S90.....Ike Housing......W-20......

[Jorgy]

Today I completed my DIY adapter to mount my Ike housing to my S&S tray, hopefully tomorrow I can get to a pool and dive the new rig........

N had posted some interesting topside pictures to demo the benefit of a WA lens so I thought I might do the same for my rig.......

So I lined up some of those Russian dolls and laid out two tape measures.......

Please see thumbnail #1.........

I then moved the camera to 12 inches from the dolls and took the next 4 pictures.......

#2 - S90 set at 28mm you get about 13.5 inches of view or about a 60 degree FOV.......

#3 - S90 set at 35mm you get about 11 inches of view or about 50 degree FOV.......

#4 - S90/W20 at 28mm you get about 36 plus inches of view or about 110 degree FOV......

#5 - S90/W20 at 35mm you get about 22 inches of view or about 85 degree FOV.....

Does this make sense? Thoughts?

When I take pictures of straight lines you can clearly see the barrel distortion and vignetteing (if those are the correct terms)......is this an issue underwater?

What are options, settings that can minimize this?

I guess I can crop in post processing to get rid of the black corners......

Thanks for any feedback or comments......

M

 

[dhaas]

Amigos,

Yesterday I jumped in the pool with my Ikelite housed Canon S90 and W20 lens. No flash.....

Tv mode, AUTO ISO and played around.....Shot some "Scene" mode shots too just to keep from getting bored.

Also shot some super looking SD video with the W20. Color and 30FPS (frames per second) looks so smooth

This camera keeps surprising me!

dhaas

 

[Nemrod]

Jorgy, none of these lenses we play with are rectilinear lenses. That means you will see barrel distortion and generally underwater it is a non issue because there are few straight lines to judge it buy. You can correct it in some Photoshop add on programs. We would rather have the FOV than the straight lines so it is a sacrifice we make.

I believe that your dark corners will be reduced in the water. An 85 degree diagonal FOV underwater is what should be expected from the Ikelite lens. Is that what you have?

Dave (dhass), do you get the corner vignetting Jorgy gets on the surface? Just curious, I assume your photos in the pool and from Coz were not cropped?

The S90 has apparent barrel distortion I see and am told when shooting in RAW as the camera has processing in JPEG files that removes it. The Canon software disc which I have not played with can also remove it I read?

All fisheye and semi fisheye lenses have barrel distortion--by definition--it is their nature.

Dave, even your pool shots are great, fun looking shots, you are just making us all look bad aren't you . You guys need to get some new regulators, that old stuff will kill you.

N

 

[dhaas]

Jorgy,

As Nemrod says most lenses made for UW use will show some barrel distortion. My pool shots illustrate this since there is a man made line (pool markers) but in nature unless there is a wreck or something else this is not as apparent.

Even with the INON 165 UFL fisheye lens shots that aren't aimed up or down too much won't show fisheye distortion UW (see a few I shot with the INON 165 UFL and Fuji E900 ages ago posted below.)

The big thing is the Canon S90 sensor and camera overall is way more advanced than P&S cameras from even a year ago.

Nemrod is also correct that the Canon S90 in JPEG shooting will automatically correct for barrel distortion. If shooting RAW the Canon DPP disc has a correction for this during post processing. I'm lazy and shoot JPEG

BUT, we usually have to zoom a bit to 35mm (at least I do) to make the very small vignetting go away with certain WA lenses. So you have to experiment with your housing and lens choice. Even if you need to crop out a teensy bit you're not throwing that much data away.....

Have fun shooting your new toy as we did diving our "ancient" dive gear.......

dhaas

 

[Jorgy]

N - yes it is the Ike lens.......

dhass - the zooming to 35mm does reduce the dark corners but decreases the FOV from 112 degrees to 85 degrees........

I guess it will depend on the picture and then post processing......

Thanks for all the good info.......

M

 

[dhaas]

Jorgy,

Zooming one "tap" on the S90 I ASSUME goes to about 35mm and then I get zero vignetting. I guess I could set the front control ring to ZOOM in "clicks" and be sure but I prefer to pop that function in and out of various parameters depending on what mode I'm shooting.

From time to time I will forget and then notice the zoom has reverted to 28mm and I have tiny dark corners. If I have time I'll tap the zoom lever one notch again. If something is happening though I shoot and sort it out on the computer.

I don't worry about the degree angle as I tend to use my LCD when framing plus get close for sharp photos. Then I get a little closer

Since LCDs show you 100% of what the sensor will capture I don't see where this is a big problem.

Get your set up ready with a hot batter in it and jump in and learn. Sitting high and dry usually doesn't teach me much. So I try and find a pool to practice every chance I get!

One final thing I discovered on my Ikelite housing........IF, and that's a big IF, you need some changes that usually are done with the REAR control wheel hold down the "PRINT button. Then you can then go LEFT an RIGHT arrows to adjust that parameter.

I found I had the SCENE mode set on SNOW and needed to get to my one favorite, NOSTALGIC where you can vary color fade and B&W intensity. Hit the PRINT button and went left or right and I was in the SCENE mode I wanted.

Good luck shooting and have fun!

dhaas

 

[Jorgy]

So yesterday I did manage to get to my LDS pool, at least for a bit.......

Some pictures......

First Shot........in manual with dual YS-110 way over exposed but shows an issue..... air bubbles between the W20 and housing as I threaded the WA lens on topside......so I undid it and let the bubbles out.......question: if you do this in the ocean don't you run the risk of particles getting trapped?

S90W2035mm........the items are about 8-10 inches across each so about 24 inches across total, camera was about 12 inches from the subject..........still shows vignetting even under water........manual.....ISO 100......shutter 1/125......aperture 7.1

S90W20Macro.......well since I was concerned about particles, just wanted to see if close-up shots were OK with the WA lens....manual.....ISO 100......shutter 1/125......aperture 4.0

No Strobe.........went to the underwater mode and shot with available light.......camera set ISO 800......shutter 1/20......aperture 2.0

TTL.........Av mode....camera set ISO 250(auto)......shutter 1/60......I set aperture at 2.0 (not sure why I set it that way).......

I thought that in Av I would have TTL?

Thoughts or feedback.........thanks, Mike

 

[CompuDude]

So yesterday I did manage to get to my LDS pool, at least for a bit.......

Some pictures......

First Shot........in manual with dual YS-110 way over exposed but shows an issue..... air bubbles between the W20 and housing as I threaded the WA lens on topside......so I undid it and let the bubbles out.......question: if you do this in the ocean don't you run the risk of particles getting trapped?

S90W2035mm........the items are about 8-10 inches across each so about 24 inches across total, camera was about 12 inches from the subject..........still shows vignetting even under water........manual.....ISO 100......shutter 1/125......aperture 7.1

S90W20Macro.......well since I was concerned about particles, just wanted to see if close-up shots were OK with the WA lens....manual.....ISO 100......shutter 1/125......aperture 4.0

No Strobe.........went to the underwater mode and shot with available light.......camera set ISO 800......shutter 1/20......aperture 2.0

TTL.........Av mode....camera set ISO 250(auto)......shutter 1/60......I set aperture at 2.0 (not sure why I set it that way).......

I thought that in Av I would have TTL?

Thoughts or feedback.........thanks, Mike

TTL requires communication between the strobes and the camera. Sometimes the strobe is smart enough to read the camera's strobe output and set it's own level (Inon strobes have this via the sTTL feature... I can't recall if the Ikelite manual control unit can set levels automatically or manually), other times the camera can tell the strobe electrically via a hot shoe how they should be set. The S90 has no hot shoe, so you only have the option of "faked" TTL (like sTTL on an Inon strobe) or manually setting your strobe.

The W20 and most other lenses are wet mount, meaning they're designed to be put on and taken off underwater, as needed. Yes, you would be wise to avoid doing this in a sandstorm, but outside of that, I've never had a problem with trapping debris with my Inon AD mount (bayonet) lenses. Those go on and off a lot faster than the threaded lenses, though.

 

[Nemrod]

So yesterday I did manage to get to my LDS pool, at least for a bit.......

Some pictures......

First Shot........in manual with dual YS-110 way over exposed but shows an issue..... air bubbles between the W20 and housing as I threaded the WA lens on topside......so I undid it and let the bubbles out.......question: if you do this in the ocean don't you run the risk of particles getting trapped?

S90W2035mm........the items are about 8-10 inches across each so about 24 inches across total, camera was about 12 inches from the subject..........still shows vignetting even under water........manual.....ISO 100......shutter 1/125......aperture 7.1

S90W20Macro.......well since I was concerned about particles, just wanted to see if close-up shots were OK with the WA lens....manual.....ISO 100......shutter 1/125......aperture 4.0

No Strobe.........went to the underwater mode and shot with available light.......camera set ISO 800......shutter 1/20......aperture 2.0

TTL.........Av mode....camera set ISO 250(auto)......shutter 1/60......I set aperture at 2.0 (not sure why I set it that way).......

I thought that in Av I would have TTL?

Thoughts or feedback.........thanks, Mike

I assume you are zooming out to 35mm?

It looks to me if that is the case, zoom at 35, that the lens is a little to far forward from the port. Perhaps ask dhass what his secret is since he has your exact outfit.

As an experiment, zoom to 50mm and retest. Then compare FOV with lens and without and camera at 28mm.

I usually mount the lenses on the surface, sometimes I get a few bubbles and if so I swish the camera around. I have more problems with bubbles on the dome myself.

I am curious why you are getting more vignetting than others have shown.

Try a f stop like f4.

There is no TTL.

Set your camera to Av, set the ring control for exposure control so you can go plus or minus--if you follow. It is a very useful way to set your S90 I am finding.

I might also ask Ikelite why your rig has so much vignetting and their opinion. Anyways, 85 degrees is the expected FOV with that lens, it looks to me like either the lens is to far out from the port or you need to zoom in a touch more.

It does look the vignetting reduced underwater but not enough. Try the f stop to f4 as a test. You don't have a filter on there do you?

OK, you cannot use the macro setting with the wide angle lens. Thinking as I read your post over and over. Try your test over with the camera in Av, f4, zoom at 35mm, distance minimum 3 feet (for testing) and see what happens. Also shoot a test photo at 50mm and 28mm from same distance still using f4.

For macro remove the W20.

N

 

[Jorgy]

I must hang my head in shame........

What a noob I am........

N was right I did not zoom to 35mm the shots with the vignetting were at 28mm.....

I feel pretty stupid right now.........but glad I found the cause............

At 28mm the vignetting is less underwater than on land and disappears at 35mm which is the same thing dhass was saying......

Well thanks to all, I least I know to reset it after the camera turns on......

We head to St. Thomas in two weeks........