I'm just wondering, alot of people get REALLY worked up over these dxo tests, however theire numbers relating to various cameras (to me anyway) dont appear to reflect real world results take the medium format digital backs for example, these are simply amazing yet score lower than a sony or a nikon?
Personally i dont put any faith in this sort of analysis
Note: lucky i cant get smited to death by the DxO brigade
I take DXO results with a nice, big, honkin grain of salt most of the time. I like the ability to include consistently-generated (hmm, grain of salt there?) low-level hardware statistics as a factor in comparing like-brand cameras (i.e. I am looking forward to seeing if they measure any hardware-level improvements between the 5D II and III), as most of the time I figure that stuff should be pretty accurate. However when it comes to some of their numbers and some of their customers (i.e. Nikon), I become more and more skeptical. With their claim of 14.4 stops of "print" DR for the Nikon D800, some 2/3rds of a stop better than the sensor itself is capable of, I've become extremely skeptical of their numbers, and usually try to have a few big, honkin grains of salt handy at all times.
Not what you said before they posted D800 results....
I may not have "said" it before, but I always take DXO results with a grain of salt. I think most of their statistics ARE accurate...within the context
of DXO, relative to each other. I think their numbers are valuable for comparing cameras, however I have never thought their numbers should be used in isolation (I've referenced DPR results as much as I've referenced DXO results in my posts, often in the same posts). Since I may also not have said so before, let me say so now: I find DPR results, even though I believe they are more subjective and less accurate, to be just as valuable as DXO results, and in some respects, much more valuable...since they represent a real-world context better. I DID actually think their Print DR (normalized) DR results were decent before, as I fully understand the value of normalized IQ comparisons. I thought that their normalized print results, since for most cameras your downscaling...which minimizes noise and multisamples source data for each pixel, was "exhibiting the full capabilities of the native sensor DR." However I entirely expected them to come out of the gates claiming the D800 scored 13.97 on their Print DR tests, not some mysterious, magical nonsense like 14.4! I REALLY expected them to say the D800 nailed 14 stops right on the head, but instead they are basically making a claim that the D800 and only the D800 offers photographers the magical ability to GAIN ADDITIONAL DR simply by DOWNSAMPLING. Then Mt. Spokane came along posted a DXO link indicating that Nikon...but not Canon...was a big time paying supporter. Sorry, but I go where the evidence leads, and there is some evidence of very fishy behavior
about DXO and Nikon these days.
For arguments sake, lets assume there is some magical gain in DR simply by downsampling. That is an ALGORITHMIC process done on DIGITIZED pixel data. The physical sensor, according to DXO's Screen DR value (which at the moment I am not suspicious of...we'll see if they claim that a future 14-bit SoNikon sensor is capable of 14.1 stops...) can produce 13.8 stops of DR strait out of the camera, no processing of any kind outside of amp and ADC. If you run into a real life scene with MORE than 13.8 stops...the theoretical possibility of using a digital algorithm to "stretch out" 14.4 stops from your RAW file isn't going to help you. A real life scene with 18 stops of DR is going to outpace even the D800 sensor, and your only option is going to be to compress the blacks into less space (and therefor less recoverability)...or use an ND filter, just like all the rest of the photographers on the great and beautiful earth.
Thanks to DXO's new D800 rating of 14.4, I am now a firm believer that Print DR is a useless measurement. Digital wizardry can not and will never be a replacement for native, hardware-level dynamic range. I now believe DXO's sole "accurate" measurement of actual hardware-level DR is their Screen DR measurement. I'm unwilling to accept Print DR measurements for any camera now as being even remotely realistic. As such, I believe the following are accurate dynamic range estimates for Nikon, Canon, and Sony cameras:
|Brand ||Model ||DR Stops||Notes|
|Nikon||D7000||13.35||Still the best from a non-magical DR standpoint|
|Nikon||D90||12.21||DXO "measured ISO" closer to ISO 200, listed as ISO 200 rather than ISO 100 in chart|
|Nikon||D70||11.85||DXO "measured ISO" closer to ISO 200, listed as ISO 200 rather than ISO 100 in chart|
|Nikon||D3s||11.66||DXO "measured ISO" closer to ISO 200, listed as ISO 200 rather than ISO 100 in chart|
NOTE: I was pretty sure DXO listed the Screen DR for the D800 at 13.8 stops before. It is currently listed as 13.23...which makes their claim of 14.4 stops "Print DR" even more insane
. That would be 1.17 stops
of MAGICAL DR
gained by the simple act of DOWNSAMPLING?!?!? BULL SH*T! BIG, STEAMING PILE OF BULL SH*T!
Print DR == worthless tool for comparison.
Given the table above, briansquibb's numbers of a about 10 stops of real-world DR for his 1DsIII seem pretty spot on. It would be very difficult to actually utilize the full 11.25 stops without at least blowing out one color channel. Its tough to determine how much shadow DR you might be capturing as well, since you can't really "clip" shadows...you just might not actually gather enough light to measure as a reading in a pixel. Real-world 10-stop DR with an 11.25 stop camera seems entirely valid and realistic to me. I would suspect something similar with the D800...you might get about 12-stop real-world DR with the 13.23 stop megapixel flagship camera if you really pushed for it.