Beginning amateur SLR - Canon Rebel

Rudi Cheow wrote:


...you should avoid it even to the point of paying
extra not to have it.


Forgive my beginner naïvety, but why is this?

Some people are more anti autofocus than others, though it is not
without reason.



Will explicitly avoiding AF at a greater cost mean greater pictures?

I think what Ted was referring to were the few cameras that are still
made as manual focus cameras in 35 mm are of generally fairly high
quality. Those would be Contax, Leica, and a couple of Nikon cameras
still available as new (FM3A, F3 (very few new), and FM2 (harder to
still find new)). Of course, there are others, or lots more for used
choices. A broad generalization about all these is that they have focus
screens (in the SLRs) that make manual focus very easy to accomplish.


All else being equal, will a MF lens that costs more than its AF
counterpart (if such a thing exists) produce better results?

The only ones I can think of like that are a few of the Nikon lenses. If
you only look at the 50 mm choices, the optical formula is nearly the
same. The lens barrel construction is different, and manual focus feel
is fairly even, while manually focusing an autofocus lens seems very
loose. Under similar conditions, the results of manually focusing either
type would be nearly indistinguishable.



Is this just some form of photography elitism (apologies for the
cynicism but as a newbie to these groups I've come across a lot of
this)?

Sometimes an elitist attitude, though not always without some truth, or
reasoning. In general again, a fixed focal length lens could provide
better image quality than a zoom, but it is such a subjective measure,
few people really notice the differences. If something is so subtle,
does it really make much difference?

Anyway, the basic idea behind autofocus is that the sensor compares
contrast differences to choose a focus plane. In some situations, a
change of contrast, or lighting, can slightly alter that autofocus
choice of plane of focus. While the DoF might cover that slight
variation, sometimes it can result in a somewhat softer image. Imagine
that the autofocus can change distance slightly, even when the subject
has not changed distance. Most of the time, you are likely to never
notice it, while looking through the viewfinder.

Of course, you can manually focus an autofocus lens. The issues with
that are some SLRs do not have a viewfinder screen that makes manual
focus easy. Some of the newer lenses barely have any area to place your
fingers to manually focus the lens (Nikon G series kit zooms are really
bad like this), which makes manually focusing a pain. Also, many zoom
lenses are not very bright in the viewfinder, which can be made worse by
a mirror set-up instead of a true prism in the SLR, making focusing
manually under lower light conditions even tougher.

While I am generally against autofocus, there is at least one instance
in which it replaces an action almost impossible with manual focus. If
an object is moving directly towards you, trying to follow that changing
focus point can be very tough, especially if that object is moving fast.
With autofocus, many SLRs allow for quickly following focus
automatically.

Ciao!

Gordon Moat
A G Studio
http://www.allgstudio.com/gallery.html Updated!

Rudi Cheow wrote:


...you should avoid it even to the point of paying
extra not to have it.


Forgive my beginner naïvety, but why is this?

Some people are more anti autofocus than others, though it is not
without reason.



Will explicitly avoiding AF at a greater cost mean greater pictures?

I think what Ted was referring to were the few cameras that are still
made as manual focus cameras in 35 mm are of generally fairly high
quality. Those would be Contax, Leica, and a couple of Nikon cameras
still available as new (FM3A, F3 (very few new), and FM2 (harder to
still find new)). Of course, there are others, or lots more for used
choices. A broad generalization about all these is that they have focus
screens (in the SLRs) that make manual focus very easy to accomplish.


All else being equal, will a MF lens that costs more than its AF
counterpart (if such a thing exists) produce better results?

The only ones I can think of like that are a few of the Nikon lenses. If
you only look at the 50 mm choices, the optical formula is nearly the
same. The lens barrel construction is different, and manual focus feel
is fairly even, while manually focusing an autofocus lens seems very
loose. Under similar conditions, the results of manually focusing either
type would be nearly indistinguishable.



Is this just some form of photography elitism (apologies for the
cynicism but as a newbie to these groups I've come across a lot of
this)?

Sometimes an elitist attitude, though not always without some truth, or
reasoning. In general again, a fixed focal length lens could provide
better image quality than a zoom, but it is such a subjective measure,
few people really notice the differences. If something is so subtle,
does it really make much difference?

Anyway, the basic idea behind autofocus is that the sensor compares
contrast differences to choose a focus plane. In some situations, a
change of contrast, or lighting, can slightly alter that autofocus
choice of plane of focus. While the DoF might cover that slight
variation, sometimes it can result in a somewhat softer image. Imagine
that the autofocus can change distance slightly, even when the subject
has not changed distance. Most of the time, you are likely to never
notice it, while looking through the viewfinder.

Of course, you can manually focus an autofocus lens. The issues with
that are some SLRs do not have a viewfinder screen that makes manual
focus easy. Some of the newer lenses barely have any area to place your
fingers to manually focus the lens (Nikon G series kit zooms are really
bad like this), which makes manually focusing a pain. Also, many zoom
lenses are not very bright in the viewfinder, which can be made worse by
a mirror set-up instead of a true prism in the SLR, making focusing
manually under lower light conditions even tougher.

While I am generally against autofocus, there is at least one instance
in which it replaces an action almost impossible with manual focus. If
an object is moving directly towards you, trying to follow that changing
focus point can be very tough, especially if that object is moving fast.
With autofocus, many SLRs allow for quickly following focus
automatically.

Ciao!

Gordon Moat
A G Studio
http://www.allgstudio.com/gallery.html Updated!

Rufio wrote:

I own a Nikon 6006 - one reason I chose it was because it has the option of
manual/single/continuous AF. Seems like a simple option & I don't understand
why some cameras DON'T have this choice. Personally, I probably wonld NOT
choose any camera that doesn't offer this.

I bought the 6006 about 10 years ago. I wanted AF because I'd had numerous
pictures out of focus using a manual focus camera (Nikon F301) , prior to
that time - my eyesight isn't so good. As the years have gone by, I've found
that I use AF less - but I still wouldn't give it up. I use manual for

Eyesight challenges are indeed a very valid reason to get AF.
However, as another poster pointed out, understanding how the AF
functions (and doesn't) is important to achieve desired focus plane.

landscapes, where I would be on infinity anyway. I also use manual for
motorsport, where AF isn't fast enough (and has a tendency to focus on the
background, behind the subject). But I still use AF alot of the rest of the

Later bodies (such as mine) do a fine job with motorsports and AF.

time, as it's one less thing to think about & I can concentrate on other
aspects of the picture - probably a good thing for a beginner to think about

While it is true that more is gained by approaching an image for
compositional value first, the technical expertise is often what
makes that composition shine. For virtually all static subjects,
AF is a hinderance, not an asset.

(not a brand-name bigotry flame - I genuinely believe they're the best
choice), my advice to anyone newbie, that asks is "get a Nikon". If I do
get a D70, I may well be using the same lenses on my D70 digital & my 30
year old Nikon FE (obviously, the AF doesn't work on the FE). I love my
NikonS.

And Nikon love you for falling into their carefully and
brillantly established marekting ploy. (Whenever you hear
someone with an F65 referring to Nikon as "what the pros use"
then you know it's a success).


So - just my opinion but - don't buy a camera that has permanent autofocus -
you gotta be able to turn it off. For me, the autofocus options are more

important, when buying a new camera, than it's metering options, for example
(you can always buy a separate light meter if you need one. But if you buy a
camera with AF always on or with no AF, you have no choice about focus).

AFAIK there are no AF SLR's where AF cannot be turned off.

Cheers,
Alan
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