Porcelain crab

Spotted Porcelain Crab.

This little fella was about a little less than an inch across and was VERY shy. I have a LOT of pictures where he moved behind the tentacles of the anemone, but I managed to get a few that worked out ok.

(Canon 10D, 100mm. 1/60 at F16.)

Here is another shot of him.

(Canon 10D, 100mm. 1/60 at F16.)

great subject!!! I don't know whether you were looking for critique, but I'll share it anyway. The eyes look a little soft to me, but based on the magnification ratio and the other areas in the image, I think you nailed the focus about right, or just a little in front of the eyes. I think that the loss of sharpness may be due to camera shake (it can be difficult to hold a housed SLR still for shots like these), and I noticed you used a ss of 60. This shot could've been taken at double that shutter speed or higher, and might have eliminated the blur. When shooting macro, I usually set my camera to its max ss, and slow it down only if I'm trying to create a special effect (blue water macro or panning shots).

HTH

forgive my ignorance -where is secret bay? or can't you tell me?

I'll tell ya, but you have to donate a kidney. :-)

Secret Bay is located at the nortwest corner of Bali in Indonesia, in a little village called Gilimanuk.

The dive site itself is located to the right of the dead end road that leads to the ferry terminal for the ferry between Bali and Java. There is a small building where you can store your gear and several large rinse tanks for camera equipment.

Be advised: the water is cold, this is a muck dive with no coral, and you will see some of the craziest things you have ever seen, so you better bring plenty of film and/or make sure your digital card is empty before the dive.

I am writing an article just about the week I spent diving in Secret Bay and will post a link as soon as I finish it.

WHAT THE HELL AM I GOING TO DO WITH FIVE THOUSAND PICTURES?? LOL

Yeah, the eyes are a little soft. I tend to shoot at 1/60 or 1/90 for just about everything, but I may try 1/120 just to see what happens. I may need to get a bigger strobe, somewhere in the 300 range.

I was using dual S&S 90s when I shot these at about -1 stop.

Camera shake shouldn't be an issue. It doesn't matter what exposure time you use for a shot such as this - all the light is coming from the strobe, which means that no matter what you have the camera set for, you're effective exposure time is the few milliseconds that the strobe fires for.

The softness comes from the focus being a bit off - this pic is focussed a little forward of the crab. Sounds like he wasn't cooperating :-)

You should shoot your macro at f22 - it will increase your depth of field, making your focus sharper. Your strobe is easily powerful enough for this, assuming you take shots like this at somewhere near the closest focusing distance of the 100mm (if not, get closer!).

You can't really fix focussing as a post-process, but a little selective sharpening can help perceptually:

Thanks for the feedback Chris... I was just sitting here thinking about something awhile ago... there is no way the softness was caused by camera shake.

I was shooting a juvenile sweetlips and their tails move back and forth far faster than my hands could ever even hope to move, and I nailed numerous shots with their tails completely frozen in time.

As you mentioned, I think the softness was just the depth of field. I had completely forgotten to use the sharpener in PS though... glad you reminded me about it. Thanks!

Hey, very nice shots !

just a small scientific comment: your "porcelain crab" is actually Lissocarcinus laevis, a true crab from the family Portunidae (swimming crabs), associated with cerianthids and corals, it is not related to the spotted porcelain crabs (Neopetrolisthes spp.)

cheers

Art

Is there a common name for this crab?

In response to your replies on shutter speed - As an experiment today, I took out my D100 in 30ft of water, turned off the strobes, and fired at ss 60/ f16. I was shooting down onto a rock and crevice like I would a macro shot, and I got dark, but substantial exposure. At ISO 200, and these settings, there is ambient light affecting the exposure. Of course, the vast majority of the light is from the strobes, but the ambient light is making an exposure significant enough to add softness as a result of camera movement.

I agree with you, in theory, and you are probably right that the above images are slightly OOF, just wanted to suggest that there is good reason to shoot moving macro subjects or in surge at faster ss when possible. A smaller aperture or darker environment would negate this argument, but f16 still lets in some light in shallow water.

Kasey

Why F16/ISO200 ? F22/ISO 100 will give you more depth of field and less noise.

hi there

Lissocarcinus laevis - let's give this guy a common name, how about "tube anemone swimming crab" ? it's usually (but not always) associated with tube anemones (cerianthids)

it's closest relative, L. orbicularis, lives on sea cucumbers

ciao

Art

Why F16/ISO200 ? F22/ISO 100 will give you more depth of field and less noise.

Wouldn't the equivalent exposure be ISO 100 - f11? Slower film needs more light so less noise but also less DOF.

The D100s lowest ISO is 200 hence my choice.

Yes, Chris has it backwards, and yes, the slowest ISO on the D100 is ISO200

Cheers

James

Needs to add more strobe power. Something's wrong if the rig is limited to ISO 200 and f/16. Why a shutter of 1/60? Doesn't the 10D sync faster?

I guess there is just a lot of confusion in this thread.

Jake took the shot at ISO100 f16 @ 1/60th - and those settings are "just fine" for that type of shot.

He probably could have shot it at f16 1/125th and we would not have seen a difference - but maybe we would have - who knows.

Cheers

James

Where did the ISO 200 come from? That would be the thing to avoid. There doesn't seem to be any reason not to use 1/125 either, though 1/60 is OK. f/16 is OK, too.

By comparison, I would set my strobes to -2 or -2.5 using my 70-180 at f/22 or f/27 and ISO 200. For really close shots I use -3 or -3.5 and f/27. My recently posted pygmy's were -3, f/27 and the subject distance was about 8 inches. My strobes may be more powerful than 90's, but not more than 1 stop.

Why F16/ISO200 ? F22/ISO 100 will give you more depth of field and less noise.

Wouldn't the equivalent exposure be ISO 100 - f11? Slower film needs more light so less noise but also less DOF.

 

The D100s lowest ISO is 200 hence my choice.

I meant "Why not shoot at iso 100, f22. This is a darker exposure which will negate the ambient light and camera shake, The f22 will give you more depth of field and the lower iso will give less noise.It will require more strobe power, but at the distances for macro, its not an issue".