(failed) experiment

I was wondering if the high shadow detail sensitivity of digital slrs,

plus the ability to change iso, could allow me to shoot "blue water" macro

by carefully balancing exposure time, iso, and aperture, and maybe underexposing a little...

well, for heavy macro subjects at deep depths, so far the answer is no. The wide aperture and high iso make it look pretty weird.

I didn't manage to achieve what I wanted which was a conventional pygmy seahorse shot, except with a blue water background. Here's the closest I got.

This is pretty much "out of camera". just cropped really.

1/60, iso 800,f16. canon d60, 100mm macro. ys90dx strobe at lowest setting and not pointing very close to subject.

Wow, that is really interesting Chris!

This is the closest I have been able to get to "blue water macro:"

This one was taken with the Nikon 60mm in about 25' of water. The EXIF says f16 @ 1/125th ISO100 - and the original shot was about 1 stop underexposed. I was using a large SB102 strobe.

Cheers

James

Chris,

An interesting try. I've seen a very experienced photographer bring along an extra strobe with a thick translucent blue piece of plastic over it to put on the other side of the pigmy seahorse to get a blue background. ...and these film photograhper accuse us of over manipulating our images.

Not sure exactly what counts as Macro for digital ... I understand that traditionally Macro means the image size on the slide or film is at least as large as the actual object? For Digital we don't have any film ...

This one was taken at about 15m depth, f4, 0.005 seconds, ISO=64. It has been cropped to about half the original size in each direction. So you can see it's not macro in the traditional sense. It's the maximum magnification possible with the Oly C5050 in "Macro" (ie not "Supermacro") mode and no add-on lenses.

I didn't do any processing other than the crop and resize to 575 pixels.

-David

Should add, I have also tried a few times to get blue water true-macro shots. But so far no shots that I would like to share with anybody else! I checked back over the last couple of dive trips and it seems all the attempts were so bad I just deleted them ...

Problem is that using wider apertures reduces the depth of field, which is usually a problem for macro anyway. Then there's some experimentation needed to get the strobe positioned correctly so that there is not too much light on the foreground. I found it more difficult than it needed to be due to having my DS50 controller stuck on "full dump" all the time. I'm intending to try again next trip when (I hope) that problem will be sorted out already.

-David

Great one Chris, just a tiny bit of camera movement? I think TTL at a wider app is the way to acheive this desired effect.

David, you can get the chance to photo that particular pygmy seahorse on a particular gorgonian on Kakaban Island. The gorgonia position will allow experimentation, last count there were 14 of these living on it. Hopefully last years babies have grown up enough to photograph too, at 2-3mm in length they looked like scatter!!!

The main sort of insurmountable problem seems to be camera shake. For a subject such as the pygmy, you are shooting at a very low

subject to lens distance, with magnification. Most of the time you will be either free floating, or stabilizing yourself with one finger. For the shot I posted, I was actually in current.

This doesn't cause much trouble for normal macro photography. Normally you are shooting at a high f-stop, and the strobe is providing

essentially _all_ of the light. The strobe emits its light in a few milliseconds, which completely "freezes" the action, negating camera shake, etc.

For blue water macro, you will be adjusting either aperture or iso (or maybe exposure time, which makes the situation worse) enough so that the

natural ambient light is actually bright enough to be exposed (to produce the blue water). This means that suddenly your camera shake

_does_ matter - the sensor is going to be integrating 1/60, 1/90, 1/125 or whatever of camera shake in creating the picture.

It does not seem possible to hold the camera steady enough to avoid some of this - at these levels of magnification, every micro movement

results in significant subject movement with respect to the sensor. You can see this in the examples posted - the only one where the effect is minimal

is james', which is at a much lower reproduction ratio.

Here is another attempt. Again, basically out of camera, except for cropping:

James - It's pretty simple to adjust the water to any color you want, so I assume that you're talking about getting blue water without having to adjust the colors. I played with your image for a couple of minutes and came up with this:

How does this look to you?

Jim

Do any of you guys have a "Rear curtain sync" facility on your digital cameras? I see the S2 has James.

This mode will allow you to select small apertures and use longer exposure times to record blue water. As the flash fires at the end of the exposure, the subject is "filled in" by TTL therefor keeping your macro image's depth of field to a maximum. A steady hand is not so important.

PauP

PaulP,

Do you have any examples of this you can post. I'm interested in trying this with my S2. If not steady, won't you get motion artifacts (blur).

Thanks,

John

You can usually see a slight black edged "shadow" on subjects which although not unsightly it may be unexceptable to some. This is a form of sillohette caused by the pre flash background exposure....... Did that make sense?

I will find an example.

PauP

Yes, I have used rear curtain sync Paul, but not lately. It's a SWEET feature that I need to play with and experiment with more, especially for schools of moving fish.

Yes, it is excellent for macro shooting to get a blue background. You can shoot at 1/30th or less and the flash fires at the end to stop the motion with a blur BEHIND a moving subject that in some cases is quite pleasing.

Cheers

James

John,

The example below shows a small 2cm crab taken @ F22. Camera is angled towards the surface for maximum available light (UK waters)

The shutter speed ?? was selected by the cameras light meter (matrix) on aperature priority. Flash mode: Rear curtain. TTL

This method is very much hit & miss using film but with the ability to review your image using digital you should be able to fine tune your results to perfection.

PauP