Shadowing of macro shots

[Packhorse]

I have a G10 with canon case and have problems with flash shadows with close up macro shots. I can get around this by moving away from the subject and zooming in but its not perfect.

So I have been working on a project. Its a LED based light ring that goes around the cameras lens. This should work realy well at eliminating shadows. Perhaps it will work too well.
By illuminating all around the lens there will be no chance of shadows at all. How important is shadowing on macro shots? Will they end up looking too 2 dimensional?
Would I be better off having the LEDs on the top half of the ring and none at the bottom?

Thoughts?

 

[Warmwater Wank]

Pack--Ringlight strobes may not be common uw but serious macro users (medical profession, CSI wannabes etc.) have made use of them for years because they were so shadowless. Some fashion photogs enjoyed them for the different look they created and the even shadows produced at the edges (not sure I found the catchlights appealing but maybe it's an acquired taste...) Might be a problem esthetically for some but shadows themselves are kinda like nitrogen bubbles, fewer = better. Your idea could certainly reduce shadows but that may not be the major concern.

Two things come to mind. One is control of light levels, which would affect the working distance and exposure. Even a built-in flash varies it's flash duration to help vary the exposure you can achieve. The led will be a constant output, good only in a narrower range of distances. If you just are doing macro and stick to that range (whatever you discover it is) it could be ok, just limited. Sure, you can vary camera exposure but being able to vary light output as well is a useful concurrent function

The other challenge is color temperature of the light source. Strobes balance close to daylight color temps (5100-5500K is common), LED's go higher (uh, depending) and produce a much bluer looking light. If they provide the sole illumination you can white balance to them easy enough but if the light is mixed (sunlight in shallower water, shots aimed up towards surface etc) it could be problematic. Grab an LED flashlight and take a few in close shots on a night dive and some in the shadows on a shallow daytime dive. Might give you an idea if color temp will present a problem for you.

So, the leak on the replacement glass for your housing went away? // ww

 

[bygolly]

Good information WW. But it got me thinking back to my electronics training days and I recall that LED colour temps can vary widely in the "white" zone. This link will take you to a chart where you will see the temps vary from 3500K to over 6500K for white LED's.

Working with LEDS - Light Emitting Diodes

IIRC the light from a LED is monochromatic, therefore the "white" LED's are merely very bright shades of red or blue and not the mix of colours that are produced by a strobe or incandescent light. So I am guessing that LED's may be problematic for photo lighting in any case (I don't know yet how well the "custom WB" settings deal with monochromatic light). Testing the theory out using a LED flashlight will be a good experiment though but keep in mind the results of that test will likely vary from your finished product since you may not be able to duplicate the colour temp of the flashlight.

Good luck though and keep me posted on your results. This is an interesting topic.

P.S. Maybe a mix of LED's throughout the colour temp range may give a more natural looking light. Just a thought.

 

[fisheyeview]

INON makes, or used to make, a ring strobe for underwater. It mounts onto the end of the flat port. It works great for close macro work. I have a friend that uses one all the time. She only shoots really small macro stuff.

 

[Packhorse]

Thanks WW.
2 very valid points.
My light system will have 3 power levels at least. I may even be able to have it continuously adjustable. It all depends on the driver electronics I end up using.

As far as colour goes, I have already tried using my LED dive light (modified by removing the optics) and found it lacked some red light. Very much as red is missing at depth. After doing a custom white balance I found it gave very good results. EDIT: I should have said the custom white balance is very much like the underwater white balance om the camera.

The LEDs I am using are different again and do have a bit more of a natural white light to them so I am hoping it will be better again. Failing that I will source LEDs with a colour temp of 5000deg K or so assuming the concept works as I hope. The ones I have are spares from another project .

As for my front lens problem, I have replaced it with normal glass and pressure tested it to 55 meters with out issue.
I dont have as much confidence in it as the stock lens so I will probably only use it to 30 meters max.

Please keep the opinions coming. I could just make up a mask to put over half the LEDs as the shot requires. This would mean I could dictate which side the shadow comes from.

 

[Packhorse]

A bit of progress today. I have all 8 Luxeon K2 LEDs mounted and powered up.

Not running at full power yet. Probably at 1/3rd or so. Results look promising.

I have also yet to fit a front lens to the light. When I do this I will probably give it a light sanding with 600 grit to make it "frosted". This should help eliminate the shadowing of each LED

 

[Warmwater Wank]

Cool Trainfish--what depth? Color balance looked good, doesn't seem like it will be an issue. Better patent things before revealing too much, this may just work out to be a good notion! Best of luck, glad the glass replacement worked out. // ww

 

[Cathy Church]

Very interesting. Everyone likes different things. I teach all of my students how important shadows are to let you know where the textures and bumps are. Everything looks flat when lit perfectly the same all around. Two strobes generally give you plenty of options to light from the front or to create shadows and texture.

In your initial question, what type of strobe were you using? Were you trying to use the G9 at its closest setting? That is a problem with the G9 because it has such a long zoom, the focus is way too close to the front of the housing. It does make it hard to light with a single strobe, especially if the arms are not adequately flexible to position the strobe correctly.

An interesting dilemma. The camera is great above water, but there are major drawbacks to using it underwater.

 

[Packhorse]

Its a G10 (splitting hairs) and I have only ever used the stock flash. No external strobe.

I know what you mean about shadows to create texture and depth. Im going to try having it set up so the top LED's switch separate to the bottom.

Lens is now ready so I will fit it next week and it should be ready to go.

 

[Packhorse]

Almost finished. Just need a battery pack