Kierstin said:
I am new to this group and have never posted anything here before. I am
a American living in London and desperately need some guidance. <snip>
I am hoping to find out something about my OM 20, as I bought it in a
auction a few weeks ago and it did not come with a manual. <snip> I
will tell you the details of the camera and then maybe someone can =
help me <snip>
It is black & silver, it says OM20 in the left hand front corner. The
lens says MACRO (on the top) with 6 different rows of numbers. It
adjusts in & out. The front part of the lens (which is missing the
black cap at the end) says SOLIGOR MC ZOOM-AUTO F2.5/3.5 f=3D35-70mm
<snip>
-----------------
Hi, Kierstin. I know someone else has already pointed you to the eSIF
where you can get a PDF file with the instruction manual for the
camera. You may be a bit confused since the lens you have (made by
Soligor) does not match the standard lens depicted in the Olympus
instruction manual.
Although the lens itself is not marked as such, if you have the original
box you will note that this lens is one of the Soligor C/D series. Like
Vivitar "Series 1" lenses of the same period the "C/D" designation means
a more expensive and better quality lens than these companies normally
produced. In other words, this should be a very good, high quality
lens. I'm sending you under separate cover a scan of the box which
gives the tecnical details of the lens and also shows that my version
was purchased Dec. 30, 1986 for $215. I bought mine "used" recently. I
put "used" in quotes since the lens is in such pristine condition it
looked like it was new in the box. Unfortunately, I don't have the
instruction sheet that presumably came with the lens or I'd scan it for
you.
I'll describe the lens functions starting from the base of the lens and
move up to the front.
1) Chrome mounting ring: There is a chrome button (the bayonet latch),
a red dot and a black button (the depth of field preview). Depress the
chrome button and twist the lens counter-clockwise to remove it from the
camera. To place the lens back on the camera align the red dot on the
lens mounting ring with a similar red dot on the camera's mounting
flange. Press lens to camera flange and twist clockwise until the
bayonet latch clicks into place. We'll come back to the black button
momentarily.
2) Aperture (or diaphragm) control ring: A ring with numbers ranging
from 2.5 to 22. The numbers are ratios between the focal length of the
lens (which is variable between 35 and 70 millimeters) and the size of
the internal aperture or opening of the lens. This controls the amount
of light that the lens admits into the camera. At a focal ratio of 2.5
(f/2.5) the lens is fully open. At f/22 the lens aperture is closed
down as small as it will go. The lens opening in combination with the
shutter speed on the camera control the amount of light that the film is
exposed to. The third exposure variable is the speed (sensitivity to
light) of the film.
With the lens off the camera turn the aperture control ring to f/22
while looking through the lens. You will notice that nothing happens.
Now press the black depth of field (DOF) preview button. As you press
it you will notice the lens' internal aperture close down to just a few
millimeters diameter. When you select a focal ratio the lens is
normally held completely open until you press the shutter release. This
is to allow as much light into the camera as possible so that you can
easily see to focus. The camera will close the lens to the selected
aperture when you press the shutter release button. It will then
instantly re-open it to full aperture. The DOF button is used to
preview the scene as the film will see it at the moment of exposure. At
large (small numerically, like f/2.5) apertures the range of sharp focus
ahead of and behind the main subject is at a minimum. As small apetures
(like f/22) the range of focus is at a maximum. This phenomenon can be
used as part of the creative process. Choosing a large aperture, for
example, can be used to throw background subjects out of focus and
reduce the distraction from the main subject.
3 and 4) Macro magnification scale and macro control ring: The ring
labeled MACRO allows extended focusing to get increased magnification of
subjects very close-up. In the lens's normal mode the yellow dot on the
MACRO control ring should be aligned with the white dot on the
magnification scale. The maximum magnification (closest focus) in the
normal mode is about 1/10 life size or a ratio of 1:10. In the normal
mode the MACRO ring is locked into position by a detent which keeps the
yellow and white dots aligned. Nearly 180 degrees opposite the yellow
dot on the MACRO control ring you will find a small detent release
button. Pressing this button will allow rotating the MACRO control ring
to higher magnifications. Note that the ring has magnification ratios
listed of 1:8, 1:6, 1:5 etc, all the way down to 1:2.7. The
magnification scale is really only accurate when the focal length is set
at the 35mm position. The magnification at the 70mm position is
somewhat less but gives you much more working distance. At maximum
magnification in the 35mm position the front of the lens will only 4.2"
away from the subject. At the 70mm position it will be about double
that.
5) Zoom ring: This changes the focal length of the lens to any value
between 35mm and 70mm. 35mm is considered moderate wide angle. 70mm is
moderate telephoto. 45-50mm is considered a "normal" field of view for
a camera using 35mm film. Others can check me here but I believe
"normal" refers the the angle of view of the concentrated focus of the
human eye or what you see in sharp focus with the eye discounting your
peripheral vision. You use the wide angle position for such things as
scenic vistas. You would use the telephoto position for such things as
portraits. Of course, how you use any of this is part of the creative
process and nothing is cast in stone. If you want to take portraits at
35mm go right ahead. The telephoto position can also make interesting
landscapes since it changes perspective and tends to compress
distances. The wide angle positions will seem to expand distances.
6) Focusing ring: Note that it is marked in feet (green) and meters
(white). The closest focus (without using the macro feature is 0.7
meters. Turn the focusing ring while looking through the viewfinder of
your camera until the subject in the viewfinder is sharp. See the
camera's instruction manual.
7) Hood: When using the lens, slide the hood to the extended position.
This will help shield the lens from stray light which will cause flare
in your pictures. Zoom lenses such as this are more subject to flare
than some others. Don't point the lens directly at the bright sun and
watch for flare in the viewfinder when the lens is pointed in the
general vicinity of the sun or very bright lights.
8) Filter ring: The threaded ring around the lens' front element is for
attaching filters of various types. Some people keep a UV
(ultra-violet) or "skylight" filter on the lens at all times. Film is
sensitive to ultra-violet light that you can't see. A UV or skylight
filter will generally give you bluer skies. The filter also serves to
protect the front element of the lens. However, one of our prior list
members (Gary Reese) has demonstrated through extensive testing that
most filters (even some expensive ones) are poorly made optically and
have a deleterious effect on the final image. So, some folks swear by
them and some swear at them. YMMV.
9) DOF scale, the missing ring: Unlike the normal 50mm lens illustrated
in the user's manual for your camera, this lens does not have a depth of
field scale. With a fixed focal length lens there is generally a scale
that shows you the depth of field at a given aperture, or how much
distance ahead of and behind the main subject will be in sharp focus at
a given aperture and distance to the main subject. It's simply
impractical to do this with a zoom lens so look through the viewfinder
and press the DOF button to see it instead of reading it off a scale.
Hope this helps. Welcome to the world of OM photography. You'll catch
on soon enough and there's plenty of help on this list. No question is
too simple. All of us were where you are sometime in the past.
Chuck Norcutt
Woburn, Massachusetts, USA
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