Disappointed with W-20/9305.92

[naimis]

I recently took my camera on a trip (not for the first time, but it was effectively the first time I was really able to use it)... and found myself very disappointed with the results using the W-20 lens.

In full telephoto (and hopefully you'll forgive any incorrect terminology or whatnot, I'm far from a professional photographer), there is vignetting in the picture. It's small enough to be difficult to see in the preview screen, but definitely noticeable in the photo when viewed on a larger device. It can be edited out, of course, but it's still mildly annoying.

On the other end, as everyone knows, you can't zoom in to full wide angle because the required short port blocks the lens. Mildly annoying, but "just don't do it" seems to be the answer to that problem...

The big issue is that the quality of lens itself is not that great. When I took shots with the camera zoomed in, the extremities of the picture were extremely blurred, and looked absolutely terrible. I had to throw away several shots and crop the heck out of others. I've attached the worst example.

I guess the best I can hope for at this point would be to install the CHDK firmware on my G9 and maybe set it up to limit the zoom range so neither effect (blurring or vignetting) are visible.

 

[friscuba]

I've never used a wide angle lens, and I could be wrong, but I'm thinking zooming in is completely counter to what photographers generally are trying to do with a wide angle lens. Isn't the goal to get as wide a possible view with as little zooming in as possible?

The good wide angle shots I've seen, the camera's been practically right on top of the primary subject, fully UN-zoomed with both the primary subject and the background in focus. I'm not sure they're made to be used with a camera fully zoomed in. That's the nice thing about wetmount lenses, if you want to zoom in, you just remove the WA lens and you're already there.

 

[naimis]

You're right in that zooming in is going telephoto, counter to a wide angle lens, but there are a few issues here... One is that I *have* to zoom in a little bit to get rid of the vignetting. Another is that the WA lens doesn't come off easily (it's threaded) so on those occasions when I want to take a close-up without risking the reef, zooming in a bit seems to be the best answer.

The combination of the vignetting from the housing/port/lens, the blurring from the shape of the WA lens, and the awkwardness of the zoom control on the housing make all this a pretty difficult prospect :-/

 

[Ikelite Staff]

There will be vignetting in the camera's widest setting (35mm). The camera has to be zoomed one or two "stops" to eliminate this completely. However you may achieve sharper images by leaving the camera in full wide angle and cropping after the fact.

You mention that you don't take the lens off very much underwater--which is still OK for macro work--however you MUST remove and replace the lens at least once. The lens requires water in between the rear element and the front of the housing port.

The biggest contribution to your blurriness is probably a very wide aperture. If you're using an automatic mode other than aperture priority, the camera is recognizing your underwater environment as being quite dark and most likely selecting something close to f/2.8. This reduces overall depth of field and leads to blurry edges. You should see improved results by shooting something narrower like f/8.

And though it seems counter-intuitive, you may try shooting in macro mode.

Regards,
Jean / Ikelite