Didn't someone, Nikon maybe, make a macro lens with a built-in light? Seem
to recall seeing one in a dentists office... Way back when l still had
teeth.
On Aug 13, 2014 11:40 AM, "Piers Hemy" <piers@xxxxxxxx> wrote:
> 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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