Shutter speeds at certain depths

Hello all,

Thank you for your useful comments on the previous thread I started.

Having read the responses I think I have actually worked out exactly what I need to know!

I appreciate that this will almost certainly be impossible to answer completely accurately, but I was hoping that people may be able to give approximate answers based on experience.

I'll be doing some deepish dives, and am simply wondering if the shutter speed that I think I'll need to shoot moving large animals (1/160?) is possible without being underexposed, or whether I need to completely alter my expectations!?
Probable conditions

20-35 depth dives

10m visibility (though hopefully more)

Aperture fixed at f2.

ISO max 400

Ambient lighting only,

Assuming these conditions, would you think 1/160 would be possible? Or no way!?

Obviously I could wack up the ISO, but I understand that there would be quite a lot of image degradation in the camera i'm planning on buying.

On land I have a fairly decent idea of what combinations of shutter speed/aperture/ISO I would need in different lighting conditions, but as I have no underwater photography experience I simply have no idea what I should expect.

If I'm not able to do the above (with the camera (TG-6) likely to force me to 1/30 or 1/60) then I think I may need to think again - or just enjoy the dives without a camera!

Thanks for the response.

Seeing example shots is really helpful (pretty cool btw, the grain and darkness adds to the atmosphere).

From my admittedly poor calculatations, I may well have to go up to at least 1600 ISO in order to stop the camera from forcing the shutter speed to blur inducing levels then?

From what i've read 1600 in the TG-6 won't look great.

I'll be in the Galapagos hoping to shoot hammerheads and I understand the conditions can be quite tricky, and thus perhaps difficult to fiddle around with camera settings.  I'm torn between the TG-6 on one hand, or just spending much less on a GoPro and reducing my photography expectations.

Nice one, I'll look into that.

I could just go more expensive and get something approaching the quality I want - but unfortunately I only get to dive once or twice a year, so hard to justify the expense.

Thanks for the very detailed response Craig. Incredibly useful information that is helping me to understand how everything works.

(And good to see some of those Old skool Nikon cameras listed!)

It seems from everything I've now read I simply won't be able to get anywhere near the shutter I need for sharp photos with the camera I was planning to get.

For snorkelling it looks great, but I had my heart set on some Hammerhead images!

Seems I'm definitely going to need to rethink here. Go really expensive or completely change my expectations!

PuravidaUK wrote:

I'll be in the Galapagos hoping to shoot hammerheads and I understand the conditions can be quite tricky, and thus perhaps difficult to fiddle around with camera settings. I'm torn between the TG-6 on one hand, or just spending much less on a GoPro and reducing my photography expectations.

You really buried the lead in not putting this in your original post.   This is the part that matters most.   Exposure at 100ft/30m varies greatly based on water clarity, time of day, and sunnyness above, and well as the subject matter (black mantas or darker sharks versus silvery ones).

the dive spot you're really talking about is Landslide on Wolf Island.   Perhaps the most exhilerating/challenging spot I've encountered in > 800 dives.   I went to there with my wife in 2013 when she had but 60 dives.  We knew it was a bit aggressive, even by California standards, but it was 2 for 1!  But because of that level of experience, and the difficulty of some of the dives, I generally put my housed camera down and just carried the go pro tray.

Landslide is full of sharks - hammers, galapagos, reef, silky, and you're on ledges right near the edge of the island.  Current flow exceeded 4 knots at times.   You basically hug a rock and hang on.   Plan to shred a pair of gloves.  If you turn your head sideways, the current starts to tug at it.     The water can be turbid - when we released to go our safety stop, we could only see clearly 10-20 feet in any direction (other than to note there were sharks in every direction).  On one, we either got caught in a pretty strong downdraft or the poor viz lead us to mishandled our BC inflation on the blind open water safety stop.

So to cut to the chase, I wouldn't recommend a camera you don't know how to use without looking at menus, and wouldn't be distracted by the wearing of gloves.  And understand the impact of the extra drag lugging it around.   Don't make this your first trip with dual strobe arms.

On positive side - with the fast current, the sharks swimming against it often are moving very slowly, so you could get away with a longer exposure.   Video shooting will do pretty well-  not nearly the same challenge around exposure and precise composition.   It will probably tell a better story too.   The TG has 4k shooting.  The smaller sensor probably works against you for the stills.   It will do fine in other spots, like the iguanas.

Great photographers can get amazing shots there.   But unlike many locales, I think it's pretty tough for us vacation shooters to do the same.  As you appear to be a newer shooter, I'd suggest the gopro or tg options over a more substantial, most costly route.  And if you assess yourself to be a greener diver, or not as experienced with rougher cold water diving, then just the gopro.   Focus on the diving and the views, don't give that up in pursuit of a photo.

Thank you Craig!

This is an incredibly helpful post. Very useful to be able to compare shutter Speed/ISO/Aperture combinations. I really didn't know where to start underwater.  Looks like you had some great trips with your late wife btw.

I think I will probably have to adjust my expectations regarding the deeper dives.

But for snorkelling I'm hoping I can get something a bit nearer to what I was originally hoping.

Thanks again for taking the time to write such a comprehensive post with examples.

Kelpdiver - Ha, yes that was actually the key point!

Thanks for the details.

It's actually Gordan's Rock/Kicker Rock that I'll be going to. Unfortunately I couldn't find a dive trip to Wolf/Darwin the corresponded to the period of time I have off from work.

I know these two do not compare, but I'm hoping to still see them. Particularly at Gordan's Rock. I've heard the conditions can be challenging, but hoping not as bad as your experience further north! That reminds me of a previous 'hammerhead' dive elsewhere (didn't see anything) where the current was like nothing I have ever experienced before. Definitely wouldn't have been able to photography anything then.

Your advice is very useful. I'm now definitely going to get the Tg-6 or the GoPro, and right now leaning towards the latter as it's half the price.

I was considering spending much more, but as you say i'd be spending half my time trying to get to grips with the camera equipment - and I'd probably completely come unstuck with my buoyancy.

So yes, GoPro or TG-6 for now - relax and enjoy the dives and then maybe one day go back with something better.

PuravidaUK wrote:

It's actually Gordan's Rock/Kicker Rock that I'll be going to. Unfortunately I couldn't find a dive trip to Wolf/Darwin the corresponded to the period of time I have off from work.

ok - then probably closer to the doable category, but still the challenge of cold water, lower viz, and surge.   Seems like operators want people with 25+ dives experience, whereas Wolf/Darwin would be double or triple that as a generic advisement.  So if that's within your dive experience, not so crazy to have with you.   Just rig a dog clip so you can hang it from your BC d-ring if things ever too harried, and you need to just focus on the diving.  Give yourself a way to free your hands on demand.

north! That reminds me of a previous 'hammerhead' dive elsewhere (didn't see anything) where the current was like nothing I have ever experienced before. Definitely wouldn't have been able to photography anything then.

yeah, the downside with hammers is they generally prefer areas with fast waters.  (or at 40+m)  At Cocos, the prime spot requires you to clip in with a reef hook.

Your advice is very useful. I'm now definitely going to get the Tg-6 or the GoPro, and right now leaning towards the latter as it's half the price.

The gopro's min focus distance is somewhere in the 3-4' range, depending on model.   Backscatter (and others) sell a close up lens that makes it about a foot, good for getting closer to medium sized objects.   There is a macro lens too, but the challenge there is a really narrow depth of field, and a so so lcd.   The TG would be better if you want ability to shoot smaller things at same time as wider, and of course have focus confirmation.  Go pro is fixed focus, just make sure min distance and aim vaguely.

I was considering spending much more, but as you say i'd be spending half my time trying to get to grips with the camera equipment - and I'd probably completely come unstuck with my buoyancy.

Ideal spot to get serious with an expensive camera is somewhere where the diving is nearly without effort.   Cayman Islands is a pretty good example.  If you think you're likely to go this direction soon enough, then I'd say get the Gopro for now.   You'll want to stick it on top of your future housed camera anyway.  That way if you set it up for macro, you can still shoot something when the whale shark sneaks up.

PuravidaUK wrote:

I'll be in the Galapagos hoping to shoot hammerheads and I understand the conditions can be quite tricky, and thus perhaps difficult to fiddle around with camera settings.

Stick with Gopro 6 or 7. Currents are strong over there by Wolf or Darwin. You'll be holding to rocks with one hand. Hammerheads are in constant move and not posing for selfie.