Re: Request for camera advice

"Chris Tolley" <cjt.7@xxxxxxxxxxx> wrote in message
news:1qygfimjoim3a.12poon2k4uzyr.dlg@xxxxxxxxxx
Andy Kirkham wrote:

I've been taking photos with a digital compact (Canon Powershot S70)
for a couple of years and I'm generally pleased with the results, but
I'm beginning to get a bit envious of the results that some people
get with SLRs. In particular I notice that in my more long-distance
shots the trains always look rather smudged (e.g. here
http://andy-kirkham.fotopic.net/p34903229.html ), in contrast with
the halucinatory hyper-sharpness that others seem to achieve.

Digital photos often benefit from a bit of mild sharpening in whatever
picture editing software you have as a final step before posting to
the web. In the picture you linked to above, there is also the issue
that if your camera is autofocusing, what is it focused on? Autofocus
systems often work by identifying contrasty items in the focusing
area, but hat picture doesn't have much that's contrasty in the
central area.

It looks to me like the camera has auto-focused on the farm buildings in
the foreground rather than the loco. The focus point is something you
need to control manually in any pic where the auto mode might pick the
wrong point. From memory, the D40 only has three focus points, which in
this case, would probably have picked the distant rather than the closer
farm buildings, which would have made the train sharper. So, by
accident, it would probably have done a better job for you with this
pic, ironically because it has fewer focus points than your current
camera.


The other thing is that although you've wanted to capture the train in
the landscape, nevertheless, the natural tendency is to judge the
sharpness of the picture according to the way the train looks - but
because it is so relatively small, it doesn't have many pixels, so all
other things being equal, it will tend to look more blurred, even if
the picture is as sharp as it could possibly be.

So with the price of digital SLR coming down I was wondering about
getting one. My budget really only stretches to an entry-level model
and I've seen that the Nikon D40 in particular is now quite
affordable. It gets excellent reviews, but a friend of mine tells me
that the 18-55 lens that comes bundled with it isn't very good. I've
also looked at pictures on Fotopic that are tagged as being taken
with a D40 and they don't generally look any sharper than the
results from my compact.

So my specific questions are:

1. Does an entry-level SLR kit straight out of the box give any
significant improvement in picture quality over a good compact?

Not necessarily. A lot depends on the lens. What you probably can say,
though is that because an SLR tends to have more access to the various
picture-taking functions, you get more opportunities to take pictures,
and because you have to think about it a bit more, your photography
tends to improve because of that.

Some people actually report worse results when they first use a DSLR.
This is because the camera assumes you know what you're doing, and lets
you keep more control. For example, when shooting JPEGs, it's likely to
do less in-camera image processing, so by default, you'll get images
with less noise reduction and sharpening. You can either tell the camera
to do more processing if that's what you prefer, or do it yourself in
post-processing (usually the favoured approach by DSLR photographers).
If you graduate to shooting RAW you'll certainly need to do quite a bit
of post-processing.


2. Would I get significantly better results with, say, the D40 if I
bought a superior lens?

Yes, you might. I have the 18-200 VR Nikon lens, which gives image
stabilisation as well as a long zoom range. It takes pretty good pics
and isn't very expensive. And with TTL lens optical viewfinders in all
SLR cameras long lenses are feasible. Most fixed lens cameras with long
zooms don't have optical view finders.

One other minor point -- I much prefer zooming with a ring on the lens,
rather than electronically, as happens with most compact cameras.


If all other things are equal, then you can expect to get better
results from more expensive lenses. The trouble is that all other
things are rarely equal.

You may find that you are paying for a wider maximum aperture. That in
turn will allow you either to stop down (most lenses give best results
one or two stops down from their maximum aperture) or else to use
faster shutter speeds. Both of those will tend to give you
better-looking pictures, if you are after freezing the action.

Back in the day, it was generally true that fixed-focal-length lenses
gave noticeably better results than zooms/varifocals, but the gap is
narrower now.

3. I understand that one the keys to picture quality is the sensor,
and that the ones in SLRs are better than those in compacts. I
wonder if there are any cameras that offer a "third way" with a
SLR-quality sensor but without the ability to exchange lenses (which
doesn't particularly bother me)?

I don't think there are any APS sized sensors (the normal DSLR size) in
fixed lens cameras. Some of the more expensive (and larger) DSLRs have
full 35mm sensors, but these are aimed more at professionals.


It's fairer to say that sensors improve over time. Compacts are being
produced today with "better" sensors than those in SLRs from a couple
of years back. It's a constant process of improvement by small
refinement.

SLRs tend to have bigger sensors than compacts, which gives you more
pixels, which gives you more creative options (you can crop more
easily, for example). They also tend to support RAW picture format,
which, if you want to invest the time in learning how to use it,
means you can have greater control over the dynamic range in the
pictures (more detail in the shadows etc.)

The much larger SLR sensors also tend to have a significantly better
signal to noise ratio, which translates into delivering clean higher ISO
shots. I can take very good quality 400 ISO or usable 800 ISO shots with
my Nikon D70 (which is an uncle of the D40) whereas I get a lot of noise
in 400 ISO shots taken with pocket cameras. The D40 has a similar but
newer (ie, improved) sensor compared to the D70, so should be better
still.


SLRs also tend to allow you to take more pictures in a burst (indeed
the one I use, a Sony Alpha100, will do a burst or over a dozen RAW
images or almost limitless jpegs at 3 per second.) This is quite an
important consideration if you like taking pictures of *moving*
trains.

They also have a very fast start-up time -- switch on the camera and
it's instantly ready to shoot. Most compacts (even the new ones) have a
noticeable delay at start-up and between shots.


.

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