My Photos Aren't Sharp
(Part 1)
By: Jason Busch
This article is intended for the DSLR camera user,
who has some notion of what DOF and apertures are,
in relation to imagers. However, I welcome you to
read the following regardless of your photographic
experience or level, because it will eventually make
sense to you. Be sure to check my other articles, as
I will be covering apertures and Depth Of Field
terminology for basic users in the future.
 Aperture
And DOF
When I'm asked about a camera's unsharp behavior
from users, I immediately ask them about what type
of camera they have--DSLR or a compact camera (DSLR-Type,
Point & Shoot, etc.). Many DSLR camera owners are
having difficulties understanding Depth Of Field (DOF),
and how it relates to apertures, and imagers. One of
the reasons for this and why there is so little
experience with DOF, is because compact cameras have
been used for the majority of a camera user's life,
and are now discovering (albeit indirectly) the
aperture ranges of a DSLR, have a much wider
variance than their compact camera.
When shooting an image at f/2.8-f/4.0 (which is the
general aperture range on compact cameras), most of
the image is going to be in focus automatically (i.e,
there is going to be a very large Depth Of Field).
The reason, is because of the size of the imager.
Basically put, the smaller the imager in relation to
a 35mm camera, the larger your DOF will be. The
average imager on a compact camera gives you
approximately FIVE TIMES as much DOF as a 35mm
camera. In other words, if you're used to shooting
images with a Point & Shoot camera, and you shoot at
an aperture of f/2.8, it would be like shooting at
f/14 on a 35mm camera (5 * 2.8 = 14.
If you have purchased a Nikon D70, Rebel XT, or a
Canon 20D, the DOF problem isn't so bad, but you
will still be experiencing the pains of getting used
to a different Depth Of Field and aperture settings
if you've been using a compact camera most of your
photographic life.
So, let's get to the first reason of why your images
are unsharp. Since your DOF was significantly larger
when you had a compact camera, and since you have a
DSLR now, this could be the reason. Be sure to check
your aperture settings on your DSLR and make mental
notes of the apertures when you shoot. And probably
the hardest thing you will need to do, is get used
to the new DOF of your DSLR. I'm not going to tell
you to FORGET the DOF of the compact camera you used
in the past, because you might be still using it as
your backup camera. So, you're going to have to
learn two different sets of rules for shooting. It
sounds hard, but it's not, once you get used to
doing it. Practice, practice, practice.
 Check
the Focusing Of Your Camera
Unfortunately, due to the exponential increase of
DSLRs being made, there are more defective cameras.
The first step is to take your camera and lens and
point it at an object that is not multi-patterned.
Next, set your camera to its largest aperture
setting for the lens (the smaller the number is the
largest). Find something with a solid color, a fair
amount of light (but not too much), and shoot with
your back to the sun on the object. Then, shoot at
f/4.0. Then shoot at the next aperture setting. If
you have a notepad, I highly recommend writing a few
notes about your observations for each aperture
setting. Record when the camera hesitates, what
aperture setting, what ISO setting, and what shutter
speed setting.
Check the Focusing Of Your Lens
And wouldn't you know, due to the exponential
increase of lenses being made, there are more
defective lenses than ever before too. Now, I'm not
saying there are so many lenses which are
problematic you should carry around a cross and
garlic to protect yourself, but for those few people
who do get a defective lens, it really doesn't carry
much weight to say, "But hey my friend, most lenses
are fine!" Initially, check your lens for any
mechanical issues. Look through both sides of the
lens against a relatively bright lamp (whiter the
light the better) and see if you can spot any lens
particles. Second, get the widest aperture of the
lens you can, then shoot at an illuminated white
material--could be a piece of white paper, white
sheet, what ceiling. Just be sure the white object
you shoot on is absolutely clean of any spots or
whatever. Why? Because this could mislead you into
thinking you have particles within your lens.
 The
Quality Of Your Lens
Suffice it to say, you really do get what you pay
for. If you've gone out and purchased a $100 lens
when most other major brand manufacturers sell an
equivalent lens for 5 times as much...there's a
reason for it. So, this could be an unfortunate
problem of your images not being as sharp as they
can be.
Electronic Contacts Of Your Lens And Camera Mount
SOME 3rd party lenses can perform just as well the
major brands. However, this performance will often
VARY FROM LENS TO LENS. Read that again. I've
experienced this myself so I can say it without a
doubt. I will not mention names but a particular 3rd
party 15mm lens varied so much in quality I think a
trip to a casino in Vegas would have resulted in
better odds. Since you're reading this article, you
have access to the net. Do some research BEFORE you
buy a 3rd party lens. Do this even for the major
brand lenses, but especially for manufacturers such
as Sigma, Tamron, Tokina, and a plethora of other
brands. Trust me, you don't want to get an inferior
lens and find this out after a once in a lifetime
vacation, a paid wedding, or even a special moment
you want to remember. It's just not worth it.
The electronic contacts of 3rd party lenses are very
temperamental. The reason is, the manufacturer has
to balance its compatibility with Canon and Nikon
cameras. Canon and Nikon have very different lens
mounts and forms of electronic controls. And Canon
and Nikon are not that helpful when it comes to
divulging important schematics and electronic
diagrams of how to best achieve maximum
compatibility. No, what basically happens, is a 3rd
party manufacturer buys a bunch of Nikon and Canon
lenses, and then takes them apart. To the bone. Then
hopefully has an idea of how the lenses interact
with the camera.
©2005 by Jason Busch (http://www.digitaldingus.com)
|
