What compact digicam has the biggest CCD pixels?

Pixel size = CCD size in square microns, divided by total number of pixels.

Nikon D70: CCD = 15 x 22 mm = 330 million sq. microns, divided by 6 MP =
about 50 square microns per pixel, pretty good.

Random compact point and shoot: CCD = 6 x 8 mm = 48 million sq. microns,
divided by 4 mp = 12 square microns per pixel, much noisier.

What I want is a compact P/S with a good 6x8 mm sensor and about 1 MP
-- do they still make those?

 

You could get lucky, but I'd say that marketing has dictated that
manufacturers need to cram in as many megapixels as possible in order
to be attractive. Ask any consumer salesperson how to improve image
quality and the answer is inevitably going to be "get the model with
more megapixels." A newly released 1 megapixel compact would
effectively be considered obsolete...

 

The Olympus C3030 has a "half inch" sensor 4:3 ratio (12.7x9.5mm?)
sensor with effective 3.14MP. It cost $800 in the year 2000.

120sq mm (120 million sq. microns?)/3.14MP = 38 square microns per pixel.

It does show purple fringing in backlit trees pretty bad and banding
with long night exposures but with a decent f/2.8 lens it does pretty
well in most lighting. ISO 100 to 400. I can say that when I got a D70
after this I was amazed how much information I could pull out of shadows
compared to the Oly 3030. I haven't compared other P&S's to it.

True but there must be some significant variation in the ratio for
different models. I've not seen such a chart comparing square microns
pixel size (12 to 50+).

Here's the closest I've seen:
http://homepages.ihug.com.au/~parsog/photo/sensors1.html
Unfortunately they don't tell megapixels.

 

Nah, that "half inch" has somewhat less sensor area than that, like
half that amount. "Half inch" refers to the diameter of vidicon tube
from the tube era that would have had a similar amount of active
imaging area. Good point about the old Olympus though.

 

ehhh that's why I put it in quotes <grin>.
I don't know, I'd like to see a chart.

 

All you need to do is ask:

http://www.dpreview.com/learn/?/key=Sensor_Sizes

 

So what does it mean when they state a sensor's size as
"1/1.8-inch CCD" ?

 

Forget about the theoretical math. Sensors aren't that good yet.
Factors like production quality, chip design, manufacturing process, and
image processing still dominate the image quality. Read the reviews,
check out some sample pictures, and then try some out.

Your specifications of a good 1MP camera is contradictory. The lack of
resolution would ruin many photos.

 

I don't believe that; for pictorial photos, megapixels are way
overrated. The 2.7MP Nikon D1 still makes better photos than any
compact 5 or 8 megapixel camera. I woke up to megapixel hype when I
saw a 16x20" or so poster print that someone was carrying around in
the street. From 5 feet away it looked great. From up close it
looked soft, but I thought that was because of the printer. I asked
what kind of camera it had been taken with. The answer was it had
been taken with a 320x240 web cam. For a while my only digicam was an
0.75 MP Canon A5 and I felt the photos it took were fine. (It helps
that I don't care about prints very much, and mainly want to view on
screen).

1MP sensors are capable of making 8x10" prints that look as good as
decent 35mm prints (use bicubic interpolation yada yada). The 6.2MP
D70 gets sort of acceptable noise performance for low light shooting
at 1600 ISO. Let's see if this makes sense: the D70 throws away two
thirds of the incoming photons in the RGB filters in front of the
sensor, so a monochrome version could do 4800 ISO. Now lower the
resolution to 1MP (6x the sensor area per pixel) and you're up to
30,000 ISO. With a fast lens (I have a 30 year old 35/1.4 MF Nikkor
that was $200 on Ebay a couple years ago and is now probably worth
almost zilch) you should be able to get good printable monochrome
shots with no flash even in the worst indoor lighting like dimly lit
bars. That's the total fix to red-eye ;-).

 

OK so the Oly 1/1.8-inch CCD=
7.15x5.32mm = 38sq mm (38 million sq. microns)
/3.14MP = 12 square microns per pixel.

The examples on that page come out to 6.4 to 7.6sq microns/px so that's
pretty good but not the 60-76sq microns/px of a DSLR.

 

Downsample an underexposed/corrected 6MP image to 1MP in that lighting
and it might look good?

 

You may be asking the wrong question. Sensor size itself may be more
important than pixel size, as you can downsample to reduce the number of
pixels. Bigger sensors can capture more photons, and produce a better
signal-to-noise ratio. However, as the pixels get smaller, they fraction
of their area which captures light may decrease.

Given all of the above, the 2/3 inch sensor (8.8 x 6.6mm) is perhaps the
largest compact camera sensor, and can be found in the Nikon 5700 (5MP)
and Nikon 8400 and 880 (8MP) cameras.

Cheers,
David

 

[A complimentary Cc of this posting was sent to
Paul Rubin

What for? To save space on your flash card? Do not be ridiculous.

Given an 8MP camera and 1MP camera with the same sensor size, the same
percentage of area which is photo-sensitive, and the same QE, the 8MP
image contains *strictly* more information than 1MP camera. If you
want to extract the 1MP information from 8MP image, just average over
8 cells.

Hope this helps,
Ilya

P.S. Of course, it may be that 8MP camera has slightly lower
percentage of photo-sensitive area (due to non-0 amount of "additional
circuitry"). However, the cameras of '05 should have higher QE than
those of '00.

 

I've been wondering about that and I think some improvement might
result, but you don't get the whole factor of six. For example,
almost all consumer video cameras these days have megapixel sensors so
they can double as still cameras. As a result, they have worse low
light performance at normal video resolution (720x480) than the
previous generation of camcorders which only had video resolution
sensors.

 

Given what I see happening in video camcorders (low light performance
at (fixed) video resolution gets worse and worse as they increase the
number of pixels on the ccd), I don't think that averaging approach
works as well as it might sound.

Obviously then the answer is a camera made in '05 that still has nice
big pixels.

The other thing missing is a monochrome digicam less exotic than the
Kodak DCS-660M.

 

I'm not sure. I think it's the pixel size that overloads when too small.

OK I started a chart:
<http://www.edgehill.net/1/Misc/photography/sensors/excel/sensor-size.htm>
That shows the Nikon 5700 2/3 @ 5MP as 11.6sq microns/px
It is an excel chart saved as html & can be opened with excel.

7.3sq microns/px

 

Modern cameras like the Canon 20D, 300D, and 350D have far less noise
than lower resolution cameras of not long ago. Like I said before, it's
more about the sensor quality. The older CCD chips grabbed lots of
light but they leaked electricity rapidly, bloomed, and the quality from
pixel to pixel was terrible. My Canon 350D has less noise at ISO 800
than my Oly C2000Z, C3030Z, and C4040Z had at ISO 100. When using the
higher pixel count for noise filtering, the Canon 350D is cleaner at ISO
1600 than the Olys were at ISO 100. CCDs are also prone to overheating.
45 minute exposures with my Canon 350D have less noise than 8 second
exposures from older CCD sensors.

Maybe you want an astronomy grade sensor.

 

[snip]

You can do 45 minute minute exposures? If so, this means these
cameras are like real film cameras. I have a feeling that next years
bonus and tax refund have just been spoken for.

Heading off to dpreview to read the specs.

Wes

 

All newer good quality digital cameras are photon + read noise
limited. Further improvements will be very slight, in the sense
that the only things left to improve are: lower read noise
(will affect shadows, no brighter parts of the image),
quantum efficiency, and higher optical transmission
throughput (total =perhaps a 2x gain here). All this will
help large as well as small sensors, so the large sensor
camera will always produce better images. See:

http://www.clarkvision.com/imagedetail/does.pixel.size.matter

Roger

 

It's a scam to fool you from knowing how small it really
is! See:
http://www.dpreview.com/learn/?/Glossary/Camera_System/Sensor_Sizes_01.htm

Roger