Re: taking pictures in the operating room


Floyd L. Davidson wrote:
cbnewman@xxxxxxxxx wrote:
thanks for all the interesting replies.

1. the only things that have to be sterile in the operating rooms are
the things that touch the patient (instruments, implants, etc). in

(Ignore "experts" who are not.)

Good advise, Floyd but the statement is a little simplified but
essentially true.

fact, i decided against the 60mm macro lens because i thought it
required me to get too close to the field.

Indeed, a focal length of 60mm means that if you can get close
the magnification will be high. A "macro" lense means that you
can indeed get close, but doesn't mean that you necessarily have
to. I.e., the difference between showing the environment
provided for working on a heart during bypass surgery is one
thing, and recording the details of the micro stitching done on
an artery bypass is another.

You really need a microscope to see arterial stitching, don't knock the
60 micro it is one of the best Nikon lenses, better than the "normal"
50s. But I would use it more as a normal lens, just for the reason that
you have to get too close for higher mags.

Hence the significant differences between the Micro Nikkor 60mm
f/2.8 and a Nikkor 50mm f/1.8. Out of the box the 50mm can be
used with half as much light, but cannot focus very close at
all. The 60mm macro lense can be focused close enough to
provide 1:1 magnification. And with neither lense are you
*ever* likely to want to use it with the aperture wide open, if
for no other reason than the resulting very limited depth of
field.

Here are some comparative numbers for fixed focal length Nikkor
lenses, first a representative group of non-macro lenses, and
then for various macro lenses:

Non-Macro Lense Aperture Min focus (m) Max Magnification
================== ============= ============= =================
50mm AF-D f/1.4 - f/16 0.45 1:6.8
50mm AF-D f/1.4 - f/16 0.45 1:6.6
85mm AF-D f/1.8 - f/16 0.85 1:9.2
180mm AF-D f/2.8 - f/22 1.5 1:6.6
200mm AF G VR f/2.0 - f/22 1.9 1:8.1

Macro Lense Min Aperture Min focus (m) Max Magnification
================== ============ ============= =================
55mm AF f/2.8 - f/32 0.223 1:1
60mm AF-D f/2.8 - f/32 0.219 1:1
105mm AF G VR f/2.8 - f/32 0.314 1:1
200mm AF-D f/4.0 - f/32 0.5 1:1

And here is the same information for a few zoom lenses:

Non-Macro Lense Min Aperture Min focus (m) Max Magnification
================== ============ ============= =================
70-200mm AF G VR f/2.8 - f/22 1.4 1:6.1
80-200mm AF-D f/2.8 - f/22 1.5 1:6.3

Macro Lense Min Aperture Min focus (m) Max Magnification
================== ============ ============= =================
70-180mm AF-D f/4.5 - f/32 0.37 1:1.32[1]

[1] Use a 2.9 diopter (Nikon 6T) for 1:1 magnification

The macros are your best lenses, and give you the most versitility,
always found diopter lenses to soften the image too much, especially
against a macro lens. If you are doing OR work it doesn't make sense to
use anything else, unless you are capturing the "OR
environment" then you want someting wide

If you want 1:1 magnification without fuss, obviously the fixed
focal length Nikkor Micro lenses are the only candidates, though
the 70-180 zoom comes close and can quickly be adapted for
higher magnification with an auxiliary closeup lense.

This is the lens no one knows about, I haven't used one but supposed to
be one good optic.



I would think that:

1) maximum aperture is not significant (provide more light)

2) minimum aperture is very significant (for depth of field)

3) Vibration Reduction (VR) might be *very* useful, because
of course all movements are magnified at the same ratio
as the image.

4) A zoom lense is *much* easier to use in terms of quickly
getting focus and framing.

And therefore, if weight, cost, etc. etc. are not taken into
account, the 70-180mm Micro zoom strikes me as very good *if*
you don't do a lot of 1:1 high magnification images and/or you
are able to use some sort of tripod or whatever to provide a
stable platform. Otherwise, either the 105mm VR Micro Nikkor
or the 200mm Micro Nikkor would be my choice. The 105mm has VR,
the 200mm has a greater working distance... take your pick.

2. medical photography is extremely common, especially in the operating
room and especially at academic institutions. we use the photos
(stripped of any information potentially identifying a patient, of
course) for teaching and for publications in journals.

(Ignore "experts" who are not. Particularly as some seem to be idiots!)

Why do you keep saying this, you are making your self sound like the
idiot. Again this is essentially a true statement.



there are two light sources in the OR. the operating lights themselves
are very bright and incandescent (i think). usually we turn these away
because they are really quite bright and harsh, but maybe it's because
of the typical point-and-shoot cameras most people use. the other
lights are flourescent. the room is quite brightly lit even with the OR
lights turned away and the field is pretty well illuminated.

I think you are going to need a flash, though there may be times
when it is merely a fill light (e.g., if the operating lights
are on). A ring light might be appropriate?

The statement about the OR lights is also essentially true, ringlights
are only good close in, and the loose their punch fast, even the HD
ring light on a Medical Nikor. For general surgery bring a strong
flash, I've used Metz potoato mashers.


Generally you are always going to want as much depth of field as
you can get with any significant amount of magnification; hence,
more light to allow a smaller aperture is always necessary.

Whatt you want to do is balance speed to aperture, as I said earlier
under OR lights I can get 1/180 at f11 an this works well. With digital
too narrow an aperture degrades your pictures.


can anyone comment on the utility of a 50mm fixed with a wide aperture?
that seems like i could blow those pictures up to be arbitrarily large.
i am looking at the Nikon 50mm 1.8D

Again a macro is a better choice.


You cannot blow up the images to be "arbitrarily large" without
finding out just how fuzzy they really are! That can be done to
a certain extent, but how much depends on how sharp the original
image actually is, plus just how many pixels it had to begin
with. (You might want to look at a D2x or D200 camera too.)

I do want to get my D200 into the OR, so much better than the Fuji I'm
now using


One question... do you want to be a photographer, or do you just
want a mechanism for obtaining images? There are an awful lot
of possibilities that come to mind for a person interested in
learning photography, but they would simply be unnecessary
mental clutter for a surgeon who just wants pictures.

What an idiotic, short sighted statement. The best medical
photographers are artists in their own right. You should get to know a
few. We get asked to solve photographic problems and add our
interpretation to the images we are asked to make, in many cases the
paramerters are narrow, in others it is wide open. When I did freelance
I felt commercial clients were far more constraining than the MDs I
work for. If this kid wants to persue medical photography for a career,
more power to him, he'll learn a lot of interesting things, if he
doesn't he won't make it.
Saw your website, lovely images, but I get bored with landscapes. You
are lucky that you have access to an area that not many folks see or
can even get to.
Sorry about returning your accusations, but I couldn't let it go
unanawered.

Tom

.

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