Does the D3 cheat ISO-wise? (Very serious)

Ken Rockwell has some high iso comparisons with different cameras. The same aperture and shutter speeds were used in each case and pictures all appear to be similarly exposed.

http://www.kenrockwell.com/nikon/d3/iso-1.htm

Remeber the Canon 5D is a little more sensitive than indicated but this doesn't really show. 100 200 400 800 1600 is actually 125 250 500 1000 2000.

MackII said:

Therefore my conclusion is that the actual ISO sensitivity of the D3 is about one stop less than displayed.

Click to expand...

Not necessarily. Unless you zoom or use different lenses (either introduces variables) to get the same viewfinder crop matrix reads different subjects for each shot, which introduces variables.

If you shoot close up the majority of modern lenses differ from infinity aperture, again introducing variables.

My D3 coincides close with my D300 on the histogram for landscapes using the 24-70 to get equal viewfinder crops.

If there was a minor discrepancy I was unhappy with on either camera I would use exposure fine tune.

You could wait for the dpreview of the D3 - they compare exposure and ISO to known constants.

--
Leonard Shepherd

Practicing and thinking can do more for good photography than buying or consuming.

zorgon said:

Ken Rockwell has some high iso comparisons with different cameras.
The same aperture and shutter speeds were used in each case and
pictures all appear to be similarly exposed.

Click to expand...

All images were shot at the same rated iso, f stop and shutter speed , and actually I'd say the D3 image appears at least .5 EV brighter than the others, if not more......Peter

--
http://www.innerimager.com

Just to put your mind at rest I've just spent the last 30 minutes on another test for you. I used my D3, D2X, and D2H to take raw shots of a Colorchecker SG chart using the 28-70 at f2.8 and 1/30th at 1600iso. The exposure was determined by incident reading from the Sekonic.

To all intents and purposes the results the results viewed in NX were identical (picture control for the D3 was set to neutral). In fact the D2X and D2H, using the 5H grey patch were identical, the D3 image was brighter by less than 1/3 of a stop. However looking at the white patches the exposure seems to be about the same. This suggests, as many have found, that the D3 uses lighter, brighter curves. Whatever, the test shows that the D3 sensitivity is almost identical to the D2X and D2H, both of which are generally acknowledged to have accurate iso ratings. The noise on the D3 shot was practically undetectable )

Nikon are not cheating.
--
Brian
Fine Art Print sales of the Isle of Skye at:
http://www.eyeofskye.co.uk/
Pbase gallery Pictures from Isle of Skye
http://www.pbase.com/xrdbear

MackII said:

This takes out some of the shine from the D3 I guess...what I thought
was ISO 6400 is actually ISO 3200, ISO 3200 becomes ISO 1600 and so
forth.

Click to expand...

I experienced exactly the same!! Moving from canon 5d and 1dsmkII I now have to bump up the iso one step to get the same shuterspeed. Because of that the d3 does not have an huge advantage over the 5d regarding noise..if at all?? This was a big disappointment but the d3 have other qualities that makes it so good so it's still a keeper
At least it's not worse than my 5d at high isos...

Jari

I've checked mine against the E3 (the same) and looked up the DPR ISO test for the E3, which also includes the D300, both are accurate, so, that's two reasons for thinking it unlikely the D3 is cheating, first it is visually the same as the E3, which is accurate, and secondly the D300 is accurate, and I'd be amazed if Nikon played straight with the D300 and fiddled the D3.

It was an interesting point to raise, but I'd say it is closed now. Unfortunately, this being DPR, any rumpus trundles on long after the answer has been found.
--
http://www.flickr.com/photos/acam

excellent! thanks for doing this....Peter
--
http://www.innerimager.com

Leonard Shepherd said:

Most of the confusion about metering arises because of the
scientifically wrong zone system dogma claiming 18% is middle grey -
Kodak say it is not and the instructions with Kodak grey cards
clarify "correct" exposure is most likely based on 12% as an average
reflectance.

Click to expand...

18% reflectance is perceptual middle gray. Look at Bruce Lindbloom's companding calculator where he uses middle gray to illustrate its use. You have to click on CALC and then COMPANDING CALCULATOR. In L*a*b 50 is middle gray. Y (luminance) is 18.42%, and the corresponding pixel value in a gamma 2.2 space is 0.4635*255= 118.2

http://brucelindbloom.com/

The Kodak Q14 target is useful for exposure visualization. It has steps of 0.1 density or 0.3 EV and M is middle gray



Julia Borg has all the values plotted out for your inspection:
http://www.pochtar.com/gamut_view/gamma.htm

Patch A, 90% reflectance, is 2 1/3 stops above middle gray. 100% is about 0.15 EV above 90% and 2.5 EV above middle gray.

Leonard Shepherd said:

Most hand held meters are calibrated on the basis of the old ANSI
standard of 12% luminance, not the 18% reflectance of a grey card.
Nikon matrix builds in some exposure compensation for many scenes so
you ideally need to compare your digital hand held with spot or
center weighted Nikon to identify any calibration differences.
It is no more true to say Nikon cheat than to say your meter makers
cheat.

Click to expand...

See my post above for digital meter calibration according to ISO standards. It is effectively 12%.

Leonard Shepherd said:

Digressing pure fresh white paint (90% reflectance) is about 2.3
stops lighter than 18% cards. With negative film and recent digital
cameras able to handle 8 or more stops dynamic range it is nonsense
to assume 18% (2.3 stops from pure white) is a middle grey - even
though zone dogma foolishly teaches that it is.
--

Click to expand...

100% is pure white. Period. Film or digital. The extended dynamic range of your 8 stops extends into the shadows.

--
Bill Janes

Thanks Brian, your test was done in a very similar way to mine. It suggests that your D3 works fine, and because working fine is expected, I beleive there may be some problems with my D3.
Let's see if we get other contributions, but your is a very good one.
Thx

from your subject line... "He" has a name, you could also refer to me as the OP, but "He" means you are trying to create a preferential bond with the previous poster.
It just shows that you are not polite, unsecure and need someone else's support.
Apart from that, your conclusions seem to be correct.

...for sharing your knowledge.

--
Philip

I don't think so. Some old Canon's cameras, including EOS 5D, are about 1/3 stp[ more sensitive than they indicate. DPreview made a good job documenting this in their reviews.

I really don't think so it's likely to find the same with "any other camera". My findings are pretty consistent: my 5D is about 1/3 stop more sensitive at the same ISO/shutter/aperture than my D3.

Pretty good to me, especially since a shot taken at ISO 1100 on D3 is definitely, visibly better (less noisy, more contrasty and sharper) than the shot taken under the very same lightning conditions & time with 5D at ISO 800. D3 doesn't cheat.

MackII said:

Do the same tests with any other camera and you're likely to find the
same. You need to lower the other cameras' ISO to get the same
results.
As you said
ISO 1000 for the D3 is ISO 800 for the 5D (no matter which is right)

Click to expand...

--
Maciej Freudenheim
http://flickr.com/photos/fahren/

MackII said:

I agree with you and that's why I have asked other readers to repeat
my test with their second or third cameras or light meters. I too
would like to know which of the four possibilities is the real one.
At this point in time I tend to beleive that option 2) is the right
one, but cannot rule out any from the "menu".
It would be nice to see additional testing done by someone else.

Click to expand...

To rule out the methodology part mostly (as I trust the rest is done ok), I would perhaps reset the D3 to factory defaults and then set again all settings needing to be changed. There might be something wrong with the settings written in your D3 (software) system and that might be invisible to you and solvable with a reset and making the needed settings again. (You know, just like Windows needs to be "fresh installed" after a few years use to make the system work again).

That way I have a few times found the reason why a computer behaved strangely (and a few times the BIOS was behaving faulty, even all settings exactly the same after reset made it work again - and no, I did not have updated the BIOS without resetting the values but had used the system for a few months without any problems - and I am not alone here, flash settings may also get corrupted in time for no obvious reason).

--
Osku

and to whom the third person singular referred in this case was quite clear - "the OP" would have looked most odd.

I must say it wouldn't have surprised me if you had been correct - the low noise of the D3 is most odd. Normally sensors at the same technology point don't deviate so markedly from predicted performance. Still - it's handy
--
http://www.flickr.com/photos/acam

I use mine in the studio and the light meter's values are exactly what the D3 needs to hear. (as an example, my last shoot's lighting needed iso 200, f/8 and at those settings, the jpegs could be printed as is, no adjustment necessary)

I never compared ambiant light metering, but I guess it should be the same as well.

The best and easiest test: ISO 200, F/16 @ 1/200th. At noon, clear sky, that's the golden rule, should be an exact mesure of light. So you just put a grey card in the sun, and compare. (The sun's light output at noon is pretty much constant. Constant enough for a camera anyways)

MackII said:

Thanks Brian, your test was done in a very similar way to mine. It
suggests that your D3 works fine, and because working fine is
expected, I beleive there may be some problems with my D3.
Let's see if we get other contributions, but your is a very good one.
Thx

Click to expand...

I really hope you get your problems sorted out so you can get the most out of your D3. I'm really happy with mine. The brighter curve they have applied may not suit some but I was struck immediately, when I looked at my first shots, how they looked more natural than those I was used to. A subjective term maybe but the best I can come up with.

--
Brian
Fine Art Print sales of the Isle of Skye at:
http://www.eyeofskye.co.uk/
Pbase gallery Pictures from Isle of Skye
http://www.pbase.com/xrdbear

sportspix said:

but Nikon has had a track history to be
somewhat optimistic with their ISO ratings on some of their cameras,
particularly at the higher ISO ratings, up to and including the D2x.
Which made Nikon's failings in controlling noise at higher ISOs even
harder to bear (not only was say, ISO 1600 worse than brand X's, but
it was also really, maybe only ISO 1250).

Click to expand...

I can't speak for the D2x, but I don't believe this to be true at all. From what I remember, Nikon's ISO settings were always dead on, and Canon was underreporting true ISO.

"This takes out some of the shine from the D3 I guess...what I thought was ISO 6400 is actually ISO 3200, ISO 3200 becomes ISO 1600 and so forth."

I am not quite sure what the fuss is all about... in case with Canon's 20D/5D, its ISO is more sensitive than it was indicated which is actually a good thing. It helps you expose to a little right and when you adjust the exposure in RAW editior, you'll get a LOT more tonality and noise is also reduced signficantly.

But considering the noise performance on Nikon 3D (from what I've seen), if it's really 3200 instead of 6400, then I'd say wow, that's impressive that it can manage to keep the noise down while boosting the ISO!

Honestly, I don't know what the point is and if Nikon 3D does the ISO error constantly, why not just shoot at 3200 knowing that it will come out as 1600, and shoot at 6400 when you want 3200?

photoaddict said:

But considering the noise performance on Nikon 3D (from what I've
seen), if it's really 3200 instead of 6400, then I'd say wow, that's
impressive that it can manage to keep the noise down while boosting
the ISO!

Click to expand...

If true, it is an issue. What the poster is saying is that if you need to shoot a scene at ISO 6400 on the D3 you can use the same shutter speed and f-stop on (for example) a Canon 5D at ISO 3200.

If that is the case then the D3 does not have a 1 stop ISO advantage over the 5D. Saying that it is impressive that the D3 manages to keep noise down while boosting ISO would be nonsense. All it says is that there is a discrepancy between the two cameras in their stated ISO ratings.
--
Mike Dawson

If the OP has a valid observation then this makes for an interesting test. I have started to do my own tests between my D200 and D3. I do not want to test the metering of the two cameras. I simply want to test the ISO sensitivity of the sensors.

With this in mind my idea is to test the cameras in manual exposure mode using the same lens. I did my first set of tests by shooting at ISO 200 on both cameras using the Nikkor 50mm f/1.8 lens. The test was to shoot a Kodak grey card at a fixed shutter speed and f-stop on both cameras, same WB setting (daylight), shooting RAW. Distance was slightly varied so that the grey card just filled the screen top to bottom on both cameras. My first pass at this test was done outdoors in the shade and ended up with the following exposure on both cameras:

shutter speed = 1/200
f-stop = f/4
ISO = 200

I then loaded both images into Capture NX. What to do now? I ended up setting the WB to 7500 on both images to get the RGB values of the grey card to be neutral (remember, I shot in the shade). I then set both the D200 and D3 images to use a Monochrome Picture Control setting and turned sharpening to 0.

I then simply used the eyedropper tool to measure the RGB values on the grey card to compare the same regions on the grey card.

Now that I have my initial results I need to back and fine tune the process. But let me give you the initial finding. Shooting at the same ISO and exposure the D3 grey card is obviously visually darker than the D200 image.

Comparing eyedropper results here are a couple of RGB value comparisons from different spots on the grey card (remember, the image is monochrome so each color is the same)

D3 D200
=== ===
137 160
143 165
141 163

I'll think about this test overnight. What I want to determine next is what ISO do I need to boost the D3 to in order to get the same RGB readings as the D200?
--
Mike Dawson