The proof is in the printing ...

Started May 30, 2013 | Discussions thread
Rriley Forum Pro • Posts: 21,846
Re: Perhaps you should re-read some stuff?

Raist3d wrote:

Rriley wrote:

John King wrote:

Sergey_Green wrote:

John King wrote:

As I stated before: as ISO (cameras) is defined by the ISO (standards organisation). Here:

Did you read it? It appears not ...

You stated before that you prefer Bill Claff's scientific approach, which, in your words, start with measuring real world examples. To which Bill Claff stated earlier that he does not measure "real" world examples, but collects manufacturer stated ISO instead. Now you are alluding that there is a well defined standard for measuring ISO (appears you know nothing about), which even more contradicts your earlier statement.
Again, Bill Claff specifically states that the native ISO of the sensor is seldom exactly a standard value, and the native ISO information is all he is interested in,
ISO Collaboration
I do not know what to say, did you not know what you write, or did you write it intentionally. If so, then for what gain, why?


Re-read what I wrote, perhaps?

Re-read what Bill Claff has written about his data collection and analysis methodology perhaps?
He does not measure ISO, he measures dynamic range from RAW files at the manufacturer's stated ISO settings, that are determined in accordance (hopefully) with the International Standards Organisation standards.

Re-read the ISO standard for the measurement and determination of ISO settings for cameras perhaps?

japanese manufacturers must comply with CIPA standards that they are co-signatories to. If there was a discussion about ISO CIPA and ISO DxO, DxO isnt ISO at all

in short, CIPA doesn't give manufacturers a choice, DxO figure can call anything they want an ISO measure,

That may be the case,

no, that IS the case

but the important part is how the DXo scores go hand in hand with each camera performance for relative comparison purposes.

which is altogether different from a cameras actual measured ISO

Let's say maybe a K-5 really doesn't have 14 stops of DR, and let's say those numbers scale to something smaller.  But I know that the difference I see between a 620 DR and the K-5 is about what Dxo relative scores suggest. Ballpark.

DxO should never have called what they are playing with 'ISO'
It has shaped a climate in which ISO is completely misunderstood, going so far as to suggest some manufacturers are cheating their ISO spec. Resulting in comparisons between sensors with psuedo adjusted ISO's to correct what the 'analyst' sees as requiring re-alignment.

another feature is this propensity to use 'eyeballing' to determine DR scores, which is entirely reminiscent of people making judgements about a sensors noise performance. Many people would both be aware how those things turned out.

BTW, you still haven't supplied any references of any description for the bald statements you made upthread ...

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Raist3d/Ricardo (Photographer, software dev.)- I photograph black cats in coal mines at night...
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