A640 Underwater tips

I'm spending 2 weeks in Egypt this summer and (after finding out how bad underwater disposables are last year) have bought the canon underwater case for my A640 to use while snorkelling in the Red Sea.

Has anyone used a powershot underwater? any experiences and practical tips you could share would be much appreciated

You're going to love it!

The manual white balance on the Canon A series works extremely well underwater. You need to set it at the depth and lighting condition of what you will be shooting for the best results. You can either take a slate or use the sand - it's close enough usually.

Some of the other WB modes work fine, too, so you'll want to do a little experimenting each day.

Set your ISO to 100 max. Sacrifice the higher ISO for something else - noise shows up big time underwater. If you just had to, go to 200, but I hate it.

I start at 4.5 and use smaller apertures from there. I hate shooting wider than 4.5 - the images just aren't crisp enough through the water for me. I usually start my shutter in relatively bright/clear water at 1/100 or 1/125. Go as fast as you need to.

Learn the half press focus lock and then frame and shoot - you'll get far fewer fish butts that way. Concentrate on stationary and slow moving things for maximum keepers - fast moving stuff is a bit of a pain for compacts with their lag.

I turn the flash down one notch as it's too overpowering up close on full. You need to use your flash up to about 4 feet away. More than that and the flash is pretty useless as water eats light. Go to manual white balance for distant subjects.

Get close to your subjects. Distance is the enemy underwater. Figure out what your minimum focus distance is and try to get there.

Limit your use of zoom - it simply enlarges the particles in the water between your lens and the subject. Zoom closer with your fins whenever possible.

Shoot up to separate your subject from the background. Shooting down rarely looks very nice.

Be gentle and kind to your oring and closely inspect it every time your housing is open.

Don't forget your video mode - these little gems do a great job with video!

You might want to check out the magic filters (google it) as they rock in the shallows.

Wow thanks for all the tips, lots of good advice... there's 2 jettys for snorkelling on the hotel's beach and I've stocked up on the memory cards so I'll have plenty of opportunity to practice

I think I might give those magic filters a go as well, that's such a simple idea!

Underwater tips

Remember to check & clean your casing's O-ring after every opening. That is after every battery change or downloading of your shots etc etc.

You will need cotton buds, o-ring remover (nothing sharp here), o-ring greese, and a clean table top to work with. No tissue paper or kitchen towels pls.

I had seen may camera setup ruined

While considensation inside the casing is rare, due to the lower heat generated by the newer Powershots, still makes sense to put the housing in the seawater or a bucket, to climatize it.

A good guide is found here, from Canon themselves....

http://web.canon.jp/im​aging/uwphoto/index-e.html

Have fun and share with us, your shots.... Have fun

heres mine using the older A620 , without extra strobe (flash light)

binliner wrote in post #5257468
I think I might give those magic filters a go as well, that's such a simple idea!

I suggest that you have a few more dive / snokelling trips before loading with these optional extras.

Your bouyancy to keep still for that shot (IS is of no use, if you whole body is moving), your distance to subject ( and not stepping on my corals as support), your breathing timing (and not scare away the fishes)....

well, take much practice and have fun...

NO cotton buds! They shed fibres which can be very very bad! I use and highly recommend those sponge eye makeup applicators. It's like they were made for servicing oring grooves

I don't remove my orings every time I open the housing. I do a serious and thorough visual inspection every single time it's open and again once it's closed, though. I also do a tactile (ie run your finger over the oring) inspection to check for any strange bumpies or things I might not see but can feel.

Oring maintenance is essential to preventing floods.

I always put my camera together in an airconditioned room and try my hardest not to have to open it on the boat or outside. This helps not only with keeping nasties out of the seal, but also with the condensation problem. Grab yourself some moisture munchers before you go and stick them in your housing while you are using it. You'll need the small ones as there isn't much room. It's ok to use more than one at a time if you want to. I often have used the little ones that come in the box of new shoes

lensmen - pretty shots!

IMHO. Here is my practice for the past 7 years, until I sold the A620 setup last December, after 3 weeks in Bali.

If you use those cheap buds , they do shed. But after 6 years of doing the same, they are cheap and easily available. Plus if your dive mate asked for one, I won't hesitate to give a few. I would use about 4 - 6 pieces per clean up. Sometimes, on a rocking LOB, I will wait till breakfast time & in broad daylight that I will dip a bud into hot water to go thru the o-ring glove (or what you call that cavity on the housing). this will help to disolve any potential salt crytals that skips my eye.

Your eyes can be deceiving and your fingers numb to a certain fine hair or sea salt crystal. Plus, your finger may have oil (finger, shaving cream, butter, peanut butter etc etc stains, that you do not know)

I am taught this simple rule : Whats another 5 - 8 mins of preventive measure to remove, clean, re-grease and put back the O-ring , to ensure that the camera housing is not flooded ? The ocean will not missed you if you are 10 mins late .

It was worse when I was using the older S-series whose batteries are good for 1 dive (60 mins). With the A620, I only need to change the batteries at the day's end (about 4 dives & 600+ shots with 90% flash)

Thank you

Good to have alternative suggestions.

I dive a couple of times a week usually and have been taking cameras underwater since the mid 90's with no problems on the visual or tactile inspections but you do bring up some good points that may be forgotten - have clean hands and fingers as well as a good light source. Very important!

kja wrote in post #5270120
Good to have alternative suggestions.

I dive a couple of times a week usually and have been taking cameras underwater since the mid 90's with no problems on the visual or tactile inspections but you do bring up some good points that may be forgotten - have clean hands and fingers as well as a good light source. Very important!

Have fun in the week and looked forward to your UW photos....

I had dried my gears for a while now, coz I had moved to HK for work and will be concentrating a lot on travels in China. Hence the sale of the A620 and the new SX100IS.

Cheers

Thanks for all the advice... I'd already read the canon guide and found it informative but it's always good to have practical 'anecdotal' advice

I frequently SCUBA dive in the Bahamas, and have recently been experimenting with underwater photography. I use an SD 800IS with the Canon UW case. I have spoken with many UW Photographers and all agree the most important thing is keeping the o-ring clean and lubricated (only with silicone grease.) I only use a lint-free cloth and a dab of grease on my fingers to lube the o-ring. Also, I use a pillow-pak of desiccant beads to keep it from fogging. I have tested my set-up to 105ft (32m) with no problems!

The only issue I have is reducing the incredible blue color of the water, especially at depths greater than 50ft. I normally use the "underwater" mode in the special scenes. I haven't had too much problems with noise, however, I do notice a little loss in fine details. I have heard that using the "cloudy" WB helps too. I figure for now I can enlist the help of Photoshop to reduce the blueish tint.

Here are a few pics, all shot w/o flash....
Lionfish

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The blue is your lighting, something due to light specturm that could still penetrate at this depth. (s

To avoid the blue, I would get close to the subject and use flash.

You will notice many fellow diver + photo buff will be using strobes. To give natural (white) lighting onto the subject as possible.

I had decide not to invest in such tools owing to the cost and bulkyness of carrying a dive bag + these delicate gears. Perhaps I still like to keep as little stuff around me as possible....

Otherwise, shoot in B & W.

There are some who recommends Magic filter and such. Personally I had not tried that

binliner wrote in post #5285362
Thanks for all the advice... I'd already read the canon guide and found it informative but it's always good to have practical 'anecdotal' advice

I was fortunate that I met a guru back in Singapore, who had patiently guided me along the way. We'd spend several evenings looking thru his works and listening to the explainations of how the shots were made.

Yes, he was using a twin strobe setup and the humble Canon Powershot. At a dive show, Canon actually invited him to stand at the booth to present.

Perhaps at your next dive trip, seek buddies who are photo buffs. Perhaps they have a few practical hints or 2 to share as well.

Really, I am still known as "run away kid" with some groups. Why ? coz I often stayed to make a few extra shots of a subject and then finds that the group has vanished. The missing diver search , taught in my Rescue C-card, comes in very handy. And the group is found, sooner or later.... Forget about the buddy, she/he usually follows the herd and forgot to check if that black suited guy next to them is actually ME (the buddy)..

hahaahah


Here are some from my old Powershot S50

lensmen wrote in post #5270837
Have fun in the week and looked forward to your UW photos....

Here you go (sorry for the hijack)
This weekend
Easter weekend

I try to put Ningaloo in the titles so they are easy to search for

lensmen wrote in post #5288942
The blue is your lighting, something due to light specturm that could still penetrate at this depth.

To avoid the blue, I would get close to the subject and use flash.

You will notice many fellow diver + photo buff will be using strobes. To give natural (white) lighting onto the subject as possible.

I had decide not to invest in such tools owing to the cost and bulkyness of carrying a dive bag + these delicate gears. Perhaps I still like to keep as little stuff around me as possible....

Otherwise, shoot in B & W.

There are some who recommends Magic filter and such. Personally I had not tried that

I still have a lot to learn. Like you, I don't like a lot of gear hanging off of me while diving, so the idea of dual strobes, etc. doesn't sound very appealing to me. Thanks for the tip on the filter, I'll look into it.