the surface it is 84 degrees diagonal. This site is a good resource:

Field of View - Rectilinear and Fisheye Lenses

The magnification of the UL-04 is stated as .42X but it is a semi fisheye lens so calculations get more challenging. The stated native FOV per Fisheye of that lens is 131 degrees. I do not know if it was designed for a 28mm or 35mm native camera lens?

My diagrams indicate at a 16:9 crop your UL-04 should yield a corner to corner diagonal FOV of between 110 and 120 degrees, assuming it is a 131 degree, .42X lens.

So you have two choices, send it back and get the Inon at nearly twice the price and hope that the larger lens diameter helps or take the plunge. You are going to have to crop. Your LX3 has some sort of full sensor cropping engine built in that I do not really understand that allows you to crop without reducing the MP count of the sensor. When you set your LX3 to 16:9 and look through the lens--what happens?

I don't understand the stack up of parts on your camera to lens arrangement. The lens must be as close as possible to the port lens.

N

 

[JackConnick]

10Bar has lots of options with their system. Pretty modular.

Jack

 

[flounderer]

I think my head is going to explode.....

 

[Nemrod]

I think my head is going to explode.....

Before your head explodes, maybe just call Mr. Jack. Of course, what he is not realizing is that you were working under a budget, lol, and trying to mount a wet lens and not a dry port options but maybe ask him what he can do since he is a dealer for that housing ------- before you get that lens wet. The accessories shown in the diagram from Mr. Jack are a dry mount port system that uses an add on dry accessories lens inside the dry port--I think.

I do not think that going to the rather expenisve Inon lens/dome will gain you anything much over the lens you already have there. This is why I was wanting you to do a little more research before jumping but like you said, sometimes the only way to get the answer is to actually do it. Vignetting is an issue with wet lenses and add on lenses, dry or wet, especially however, wet lenses, more with some cameras and housings than others. Been there and doing that now myself and my head has already exploded but I glued it back together.

Sometimes spending more money up front can save you money down the road, if you think that lens is not going to work then maybe Jack can give you another direction before you commit. It would help if there were photos showing the expected results of various lenses.

I would buy the lens from you but I am just momentarily broke from my S90/FIX ongoing expenditures. I am wanting one of those.

Hang in there.

N

 

[mofongo_max]

Just to add to the pot...

There was this thread back at the end of 2009 for the Dyron WAL15, which was claimed to be custom made for the 10Bar LX3 housing (no zoom necessary to lose the vignetting). Though the pics in the thread show severe (at least to me) blur at the corners. Without seeing any other (better) examples with this lens, I've been hesitant to even seek out US distributors.

http://www.scubaboard.com/forums/underwater-photography/314236-lx3-dyron-wa15.html


Looks like you're already on wetpixel as well. There's a thread there for the housing in general that have some examples of dry shots taken with Ikelite WA20 and INON UFL165AD. Both obviously requiring lots of zooming to lose the vignetting. Haven't seen any wet shots with either of these two lenses with the 10Bar. There also appear to be options to use the wide-angle lens made by Panasonic with 10Bar's dome too.

10Bar LX3 Housing - Wetpixel :: Underwater Photography Forums


I already have a WAL-100 Type 2 that I'm planning on using to start with. Though you do have to zoom to 35mm, the lens doesn't retract much from the port (camera lens retracts when zooming out, it's at its longest when at 24mm)... so it should stay pretty close. May bite the bullet and get the dome port eventually, since I already have the WAL-100. If I could get images half as good as Edvin I'd be happy.