|
Although
I've been taking pictures for many years, I still find myself relearning
some of photography's basic teachings. Such a recent relearning experience
was that of what happens when stray light enters through the viewfinder of
an SLR camera and the effect it has on the captured images.
Let me set
the stage for you so you get an idea of the situation I was dealing with
because it's a common situation you may well encounter yourself.
Setting the Stage Of Events
Our next
door neighbors called and asked Linda and I if we'd take some indoor group pictures of
their family gathering, which is an extremely rare event for them. As soon
as we hung up the phone I grabbed the
tripod,
Olympus E20-N digital SLR camera and remote shutter release cable and
off we traipsed to the neighbors.
Because
their house has windows all along its west side, I decided to use the
afternoon's ambient light coming in from the windows as the main light source and the camera's
built-in flash for fill light to control shadows.
While I
was taking care of the camera set up, Linda began positioning the family in nice, natural
poses and coached them on what to do to look their best for the picture. I took my usual regiment of test shots just to
make sure the lighting was the way I wanted it.
When
shooting people pictures, rather than squint through the cameras
viewfinder to take the shot I prefer to stand up and look over the camera
so I am more cognizant of everyone's expressions. That way I can better gauge the perfect moment
when everyone has their eyes open and is looking at the camera to click
the button.
Stray Light In The Shots
 After
rattling off my test shots, I viewed the images in the camera's LCD screen
to make sure everything was just the way I wanted it. But to my horror I saw what looked
like lens flare or ghosting in the test images. This problem is usually caused
by stray light entering in through the camera lens or a light leak in the
camera somewhere.
But how could that be in this case? There were no other light
sources in front of the camera and I knew the camera didn't have a
light leak. So where did the stray light come from?
Then it dawned on me.
It was the light coming in from the windows behind me entering the viewfinder.
Why? Because an SLR viewfinder uses the lenses optics to show you what
you're taking a picture of. Light coming in through the viewfinder will
bounce off of the camera's prism mechanism and have the same effect on the
image as stray light entering through the lens from in front of the
camera.
Film & Digital SLR's Share Issues
While I'd
experienced this phenomena with my my 35mm cameras, it didn't even dawn on me that it
could
also occur with my digital SLR camera. But then again, why not? After all,
the main difference between the two cameras is that one uses film and the
other a CCD chip to capture the image. Other than that they both do the same
job.
Once I'd figured out what had
happened I
took another series of shots but this time with my thumb over the viewfinder to prevent
stray light from entering the viewfinder. Those shots turned out fine
with no sign of any unwanted light in the images.
I Wonder What That Lever Does?
Then, as I continued taking pictures and adjusting camera settings I noticed
a little lever on the side of the viewfinder. What was that, I wondered?
Well I'll be darned if upon closer inspection it wasn't the lever to drop down an internal
viewfinder curtain. It's purpose... to prevent stray light from entering
through the viewfinder. Duh!
Now I felt like a real idiot! I'd
had the camera nearly 2 years and only now discovered my digital SLR
camera had a viewfinder curtain! Talk about a slow learner!
So you see, it doesn't matter how long you've been doing photography you'll always be presented with learning -- or relearning -- opportunities.
Moral Of The Story...
Okay, so there are two morals to finish this story with:
When you're taking
pictures and there's a strong light source behind you, always make sure to
cover the viewfinder so as to prevent stray light from entering the camera. If
you've got the camera up to your face that should be sufficient unless
the light's coming in from the side and hitting the viewfinder. If you've got the camera on a tripod, make sure to use some other means
to block the light. Read your camera's manual
and learn what all those little knobs, buttons and levers do on your
camera. The manufacturer usually puts them there for a good reason. Who
knows, one of them might do something useful like activate a
viewfinder curtain to stop light from entering the camera and
ruining your shots!
SLR Cameras Only Just to clarify,
this particular issue of stray light entering the viewfinder only occurs
with SLR camera's. SLR's use the lens optics to produce the image in the
viewfinder so you see exactly what you're taking a picture of. Rangefinder
cameras use a viewfinder that's totally separate from the lens so these
cameras will not experience this problem.
Just be sure to read the manual to see what type of viewfinder your camera
has. [Back
To Top] | 
