Myth busted: Canon's 14-bit snake oil

[Kayaker72]

Goodthread/rant. []


I decided to play around with this a little andam aware of two groups that have evaluated dynamic range, so I picked a couple of Canons and Nikons and created this table.
<table align="center" cellpadding="0" cellspacing="0" border="0" style="width: 746px; border-collapse: collapse;"]
<colgroup><col width="64" span="5" style="width: 48pt;"]</col><col></col><col width="71" span="2" style="width: 53pt; mso-width-source: userset; mso-width-alt: 2596;"]</col><col></col><col width="284" style="width: 213pt; mso-width-source: userset; mso-width-alt: 10386;"]</col><col></col></colgroup>
<tbody>
<tr height="20" style="height: 15pt;"]
<td width="64" rowspan="3" height="60" class="xl66" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; width: 48pt; height: 45pt; border-top: windowtext 0.5pt solid; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Brand</td>
<td width="64" rowspan="3" class="xl66" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; width: 48pt; border-top: windowtext 0.5pt solid; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Model</td>
<td colspan="4" width="263" class="xl66" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; width: 197pt; border-top: windowtext 0.5pt solid; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]dpreview.com</td>
<td width="71" rowspan="3" class="xl67" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; width: 53pt; border-top: windowtext 0.5pt solid; border-right: #f0f0f0;"]<span style="font-size: small;"]<span style="font-family: Calibri;"]DXO<span style="mso-spacerun: yes;"]</td>
<td width="284" rowspan="3" class="xl66" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; width: 213pt; border-top: windowtext 0.5pt solid; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Comments</td>
</tr>
<tr height="20" style="height: 15pt;"]
<td rowspan="2" height="40" class="xl68" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; height: 30pt; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]JPEG</td>
<td colspan="3" class="xl68" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]RAW (ACR)</td>
</tr>
<tr height="20" style="height: 15pt;"]
<td height="20" class="xl70" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; height: 15pt; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Default</td>
<td class="xl70" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Auto</td>
<td class="xl70" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]"best"</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td rowspan="6" height="162" class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; height: 121.5pt; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Canon</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]T2i</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.8</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7.4</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.7</td>
<td class="xl63" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.5</td>
<td class="xl72" style="border-bottom: #f0f0f0; border-left: #f0f0f0; background-color: transparent; border-top: windowtext; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]60D</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.3</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.5</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]dpreview--new format.<span style="mso-spacerun: yes;"] No RAW evaluation</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7D</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.3</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.6</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.8</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.7</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]5DII</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.4</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.9</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.1</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.9</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]1DIV</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.6</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7.2</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]10</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]1DsIII</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.6</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]6.9</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]10.7</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td rowspan="6" height="175" class="xl64" style="border-bottom: black 0.5pt solid; border-left: #f0f0f0; background-color: transparent; height: 131.25pt; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]Nikon</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D3000</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.9</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7.4</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.3</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.5</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]11.1</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D5000</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.8</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7.2</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.5</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12.7</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12.5</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D7000</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.2</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]13.9</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]dpreview--new format.<span style="mso-spacerun: yes;"] No RAW evaluation</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl64" style="background-color: transparent; height: 20.25pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D300s</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.4</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]6.8</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]9.1</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]10.1</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12.2</td>
<td style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
<tr height="40" style="height: 30pt;"]
<td height="40" class="xl64" style="background-color: transparent; height: 30pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D3x</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.4</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]6.9</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12.6+</td>
<td class="xl64" style="background-color: transparent; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]13.7</td>
<td width="284" class="xl73" style="background-color: transparent; width: 213pt; border: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]dpreview--"best" 12.6 was 12 bit and 14 bit was off the chart</td>
</tr>
<tr height="27" style="height: 20.25pt; mso-height-source: userset;"]
<td height="27" class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; height: 20.25pt; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]D3s</td>
<td class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]8.3</td>
<td class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]7.4</td>
<td class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
<td class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12.2</td>
<td class="xl65" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]12</td>
<td class="xl74" style="border-bottom: windowtext 0.5pt solid; border-left: #f0f0f0; background-color: transparent; border-top: #f0f0f0; border-right: #f0f0f0;"]<span style="font-family: Calibri; font-size: small;"]</td>
</tr>
</tbody>
</table>


First of all, I may be off on some of the numbers as I was often reading off their figures and calculating DR. Overall, looking at this table, it really is just the numerical version of what Daniel has already said:

• Jpeg out of cameras are pretty similar
• Recent Nikons (D7000/D3x)have a 1-2+ stop advantage over recent Canon's

As I am pretty new to shooting in RAW and post-processing, can anyone explain why DR in RAW varies so much?Compared todefault settings in ACR, dpreview was actually getting better DR out of in camera jpgs.


Thanks,


Brant

[nickds7]

I believe that just like with auto manufacturers, no company is going to release the best stuff they can make, until they know they can make something better - EVER (unless they make it really costly, obviously). It would risk the future of the company too greatly. This of course has to be balanced with what the competition has out there as well.


I'm sure next generation of Canons will be leap frogging Nikon. Too bad there is a pretty slim chance they will not likely fix dynamic range/noise levels with firmware updates.

Some people like to say "oh canon has inferior engineers".. I think that is completely false. Just like with Microsoft/Apple, you can't say either side has better engineers. They both likely went to similar or same schools, they likely get paid around the same. Whats the difference? Management.

ramble, ramble, ramble, ramble... and so on.

[Daniel Browning]

Thanks for the response, Brant. Unfortunately, the way DPR analyzes dyanamic range has some flaws.Their dynamic range is based on all the processing that Adobe ACR does. One of the big ones is Adobe's "blown out color guessing" software (which can't be disabled and is automatically utilized any time you move the exposure slider to the left). This has several problems:

• It biases the test results towards cameras that happen to have a spectral response similar to DPR lighting. Not everyone is going to use the exact same lights as DPR.
• Not everyone uses Adobe.
• Not everyone likes the results of automated guessing software. Some of us feel the resulting colors, while a good guess, are not realistic and therefore we don't consider that a valid part of the dynamic range.

So their results are really only useful if you use JPEG on the default settings or you use ACR and your tastes match theirs.

can anyone explain why DR in RAW varies so much?

Well, it depends on what you are measuring. If you are processing a raw file in a program, then measuring the JPEG file that comes out the other end (like DPR is doing), then the raw settings in the convert will have a huge effect, as you can see in your chart. The default settings in Adobe are tuned to be "pleasing", which means very low dynamic range (crushed shadows and blown higlights give an image lots of contrast or "punch"), while DPR "best" settings will have more shadow and highlight detail, but lower contrast ("flat" or "dull", to some photographers).


As for the difference between DXOMark and DPR, that is because DXO is making actual scientific measurements of the camera raw files themselves -- not seeing how the raw file does with some proprietary black box software like Adobe.

[Kayaker72]

Thanks for the explanation. It makes a lot of sense.


Brant

[Kamelot]

Ok...I read about that Daniel tried to contact to Canon ant explain all this. But what would be, if we all here (this forum) arrange to write letter each to Canon and explaint that this is not some kind of improvement to camera sensor, but this is like bug [] Forum members explain all this writting a letters, off course, in other words, that it wouldn't similar to sabotage. I think, if the Canon will see, that not one, but many people complaining about that, maybe then it's attention would be attracted.


Off course, in every letter we should try to explain that:

• "I did some test with my camera and noticed that it did not deliver real 14 bit depth" or "my company which uses Canon cameras technicians did some kind of real hight level test and revealed this malfunction". Maybe it would be a "white" lie [], but it would be worth it jut for attract an attention.
• this is some kind of bug or malfunction that is not acceptable for all high-end users and have to be fixed.
• other manufacturers already fixed that and theirs camera sensors deliver real 14-bit depth.

All our letters will not be a cunami in the ocean, but still would be some kind of waves []


For memeber who do not know, what exactly to write to the letter, we could try to write a pattern. And all, who wants to join this action, should write here or write into newly created thread just for registration.


Just my thoughts []

[andnowimbroke]

Let's say there are only 20,000 people that check out this site. Each one of those knows of at least ten others that shoot canon. If only this "small group" fork over $10USD for example, that's $2,000,000. I'm not sure the developement costs for firmmware manipulation are, but I think this type of situation is exactly what spurs small businesses into fruition. If they are good ideas, people will buy the product, or even get bought out by bigger companies. I'm sure there are a lot of good folks that would even do this stuff for free (UNIX) if they knew there was a need for it. Yes, Canon could come up and say "I'm gonna sue you folks because you worked around our glitches to provides services that we promised but failed to deliver..and still charged you for." Actually, if you wany my honest opinion, we're not too far away from having Apple apps that could be bought for our cameras legally anyway. Kinda open source-type stuff. Canon wants to think out of the box and push the edges. That's pretty edgy! Sell a camera for cheap with options to update firmware as needed or can afford. You can prolly take this to the bank. I guessed the swivel screen popping up on the next version of the 50D which, as far as I can tell, gives me CR2 creds

[Sinh Nhut Nguyen]

what are you guys talking about? I went through 5 pages of this thread in hope of seeing a single photograph of snakes.......

[DavidEccleston]

Well, I can fix that for you.


T1i + 100-400mm L @ 260mm, f/6.3, 1/200s, ISO-400