Re: Macro photography

In article <gjaqr19bhig8m492khm4pjlh6e8nkfdek6@xxxxxxx>,
Tony Cooper <tony_cooper213@xxxxxxxxxxxxx> wrote:

I'm still finalizing my decision on which dSLR/lenses to buy, but
meanwhile I've been doing a fair bit of reading up on 'real' macro (1x
up) and photomicrography, since I expect to do a lot of it. My current
main microscope is a LOMO stereo scope, 7x-56x (8x eyepieces). I have
the optional camera port. Alas, it's a pentax mount, not a proper
T-mount, so I'll have to do some fiddling...

One thing to note about camera ports: the photographic magnfication you
get is (roughly) the objective magnification, not the total
magnification. So as is, my Lomo will give me 1x-7x in photos, not the
8x-56x I see using my 8x eyepieces. If you want higher magnification,
you'll need to look for an adapter that connects with an eyepiece in
place. Scopetronix has gadgets to fit just about any eyepiece or tube
to any camera, though they aren't cheap. <http://www.scopetronix.com/>.
Adorama has a variety of adapters, too, though they can be hard to find
in the catalog. Also not cheap, sigh.

> Light is also a factor.

One might almost say the most important factor--just as in data
processing, garbage in=garbage out. It's common to spend a surprisingly
large fraction of the budget on illumination. The most versatile
lighting for stereomicroscopy, a fiber optics light system, can
typically run $600-$1500, though a handy person can presumably build one
for less. (If you build one, be sure to take into account good cooling
so you don't start a fire, and excellent vibration reduction so you
don't shake the 'scope and camera!) The light box has a high intensity
bulb (often halogen), variable output, with an IR filter to reduce heat,
sent into one of several interchangeable light pipes, such as simple
pipe, bifurcated, or ring light. The pipes are flexible but stiff and
(mostly) stay where you put them, unless you choose floppy ones that
have to be tied down. Bifurcated (a double pipe) with focusable tips is
good; it lets you easily have a primary source and then fill for
shadows, and change the spot size to match the subject.

Heat reduction for any incandescent illuminator is crucial--enough light
to get a good exposure without a heat filter can turn your subject into
tendrils of blue smoke. Don't ask how I know this...

You can also get LED based microscope illuminators at outrageous prices,
or make your own. I'm experimenting with some very bright Photon
Freedom mini LED pocket flashes. $20 each, but they come with handy
clip holders that let you aim the light nicely. I got the 'covert tip'
version since they screen the side light, producing a narrower cone of
light. They've been great at 50x for visual use. I doubt they'll be
bright enough for photos on their own. But I can probably arrange to
focus them to get smaller brighter spots, and I can buy an awful lot of
LEDs, wire, and solder for lots less than I can buy a commercial version.

As an example of what a crucial difference good illumination makes,
wander by Molecular Expressions. They have a section for the Intel Play
QX3 USB 'scope. They get some amazingly good pictures (considering the
intrinsic low resolution of the sensor) out of that toy, simply by using
the intense fiber optics lighting, and standard tricks such as darkfield
illumination. The site is in any case the first stop one should make
while learning microscopy. They have excellent tutorials on microscopy
and illumination in general, and even have simulators for different
types of microscopes.

<http://www.molecularexpressions.com/optics/intelplay/qx3brightfield.html
>
<http://www.molecularexpressions.com/optics/intelplay/gallery/index.html>


Other excellent web resources:

Nikon's Microscopy U, similar to Molecular Expressions, but somewhat
more advanced:
<http://www.microscopyu.com/>

Micscape, an online journal for amateur microscopists (lots of how-tos):
<http://www.microscopy-uk.org.uk/mag/indexmag.html>

The Microscope on a Budget:
<http://www.mbstevens.com/mscope/>

Amateur Microscopy.net:
<http://www.amateurmicroscopy.net/>

Gordon Cougar's Microscopy Links:
<http://www.couger.com/microscope/links/gclinks.html>


An outstanding print reference is Alfred Blaker's "Handbook of
Scientific Photography" from the '70s, fairly easily found via the net
(powells.com, abebooks.com, etc). It's mostly studio based (he has
another book "Field Photography" which I don't have yet), and covers not
just photomacrography and photomicrography, but gives extensive tips on
lighting, with a big section on special problems and special subjects,
from rocks with near invisible striations to larvae in glass vials,
tribal masks to insects. Some people might find it dry to read, though
there is understated humor to be detected by anyone who's fiddled in a
lab enough! Best photo book I've read in a while, because he doesn't
patronizingly ***-foot around the technical issues, but is still
practical, not theoretical. Adapting what he says to digital is not
much of a stretch.


> If I came across a used microscope at a reasonable price, I'd get it
> just to play around.

There's a newish design of inexpensive microscope that's far better than
you'd expect from looking at them instead of through them. They look
very odd, kind of like big hockey pucks, because they use a folded
inverted light path. They're small enough to stick in a jacket pocket
(4" diameter), or into some empty space in your camera bag (is there
ever such a thing?) Two instances, one is 35x, the Trekker, and the
other 80x/160x, the Readiview. Roughly $100 each. They can both take an
optional T-mount adapter (TrekLink) for connecting to an SLR. Built in
LED lighting works pretty well, and they can also easily use ambient
light; even a room light's not bad, though outdoors (even overcast) is
better. The Readiview includes a rotating arm for an LED that lets you
do darkfield. They'll presumably need a brighter light for good photos.

I was really surprised at how good they are for the price. The useful
resolution on my Readiview is about a micron. YMMV, I don't know how
good the quality control is. There are certainly trade offs for the low
price (plastic, fragile focus, inclined to get dusty inside if you
aren't careful), but bang for buck they're hard to beat just now. I'm
hoping for more robust models with improved optics and focus mechanism
in the future.

Meade distributes the Readiview (in the US at least), and includes quite
a nice set of 25 prepared slides. Trekker is distributed by it's own
company, <http://www.looksmall.com/>. Froogle is your friend for
finding your favorite vendor of either. Sherwoods Photo in Britain is
the easiest source of specs:

<http://www.sherwoods-photo.com/field_mscope/trekker_fs.htm> (includes
sample photo of fly head, eye extends from top to botom of frame)
<http://www.sherwoods-photo.com/meade_field_microscope/meade_fieldmicrosc
ope_fs.htm>

Half wishing I'd bought my camera for christmas even though I'm not
ready, instead of waiting until after PMA...

--
Allyn Weaks allyn.3615@xxxxxxxxxxxxxx Seattle WA Sunset Zone 5
Pacific Northwest Wildlife Gardening: <http://www.tardigrade.org/natives/
Confidential to Am I Normal: Yes. No one who can read is ever successful
at cleaning out the attic.
.