Latest or all posts or last 15, 30, 90 or 180 days.
Upgrade the memory of your 2019 iMac up to 128GB
Handpicked deals...
$1799 $1399
SAVE $400

$719 $230
SAVE $489

$198 $138
SAVE $60

$795 $344
SAVE $451

$1997 $897
SAVE $1100

$1100 $900
SAVE $200

$348 $278
SAVE $70

$3099 $2499
SAVE $600

$2099 $1799
SAVE $300

$275 $275
SAVE $0

$699 $499
SAVE $200

$1699 $1299
SAVE $400

$2999 $2999
SAVE $0

$1699 $1443
SAVE $256

$2798 $2498
SAVE $300

$2399 $2249
SAVE $150

$3798 $1898
SAVE $1900

$2798 $2498
SAVE $300

$2497 $1997
SAVE $500

$2498 $1798
SAVE $700

$3297 $2197
SAVE $1100

$2798 $2498
SAVE $300

$2998 $2498
SAVE $500

$1398 $1198
SAVE $200

$898 $798
SAVE $100

$400 $250
SAVE $150

$1299 $939
SAVE $360

$4499 $2999
SAVE $1500

$4999 $4599
SAVE $400

$2199 $1999
SAVE $200

$2799 $2349
SAVE $450

$3099 $2499
SAVE $600

$2001 $1298
SAVE $703

$249 $149
SAVE $100

$2844 $2297
SAVE $547

$1199 $1099
SAVE $100

$2019 $1399
SAVE $620

$999 $949
SAVE $50

$348 $278
SAVE $70

Sigma sd Quattro-H: Shoots X3F as Usual, or DNG With a Huge Size Penalty

See my Sigma mirrorless wish list.

I go into both the bit depth and file size issues in more detail in File Size: DNG vs X3F in my review of the Sigma sd Quattro-H in Guide to Mirrorless.

Be careful what you wish for: the about $1199 Sigma sd Quattro-H shoots DNG as one option, but the 150MB file sizes vs 68MB for X3F are a huge (literally!) downside that certainly gives me pause about using DNG.

Shoot 10 frames and you’re at a whopping 1.5GB. Yikes. It seems to me that an X3F to DNG converter makes a lot more sense, perhaps one that could properly compress the data in the DGN.

Image dimensions as processed from DNG is 6192 x 4128 = 25.5 megapixels, which by basic math means that each pixel in the finished image consumes 5.88 bytes of storage = ~47 bits per image pixel.

Sigma sd Quattro-H

The Sigma sd Quattro-H sensor is a semi true-color sensor with multiple layers. See Sigma dp Quattro Sensor Design. These Quattro sensor layers are not all full resolution as they are in the Sigma DP Merrill sensor:

  • Blue layer: full spatial resolution, broad panchromatic sensitivity
  • Red layer: 1/2 spatial resolution = 1/4 the data of the blue layer
  • Green layer: 1/2 spatial resolution = 1/4 the data of the blue layer

Which implies 14 bits + 7 bits = 21 bits per image pixel.

Why are 47 bits per image pixel stored if the sensor data requires only 21 bits? Does the DNG contain both the X3F as well as a duplicate perhaps? If so, why won’t Sigma Photo Pro 6.5.0 process DNG files?

Sigma sd Quattro DNG file size is little different from 16-bit uncompressed TIF. But see Sigma sd Quattro-H: DNG Files Shrink by More than 50% After Adobe DNG Converter.

File sizes for Sigma sd Quattro-H: DNG vs X3F vs TIF
16-bit TIF: 25.5 MP * 6 bytes per pixel = 153 MB of pixel data

Bits per pixel

That’s all theory. RawDigger shows that DNG is 12-bit and that X3F is 14-bit. So bigger files with DNG and you lose 2 bits. Not so appealing and rather strange too.

It’s discouraging that using DNG will extract its pound of flesh: the 36MP Pentax K-1 in SuperRes pixel shift mode stores 4 exposures in one file, which implies up to 260MB, but it actually produces files around 191MB on average. The Pentax uses lossless compression to keep file sizes “reasonable”. Apparently the Sigma sd Quattro is not nearly so successful (3 layers and only 2/3 the pixels per layer implies something much less efficient).

CLICK TO VIEW: Sigma sd Quattro


MacPerformanceGuide.com
View all handpicked deals...

Dell UltraSharp 27 U2717D 27" 16:9 InfinityEdge IPS Monitor
$719 $230
SAVE $489

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2019 diglloyd Inc, all rights reserved.