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Robert Beacon said:
This is the basis of my
gripe about certain posters who seem hellbent on discouraging
others from buying the camera.I am not suggesting that they are
deliberatley doing it, but they should learn to use it before
commenting on the possible drawbacks that they imagine If a lot of
people are getting good images from the camera surely then there is
nothing wrong with the autofocus As another poster points out it is
NOT helpfull to keep comparing the G2 to film based SLR'S.
Click to expand...
Your statements seem a bit presumtuous. Why isn't it helpful to compare the G2 to film-based SLR's? As I said in my previous post, some of us are moving from film-based to digital, and such comparison would be a useful reference point to know the pros/cons of the G2 so that we can adjust our expectations and use accordingly. For those with no serious experience or knowledge using film-based SLRs, one can see how such comparison would be of no help, and they can ignore the post As to the individual agendas of people posting to this board, I would think most of us are intelligent enough to decide for ourselves whether a particular poster is helpful or not. Rather than try to shut people up, I would prefer to hear and filter their gripes myself.
 
GKL- would you please expound on your comment about maximum sharpness at f4/5.6? Thanks--

--
Eric
http://www.pbase.com/haglunde
gkl said:
1) The G2 is selling very well, and the forum is very active.

2) Canon undersharpens images in camera compared to others -
sharpening is best done in post processing.

3) The G2 max aperture is f2, which gives a softer image and
narrower depth of field. Other digicams are often f2.8 or f4, which
is sharper and has greater depth of field - it's easier to focus.

4) The G2 A, P and Tv modes with flash default to f2, which is
softer - for sharper flash pictures you need to use Av mode (but
watch out for underexposure).

There lots of complaints about G2 softness with f2 and f8 apertures
  • maximum sharpness for the G2 lens occurs at f4/5.6. The f2/8
softness sometimes gets mistaken for a focus problem, particularly
when pics are viewed at 100% on a monitor - this usually works out
to a huge 24 inch to 36 inch image size - far too big for a 4MP
camera.

So why does a 1 or 2 Meg digicam look like it focuses better? It
probaby takes most pictures around f4. It focuses faster because
the depth of field is greater and there are fewer focus zones.

Re Gary's question, I don't think more MP cause a problem with AF.
E.g. the G1 with 3 MP had more frequent focus problems than the 4MP
G2. Vertical contrasty lines and edges in the image are what the
algorithm needs to focus. The algorithm will look for changes in
neighbouring pixels.
Hope this helps, GKL
gary ng said:
ddbailie said:
I'm still new to the G2 and have not gotten all the tricks down for
acheiving the perfect focus most of the time. It is obvious this
is a great camera, but would there be so many complaints if it
didn't have some limitations with the focus system? There are
obviously tricks that you have to learn. You don't see near the
number of focus complaints on Sony's forum or Nikon's forum.
Perhaps Canon's focus algorithm does need a bit of work.

I have used a 1 Meg Kodak digital cam for many years and hardly
ever had problems with the focus unless it was in low light
conditions. Grated that camera has many other limitations, and
that is percisely why I've upgrade to the G2. I'm not ready to
take my G2 back, but if I take side by side pictures with my Kodak
and G2, the Kodak will focus faster (and more accurately in the
majority of brightly lit shots). Is this a difference between 1
Meg and 4 Meg?
Click to expand...
Click to expand...
Click to expand...
 
Eric Haglund said:
GKL- would you please expound on your comment about maximum
sharpness at f4/5.6? Thanks--
Click to expand...
As a rule of thumb, decent lenses reach their optimum sharpness at 2 to 3 stops below their largest aperture. For the G2 this is f4 to f 5.6. Why isn't f8 even sharper? Well the aperture on this small lens is tiny enough to introduce notieceable diffraction effects from the diaphragm, which also decreases sharpness. This is one reason why there is no f11 on the G2 or similar digicams. Why do I say "decent" lenses? Cheap lenses only have a small maximum aperture (and only a couple of fstops), to save glass (or plastic).

Other useful optical rules of thumb:

Lens sharpness is higher in the center of the image than at the edge.

Wide-range zooms (e.g. 10X) represent a design tradeoff. Usually they are optimized for mid-range focal lengths, and tele performance suffers the most.

cheers, GKL
 
Robert Beacon said:
Is it not about time this forum put the issue of focusing with the
G2 "to bed" The camera is perfectly capable of taking properly
exposed & focused images (unless defective) if used properly. The
problems are USER INEXPERIENCE. A simple search will produce happy
users of the camera. They all can't be wrong. Learning photography
in general as well as the camera's different modes are a MUST. I
speak as someone who has taken over 2000 images without any
problems I wonder how many would be purchasers have been put of by
the misleading posts in the past?
Click to expand...
--

I agree, I have a G1 & Pro90. I seldom get an oof picture. When I do, I dont blame the camera. I just delete & try again.
 
Brian Schneider said:
Robert Beacon said:
Is it not about time this forum put the issue of focusing with the
G2 "to bed" The camera is perfectly capable of taking properly
exposed & focused images (unless defective) if used properly. The
problems are USER INEXPERIENCE. A simple search will produce happy
users of the camera. They all can't be wrong. Learning photography
in general as well as the camera's different modes are a MUST. I
speak as someone who has taken over 2000 images without any
problems I wonder how many would be purchasers have been put of by
the misleading posts in the past?
Click to expand...
--
I agree, I have a G1 & Pro90. I seldom get an oof picture. When I
do, I dont blame the camera. I just delete & try again.
Click to expand...
One of the reasons that different posters disagree about the autofocus is that they use different settings from each other Eg some use continuous other use single (probably best) Spot AE point Af point (probably best) instead of center Some use P mode and never manual or shutter priority or aperature priority What is really needed is an experienced and well respected digital photographer to use the camera and give his/her unbiased opinion The reviewers from magazines probably don't have the camera long enough in ther possesion to give a definitive answer
 
Thanks for that, very informative. Seems there's always some tradeoff. I try to use f8 or 7.x to increase my depth of field when there is enough light. But of course, motion becomes an issue then. Would you recommend using or trying the f4/5.6 on landscapes or when might I actually want to dial in Av at that range? Thanks--

--
Eric
http://www.pbase.com/haglunde
gkl said:
Eric Haglund said:
GKL- would you please expound on your comment about maximum
sharpness at f4/5.6? Thanks--
Click to expand...
As a rule of thumb, decent lenses reach their optimum sharpness at
2 to 3 stops below their largest aperture. For the G2 this is f4 to
f 5.6. Why isn't f8 even sharper? Well the aperture on this small
lens is tiny enough to introduce notieceable diffraction effects
from the diaphragm, which also decreases sharpness. This is one
reason why there is no f11 on the G2 or similar digicams. Why do I
say "decent" lenses? Cheap lenses only have a small maximum
aperture (and only a couple of fstops), to save glass (or plastic).

Other useful optical rules of thumb:

Lens sharpness is higher in the center of the image than at the edge.

Wide-range zooms (e.g. 10X) represent a design tradeoff. Usually
they are optimized for mid-range focal lengths, and tele
performance suffers the most.

cheers, GKL
Click to expand...
 
Eric Haglund said:
Thanks for that, very informative. Seems there's always some
tradeoff. I try to use f8 or 7.x to increase my depth of field when
there is enough light. But of course, motion becomes an issue then.
Would you recommend using or trying the f4/5.6 on landscapes or
when might I actually want to dial in Av at that range? Thanks--
Click to expand...
I frequently shoot landscapes at f4 - f 5.6 and the G2 Landscape mode uses f 5.6. If you are worried about depth of field, remember the G2 has a 7 to 21 mm lens - the depth of field is much greater than for the equivalent 35mm focal lengths. GKL
 
Mike

I think it was you who wrote that you felt that the linear polarizer was a source of focus problems despite many forceful comments that a linear polarizer was fine for the G2 (or other camera). I never researched further whether this discussion went somewhere so I'd like to follow up with you.

Do you think that there is a qualitative difference between linear and circular polarizers and that linear polarizers may be causing problems which cameras with circular polarizers avoid?
 
The problem is, the G2 has one of the worse autofocus systems ever put into a camera. It is painfully slow, and you have to babysit every shot. The G2's AF sensetivity is very poor, and it has trouble locking focus even in good light.

Most, if not all, of the G2's AF issues can be overcome by (extremely) careful use. I have never used a camera with a focus system that requires this amount of babysitting to get properly focused shots.
 
Allen Frankel said:
Mike
I think it was you who wrote that you felt that the linear
polarizer was a source of focus problems despite many forceful
comments that a linear polarizer was fine for the G2 (or other
camera). I never researched further whether this discussion went
somewhere so I'd like to follow up with you.

Do you think that there is a qualitative difference between linear
and circular polarizers and that linear polarizers may be causing
problems which cameras with circular polarizers avoid?
Click to expand...
I ain't Mike, but I can answer this. G2 AF uses contrast detection off the CCD. SLRs that require circular polarizers use a split beam (rangefinder type focus) and a linear polarizer will in many cases blank out one of the beams.
See http://www.cliffshade.com/dpfwiw/polarizer.htm for more info. GKL
 
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