In this post I’d
like to talk more about the view finder, and some of the things that make a
good one (or a bad one). Now, to completely honest, this post was born out of my
curiosity to learn more about the viewfinder and not my immense store of
knowledge, but I try my best to explain things as simply as I can!
Mirror, Mirror in the Camera
When you look
through look through the view finder, that image was put there by a system of
mirrors that “mirror” (I know, bad pun) the image that the sensor will capture.
If you’ve taken off the lens of your SLR you’ve seen the see the rather large
mirror that sits in front of your sensor. This mirror reflects the image that
the sensor will capture, up into the top of the camera where the viewfinder is.
Only thing, it’s not a straight shot, it has to be reflected several more times
before it gets there. There are two ways to do this. You could use a
pentaprism, which is literally a prism, a solid piece of glass that reflects
the image to the viewfinder; or a pentamirror, which does what a prism does
only with mirrors. Pentaprisms are king. Since they’re a solid piece of glass, there’s
minimal light loss.
*Now, you might be
wondering why it’s important to have a bright view finder. Well, do me a favor;
turn down the brightness on your computer a couple notches. Instantly you’ll
see that it’s generally harder to see and has less contrast. The same applies
to a viewfinder, keeping the brightness in the viewfinder the same, as the
actually scene is crucial. In addition, if your viewfinder is dark, it can be
much harder to see what’s in focus. So, if you decided to use manual focus, you’d
find it hard to tell what exactly you’re focusing on.
As I said before,
the pentaprism has minimal light loss, and if you were to look through one, you’d
instantly note it’s bright, big, and accurately represents what you’re shooting.
Only problem is that they’re expensive, so camera companies don’t use them on
their lower end SLRs, opting instead for pentamirrors. Pentamirror viewfinders
are a box of mirrors that mimics what a pentaprism does. However, a very noticeable
amount of light is lost as it bounces from mirror to mirror. Looking through
one you’d notice that they are smaller, they’re dark (often darker than the
actual scene), and it’s harder to judge what’s in focus. In short, they’re what
you want to avoid.
Get Coverage!
When using
pentamirrors, you run into another problem, it doesn’t give you an accurate
representation of what you’re shooting. Unless it specifies otherwise, they
usually don’t show 100% of what the sensor sees (90-100% is good). This could
be a problem when lining up your shot, and having the picture come out
different than what you saw in the viewfinder.
Now, I know you
may have thought of clothing related topics when you saw the title, but
comparing clothing coverage to viewfinder coverage does lead its self to an
interesting comparison. Say you went shopping, and bought a few shirts without
trying them on. You get home and put them on, only to realize that they’re too
small, and uh, don’t you enough “coverage.” If you expect coverage from your
clothes, why shouldn’t you from your viewfinder? It could be potentially more
awkward to be taking family photos, and have them framed perfectly in your
viewfinder, only to realize that parts of Aunt Barbara’s slightly inappropriate
garden sculpture snuck into your photo. You probably won’t be asked to take
photos again, and continue to the subject of a many hilarious (not to you) Thanksgiving
conversations for decades to come.
Magnification
50mm is
approximately what you see with you naked eye. Say your camera is set at 50mm, and
you viewfinder magnification is 1X, than you’re seeing exactly the same
magnification you’d see with your naked eye. Say, the magnification is 0.75X
than it would be three-fourths the size as seeing it with your naked eye.
Basically, the closer a viewfinder’s magnification is to 1X usually the better
it is. After all, who wants to look through their viewfinder, to find that they’re
looking at a miniature of their actual shot?
There is a problem
though. And that is, when you start to get closer to 100% coverage, the magnification
decreases, especially on full-frame cameras.
For instance, the Cannon X-1, their flagship full-frame SLR, has 100%
coverage, but only 0.75X magnification. The Pentax K-30, a 3/4 size sensor, has
100% coverage and has 0.92X magnification. Both cameras’ have pentaprism
viewfinders.
Which view finder
is better? I’d say the X-1. Even though it has 0.75X, it has a considerably larger
viewfinder, about 1/3 bigger! Having a bigger viewfinder, in some ways, make up
for low magnification. However, before you believe me, I’d suggest you go to a
camera store, experiment, and see for yourself.
Size Matters
The size
comparison is interesting. We’ve all seen the cheap cameras with pinholes for
viewfinders, and compared to any SLR viewfinder, the SLR will win. But you may
not know what you’re missing out on. I have a Pentax K-x, which has a
pentamirror viewfinder, but I recently got to see through a friend’s Cannon
5-D, which has a pentaprism viewfinder. The 5-D’s viewfinder is about 1/3
bigger than the K-x’s, much brighter, easier to tell what’s in focus, and much
more enjoyable to use! I had a hard time going back to my K-x.
Conclusion
I hoped this post
was helpful, and you came away with a better understanding of viewfinders. If
you’re interested in reading more, I’ve included a link below.
Other Resources:
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