Seriously: What is going on with Contax Exposure/Noise

it occured to me that the exposure problem, i.e. two stops underexposure, and noise problem could be linked. Maybe the noise is caused in part by trying to bring up an underexposed image. Maybe there is a software glitch that is just one fix away from solving both problems. Wouldn't that be funny? They would have to upgrade the top ISO back to 1600. Hey, maybe I should try to buy one of these cameras off a dissappointed owner before the fix........
Anyone willing to sell for $2,500 cash? --
TJ

The first part was serious. Forget the $2,500 offer. But......

tom jacobson said:

it occured to me that the exposure problem, i.e. two stops
underexposure, and noise problem could be linked. Maybe the noise
is caused in part by trying to bring up an underexposed image.
Maybe there is a software glitch that is just one fix away from
solving both problems. Wouldn't that be funny? They would have to
upgrade the top ISO back to 1600. Hey, maybe I should try to buy
one of these cameras off a dissappointed owner before the
fix........
Anyone willing to sell for $2,500 cash? --
TJ

Click to expand...

--
TJ

There seems to be an inordinate amount of speculation in comparison to the actual number of images posted - and to the information supplied with those images.

I love Contax and have been using them for years - I hope that the N-Digital isn't the flop that some are predicting - I use a 645 and a digital back - if nothing else a good release from Contax would bring the price of the Pro backs down a little.

Currently I also use a D30 - and have done some great corporate work with it. A marriage of the D30 and 1D could produce something truly magical.

Cheers, Ivan

tom jacobson said:

it occured to me that the exposure problem, i.e. two stops
underexposure, and noise problem could be linked. Maybe the noise
is caused in part by trying to bring up an underexposed image.
Maybe there is a software glitch that is just one fix away from
solving both problems. Wouldn't that be funny? They would have to
upgrade the top ISO back to 1600. Hey, maybe I should try to buy
one of these cameras off a dissappointed owner before the
fix........
Anyone willing to sell for $2,500 cash? --
TJ

Click to expand...

--

I believe Contax problems (delayed delivery, low ISO etc.) comes from the use of immature technology. A CCD-chip of the size and resolution (at the same time) they aimed for was simply not ready for prime time.

It seems that the (analogue) signal they get out from the chip is too low and too noisy. This means that they have to amplify it heavily, thus introducing new noise (amplifiers are noisy!) and amplifying the noise already there. No firmware change can change this fundamental issue. This probable root cause is also consistent with the late lowering of the ISO. Electronically the lowered ISO simply means that they lowered the upper limit of the amplification. Some noise reduction is possible digitally but not that much without destroying something else.

Remember that a CCD is basically an analogue device. The charge collected in each cell is proportional to the number of photons hitting it. This signal, and it is a very low signal, is then, by way of an analogue amplifier, fed to an analogue/digital converter. The digital output is the processed (white balanced etc.) before being stored in memory.

HansB

Hans,

This sensor was used at previously in a digital back with great success at ISO 100. Surely they tested the sensor to see what they could get out of it before committing to the use of it. Something went wrong. I am saying it could be a firmware problem, and the firmware glitch could be effecting both the exposure and sensing system. This all said by someone who knows nothing of the details of such things (me). TJ

HansB said:

tom jacobson said:

it occured to me that the exposure problem, i.e. two stops
underexposure, and noise problem could be linked. Maybe the noise
is caused in part by trying to bring up an underexposed image.
Maybe there is a software glitch that is just one fix away from
solving both problems. Wouldn't that be funny? They would have to
upgrade the top ISO back to 1600. Hey, maybe I should try to buy
one of these cameras off a dissappointed owner before the
fix........
Anyone willing to sell for $2,500 cash? --
TJ

Click to expand...

--
I believe Contax problems (delayed delivery, low ISO etc.) comes
from the use of immature technology. A CCD-chip of the size and
resolution (at the same time) they aimed for was simply not ready
for prime time.

It seems that the (analogue) signal they get out from the chip is
too low and too noisy. This means that they have to amplify it
heavily, thus introducing new noise (amplifiers are noisy!) and
amplifying the noise already there. No firmware change can change
this fundamental issue. This probable root cause is also consistent
with the late lowering of the ISO. Electronically the lowered ISO
simply means that they lowered the upper limit of the
amplification. Some noise reduction is possible digitally but not
that much without destroying something else.

Remember that a CCD is basically an analogue device. The charge
collected in each cell is proportional to the number of photons
hitting it. This signal, and it is a very low signal, is then, by
way of an analogue amplifier, fed to an analogue/digital converter.
The digital output is the processed (white balanced etc.) before
being stored in memory.

HansB

Click to expand...

HansB said:

I believe Contax problems (delayed delivery, low ISO etc.) comes
from the use of immature technology. A CCD-chip of the size and
resolution (at the same time) they aimed for was simply not ready
for prime time.

Click to expand...

Others have pointed out that the very same chip has been used in
MF backs for some time. But Kodak is building a chip both bigger and
higher in resolution than the Philips chip used in the Contax: the KAF-16801CE.
It's 36.7x36.7mm and 4080x4080 sensels.

It's used successfully in both Kodak's own Pro Back series and in Phase One's H20.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.

Want my idea? Contax has not enough esperience in the signal processing area. In digital backs this problem is minor: a lot of work is done by the tethered computer. It took a lot of work and experience to Nikon and Canon to develop the right algorithms, avoid blooming, treat moire and so on. The current DSLRs are second or third generation. Contax is first generation, and they pay the price.

Fabio

Interesting.

There's something telling in the data files provided by Contax - they contain the word "Megavision".

This is an older chip, so it's relatively mature in terms of hardware design. What's new is the integration with the system.

I'm speculating that they are related (and have a large number of files that provide some hints). My theory relates to power management, although the amplification angle sounds plausible (and they might be related as well).

I have a specific sequence of shots where there was absolutely no lighting change. The first shot was correctly exposed - but the other two shots progressively drop off in exposure. Just a guess, but voltage levels for image buffering and flashwriting may be 'starving' the internal meter or another part of the system related to exposure. Consider that the meter system was originally on the N1, which was film and didn't have to contend with other electronics. I've tried to reproduce this bug, but it's not consistent (and in so doing have exposed other things...).

I develop software and have developed embedded firmware in the past. Throwing meters onto hardware is pretty easy to do, tracing down application bugs, while not easy, is still rather straightforward. When you get to a systems level the interaction between hardware and software sometimes becomes strange. Often adding to the confusion is lack of documentation in your native language. It happens a lot. I once spent three weeks going crazy trying to get a Yamaha 2202 FM synthesis sound chip to work.(This was pre-Creative Labs) The docs were in Japanese and the only code samples were for older chips. I kept thinking it was a hardware issue. The hardware guy kept saying it was a software issue. I finally did an exhaustive test which I thought was nuts. Halfway through the series of tests - bing - the card played a beautiful trumpet note. I actually was doing things backwards from how the other chip worked.

Sorry about getting off track here - but the point is for all the simplicity of clicking a shutter, making this stuff easy is really hard work.

And you never know when saying something out here might lead to that aha moment for the engineers.

Chris

BTW Tom - a firmware fix seems plausible, because development usually is ahead of marketing.

tom jacobson said:

This sensor was used at previously in a digital back with great
success at ISO 100. Surely they tested the sensor to see what they
could get out of it before committing to the use of it. Something
went wrong. I am saying it could be a firmware problem, and the
firmware glitch could be effecting both the exposure and sensing
system. This all said by someone who knows nothing of the details
of such things (me). TJ

HansB said:

tom jacobson said:

it occured to me that the exposure problem, i.e. two stops
underexposure, and noise problem could be linked. Maybe the noise
is caused in part by trying to bring up an underexposed image.
Maybe there is a software glitch that is just one fix away from
solving both problems. Wouldn't that be funny? They would have to
upgrade the top ISO back to 1600. Hey, maybe I should try to buy
one of these cameras off a dissappointed owner before the
fix........
Anyone willing to sell for $2,500 cash? --
TJ

Click to expand...

--
I believe Contax problems (delayed delivery, low ISO etc.) comes
from the use of immature technology. A CCD-chip of the size and
resolution (at the same time) they aimed for was simply not ready
for prime time.

It seems that the (analogue) signal they get out from the chip is
too low and too noisy. This means that they have to amplify it
heavily, thus introducing new noise (amplifiers are noisy!) and
amplifying the noise already there. No firmware change can change
this fundamental issue. This probable root cause is also consistent
with the late lowering of the ISO. Electronically the lowered ISO
simply means that they lowered the upper limit of the
amplification. Some noise reduction is possible digitally but not
that much without destroying something else.

Remember that a CCD is basically an analogue device. The charge
collected in each cell is proportional to the number of photons
hitting it. This signal, and it is a very low signal, is then, by
way of an analogue amplifier, fed to an analogue/digital converter.
The digital output is the processed (white balanced etc.) before
being stored in memory.

HansB

Click to expand...

--

Click to expand...

Chrisat said:

There's something telling in the data files provided by Contax -
they contain the word "Megavision".

This is an older chip, so it's relatively mature in terms of
hardware design. What's new is the integration with the system.

I'm speculating that they are related (and have a large number of
files that provide some hints). My theory relates to power
management, although the amplification angle sounds plausible (and
they might be related as well).

I have a specific sequence of shots where there was absolutely no
lighting change. The first shot was correctly exposed - but the
other two shots progressively drop off in exposure. Just a guess,
but voltage levels for image buffering and flashwriting may be
'starving' the internal meter or another part of the system related
to exposure. Consider that the meter system was originally on the
N1, which was film and didn't have to contend with other
electronics. I've tried to reproduce this bug, but it's not
consistent (and in so doing have exposed other things...).

to the use of it. Something

Chris Arsenault said:

went wrong. I am saying it could be a firmware problem, and the
firmware glitch could be effecting both the exposure and sensing
system. This all said by someone who knows nothing of the details
of such things (me). TJ

Click to expand...

Click to expand...

I remember reading somewhere that at least one user of the Philips sensor has some sort of active cooling in their digital back. Perhaps the exposure problem you are describing (and some of the noise too) is related to overheating of the sensor. Does the problem seem worse when the sequence is made quickly?

Brian

Brian Slater said:

Chrisat said:

There's something telling in the data files provided by Contax -
they contain the word "Megavision".

This is an older chip, so it's relatively mature in terms of
hardware design. What's new is the integration with the system.

I'm speculating that they are related (and have a large number of
files that provide some hints). My theory relates to power
management, although the amplification angle sounds plausible (and
they might be related as well).

I have a specific sequence of shots where there was absolutely no
lighting change. The first shot was correctly exposed - but the
other two shots progressively drop off in exposure. Just a guess,
but voltage levels for image buffering and flashwriting may be
'starving' the internal meter or another part of the system related
to exposure. Consider that the meter system was originally on the
N1, which was film and didn't have to contend with other
electronics. I've tried to reproduce this bug, but it's not
consistent (and in so doing have exposed other things...).

to the use of it. Something

Brian Slater said:

went wrong. I am saying it could be a firmware problem, and the
firmware glitch could be effecting both the exposure and sensing
system. This all said by someone who knows nothing of the details
of such things (me). TJ

Click to expand...

Click to expand...

I remember reading somewhere that at least one user of the Philips
sensor has some sort of active cooling in their digital back.
Perhaps the exposure problem you are describing (and some of the
noise too) is related to overheating of the sensor. Does the
problem seem worse when the sequence is made quickly?

Click to expand...

Interesting idea, but doesn't seem to be the case. I checked times between exposures on my ISO 400 shots and there was plenty of cool time between, but no apparent drop in noise. I wasn't studying the patterns of the noise before specifically, but it seems even in the same image it's not consistent across the board. Above a particular pixel value the noise diminishes rapidly, while like at mid point and below it increases. You can see this in my ISO 400 sample. The girl's left arm around the wrist area is clean (has noise, but would be acceptable if stayed at this level across entire image), but noise increases as you get progressively darker.

Chris

Chris,

Although I do not write software and really don't much about the technical details, it seemed to me that the problems of exposure and noise might be related somehow. Have you used an independent meter, set the exposure to manual and tested a few consecutive shots? Perhaps the meter on the camera is even working perfectly, but sending the wrong signal to the shutter, or the lens. If the sensor is starved for light, the image will have to be ultra amplified, and more noise will result. Just a thought. I will be happy for you if there is a global fix for your problems with the camera. I do want it to be good - for your sake and everyone who buys one's sake. and,.... maybe some day I will buy one used!

PS> have you seen a perfectly exposed histogram on an image and looked at the noise in that image? If the exposure system somehow is out of wack, it would cause an image exposed at ISO 64 to be in fact exposed at ISO 400, for example. It is odd that we have a two stop drop in top ISO also associated with a two or three stop underexposure problem. That seems related.

TJ

Chrisat said:

Brian Slater said:

Chrisat said:

There's something telling in the data files provided by Contax -
they contain the word "Megavision".

This is an older chip, so it's relatively mature in terms of
hardware design. What's new is the integration with the system.

I'm speculating that they are related (and have a large number of
files that provide some hints). My theory relates to power
management, although the amplification angle sounds plausible (and
they might be related as well).

I have a specific sequence of shots where there was absolutely no
lighting change. The first shot was correctly exposed - but the
other two shots progressively drop off in exposure. Just a guess,
but voltage levels for image buffering and flashwriting may be
'starving' the internal meter or another part of the system related
to exposure. Consider that the meter system was originally on the
N1, which was film and didn't have to contend with other
electronics. I've tried to reproduce this bug, but it's not
consistent (and in so doing have exposed other things...).

to the use of it. Something

Chris Arsenault said:

went wrong. I am saying it could be a firmware problem, and the
firmware glitch could be effecting both the exposure and sensing
system. This all said by someone who knows nothing of the details
of such things (me). TJ

Click to expand...

Click to expand...

I remember reading somewhere that at least one user of the Philips
sensor has some sort of active cooling in their digital back.
Perhaps the exposure problem you are describing (and some of the
noise too) is related to overheating of the sensor. Does the
problem seem worse when the sequence is made quickly?

Click to expand...

Interesting idea, but doesn't seem to be the case. I checked times
between exposures on my ISO 400 shots and there was plenty of cool
time between, but no apparent drop in noise. I wasn't studying the
patterns of the noise before specifically, but it seems even in the
same image it's not consistent across the board. Above a
particular pixel value the noise diminishes rapidly, while like at
mid point and below it increases. You can see this in my ISO 400
sample. The girl's left arm around the wrist area is clean (has
noise, but would be acceptable if stayed at this level across
entire image), but noise increases as you get progressively darker.

Chris

Click to expand...

--
TJ

If there is an underexposure problem this should only have an effect on relatively full scale subjects.

For short scale subjects shot under dull even lighting (say an overcast day) the subject brightness scale might only be 2 1/2 -3 1/2 stops.

You should be able to shoot such as subject at say +2 stop over or -3 stops under without getting either an overexposed or underexposed result
as there should be sufficient dynamic range available.

tom jacobson said:

PS> have you seen a perfectly exposed histogram on an image and
looked at the noise in that image? If the exposure system somehow
is out of wack, it would cause an image exposed at ISO 64 to be in
fact exposed at ISO 400, for example. It is odd that we have a two
stop drop in top ISO also associated with a two or three stop
underexposure problem. That seems related.

TJ

Chrisat said:

Brian Slater said:

Chrisat said:

There's something telling in the data files provided by Contax -
they contain the word "Megavision".

This is an older chip, so it's relatively mature in terms of
hardware design. What's new is the integration with the system.

I'm speculating that they are related (and have a large number of
files that provide some hints). My theory relates to power
management, although the amplification angle sounds plausible (and
they might be related as well).

I have a specific sequence of shots where there was absolutely no
lighting change. The first shot was correctly exposed - but the
other two shots progressively drop off in exposure. Just a guess,
but voltage levels for image buffering and flashwriting may be
'starving' the internal meter or another part of the system related
to exposure. Consider that the meter system was originally on the
N1, which was film and didn't have to contend with other
electronics. I've tried to reproduce this bug, but it's not
consistent (and in so doing have exposed other things...).

to the use of it. Something

tom jacobson said:

went wrong. I am saying it could be a firmware problem, and the
firmware glitch could be effecting both the exposure and sensing
system. This all said by someone who knows nothing of the details
of such things (me). TJ

Click to expand...

Click to expand...

I remember reading somewhere that at least one user of the Philips
sensor has some sort of active cooling in their digital back.
Perhaps the exposure problem you are describing (and some of the
noise too) is related to overheating of the sensor. Does the
problem seem worse when the sequence is made quickly?

Click to expand...

Interesting idea, but doesn't seem to be the case. I checked times
between exposures on my ISO 400 shots and there was plenty of cool
time between, but no apparent drop in noise. I wasn't studying the
patterns of the noise before specifically, but it seems even in the
same image it's not consistent across the board. Above a
particular pixel value the noise diminishes rapidly, while like at
mid point and below it increases. You can see this in my ISO 400
sample. The girl's left arm around the wrist area is clean (has
noise, but would be acceptable if stayed at this level across
entire image), but noise increases as you get progressively darker.

Chris

Click to expand...

--
TJ

Click to expand...

Hello Everybody

Slightly off Toms topic so let me offer my due apologies to the members. But I just thought that Pentax dropped their 6 MP camera most probably because they were having problems getting it to work exactly as they would have wished for.

Contax has gone ahead and released theirs warts and all and are bold enough to charge a hefty price despite its obvious problems. Personally I think it says something about the two companies, about how they are managed and more importantly care about their customers.

Off topic so apologies are due Tom ; )

Stephen

tom jacobson said:

it occured to me that the exposure problem, i.e. two stops
underexposure, and noise problem could be linked. Maybe the noise
is caused in part by trying to bring up an underexposed image.
Maybe there is a software glitch that is just one fix away from
solving both problems. Wouldn't that be funny? They would have to
upgrade the top ISO back to 1600. Hey, maybe I should try to buy
one of these cameras off a dissappointed owner before the
fix........
Anyone willing to sell for $2,500 cash? --
TJ

Click to expand...

--
On A Quest Seeking Vision!

http://www.livick.com

Sadly I must concur. These folks elected to bring a knife to a gunfight .... a very over priced knife. But then ... the "fight" isn't over.
Regards
Karl
Karl H. Timmerman M.A.,J.D.
http://www.karltimmerman.com

tom jacobson said:

Chris,
Although I do not write software and really don't much about the
technical details, it seemed to me that the problems of exposure
and noise might be related somehow. Have you used an independent
meter, set the exposure to manual and tested a few consecutive
shots? Perhaps the meter on the camera is even working perfectly,
but sending the wrong signal to the shutter, or the lens. If the
sensor is starved for light, the image will have to be ultra
amplified, and more noise will result. Just a thought. I will be
happy for you if there is a global fix for your problems with the
camera. I do want it to be good - for your sake and everyone who
buys one's sake. and,.... maybe some day I will buy one used!

PS> have you seen a perfectly exposed histogram on an image and
looked at the noise in that image? If the exposure system somehow
is out of wack, it would cause an image exposed at ISO 64 to be in
fact exposed at ISO 400, for example. It is odd that we have a two
stop drop in top ISO also associated with a two or three stop
underexposure problem. That seems related.

Click to expand...

If you check out my samples page at http://users.ids.net/~chrisat/samples.html you'll find more samples.

If you notice both pictures of the girl have decent histograms. The flower shot (done inside a greenhouse with great diffused lighting under a full sun) has a decent histogram. This is the frustrating part - it appears random.

I did conduct some tests and there were anomalies. There might have been a discrepancy in my tests - ideally both the camera meter and the handheld lightmeter should be measuring the exact same target space. I didn't get down to that level of precision. There were other things involved, including exposure compensation.

This assessment has take a considerable amount of time. There will probably be more to this story later.

Chris

Chrisat,

Do you by chance have, or can you beg, borrow or steal (laugh), a 1D, D1X or D60, to take the exact same shot of the girl? I am just curious how it will compare coming across the web? I noticed that after loaded on my dinosaur system, the shot is the equivalent of a photoshop blow up at 100%. When bringing it up in photoshop it is 16% initially, but I have to increase the size to 100% to match what I am seeing on the screen directly after it loads.

I am wondering if the other camera's will come in the same and then when brought up in photoshop, also be at 16%? This all probably makes no difference. But as some have said in the Canon forum, the 64 ISO little girl shot just isn't all that bad. A side by side comparison with another camera on your site might be really beneficial. And if nothing else, it will show just how bad the camera may really be performing?

Mel

Chrisat said:

tom jacobson said:

Chris,
Although I do not write software and really don't much about the
technical details, it seemed to me that the problems of exposure
and noise might be related somehow. Have you used an independent
meter, set the exposure to manual and tested a few consecutive
shots? Perhaps the meter on the camera is even working perfectly,
but sending the wrong signal to the shutter, or the lens. If the
sensor is starved for light, the image will have to be ultra
amplified, and more noise will result. Just a thought. I will be
happy for you if there is a global fix for your problems with the
camera. I do want it to be good - for your sake and everyone who
buys one's sake. and,.... maybe some day I will buy one used!

PS> have you seen a perfectly exposed histogram on an image and
looked at the noise in that image? If the exposure system somehow
is out of wack, it would cause an image exposed at ISO 64 to be in
fact exposed at ISO 400, for example. It is odd that we have a two
stop drop in top ISO also associated with a two or three stop
underexposure problem. That seems related.

Click to expand...

If you check out my samples page at
http://users.ids.net/~chrisat/samples.html you'll find more
samples.

If you notice both pictures of the girl have decent histograms.
The flower shot (done inside a greenhouse with great diffused
lighting under a full sun) has a decent histogram. This is the
frustrating part - it appears random.

I did conduct some tests and there were anomalies. There might have
been a discrepancy in my tests - ideally both the camera meter and
the handheld lightmeter should be measuring the exact same target
space. I didn't get down to that level of precision. There were
other things involved, including exposure compensation.

This assessment has take a considerable amount of time. There will
probably be more to this story later.

Chris

Click to expand...

--
Mel

Mel said:

Chrisat,

Do you by chance have, or can you beg, borrow or steal (laugh), a
1D, D1X or D60, to take the exact same shot of the girl? I am just
curious how it will compare coming across the web? I noticed that
after loaded on my dinosaur system, the shot is the equivalent of a
photoshop blow up at 100%. When bringing it up in photoshop it is
16% initially, but I have to increase the size to 100% to match
what I am seeing on the screen directly after it loads.

Click to expand...

Member said:

I am wondering if the other camera's will come in the same and then
when brought up in photoshop, also be at 16%? This all probably
makes no difference. But as some have said in the Canon forum, the
64 ISO little girl shot just isn't all that bad. A side by side
comparison with another camera on your site might be really
beneficial. And if nothing else, it will show just how bad the
camera may really be performing?

Click to expand...

Because I posted FULL size original images of the girl, what you will see will always be a 1:1 pixel relation (2008h x 3008v) between the image and your monitor display. The mapping is strictly on pixels, so the physical size of your screen resolution (72 ppi, 96ppi or other) would be different. Almost every other 6mp camera out there has similar dimensions, so that's not a factor.

As for comparisons, I'm working on it.

Chris

Thanks for the explanation and for taking the time in whatever you come up with.

Chrisat said:

Mel said:

Chrisat,

Do you by chance have, or can you beg, borrow or steal (laugh), a
1D, D1X or D60, to take the exact same shot of the girl? I am just
curious how it will compare coming across the web? I noticed that
after loaded on my dinosaur system, the shot is the equivalent of a
photoshop blow up at 100%. When bringing it up in photoshop it is
16% initially, but I have to increase the size to 100% to match
what I am seeing on the screen directly after it loads.

Click to expand...

Chris Arsenault said:

I am wondering if the other camera's will come in the same and then
when brought up in photoshop, also be at 16%? This all probably
makes no difference. But as some have said in the Canon forum, the
64 ISO little girl shot just isn't all that bad. A side by side
comparison with another camera on your site might be really
beneficial. And if nothing else, it will show just how bad the
camera may really be performing?

Click to expand...

Because I posted FULL size original images of the girl, what you
will see will always be a 1:1 pixel relation (2008h x 3008v)
between the image and your monitor display. The mapping is strictly
on pixels, so the physical size of your screen resolution (72 ppi,
96ppi or other) would be different. Almost every other 6mp camera
out there has similar dimensions, so that's not a factor.

As for comparisons, I'm working on it.

Chris

Click to expand...

--
Mel

Chris,

I know this gets to the painful part.... but..... any chance you can return this camera as defective? Most stores have a 14 day trial period. I would seriously consider returning it, if you can. If the problems are ironed out later, you can always get another one. Don't be afraid to ask. Most stores will accomodate. Your camera is just not functioning as a high end camera should. No reason for you to suffer. The noise and banding on the 400 shot of the girl, the vertical shot, is horrible. I would not put up with it. Maybe its time to bail. TJ

Chrisat said:

tom jacobson said:

Chris,
Although I do not write software and really don't much about the
technical details, it seemed to me that the problems of exposure
and noise might be related somehow. Have you used an independent
meter, set the exposure to manual and tested a few consecutive
shots? Perhaps the meter on the camera is even working perfectly,
but sending the wrong signal to the shutter, or the lens. If the
sensor is starved for light, the image will have to be ultra
amplified, and more noise will result. Just a thought. I will be
happy for you if there is a global fix for your problems with the
camera. I do want it to be good - for your sake and everyone who
buys one's sake. and,.... maybe some day I will buy one used!

PS> have you seen a perfectly exposed histogram on an image and
looked at the noise in that image? If the exposure system somehow
is out of wack, it would cause an image exposed at ISO 64 to be in
fact exposed at ISO 400, for example. It is odd that we have a two
stop drop in top ISO also associated with a two or three stop
underexposure problem. That seems related.

Click to expand...

If you check out my samples page at
http://users.ids.net/~chrisat/samples.html you'll find more
samples.

If you notice both pictures of the girl have decent histograms.
The flower shot (done inside a greenhouse with great diffused
lighting under a full sun) has a decent histogram. This is the
frustrating part - it appears random.

I did conduct some tests and there were anomalies. There might have
been a discrepancy in my tests - ideally both the camera meter and
the handheld lightmeter should be measuring the exact same target
space. I didn't get down to that level of precision. There were
other things involved, including exposure compensation.

This assessment has take a considerable amount of time. There will
probably be more to this story later.

Chris

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--
TJ

Some people need to wake up here. Contax is breaking new ground here with this 1-1 stuff no matter how much noise or crappy the image is.

Comparing it to what canon & nikon have done working with current technology is completely unfair.Consider when Kodak broke ground with the first somewhat usable camera a few years ago, the thing cost $20,000 +.

I'm not defending the N here, as the proof, performance, and Professional Reviews are still pending, but you can't bash Contax for releasing this camera until someone has a better 1-1. No one should buy the thing until the results are in. Critisising Contax for raising the bar, pushing the limits or attempting what has not been done before is just foolish. This is good for all of use creating more options and competition. Now that contax has there FIRST 1-1 digital camera out puts them in the lead with 1-1 experience, even if the N falls way short of current none 1-1 pro digital cameras. The fact that you buy it if it does not perform up to your needs is not Contax fault. Actually buying the First rev of anything is usually a mistake and expensive when it comes to anything new. Wait until this thing gets put through extensive testing and probably a firmware update before you plop down $10,000 ( cam 7,000 lens 2,000 storage 500+ ) on a unknown system.

Karl H. Timmerman M.A.J.D. said:

Sadly I must concur. These folks elected to bring a knife to a
gunfight .... a very over priced knife. But then ... the "fight"
isn't over.
Regards
Karl
Karl H. Timmerman M.A.,J.D.
http://www.karltimmerman.com

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