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Friday, 11 December 2009

Comments

Uninformed question of the day: Does DxO Optics by any chance automatically support cameras that can shoot RAW DNG files? How about RAW files converted to DNG on a computer?

I notice that DxO doesn't support any of the m4/3 cameras. Wonder if that's coming?

JC

Now that's interesting. For me, anyway. Since I'm still contemplating to buy a small camera that complements my Nikons.

According to DXO the small sensor Canon G11 delivers more dynamic range than the m43 Olympus EP1 and Panasonic G1.

That comes as a surprise. When have smaller sensors ever had more DR than larger ones?

Another problem with DxOMark - the 'print' setting and the various values are based on 8x10 prints - so if you print larger than 8x10, none of the DxOMark values are relevant.
This also means that all the ratings are biased towards 8 megapixel cameras, as more than 8 megapixels doesn't increase the quality of 8x10 prints significantly. This is one of the reasons that medium format cameras and 24 megapixel full frame cameras don't rate very highly in their testing.

Dear Anonymouse,

This is true in lots of cameras. Exposure range and sensor (or even pixel) size don't correlate all that well. Someone, somewhere may very well have promulgated an opinion that says otherwise, but the real world data doesn't support that.

There is a CRUDE correlation between pixel size and light sensitivity. I say crude, because there is more than +/- 1 stop variation about the mean, depending on the camera model.

I've found the detailed DxO stats to be accurate (as close as I can measure these things, which is nowhere as good as they can).

My Fuji S100 (you can look it up on DxO; they just added data for it), beats out the EP1 and G1, too. It matches the Nikon D200, with a MUCH larger sensor and MUCH larger pixels.

Confirmed this experimentally, myself.

As I've written many times, you don't buy trends, you don't buy blanket opinions, you buy specific cameras. Which will always be better or worse than any blanket generalizations you may read.

pax / Ctein

I don't know how anybody can even understand that website...and comparing the G11 to cameras like the D3X and MF backs is ludicrous. What a waste of time...

Photographers made great pictures with the Nikon D1, photographers are now making great pictures with the Canon 5D mrk II or the D3X or even the much scoffed at M8 or 50D...

Buy what you like to use! You'll get great pictures.

I was waiting for these results. Isn't it amazing to find that the new 7D which currently generates hundreds of forum posts every day, specifically with regard to its sensor qualities (or deficiencies) is not at all different from every other Canon crop cam? Stack it up against the 50D and 500D and put it through the graphs. A glorified Rebel for all intents and purposes.

Dear Aaron,

That is utterly wrong. You have completely misunderstood the DxO technical papers.

First, the reported measurements are simply not scaled to any size of prints. They stand regardless of whether you print 4x5 or 40x50.

Second, the "print" measurements *are* scaled to an 8 megapixel sensor, as an arbitrary reference point, but the import of that is that the "print" measurements FAVOR larger-count sensors. You got the meaning of the technical paper on print vs screen entirely backwards. Smaller 'printed' pixels reduce noise and improve image characteristics (this is explained in other DxO papers).

You can confirm this for yourself by pulling up a comparison between several different cameras of different pixel counts. Compare the graphs for, say, noise in both 'screen' and 'print' weightings. The high pixel count sensors get BETTER in 'print', relative to low pixel count ones, not worse!

8 megapxels is used as an arbitrary reference point, nothing more. Meaning that the graphs for an 8 megapixel camera won't change between screen and print weightings. Cameras with pixel counts higher than 8 Mpx get BETTER when you look at the print weighting vs the screen. Cameras with fewer than 8 Mpx get worse.

pax / Ctein

P.S. to Anonymouse: To clarify my comments, I meant comparing the Fuji S100 to the other cameras with regards to exposure range only. You probably figured that out, but since I wandered a bit off your point...

pax / Ctein

re "Uninformed question of the day" about RAW DNG files. (and why does everybody capitalize raw? It isn't an acronym like TIFF, JPEG or TWAIN.)

DNG isn't a raw data standard it is a file format standard based on TIFF ( which isn't a data standard either ) for describing the data with metadata like what is the Bayer layout, antialiasing strength, data compression etc. expressed using standards like XMP and Dublin Core.

Barry Pearson maintains a good resource that explains DNG as well as any.

http://www.barrypearson.co.uk/articles/dng/specification.htm
and
http://www.barrypearson.co.uk/articles/dng/innovation.htm
are good places to start.

Dear Hugh,

RAW vs raw-- it's a style thing-- what looks right when printed on the page. Some folks think raw looks right, others think RAW looks right. I'm in the latter camp. Currently, there's no agreed-upon correct form.

Style doesn't need historically justification, but originally RAW *was* one specific format with an acronym. Don't remember which camera maker it was or what it stood for. Doesn't really matter-- most folks don't know what TWAIN stands for. Nowadays RAW is a zillion different subformats... but then so is TIFF.

But, yeah, RAW ain't DNG.

(Or, raw ain't dng [s])

pax / Ctein

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