From: Rod Fleming (rodfleming@sol.co.uk)
Date: 05/04/00-01:58:25 AM Z
Hi
Martin Salowey wrote
>
> At 44, my 20/20 vision has become challenged. Seeing both close up and
> distance are getting a bit difficult. This I can deal with, but when using
> a camera with tack sharp optics that produce out of focus prints and
> transparencies, this becomes a major issue. Hey, soft focus wheather I
want
> it or not!
>
> I shoot with many cameras and all have become a challenge focusing, but
one
> in particular started the whole issue. When shooting with my Hasselblad,
> with either the "stove pipe" or prism finder, I was getting slightly out
of
> focus results... consistently. This gets a bit difficult to explain to
> clients after a while. I took the camera to Hasselblad and had them
service
> the camera bringing it back to factory specifications; same problem
> occurred. "Hey you guys did a crappy job" I told Hasselblad. They went
back
> over the system with a fine tooth comb. Results: the camera is working
> perfectly, including focusing. The Hasselblad technicians indicated that
> both of the finders "focus" at about 7 or 8 feet.
>
> OK, next stop, an ophthalmologist. Guess what - 20/20 vision, although I
am
> getting older and do not expect this to last much longer. They indicated
> that I have a slightly astigmatic condition also. "Should this affect my
> ability to focus my camera" I ask, "Nope" was the reply. Not convinced
that
> this fellow knew what he was talking about I chatted with others in the
> "eye business". All collaborated his findings. " Why am I having problems
> focusing?" everyone shrugs their shoulders not at all understanding what a
> disaster this is for a photographer.
>
> Here are my questions: Has anyone had similar experiences? and any
> recommendations on where to find reliable help? I live in the NY metro
area
> and work in healthcare and I have had not luck finding resources. I have
an
> additional concern that my mother went blind from macular degeneration.
> There has been not evidence indicating that there is a genetic connection
> but it does add fuel to the fire.
SNIP
My deepest sympathies, Marty- this sort of thing has happened to me.
The very very first thing to do, and I don't wish to be alarmist, is to get
specialist advice from an opthalmist and a neurologist to make sure that
there is no chance that the issue is either being caused by macular
degeneration as you suggest, or by damage to or pressure on the optic nerve-
this can be a typical symptom of problems on the pituitary gland, which is
situated very close to the optic nerve. (I'm sure Marty knows that, but just
in case anyone else is unsure.....)
Now, in my case it was not any of those, so I went back to the optician-
that's the guy who prescribes the correction lenses. SO we went through the
routine- everything's just a touch soft. Optician does the test and says
everything's fine, stop talking nonsense, go home. (Young whippersnapper
straight out of college.) Now I am a contact lens wearer and have been for
many years, and it occurred to me that the problem had started after a
change of lenses- I get new ones every six months,(they are GP lenses), and
a test once a year. So I got out an old pair of lenses and clapped them in-
bingo! Crispy negs! Sharp focus!
So, back again to whippersnapper to confront him with this. He is not
compliant; he says, "But those old lenses were too powerful; they were
making you longsighted, so I reduced the power. The new prescription is
correct." Well, says I, what is correct is what gets my negs sharp, cos
that's what gets me the income I have gotten used to, and if that means
being slightly longsighted, tough. It happens I used to be Picture Editor on
a national newspaper here, so my "polite but firm" is worthy of note.
Reluctant compliance ensues.
And so we found this out:
Most cameras with optical viewfinder systems are set so that the image
appears to be at infinity- ie, where your eye is at it's most relaxed. But
opticians set your prescription so your eyes are right at _6 metres_! Yes,
it's true, that's why that damned board is where it is. This is the
compromise they select between near and far vision. So in effect, when the
optician says your eyes are perfect, you are actually a smidge
SHORT-SIGHTED!
Now when you are young and frisky the lens in your eye is very supple and it
will relax into the furthest focus position very quickly, and so cope with
the above, but as you get older, typically in your early forties (I am 44
like Marty) this last little bit gets slower and slower as the lens stiffens
up. So your eye finds it more and more difficult to establish what is sharp
at infinity and what is not.
Most people know that a similar thing in reverse happens as you lose your
close focus with age- but no-one had ever explained to me before the fact
that a similar thing happens at infinity focus! But when you think about it,
it's obvious.
Try this. Go outside and select a target at infinity- a tree or a television
aeriel. Now turn away and then just look quickjly at it. Does it snap into
focus right away, or does it appear to resolve over a second or so? (Do this
with one eye shut at a time). If so you probably have the problem I have
described.
What you need to do, if you think this may be your problem, is to persuade
your optician to prescribe you lenses that he thinks will render you "just"
longsighted. Then the apparent infinity of your viewfinder image will be
within the "fast reaction" zone of your eyeball lens, and normality will be
resumed. You should be able- since you are not normally a wearer of
prescription lenses- to get eyepiece correctors for the cameras in the
powers prescribed, and do it that way; because I already wear lenses I just
changed back to my old prescription.
Opticians are reluctant to do this because they are trained to believe that
near focus is more critical than long focus- they obviously don't meet
enough photographers. Your man will test you and tell you your eyes are
right- but that's only at 6 metres, as you can see. He will tell you that
the prescription might make it difficult to read or use a computer, stuff
like that. You will have to explain exactly what you want, what you do, and
show him that you know what you're on about. Explain that you need to have
the infinity focus within the highly elastic part of your eye's lens's
range. You will also have to be aware that things will continue to get worse
as time goes by, but you will be able to correct it by increasing the power
of the correction.
At least, it worked for me.
Best
Rod
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