Posts Tagged ‘DSLR’

An explanation of Fujifilm’s Super CCD EXR sensor

A look at Fujifilm’s innovative EXR sensor, the latest iteration of its flagship Super CCD sensor, along with some analysis of images from production cameras. Admittedly this would have been more interesting as a speculative piece a year ago, but better late than never

tl;dr: Fujifilm’s EXR sensor is extraordinary, mostly for its dynamic range. If you’re after the best non-DSLR image quality around, your choices start at the Fuji F200EXR, F70EXR, S200EXR, and end there.

Fujifilm has long been a leader in revolutionary sensor technology, particularly at the smaller scale sensor market where the majority of manufacturers have long been content pumping out traditional, vanilla CCD sensors with square grid-based Bayer Filter Arrays.

In September of 2008, announced plans for their latest sensor: the Super CCD EXR, which combines the unique color filter array (CFA) and pixel binning features of various previous sensors into a single “switchable” sensor that can be optimized in one of several areas (which are typically mutually exclusive when designing a sensor): high resolution, high dynamic range, and low noise.

High resolution

High resolution mode is the default mode, which utilizes the full set of photosites on the sensor and produces an image with a corresponding pixel on each photosite – nothing too special here, though Fuji claims the diagonal layout of photosites (as opposed to simple square grid) helps to improve resolution.

High sensitivity

A comparison of a typical Bayer CFA (left) and the CFA on Fujifilm's new EXR sensor (right)

The second mode of operation for the EXR sensor is a high-sensitivity mode which Fuji calls “Pixel Fusion Technology”, which is fancy marketspeak for pixel-binning (combining reading from adjacent pixels together to produce a better signal). With the EXR’s pair-based CFA layout, Fujifilm claims that interpolation (and thus color resolution) will be more accurate because the binned pixels are closer together (e.g. the pair blue pixels are pretty much in the same location, while they’re separated by two pixel lengths in a standard square-grid Bayer array. I don’t know that I buy this argument particularly well – it’s true that same-color pixel values will be more accurate since they’re closer, but you can’t get something for nothing: for example, the average distance from red-to-blue is going to be increased, which lowers accuracy for interpolating blue values at red pixels.


Pentax K-x

Pentax K-x (space white)

Following up on their K-7, Pentax has now come up with an entry-level K-x. While it doesn’t bring anything groundbreaking that wasn’t already seen on the K-7, it packs in many of the features seen on many competitors’ midrange model, and perhaps pending reviews on image quality and disregarding the overall Pentax system upgrade options, is probably the best choice out there currently for the beginning photographer/student.

The big headline features:

  • 12.4MP CMOS (different from the K-7 14.6MP sensor, but interestingly also uses CMOS unlike all previous Pentaxes which used CCDs)
  • ISO up to 12.8k
  • Live-view with face-detect AF
  • 720p, 24fps video
  • 4.7fps continuous shooting
  • $650 MSRP with 18-55 kit lens (and likely to drop further once it gets off pre-order)
With the specs listed, this is a camera you’d expect in the high-hundreds, competing with the likes of Canon’s Rebel T1i or Nikon’s D5000/D90, yet it’s got a price closer to that of the entry-level Rebel XS or D3000.

A comparison:

Pentax K-x comparison

Camera Canon Rebel XS Nikon D3000 Pentax K-x Nikon D5000 Canon Rebel T1i
Sensor, crop 10MP, 1.6x 10MP, 1.5x 12MP, 1.5x 12MP, 1.5x 15MP, 1.6x
ISO range 100-1600 100-3200 100-12800 200-6400 100-12800
Live-view? Yes No Yes Yes Yes
Live view AF Yes None Yes, face-detect Yes, face-detect Yes, face-detect
Video None None 1280x720, 24fps 1280x720, 24fps 1920x1080, 20fps
AF 7pt, 1 cross-type 11pt, no cross 11pt, 9 cross-type 11pt, 1 cross-type 9pt, 1 cross-type
Continuous FPS 3fps jpg, 1.5fps raw 3fps 4.7fps 4fps 3.4fps
Image stabilization lens-based lens-based sensor-based lens-based lens-based
Size 127 x 97 x 61mm 127 x 97 x 64mm 122 x 91 x 69mm 127 x 104 x 79mm 130 x 97 x 61mm
Weight 450g 485g 516g 560g 480g
Price (with kit lens, Amazon) $499.95 $529.95 $649.95 $719.63 $781.89

In a comparison with the $500 entry-level cameras, the K-x blows them away in nearly aspect, and goes toe-to-toe or even exceeds the D5000 and Rebel T1i in every single category, despite being significantly cheaper (especially once the street price drops lower from MSRP)

Interestingly enough, the Pentax K-x will come in a variety of colors, including an ultra-spiffy red (below), the space white shown above, and your ordinary black.

Interestingly enough, Pentax Japan features a site where you can come up with your own custom color scheme, and apparently order it as well, which personally is an insanely appealing prospect.

Pentax K-x (red)

Pentax K-x custom design - design your own!

Pentax K-x custom design - design your own!

I think this is a ranking of custom designs that users have created

I think this is a ranking of custom designs that users have created

Pentax K-x press release

Past three months in camera news: Nikon

Apologies to all for dropping the ball for the past three months – it’s been a whirlwind start to the semester here. Big, recent developments:

Nikon SLR Refresh

Nikon introduced a couple of new SLR updates, the updated D300s and D3s. The D300 is a pretty incremental upgrade to the mid-level D300, offering a modest +1fps improvement in continuous shooting (up to 7fps), and bringing the video capability that’s now standard on every new DSLR.

The bigger story came a few months later, in the form of the D3s. While still not a revolutionary introduction, it is much more than a software refresh. Among the features of note were a video mode (at 24fps!, albeit only at 1280×720 (720p) resolution), 11fps available in a higher-res crop mode (it now crops only 1.2x instead of 1.5x), and an increase in ISO range, up to ISO12.8k natively with a boost to ISO100k. The D3s presumably packs a different sensor, though it still maintains the same 12.1MP resolution.

People have been going goo-gah over the last spec in particular, especially given such a high linear number for ISO (and from here, it’s just four more stops til we get to ISO1.6 MILLION), though it’s really just +1 stop natively and +2 stop boost over the previous D3. And it’s important to note that the simple availability of an ISO capability says nothing about image quality at that level – that would be the same mistake as having the maximum shutter speed expanded from 30 seconds to a minute, and somehow thinking this magically makes photos at 1/500s less blurry. Given that the resolution (and thus pixel pitch) remained the exact same, I certainly wouldn’t expect quality to be any worse than the D3, and quite probably will be a tad better (although I have extreme doubts about the ISO100k mode, which is digitally boosted 3 stops; things have always looked terrible at just +2 stops digitally, even boosting ISO100+2 to 400.)

All in all, about as much as you could expect from Nikon, who seems to do very incremental updates and waits a long time to deliver big, revolutionary refreshes. Here’s hoping we see that D3s sensor in a D700s soon, though 1080p at 24fps would be nice (and completely feasible: 1920x1080x24fps = 49.8MP/s throughput, while we definitely know that the D700 supports 12.1MPx9fps = 108.9MP/s throughput in its continuous shooting mode).

Nikon D3s press release (I don’t know why they keep referring to it as “D3S”, past history and even the logo in the image clearly denote “D3s”)

The Nikon DS3, now with 720p video and ISO up to 12.8K/100K(boost)

The Nikon DS3, now with 720p video and ISO up to 12.8K/100K(boost)

Nikon also announced a couple of lens refreshes, with Version II’s of their popular 18-200mm VR ultrazoom and a long-awaited update to the 70-200 f/2.8 VR to optimize it for full-frame (FX) sensors. As Nikon had long trumpeted 1.5x crop DX sensors before their introduction of the full-frame D3 in 2007, they cut corners with their introduction of the 70-200 f/2.8 VR in 2003, building a lens that was technically full-frame but had an abysmal drop-off in performance once you actually got to the corners outside of a 1.5x imaging circle. This wasn’t found out until a bit after the D3 was released, finally giving digital photographers a platform to test the lens’ full frame performance, which resulted in tests like these:

The new 70-200 II promises to fix all of these problems with a new optical design and coatings, and promises to throw in a more effective “4-stop” VR system as well. There haven’t been too many authoritative tests yet to show how it performs (if you’ve found any, send me a link!), but presumably they should have no problem building such a lens – Canon has had two 70-200 2.8’s that’ve performed flawlessly on full-frame, and Nikon itself had a great 80-200 2.8 lens prior to the 70-200 VR I.

The one stickler? As if Nikon’s $2019 price on the original 70-200 I wasn’t enough, the 70-200 VR II will now set you back a cool $2400.

Nikon 18-200 II and 70-200 2.8 VR II press release

Pentax’s K7 surprise

Haven’t been keeping this blog updated lately – now that I’m into summer hopefully I’ll have the time for more frequent updates.  What follows is a flurry of tidbits on recent happenings.

This one caught me by surprise for sure – Pentax just last week announced their new midrange K7, which is their first significant DSLR announcement in over a year.  Just as I started assuming Pentax had all but become a bit player in the increasingly crowded DSLR market (with Sony developing the KM/Alpha system into the #3 brand, and relative newcomers Panasonic and Samsung taking the initiative to forge ahead on the cutting edge digital frontier), they come out with a new flagship midrange camera that, on paper at least, rivals and even beats the Canon and Nikon midranges in quite a few areas.

Pentax K7

Pentax K7

Some of the highlights of the K7:

  • A new, 14.6MP CMOS sensor “rebuilt from the ground up”.  At the outset, this would seem to be a slightly revised version of the same 14.6MP sensor used on the previous K20D.  We’ll have to see how much improvement “rebuilding” the sensor has (my guess: not much), but this is encouraging news – Pentax sensors (the K20D’s 14MP sensor especially) have always produced excellent quality with regards to high ISO, if a tad conservative on the default in-camera noise reduction setting.  The K20D also seemed to buck the recent Pentax trend of poor JPEG rendering of RAW images (in other cameras, the in-camera JPEGs were significantly inferior to JPEGs rendered using an off-camera converter like Adobe Camera Raw) – maybe it was simply a different rendering approach to their higher-end midrange cameras, or perhaps Pentax just knows how to deal with raw data from the Samsung-developed K20D sensor better than the Sony chips used in all their other cameras.
  • (more…)