Advanced Techniques - Super macro

[Chris Bangs]

I received a message inquiring about my super macro rig and what I use to shoot it. thought it might be of interest. although this is somewhat advanced, the beginners should still give it a look as there is a lot of basic techniques covered in the post

first, the original question


I was using a Nikon N90s in a Sea&Sea housing. Just upgraded to a Nikon D70
also in a Sea&Sea housing. I have use a 1.4 teleconverter with a external
diopter the macromate from Backscatter but the depth of field was extremely
limited and very hard to get sharp pictures. You ever use external
diopters? Your depth of field seems better than mine. I was only using one
strobe, Ikelite 200, usually shooting mid range f-stops 5.6-8. Any advice?

My answer

your DOF is suffering due the the apertures you are using. you need to
be able to use f16 to f32.

I have in the past used a external diopter - once! I did not like the
image quality. The images were ok just not razor sharp, although some
were correctable in photoshop.

I seldom ever use diopters anyway, as they reduce my working distance making it
difficult to light the subject using strobes. I may try using diopters again when I
try the 200 mm micro lens as the reduced working distance won't be a problem

when I do use diopters, I use the highest quality multi element type. pricey,
but these produce acceptable images.

But good news, the D70 like any digital camera that does not use a full frame size sensor will actually improve the images shot with diopters and teleconverters as the Digital "crop" cuts out the outer edges of the frame which tend to suffer when using such lens accessories.

For my extreme stuff 5:1 -10:1+ I use Teleconverters ( Kenko PRO 300,
1.4x, 2x, 3x ) either separately or stacked in various combinations
depending on what magnification I am trying to achieve ( actually known
as reproduction ratio ) and sometimes I add a +3 0r +4 diopter. as you
can imagine this adds a lot of length the the port as you can see in the
shot of my old N 8008 rig in my gallery.

now for the expensive part my friend.

strobes!

the IKE 200 is a wonderful wide angle strobe ( I have a couple
myself ) and is fine for normal macro up to say 1:1 and possibly even
3:1. BUT wide angle strobes with 100 degree beam angles, are not very useful for extreme macro since the image area is so tiny ( maybe les than 5 degrees ) only a very small fraction of the strobe output strikes the subject. therefore 95% of the light produced goes to waste.

another drawback is the size of the flash itself, as
you know, you are getting extremely close to the subject. possibly with
a working distance between the port and subject of 2 to 3 inches,
therefore positioning a big strobe properly is all but impossible.

What you need is a narrow beam strobe. even though these strobes may
less powerful than the 200, the narrow beam will actually put more light
on the tiny subject. Dual strobes are also required as that provides
more light and more positioning options. I have used the Ike 50s and
they did fine up to about 7:1 but the SB 105s were a tad bit more
powerful and allowed me to shoot up to 10:1.

remember that the more you magnify the image the more you are spreading
the light out across the film/sensor, therefore 2:1 will reduce the
light by half that of 1:1. greater magnification less light. that is
also why you will see some very high F stop numbers in the viewfinder as
the camera will give you the "effective" F stop which is a LOT different
than the actual aperture setting.

Hope this helps

I apologize for the rather poor wording, not much of a writer!

feel free to keep picking my brain. I love rambling on about it. this
stuff IS my specialty and also my passion.

Chris

 

[Mike Veitch]

Cool, thanks Chris. Never been much of a macro shooter myself so this gives good insight to what you do.
You must have some seriously steady hands!

 

[Chris Bangs]

Cool, thanks Chris. Never been much of a macro shooter myself so this gives good insight to what you do.
You must have some seriously steady hands!

Thanks Mike

I will work up something today on the actuall shooting.

sorry I won't be at DEMA, please say hello to Sam and Kevin for me.

Chris

 

[Chris Bangs]

Additional Shooting techniques.

Due the loss of light encountered at high reproduction ratios, and subjects that are 1/8 inch is size, or even smaller, another mandatory item in a bright narrow beam spotting light. ( I use the Ikelite PCA mounted on a jointed arm using the ULCS light bracket. ) you need lots of light in order to see the subject in the viewfinder, otherwise you cannot determine if it is in focus. the light also can be used to aim the camera before looking through the finder

Here is how I do it

I preset the light so that it will strike the subject at the point where it is in focus. I do this before I approach the subject, usually by focusing on a stationary surface and positioning the light while I look through the view finder. then when do approach the subject, I position the light beam on it before I look through the viewfinder. then carefully peer through the finder and "hopefully" find the subject quite easily.


Auto focus will NOT work, as the camera will never lock focus long enough to allow the shutter to be released, therefore the camera servo has to be set to M when shooting, this will allow the shutter to be released when I want it to, yes lots of soft shots BUT it is the ONLY way to get the camera to fire.

BUT you can still use the auto focus function to make adjustments to the reproduction ratio. My housing allows me to control the lens servo. therefore I can switch it to S ( single focus ) and use auto focus to get me in the ballpark. then turn it off and shoot.


chris