D3X vs 5D2 - myth and reality

Started Jan 26, 2009 | Discussions
S Kumar Junior Member • Posts: 29
Re: A 40D welding amateur

bobn2 wrote:

Fred Ferkel wrote:

A 40D welding amateur should not make big boy type statements, it
always turns out wrong.
--

I wouldn't try to weld your 40D. It's made of magnesium, when the
torch hits it it will go fzzzzzzzt.

Haa haa - after reading thousands of antagonistic posts on this forum, I finally had a hearty laugh at this one.
Well done!!!

S Kumar
--
I have cameras, and lenses, and I'm not afraid to use them

Iliah Borg Forum Pro • Posts: 25,835
Re: A 40D welding amateur

I wouldn't try to weld your 40D. It's made of magnesium, when the
torch hits it it will go fzzzzzzzt.

Haa haa - after reading thousands of antagonistic posts on this
forum, I finally had a hearty laugh at this one.
Well done!!!

Regretfully, it is same "well-done" as many other posts in this and other threads. Magnesium alloys are weldable, using TIG torch and other methods.

-- hide signature --
Mel Veteran Member • Posts: 3,716
Re: THIS is the point

Thank you for responding and I believe that I do see your intent here. Forgive my skepticism that it might be something else.
I do believe you reach the edge with this generalization though:

"The vast majority of top photographers, who are the prospective buyers of the D3X, don't have any idea of the details we are dicussing here (the more expensive the camera, the less technical knowledge the owner has)."

Not all are dummies like me gentlemen. And that is not to place myself anywhere near the top, but I do understand much of this even if I cannot put it into words such as yourselves. I still believe that the bottom line to such comparisons is far more than simply image quality. AF, dual cards slots, build quality and metering just to name what comes to mind, ALL play an important part in the professional photography I am able to offer my clients.

When it comes to viewing the final product, I dare suspect that only very specialized applications will even be able to see or discern in image quality the DR differences you speak of here.

Your abilities and knowledge with such must be applauded. But your real world applications department for the "bulk" of professional D3X photographers might need another look. Make note that I say "might" gentlemen. For by your own description, "(the more expensive the camera, the less technical knowledge the owner has)" "The vast majority of top photographers, don't have any idea of the details we are dicussing here". Pretty well explains why this entire discussion and post "might" need another look if it is to be applied or have some meaning to the bulk of the actual users.

Mel Veteran Member • Posts: 3,716
Also?

You end with:

"but even the best one can become cr@p for an owner if the expectation is too high."

Can you then call it cr@p for owners other than youself if they do not feel it to be? If they infact have and hold their expectations high. That is their lone perogative is it not?

OP GaborSch Veteran Member • Posts: 7,203
Expectations

Mel wrote:

Can you then call it cr@p for owners other than youself if they do
not feel it to be?

I'm afraid you misunderstood what I wrote. If you purchase something in this price range with certain expectations in mind and it turned out not to fulfill that, then are you happy with your purchase?

Re the generic level of knowledge:

1. look at the thread "NEF compression"; how many members don't know the difference between uncompressed, compressed and losslessly compressed. This is not the first thread; there are many, who believe that the lossy compression does not cause any visible loss. The same on other forums.

2. look at threads about using the "wrong" ISOs. The majority of photogs do not even know, that some of the ISOs are fake. The camera makers actively contribute to the confusion; for example the 5D2 manual declared ISO 12800 and 25600 as "expansion", while in fact already 6400 is fake. The same is happening with some Nikons. I see this on other forums as well.

3. I see sometimes issues with cameras, which cost $20,000-$30,000, and the owners do not know exactly how their camera is doing ISO (most MFDBs do not have any ISO, only post processing), etc.

4. Those photogs participation or at least reading these forums are the better informed ones; think of those, who buy the camera, read the manual and the education is done.

So, yes, I was serious with my statement re the knowledge of the owners of expensive cameras. It does not mean that the owners of cheaper cameras are generally more knowledable, but the price/knowledge relation is different.

Anyway, let's get back to the topic.

Mel Veteran Member • Posts: 3,716
Re: Expectations

Okay, agreed unfortunately for much of what you say. However I do believe the pros I have worked closely with, completely appreciate and understand the functioning of their camera's, but more importantly the target itself in relationship to the light at hand. And I am a small piece of the pie. So I feel very safe in speculation that many many others around the globe have equal to superior understanding of the same.

But back to the topic as you say:

Again, does this necessity to technical understanding really apply for the bulk of real world usages? Will it be appreciated in the prints to the vast numbers of purchasers, again, other than those specialized niche applications?
I believe jewelry was mentioned?

OP GaborSch Veteran Member • Posts: 7,203
Application of the knowledge

Mel wrote:

Again, does this necessity to technical understanding really apply
for the bulk of real world usages?

Well, choosing the "wrong" ISO can reduce the dynamic range of the camera by even several stops. Exposing too low causes excessive noise. Misunderstanding the signs causes noise and loss of color. Did you see the thread about "red clipping"? That's a myth.

These issue may not mean anything for some; they may be very important for others. When you see photogs raving about the high DR of the D3X, do you believe that that is important for them? If the camera's capability is important, then its optimal usage is at least so important.

I am constantly suffering because of the low DR of my camera (Canon 40D), but at least I am using it as good as possible. For example knowing the raw exposure immediately after shooting (based on the RGB histogram and clipping indication) helps maximizing the DR usage; but you have to know its technique, otherwise the in-camera histogram is misleading.

Iliah Borg Forum Pro • Posts: 25,835
Red herrings

Again, does this necessity to technical understanding really apply
for the bulk of real world usages?

Look, cameras are noisy, clip highlights, blow out reds, plugging down shadows, produce wrong colour, can't focus, do not resolve, what else?

-- hide signature --
Tom Christiansen Senior Member • Posts: 2,239
About wrong/faux ISOs

GaborSch wrote:

2. look at threads about using the "wrong" ISOs. The
majority of photogs do not even know, that some of the
ISOs are fake. The camera makers actively contribute to
the confusion; for example the 5D2 manual declared ISO
12800 and 25600 as "expansion", while in fact already
6400 is fake. The same is happening with some Nikons. I
see this on other forums as well.

I'm not sure what you mean when you say that some of the ISOs
are fake. I'd thought all but one of them was! Am I mistaken,
or are we using the same terminology, differently?

I tried to talk about this under "Faux ISOs" in

http://forums.dpreview.com/forums/read.asp?forum=1021&message=30695792

and

http://forums.dpreview.com/forums/read.asp?forum=1021&message=30706555

Are you defining those ISOs as "fake" the ones that use
any gain, or those which use only digital/high gain?
If the latter, why?

The low expansions are also dubious; remember the ISO 6 (yes,
"6" as in six) of the Kodaks--which, IIRC, used stacking. But I
think current cameras' low expansions are just overexposures
of base ISO (whatever that is/means!) with compensating tonal
curves applied. Right?

-- hide signature --

tom

genotypewriter Veteran Member • Posts: 4,846
Re: Canon friends problem is

Livio Spallone wrote:

They are discovering that 5dII is a very good prosumer camera that
values no more than Canon ask for and it is not the groundbreaking
champion they dreamed of.

Have you even used a 5D2? lol

Consumer body ,

The biggest give away of loser talk... it's an exceptionally good full frame camera... the rest is up to the photographer. There are people making money with 350D's.. you can't always blame the tools because when you get it right and hang it on a wall it's your name that goes at the bottom, not the camera's logo.

And are you saying that anyone who gets their hands on a D3/D700/D3x ever becomes non-consuming professional creator of art? ROFL

autofocus ,

Again a load of BS... any real advantages are there when using 51 points to spraying and praying situations. If you can't do with 15 points it's not the camera's fault. And for once why don't you try to compose the shot?

battery

Yeah carrying a 15Kg backpack of lenses and bodies on your back up a mountain is fine to get that "perfect shot" but carrying an extra battery or two is a crime against mankind. lol

and the famous creaking door.

Does it scare you at night? Again... this is the poorest set of excuses I've ever heard of.

None of the things that you mentioned... I mean NONE of the things prevent you from getting great shots except it might make it slightly easier to do certain things (e.g. spraying and praying) with a Nikon than with a 5D2.

General quality control issues and frequent problem on sensor hot
pixel mapping.

This is what makes me laugh at Nikon fanboys... they think by having a camera of a certain brand gives a new meaning to their lives. And they forget all their own QC issues with their super-pro-i-m-better-than-everyone grade cameras lol

It is still a camera I would buy if I had Canon lenses (should be
also the perfect underwater cam :good photo , good movies , sound not
a problem).

I'm surprised how lenses got mentioned here because for some people SLR photography is about the build quality of the body.

My unscientific opinion is that Canon "stretched" too much the sensor
to compete with Nikon : declared iso far from real , pattern noise
also at low iso, hot pixel coming up in long exposures.

If it's not scientific then why bother?

GTW
--
http://www.flickr.com/genotypewriter

bobn2
bobn2 Forum Pro • Posts: 61,418
Re: Still measurements

GaborSch wrote:

bobn2 wrote:
Honestly, I don't give a fig for their "measurements", nor for the
view of "most of you", for my measurements are good enough for me,
beside being consistent. As soon as I see a contradicting
measurement (which is not the same as a "statement"), I am ready to
revisit my ones.

Well, you might excuse us for not giving a fig for your measurements, then. Emil's measurements are posted on his site.
I am measuring raw channels .

Yes, but sensor DR is in th end to do with incident light not just the photoelectrons created in it. the CFA is part of the system, and needs to be taken into account.

A basic problem with measuring the DR on specific images under
specific illumination is, that that result is totally useless in
other setting or under other illumination.

A problem with any lab based measurement. What one seeks to do is make measurements which are based on commonly used situations or can be readily extrapolated to a range of them.

I am using the data gained from the sensor to measure the sensor's
chartacteristics. I don't understand your objection. Should I use
data from a specification sheet to support the specification sheet,
or what?

There is no triangulation against any calibrated instrument. Nonlinearities and messing around in the signal chain could be transparent to your measurements.

I don't understand this problem (but really). I measure the
saturation levels on any image created by the same model with the
same ISO. Although it does happen, that some copies have different
saturation levels, the deviation is always negligable from the
perspective of dynamic range. (The deviations are important when
determining if some patch really clipped ot not.)

The problem is simply that the saturation level is one end of the DR calculation. I've been trying to work out whether your 'measure noise at a fixed fraction of saturation' somehow gives you a measure of DR, I can't see that it does, but I could be missing something.

Thus it is enough for me to find some other shots to measure the
saturation levels; it is not relevant, that the actual images used in
these demo are clipping or not.

Besides, all the above becomes irrelevant, when you regard that my
demonstration used only the red channel, the saturation of which is
very firm.

I'll take your word for it.

But that is a very different statement and says little about the DR.
The bottom end of the DR is the read noise, and in your measurement
that is swamped by the shot noise, which is about 2.5 stops higher
than the read noise

1. The DR is determined by noise . Not by "this noise" or "that
noise" but simply be "noise".

We have a different understanding of DR then. Different levels of incident light have different noise in them. You should only be interested in sensor noise, you are measuring the noise in the light as well.

2. You would have to show me hard proof before I accept that the
shot noise is 2.5 times higher than the read noise in the range I
used for the demo
.

Well, you should also be giving hard proof that your method measures the DR. I gave you the calculations, that pretty much constitutes a proof, unless you want to dispute the measurements they are based on (oh, sorry I forgot, you don't give a fig for any measurements but yours). In fact, you could probably calculate the same figures from your measurements, I might do it if i get a little more time.

The bottom end of the DR ratio is set by what you think is the
minimum acceptable signal distinguishable from the read noise. If you
take it as at the read noise floor you get one figure. If you decide
you want it one stop above the read noise floor, your DR measurement
would be one stop less. So, if you had two cameras with one stop
difference measured to the noise floor, the difference would still be
one stop measured to one stop above the noise floor

I have not measured anything from the noise floor. I don't even have
to know where the noise floor is. (In fact, I don't know that.)

Than what you are measuring is not the DR. I think that's your basic misunderstanding. measure what you like, but don't call it DR, and don't make sweeping statements saying others are misrepresenting the DR based on your measurements, which are not the DR.

Consequence is that differences in read noise will be masked by shot
noise

It is of no relevance whatsoever. Does the difference make one camera
better than the other? (Beside the max. 1/3 EV difference I noted at
the beginning?)

It is of clear relevance if you want to measure the DR. If you want to measure noise at some arbitrary fraction of FS, OK. In fact, the calculation I showed you is a pretty good indication of why in the majority of situations, most cameras produce pretty similar results. It's only in the deep so-called 'shadow noise' where the read noise floor becomes visible.

Sorry, Gabor, I just don't think your measurements support the
conclusions you make, they are quite consistent with the D3x have
somewhere around two stops more DR than the 5DII

I don't see this.

Evidently.

I think you are using a different definition of 'DR' to everyone else

I need to repeat it: I have not used the term DR in my demo . I used
the terms "noise" and "intensity".

You used the term 'DR' repeatedly. Just go back and read what you actually posted in your OP. If you want to use some other term, we have no dispute.

-- hide signature --

Bob

bobn2
bobn2 Forum Pro • Posts: 61,418
Re: A 40D welding amateur

Iliah Borg wrote:

I wouldn't try to weld your 40D. It's made of magnesium, when the
torch hits it it will go fzzzzzzzt.

Haa haa - after reading thousands of antagonistic posts on this
forum, I finally had a hearty laugh at this one.
Well done!!!

Regretfully, it is same "well-done" as many other posts in this and
other threads. Magnesium alloys are weldable, using TIG torch and
other methods.

Yes, Iliah, I did know that. Excuse me for stretching reality a little for the sake of a joke

-- hide signature --

Bob

knickerhawk Veteran Member • Posts: 6,098
What is DxO's claim?

GaborSch wrote:

The DxO results as well as the "professionally done" tests of Lloyd
have been too suspicious for me to let them pass unchecked.

The result proves, that the claim "two stops higher DR than the 5D2"
is ridiculous , like some other claims. In fact, the DR of the D3X
is max. 0.5 EV greater than that of the 5D2 at ISO 100, and at ISO
400 the 5D2 is already better.

If you look at the DxO "overview" figure for dynamic range, the D3X is rated at 13.7 and the 5D2 is rated at 11.9. I assume that's the basis for your statement that DxO claims a 2 stop difference. What doesn't make sense to me is how DxO derives its "overview" dynamic range figures. If you look at the actual dynamic range charts for the two cameras published by DxO, the D3X is slightly less than one EV (12.84) greater than the 5D2 (11.9) at their lowest measured ISOs (78 and 73 respectively). By about 250 the graphs cross and from thereon the 5D2 is measured at having greater dynamic range. Other than the "overview" figure, DxO's findings would appear to be pretty consistent with Gabor's. Or am I missing something?

(Note to Gabor: as usual, you would be better served to report your findings in a neutral way instead of with such certitude and dismissiveness. They are interesting, even if based on very limited input data that you didn't produce yourself, but no more definitive than DxO and various other reviews and measurements.)
--
My photos: http://www.pbase.com/imageiseverything/root

pertti Senior Member • Posts: 1,043
The bottomline (photographywise)

Give 5DMKII, D3x and A900 to a selection of good photographers. Let them out for real shooting a day or two. Look then results on big prints: who can tell the practical difference in quality?

Nowadays high-end cameras are ridiculously good. In fact I'm more worried about my shooting skills and effort I'm putting in than worrying about that extra 1% boost for camera performance.

-- hide signature --
bobn2
bobn2 Forum Pro • Posts: 61,418
Re: What is DxO's claim?

knickerhawk wrote:

GaborSch wrote:

The DxO results as well as the "professionally done" tests of Lloyd
have been too suspicious for me to let them pass unchecked.

The result proves, that the claim "two stops higher DR than the 5D2"
is ridiculous , like some other claims. In fact, the DR of the D3X
is max. 0.5 EV greater than that of the 5D2 at ISO 100, and at ISO
400 the 5D2 is already better.

If you look at the DxO "overview" figure for dynamic range, the D3X
is rated at 13.7 and the 5D2 is rated at 11.9. I assume that's the
basis for your statement that DxO claims a 2 stop difference. What
doesn't make sense to me is how DxO derives its "overview" dynamic
range figures. If you look at the actual dynamic range charts for
the two cameras published by DxO, the D3X is slightly less than one
EV (12.84) greater than the 5D2 (11.9) at their lowest measured ISOs
(78 and 73 respectively). By about 250 the graphs cross and from
thereon the 5D2 is measured at having greater dynamic range. Other
than the "overview" figure, DxO's findings would appear to be pretty
consistent with Gabor's. Or am I missing something?

The 'two stops' comes from the normalised 'print' figures, which give 13.65 for the D3x and 11.9 for the 5DII. By and large, the different measurements stack up quite well, including Gabor's. The problem of interpretation comes from many of the measurers (including DxO) being less than clear what they are actually measuring.

(Note to Gabor: as usual, you would be better served to report your
findings in a neutral way instead of with such certitude and
dismissiveness. They are interesting, even if based on very limited
input data that you didn't produce yourself, but no more definitive
than DxO and various other reviews and measurements.)
--

DPR wouldn't be DPR with Gabors around. He's uncovered some interesting things about the workings of these cameras.

My photos: http://www.pbase.com/imageiseverything/root

-- hide signature --

Bob

bobn2
bobn2 Forum Pro • Posts: 61,418
Re: What is DxO's claim?

Another point on this. If you look at the DxO DR charts, you'll see that the D3x, D300, D90 (at low ISO's) and A900 share this straight-line DR curve which is characteristic of the Sony column ADC architecture, where the read noise is really rather constant over the ISO range (which is what causes the straight line, the only thing changing the DR is the reduction in effective saturation, cause by ISO amplification). By contrast, conventional ADC systems such as the 5DII and D3 have a DR curve which droops at low ISO's, since they typically have read noise which doubles with each lower ISO step.

knickerhawk wrote:

GaborSch wrote:

The DxO results as well as the "professionally done" tests of Lloyd
have been too suspicious for me to let them pass unchecked.

The result proves, that the claim "two stops higher DR than the 5D2"
is ridiculous , like some other claims. In fact, the DR of the D3X
is max. 0.5 EV greater than that of the 5D2 at ISO 100, and at ISO
400 the 5D2 is already better.

If you look at the DxO "overview" figure for dynamic range, the D3X
is rated at 13.7 and the 5D2 is rated at 11.9. I assume that's the
basis for your statement that DxO claims a 2 stop difference. What
doesn't make sense to me is how DxO derives its "overview" dynamic
range figures. If you look at the actual dynamic range charts for
the two cameras published by DxO, the D3X is slightly less than one
EV (12.84) greater than the 5D2 (11.9) at their lowest measured ISOs
(78 and 73 respectively). By about 250 the graphs cross and from
thereon the 5D2 is measured at having greater dynamic range. Other
than the "overview" figure, DxO's findings would appear to be pretty
consistent with Gabor's. Or am I missing something?

(Note to Gabor: as usual, you would be better served to report your
findings in a neutral way instead of with such certitude and
dismissiveness. They are interesting, even if based on very limited
input data that you didn't produce yourself, but no more definitive
than DxO and various other reviews and measurements.)
--
My photos: http://www.pbase.com/imageiseverything/root

-- hide signature --

Bob

Mel Veteran Member • Posts: 3,716
Re: Application of the knowledge

"Well, choosing the "wrong" ISO can reduce the dynamic range of the camera by even several stops. Exposing too low causes excessive noise. "

But you started this post about DR between the 5DII and the D3X and your belief that there is NOT such a large difference favoring the D3X.

You then further identified the users of the D3X as uninformed knowledge wise in regards to understanding all of this.

Why then does it matter whether or not the average user of the model realizes a small DR difference that cannot be seen or realized in the bulk of the "type" of images that will be obtained from this model?

You are saying on one hand that the owners aren't smart enough basically to understand and use their equipment properly. THEN, on the other hand you say they need to step up to the plate and realize these things for proper usage.

Have you considered that perhaps this DR difference will not matter to most of the users because it will not be visible in their images in print?
--
Mel
http://www.mellockhartphotography.zenfolio.com
http://www.mellockhartphotography.net

Toermalijn
Toermalijn Forum Pro • Posts: 15,853
Re: Canon friends problem is

genotypewriter wrote:

Livio Spallone wrote:

They are discovering that 5dII is a very good prosumer camera that
values no more than Canon ask for and it is not the groundbreaking
champion they dreamed of.

Have you even used a 5D2? lol

Consumer body ,

The biggest give away of loser talk... it's an exceptionally good
full frame camera... the rest is up to the photographer. There are
people making money with 350D's.. you can't always blame the tools
because when you get it right and hang it on a wall it's your name
that goes at the bottom, not the camera's logo.

And are you saying that anyone who gets their hands on a D3/D700/D3x
ever becomes non-consuming professional creator of art? ROFL

autofocus ,

Again a load of BS... any real advantages are there when using 51
points to spraying and praying situations. If you can't do with 15
points it's not the camera's fault. And for once why don't you try to
compose the shot?

battery

Yeah carrying a 15Kg backpack of lenses and bodies on your back up a
mountain is fine to get that "perfect shot" but carrying an extra
battery or two is a crime against mankind. lol

and the famous creaking door.

Does it scare you at night? Again... this is the poorest set of
excuses I've ever heard of.

None of the things that you mentioned... I mean NONE of the things
prevent you from getting great shots except it might make it slightly
easier to do certain things (e.g. spraying and praying) with a Nikon
than with a 5D2.

General quality control issues and frequent problem on sensor hot
pixel mapping.

This is what makes me laugh at Nikon fanboys... they think by having
a camera of a certain brand gives a new meaning to their lives. And
they forget all their own QC issues with their
super-pro-i-m-better-than-everyone grade cameras lol

It is still a camera I would buy if I had Canon lenses (should be
also the perfect underwater cam :good photo , good movies , sound not
a problem).

I'm surprised how lenses got mentioned here because for some people
SLR photography is about the build quality of the body.

My unscientific opinion is that Canon "stretched" too much the sensor
to compete with Nikon : declared iso far from real , pattern noise
also at low iso, hot pixel coming up in long exposures.

If it's not scientific then why bother?

GTW
--
http://www.flickr.com/genotypewriter

LOL, the losers to me seem the canon fanboys....all eyes were on the 5dII and now every review is trashing their trumph...

Deep in your hard, you know the d3x IS the best dslr on the planet at the moment...build quality wise and image quality wise...

it doesn't mean that the 5dII isn't a good camera for the money, it just isn't the camera that can compete with the d3x.

Canon had the lead, nikon is taking it over again, like in the film days!

Toermalijn
Toermalijn Forum Pro • Posts: 15,853
Re: A 40D welding amateur

Iliah Borg wrote:

I wouldn't try to weld your 40D. It's made of magnesium, when the
torch hits it it will go fzzzzzzzt.

Haa haa - after reading thousands of antagonistic posts on this
forum, I finally had a hearty laugh at this one.
Well done!!!

Regretfully, it is same "well-done" as many other posts in this and
other threads. Magnesium alloys are weldable, using TIG torch and
other methods.

I just don't hope this is the general knowledge of an average canon shooter!

But then again, we all make mistakes!

fredericFahraeus Regular Member • Posts: 302
Re: The bottomline (photographywise)

True! its splitting hairs. In the end of day theres really nothing in it. As with the D3X, if you dont know how to set in-camera settings, how to get the most out of the raw-converter and in general 110% skill of post-processing correctly, you might as well forget these high end MPs cameras. Pics wont look any better then half the camera.

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