Last Questions before first DSLR Trip

Hi,

next Thursday I will travel to Egypt for my first UW-DSLR Trip with my D60 in Erics former S&S Housing.

I have some last Questions:

1) Based on what facts do you decide which Lens to take before a Dive?

2) What Iso do you use under which circumstances?

3) What is a good Shutter Speed, Fstop Combination to start with and work from there?

Thanks Simon

I have some last Questions:

1) Based on what facts do you decide which Lens to take before a Dive?

Visability. First if the vis sucks you have to shoot macro.

Then if the vis is good, Whats down there/what you want to shoot.

2) What Iso do you use under which circumstances?

200. No/very little noticable degredation in immage quality and allows for smaller aperature.

3) What is a good Shutter Speed, Fstop Combination to start with and work from there?

I start with ISO 200 1/160, F/16 for macro or F/10 for wide angle.

Hi, Simon! Good luck with the rig!

1) Based on what facts do you decide which Lens to take before a Dive?

I usually ask the dive master leading the next dive whether the dive is a WA or macro dive. If it's somewhere in between, I might put on the 16-35, with a +4 diopter so I can do both.

2) What Iso do you use under which circumstances?

I always shoot 100, unless light starts to fall off. Then, I start increasing it slowly -- but I don't think I've ever shot at 800 underwater.

3) What is a good Shutter Speed, Fstop Combination to start with and work from there?

I typically start at around 1/125 f9 ISO 100 for clear water on a very sunny day. For macro, I typically shoot at 1/250, and stop down as much as I can, depending on what my strobes will allow.

1) Based on what facts do you decide which Lens to take before a Dive?

I ask what the site is like and what critters will be seen.

2) What Iso do you use under which circumstances?

Lowest possible, unless shooting ambient light wide angle, which I boost to 320.

3) What is a good Shutter Speed, Fstop Combination to start with and work from there?

If you have plenty of strobe power, then f/22 for macro, shutter speed mostly irrelevant, but start with 1/60.

Wide angle: 1/60, ISO 100, f/8 and then use you camera's meter to figure out what will work best.

Eric, why bother with 1/250 shutter speed for macro? Why lose 2 stops of light when you push the limits of your strobe power?

Eric, why bother with 1/250 shutter speed for macro?  Why lose 2 stops of light when you push the limits of your strobe power?

The strobe pulse is much faster than 1/60. I've found really no difference between different shutter speeds, so I try to shoot on fastest sync to avoid any possibility of a blurry halo.

1)

If you have plenty of strobe power, then f/22 for macro, shutter speed mostly irrelevant, but start with 1/60.

 

Eric, why bother with 1/250 shutter speed for macro?  Why lose 2 stops of light when you push the limits of your strobe power?

As you said suhtter speed is irrelevent. This is because you assume that your flash is >> natural light. Since the flash duration is < T, T has no effect on exposure. For exampe let T = 1/60 and lets say the strobe a brighness 100 and natural light 5. Your total light is 105. Now set T=1/250. Strobe power is still 100 but natural light is only 1. Your total light is 101@1/250 vs 105 @1/60. As you can see there is hardly any effect on the exposure but the faster speed will reduce shake.

Hum....doubble.

I understand that shutter speed has no effect on the exposure when lit by strobe.

But lets face it, we've all stretched stretched the limits of our strobe to subject distance. This leaves us with some possible ambient exposure in the negative space. If you want it black, 1/250 is fine. If not, why not give yourself two stops of light to play with?

I've not experienced this blurry halo thing.

Strobe power is still 100 but natural light is only 1. Your total light is 101@1/250 vs 105 @1/60. As you can see there is hardly any effect on the exposure but the faster speed will reduce shake.

The amount of light reflected off your subject and on to the sensor will vary based on strobe to subject distance. In your example the factor of 100 is only at a specific distance. If it indeed a 100:1 relationship, then there will be no effect from a changing shutter speed and there will be no shake.

You don't really get two most stops of light. The amount of light that comes in the extra 1/190 sec is negligable compared to the amount that comes in when the strobe pops. But I want the strobe to illuminate my subject -- and that's it. Any other light that gets recorded due to a long shutter speed will just make my image less sharp.

So I shoot at a fast shutter speed. In practice, it doesn't really matter, anyway.

Of course, if I'm shooting with a background, then I may shoot with ambient exposure. But that's different.

Thanks for the Tips!

Eric: Did you use 1/250 with the D60? I thought 1/200 is the max sync speed?

The housing is securly packed away between my neopren suites in my diveing Suitecase, and the insurance confirmation from DEPP just arrived by Email this morning.

But still two days to wait until Thurday when we fly out and another one 'til going diving on Friday morning.... patience is somtimes really hard to achive.

Simon, I'm sure you are going to have a great time in the Red Sea. Make sure you share your shots with us when you are back. Alex

I have pretty good net access down there, I'll try to post some from there.

But I have to try not to sit in front of the computer to long or my girlfriend will kill me ;-)

Simon

Simon, where are you in Egypt?

Alto: I'm in El Gouna, thats approx 30km North of Hurghada.

Simon

I understand that shutter speed has no effect on the exposure when lit by strobe.

My focusing light (UKQ40) will appear as an orange glow at 60th/s @ F22 when shooting close-up/macro. At 125th/s @ F22 it does not get recorded.

I have ruined a few night dive shots by selecting a 60th/s shutter speed.

Also with daylight rear-sync shots the torch light will creep in.

PauP

One constant rule of UW photography is that you will take the wrong lens. If you take your macro lens you will see a blue whale and calf. Wide angel lens? You will fine matting nudibranchs. To understand this concept read Steinbeck's "The journal from the Sea of Cortez" They had an outboard motor that would only work if it was heading into port. They would trick it by pretending to go back to port and when the motor would start then they would start off on their collection trip. In the same way I would suggest tricking the fates by pretending to take one lens and then at the last second switch to the other.

If this doesn't work the best thing to do would be to take 2 cameras. One for WA and one for Macro. If you don't have two then you might ask the dive master They are notorious for not committing but if you ask the right conditions about what to expect on the dive you will get the clues you need.

One approach favoured by a lot of experienced photographers I know is to select a lens for an entire day of diving. This means that they have 2 do less camera fettling between dives, but more importantly it helps them search out the right kind of subjects. So you spend one day looking for 105mm subjects and the next day looking for scenery suitable for the fisheye.

Personally I like changing lenses more frequently like that, but I must admit that the results of those that use the stick with a lens for a day or so, do speak for themselves,

Alex