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Re: [OM] How to photograph the eye

Subject: Re: [OM] How to photograph the eye
From: "Piers Hemy" <piers@xxxxxxxx>
Date: Wed, 13 Aug 2014 16:40:43 +0100
I did the same as Chuck. It's not going to be easy.

First, never mind the equipment side, think of the subject - you (Kerstin)
will need a way to keep the subject's head still in a fixed position, with
the eyeball staring at a fixed point (actually, get the _other_ eyeball
staring).

Second, illumination is key. Assuming that the idea is to get detailed
images of the structure of the iris, the problem is that you need lots of
light (given the high magnification) but the iris is buried in highly
reflective material, so reflections are as big a problem as illumination.
While a ring flash will probably overcome these two problems, it will also,
probably, blind the subject! So more illumination isn't the answer - you
need highly concentrated light, and likely off-axis (the opposite of what
you would need for retinal photography).

Here's a couple of pretty technical papers showing how it's done for real.
The first is in German (OK for Kerstin?) and is historical, but might be
useful to explain the general set-up:
http://www.med-hist.uni-kiel.de/images/stories/pdf/Spaltlampen_Koppenhoefer.
pdf
The second is the current Zeiss approach:
http://www.meditec.zeiss.com/88256DE3007B916B/0/506FBA0E8FCB598E882571D8007D
4B40/$file/spaltlampen_eye_exam_en.pdf

If you want to search further, try the term "slit lamp camera".

I don't suppose that either of the links will provide what is wanted, but
will give hints as to how to get started. Aside from the "fixing the head in
position" issue, I suspect a small, bright LED penlight shining obliquely on
the iris might be the way to go.

Piers


-----Original Message-----
From: olympus
[mailto:olympus-bounces+piers.hemy=gmail.com@xxxxxxxxxxxxxxxxx] On Behalf Of
Chuck Norcutt
Sent: 13 August 2014 01:47
To: Olympus Camera Discussion
Subject: Re: [OM] How to photograph the eye

I looked around on the web for suggestions on photographing eyes.  I thought
most of the suggestions were pretty useless.  Some using ring lights showed
reflections of the lens but nothing quite so distinct as what you got here.
Some showed beautiful images sans reflections but the advice usually ended
with something like "use a macro lens".  None gave any good advice on
lighting.

Chuck Norcutt


On 8/12/2014 12:15 PM, Jez Cunningham wrote:
> Like this?  ;-)
>
> http://zone-10.com/tope2/main.php?g2_itemId=14118
>
>
> On 12 August 2014 15:41, SwissPace <ian@xxxxxxxxxxxxxxxx> wrote:
>
>> Kerstin wants to take images of her clients/patients eyes, not the 
>> inner eye but a close up of the cornea etc.
>>
>> any ideas on the best way to do this and get onsistent results, i.e. 
>> the same distance from the eye, she has an OMD with a few lenses plus 
>> access to an infinite number of OM lenses :-)
>>
>> my first thought is of some translucent tube with an on  camera flash 
>> but I am sure the list members will have better ideas
>>
>> thanks in advance
>>
>> IanW
>> --
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