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I'm not convinced that Sigma actually wants to sell cameras . .

Started May 7, 2015 | Discussions thread
Tom Zimmer
Tom Zimmer Contributing Member • Posts: 627
Re: I'm not convinced that Sigma actually wants to sell cameras . .
1

xpatUSA wrote:

Tom Zimmer wrote:

xpatUSA wrote:

. . well after a couple of beers, I'm beginning to wonder!

OK, they take nice pictures but, after playing with my newly acquired DP1s and DP2s, I find it quite cynical that the DP1s comes with a DP1 manual and a scruffy fold-up sheet in a hundred different languages with the English bit spread across several folds to tell us the differences between the DP1s and it's predecessor.

But then, examining a raw histogram, I was amazed to see that the maximum raw level attainable with these two cameras is around 2,300 !!

I mean, the SD9 raw values can be up in the 10,000s the SD10 even higher, then the SD14 more like 9,000 and the SD1M more like a sane 4070 - which almost bears a resemblance to the ADCs output. God knows what the Quattro puts out, something different, I'm sure.

With scaling variations like this, and the X3F format changing with each new model, it is small wonder that so few converter providers have anything to do Sigma's products.

I actually bought these two cameras thinking they would be no different to the SD14 (same sensor, right?). Ha, how naïve can one get?!!

A storm in a tea-cup, you might say - but every time I open an X3F in RawDigger, I now have to set the over/under exposure levels to suit the stupid camera used. Ridiculous!

Ok, I looked at the RAW files from my DP2, and a bit over 2000 appears to be the limit.

Yep, I shot the sky and got 2293, 2302, 2295 and another scene with specular highlights gave 2323, 2320 and 2340.

Sigma is probably using 11 bits of a 12 bit DAC for intensity, or perhaps the DAC is signed instead of unsigned. Though I can't imagine why they would want to use a signed DAC for intensity. Cost?

Laid yourself wide open to the circling sharks, there, Tom

Who'll be first in, I wonder?

Ok, Ted, thank you for the "off line" correction. Smarty me, it's A2D (Analog to Digital converter), not DAC. That's what I get from being away from electronics for so long.

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Tom Zimmer
http://photobubba.com/
Sigma DP1 Quattro, Fuji X-T1, X-E1, X-M1
And my old friends - Sigma DP2, SD10, SD14

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