Canon A590 - quality a disappointment - lemon, or typical?

Given that my (fairly beloved) Canon a630 had acquired some dirt inside its lens (no, I don't know how). I purchased a a590, and used it to take some holiday shots.

I was pretty disappointed.

This morning I took the same test shot, in the same circumstances, with both my a630 and a590.

Here is a zoom down, and a 100% crop from both images; both are saved at 95% quality in Gimp, and the zoom down was bicubic.

whole frame, a630:

http://i48.photobucket.com/albums/f2..._tech/6302.jpg

100% Crop, a630:

http://i48.photobucket.com/albums/f2...h/6302crop.jpg

whole frame, a590:

http://i48.photobucket.com/albums/f2..._tech/5902.jpg

100% Crop, a590:

http://i48.photobucket.com/albums/f2...h/5902crop.jpg

Now, I can't quite put a technical description to what's happened, but at the observational level, the a590 shots are
a good deal softer, verging on blurred, and the colours (especially in the roof tiles in the 100% crop) are less well shown.

My particular a590 is clearly less good than my particular a630. What I need to know is:

Do I have a duff a590 (which needs returning to the retailer), or is my a630 an unfair basis for comparison?

I don't have multiple spare a590s for comparison - but I'm hoping denizens here can help me out.

Comments keenly appreciated (except the ones "saying get a DSLR")

BugBear

bugbear wrote:
Given that my (fairly beloved) Canon a630 had acquired some dirt inside its lens (no, I don't know how). I purchased a a590, and used it to take some holiday shots.

I was pretty disappointed.

This morning I took the same test shot, in the same circumstances, with both my a630 and a590.

Here is a zoom down, and a 100% crop from both images; both are saved at 95% quality in Gimp, and the zoom down was bicubic.

whole frame, a630:

http://i48.photobucket.com/albums/f2..._tech/6302.jpg

100% Crop, a630:

http://i48.photobucket.com/albums/f2...h/6302crop.jpg

whole frame, a590:

http://i48.photobucket.com/albums/f2..._tech/5902.jpg

100% Crop, a590:

http://i48.photobucket.com/albums/f2...h/5902crop.jpg

Now, I can't quite put a technical description to what's happened, but at the observational level, the a590 shots are
a good deal softer, verging on blurred, and the colours (especially in the roof tiles in the 100% crop) are less well shown.

My particular a590 is clearly less good than my particular a630. What I need to know is:

Do I have a duff a590 (which needs returning to the retailer), or is my a630 an unfair basis for comparison?

I have two cameras with the same kind of differences between their
out-of-the-box ex-camera jpegs as that. Some minor adjustment to the
jpeg mode parameters in the apparently worse camera (vividness,
sharpness, etc.) makes it apparently the better camera.

--
Chris Malcolm

Chris Malcolm wrote:

Do I have a duff a590 (which needs returning to the retailer), or is my a630 an unfair basis for comparison?

I have two cameras with the same kind of differences between their
out-of-the-box ex-camera jpegs as that. Some minor adjustment to the
jpeg mode parameters in the apparently worse camera (vividness,
sharpness, etc.) makes it apparently the better camera.

I note your use of the word "apparently"; I would (genuinely)
welcome any advice on working out if I have an "actual"
problem, as opposed to an apparent one.

Certainly, in regard to my (irreplacable) holiday
photos, I am already experimenting with increasing saturation,
altering the exposure curves (even using enfuse to blend multiple
exposure mapped photos), and post sharpening.

But I don't want to HAVE to do this (especially
on 600 photos!)

BugBear

On Tue, 19 May 2009 12:27:04 +0100, bugbear wrote:

I note your use of the word "apparently"; I would (genuinely)
welcome any advice on working out if I have an "actual"
problem, as opposed to an apparent one.

Do some tests. The A590 is a pretty nice camera, but it's not
rare for Canons (even some of their DSLRs) to have sensors that
aren't properly positioned or have other alignment problems. It
should produce pictures competitive with the A630 unless the light
is low, and then it will also focus more slowly and less accurately.

Now that I've looked at your images, I don't think that your A590
is performing below par. Speaking of low light, unlike you, I see
little difference between the crops as far as detail goes except for
the darker area of the tiles. There, it doesn't even seem that the
A590 is lacking detail so much as the color is muddier, which helps
to give the appearance of reduced sharpness. But the A590 uses a
much smaller 1/2.5" sensor compared with the A630's 1/1.8" sensor.
Both are 8mp sensors, so it would be reasonable to assume that the
A630's larger pixels do better because they'd have a better dynamic
range, which would allow it to perform better than the A590 in the
darker shadow regions. In other words, if you gave both cameras
+2.0 exposure compensation (probably blowing highlights and
whitening the blue sky), the A590 would probably put in a better,
similar showing in the shadowy tile areas.

Put the A630's images side by side with those from larger sensor
P&S cameras (such as Panasonic's LX3, Fuji's F100fs, and S100fs) and
the A630's images will also appear worse in the shadow areas. In
other words . . .

My particular a590 is clearly less good than my particular a630.
What I need to know is:

Do I have a duff a590 (which needs returning to the retailer), or
is my a630 an unfair basis for comparison?

By its nature, the A630 is a better camera than the A590, but both
are very good for their class, and your A590 is being unfairly
compared. Keep the A590. I don't think a replacement would perform
any better. If your tests showed similar results from both cameras,
I'd worry about what might be wrong with your A630.

bugbear wrote:

Do I have a duff a590 (which needs returning to the retailer), or is my
a630 an unfair basis for comparison?

I don't have multiple spare a590s for comparison - but I'm hoping
denizens here can help me out.

Comments keenly appreciated (except the ones "saying get a DSLR")

See if the retailer has any A570s left. The A590 is rather
disappointing. The increase in pixel density from the A570 seems to have
gone right across the line from good to mediocre, even though the
increase was only from 7.1MP to 8MP. Maybe it has to do with the OIS,
since the A630 is 8 MP and is fine. I ran out and bought a second A570
before they were discontinued.

Since it's the same engine (A570 versus A590), but with a higher density
sensor, there were other compromises as well, i.e. the video frame rate
went from 30 fps on the A570 to 20 fps on the A590, because the CPU
couldn't keep up with the higher density sensor. Low light performance
is better on the A570 as well, though "better" is relative since all
small sensor cameras have pretty crappy low light performance.

Consider the Panasonic Lumix DMC-G1. It's not a D-SLR, but it has many
of the advantages of a D-SLR, including the same size sensor used on the
4:3 D-SLRs (small for a D-SLR, but huge for a P&S).

Chris Malcolm wrote:
bugbear wrote:
Given that my (fairly beloved) Canon a630 had acquired some dirt inside its lens (no, I don't know how). I purchased a a590, and used it to take some holiday shots.

I was pretty disappointed.

I have two cameras with the same kind of differences between their
out-of-the-box ex-camera jpegs as that. Some minor adjustment to the
jpeg mode parameters in the apparently worse camera (vividness,
sharpness, etc.) makes it apparently the better camera.


I have just found (with help
http://www.impulseadventure.com/photo/jpeg-snoop.html)
that the two camera are using the same JPEG compression (quantization)
factors (both are at what Canon call "SuperFine").

It looks like Canon have been using the same number for ages.

This page:

http://www.impulseadventure.com/phot...ntization.html

shows the Canon G3's JPEG tables to be the same
as my A640 and A590.

One more potential difference eliminated.

BugBear

SMS wrote:
Maybe it has to do with the OIS,
since the A630 is 8 MP and is fine.

Since I was shooting from a (overkill, Benbo mk 1 !!)
tripod, I had disabled IS, so I don't think
that's "the smoking gun"

Actually, I'm rather impressed by the IS, getting a crisp(ish)
photo of some chair joinery in the dark foyer
of a hotel, at 1/4 second hand held.

BugBear

On Tue, 19 May 2009 06:48:24 -0700, SMS wrote:

See if the retailer has any A570s left. The A590 is rather
disappointing. The increase in pixel density from the A570 seems to have
gone right across the line from good to mediocre, even though the
increase was only from 7.1MP to 8MP. Maybe it has to do with the OIS,
since the A630 is 8 MP and is fine. I ran out and bought a second A570
before they were discontinued.

Ah yes. After trolling the newsgroups for almost half a year,
telling us how terrible the A570 is because your female relative
that borrowed your A570 claimed that battery life was terrible. You
repeatedly stated that fresh alkalines were only good for dozen or
so shots and that you'd check into it when the camera was returned.
I'll bet that your female relative bought cheap counterfeit "heavy
duty" batteries labeled to look like alkalines. You never retracted
any of what must have been a dozen to two dozen of these bogus
statements in the newsgroup, when Canon's manual (and personal
testing) showed that the A570 was good for up to 400 shots from each
pair of AA alkalines and up to 900 shots from a pair of AA NiMH
batteries. About 1/2 that number if the LCD display is used instead
of the optical viewfinder. Is that female relative of yours hiding
in an undisclosed location?

Anyone without your well known anti-AA battery agenda would have
known better than to make such rash, improbable statements tarring
all A570s, and would have assumed that either bad batteries or a
defective camera was responsible. You, on the other hand stayed
true to form, spouting absurd nonsense. Canon says up to 400 shots.
You said no more than 20. In fact, your illogical bogus statement
still hasn't been removed from your vanity battery website :

I didn't realize just how bad alkaline batteries were until I lent
an AA powered camera (Canon A570IS) to a relative that tried
to use alkaline AA batteries while on a cruise. She reported getting
about ten pictures per set of batteries. When I inquired if this was
normal on rec.photo.digital I got a slew of responses and every one
of them reported similar results with alkaline batteries.

http://batterydata.com/

And of course the claim that "every one of them reported similar
results" is either an outright fabrication or you can't separate
delusion from reality. If the camera went through batteries that
quickly, nobody in their right mind would have bought a second, but
many have done so, and now, according to your reply, so did you.

More interesting SMS info that a quick google search turned up :


http://newsgroups.derkeiler.com/Arch.../msg01459.html

bugbear wrote:
Given that my (fairly beloved) Canon a630 had acquired some dirt inside
its lens (no, I don't know how). I purchased a a590, and used it to take
some holiday shots.

I was pretty disappointed.

This morning I took the same test shot, in the same circumstances, with
both my a630 and a590.

Here is a zoom down, and a 100% crop from both images; both are saved at
95% quality in Gimp, and the zoom down was bicubic.

whole frame, a630:

http://i48.photobucket.com/albums/f2..._tech/6302.jpg

100% Crop, a630:

http://i48.photobucket.com/albums/f2...h/6302crop.jpg

whole frame, a590:

http://i48.photobucket.com/albums/f2..._tech/5902.jpg

100% Crop, a590:

http://i48.photobucket.com/albums/f2...h/5902crop.jpg

Now, I can't quite put a technical description to what's happened, but
at the observational level, the a590 shots are
a good deal softer, verging on blurred, and the colours (especially in
the roof tiles in the 100% crop) are less well shown.

Noodling around with Gimp, I have discovered that the tonal range
in the tiles is about 30% greater in the A630 shot; I'm now trying to work
out if this is a sensor issue, or a processing sensor-jpeg in the camera issue.

I may have to use CHDK/Raw mode to answer that question (sigh)

BugBear

"bugbear" wrote in message
news
Given that my (fairly beloved) Canon a630 had acquired some dirt inside
its lens (no, I don't know how). I purchased a a590, and used it to take
some holiday shots.

I was pretty disappointed.

This morning I took the same test shot, in the same circumstances, with
both my a630 and a590.

Here is a zoom down, and a 100% crop from both images; both are saved at
95% quality in Gimp, and the zoom down was bicubic.

whole frame, a630:

http://i48.photobucket.com/albums/f2..._tech/6302.jpg

100% Crop, a630:

http://i48.photobucket.com/albums/f2...h/6302crop.jpg

whole frame, a590:

http://i48.photobucket.com/albums/f2..._tech/5902.jpg

100% Crop, a590:

http://i48.photobucket.com/albums/f2...h/5902crop.jpg

Now, I can't quite put a technical description to what's happened, but at
the observational level, the a590 shots are
a good deal softer, verging on blurred, and the colours (especially in the
roof tiles in the 100% crop) are less well shown.

My particular a590 is clearly less good than my particular a630. What I
need to know is:

Do I have a duff a590 (which needs returning to the retailer), or is my
a630 an unfair basis for comparison?

I don't have multiple spare a590s for comparison - but I'm hoping denizens
here can help me out.

Comments keenly appreciated (except the ones "saying get a DSLR")

BugBear

The photos look ok for a cheap compact, which is what the a590 & a630 are.