I bought the Ixus 800IS hoping to get some nice underwater photos.  Unfortunately I have been very disappointed with the performance.  On land photos are pretty impressive but most of my underwater photos are very grainy. I’ve tried hundreds of photos on different dive trips and at different depths adjusting the ISO settings in low light, trying manual white balance, the underwater setting and auto function.  I’ve also downloaded the canon software and manuals looking for clues.

I compared my downloaded photos with a guy on the same dive trip who has an Ixus 850IS.  His photos were nowhere near as grainy as mine and he could zoom into a higher resolution and definition on the same underwater subject taken under the same conditions.  My colors are also slightly duller than his with the same settings (we used underwater in this instance).

I have a new underwater housing for the camera and there are no visible imperfections on the housing.

If anyone has any suggestions on why this noise might be evident I would really appreciate your assistance.  For example would the image stabilization setting make a difference?  That’s one setting I haven’t experimented with.

Anyway I’m just about to give up on this camera and buy an Olympus (although I’m a Canon faithfull).  I actually had a Canon Powershot S45 (4 megapixel) which took better underwater photos.

I’ve attached an example photo so you can get the drift.....this bumphead parrotfish photo was taken in about 5 meters of water in ‘underwater’ setting.  The visibility was very good.

Regards, Sheryl

Hi Sheryl

Looking at the picture, it appears to me that the entire shot is slightly out of focus.  At the shutter speed of 1/60th, it might be down to a small amount of movement blur, but with IS active, I wouldn’t have thought that was the case, and it doesn’t look like it was movement blur in the shot.

Are you pre-focussing your shot with a half press on the shutter button?  If you don’t pre-focus, you don’t know whether your camera was able to get a focus fix or not, and what it had actually focussed on (e.g. has it focussed on the subject, or something in the background?).  Also, without pre-focussing, if the camera can’t get a focus fix, it just picks a focus point (probably infinity) and takes the picture.

From the EXIF settings the ISO used for that example shot is missing, so unfortunately its not possible to judge whether that shot was taken at a high ISO or not.  In general, most point and shoot cameras give pretty grainy results much above ISO400.  I always use the lowest ISO available from the camera I am using, and I don’t use the Auto ISO setting which allows the camera to pick the ISO - I fix it to one specific ISO.  All that said, the appearance of the shot doesn’t suggest graininess being the problem - I still think it lies with the focus.

According to the EXIF, your camera has used a 1/60th shutter speed at a fairly wide aperture for your camera.  I can’t find any indication of whether the camera used flash in the EXIF.  The 1/60th shutter speed suggests it may well have used flash as that is commonly the flash sync speed.  The wide aperture suggests that the camera was struggling to get enough light.

The Lense setting of 23.2mm suggests that the shot was taken at a reasonable zoom (probably around 140mm in 35mm equivalent terms), which suggests to me that your subject was a more than a meter or so away.  At that distance, the flash on your camera would probably not be of much use - the water absorbs the flash much more than air, so their range underwater is very much less than in air.  That’s why external strobes are so widely used, and so much bigger and more powerful than the strobes on cameras.

All this combined makes me think that focussing was the problem.  If that’s the case, I don’t think you will get much benefit from changing cameras.  I have generally found Canon’s autofocus to be at least as good as any other manufacturer.  Maybe the Olympus will be better, but I wouldn’t give up on the Canon just yet.

The following tips work well for me - perhaps they might help you too.
- always pre-focus (with the half press on the shutter button.) If the focus doesn’t fix, or fixes on the wrong part of the shot, you can re-compose and try again.
- use the widest zoom setting, and ‘zoom with your fins’ i.e. if you want to get closer, swim closer to the subject, don’t use the camera’s zoom.
- if using flash, you need to be no more than 1m or at worst 2m from your subject.
- if not using flash, look for shutter speeds faster than 1/60th, unless you have a really steady hand, and are positioned really well to keep still.

Hope that helps