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Archive for the ‘Technology’ Topic

2012.02.22

The Digital Photography Computer Buying Guide was just updated for 2012. This new feature article covers the basics of choosing a computer for working with digital images and specific up-to-date recommendations for computers and components. Every part from the display to the power-supply is covered, how to build your own image processing powerhouse or how to find one already built and then improve it.

Writing this feature was a hands-on experience since it was time to make new computer to go along the one built for the 2009 article. Costs have gone down quite a bit and the potential for performance even higher.

As expected, this new computer really rocks with the Adobe Creative Suite 5.5 Web Premium including Photoshop, Illustrator, Acrobat and Photoshop Lightroom 3.6. Those not upgrading a previous computer will also need a system. For working with these essential Adobe products to their full potential, a 64-bit operating system such as Windows 7 Home Premium 64-bits.


Neocamera Blog Neocamera.com © Cybernium

2011.08.31

This morning a technical article appeared on Luminous Landscape regarding image quality of what they call Compact System Cameras and we call Single Lens Digital. The article attempts to quantify image quality differences between Digital SLRs and CSCs. However, unlike most articles on Luminous Landscape, this one is riddled with vague statements which do not support the article’s conclusions.

By the definition they present, a CSC could be the same as an SLD or pehaprs a subset, if one excludes Sony Alpha SLT-series. Note point #2, unlike DSLRs, there is no flip mirror or pentaprism, does not exclude digital cameras with translucent mirrors. Point #1, [CSCs] rather employ an electronic viewfinder, excludes a number of SLDs, depending if the optional EVF counts, as offered by many models from Panasonic and Olympus. At least we can see that most Panasonic and  Olympus Micro Four-Thirds cameras, as well as Sony NEX models, fall within their definition of a CSC.

When doing such an analysis, one must understand the separation of facts which are inherent to the system from those which are currently implemented. A simple example is the shutter-lag which presently favors DSLRs while having no technical reason for it to be slower on an SLD. A DSLR even has to move a mirror within the shutter-lag.

When describing the impact of using an EVF – or we would say of not having an Optical Reflex Viewfinder – the article correctly points the possibility of much smaller and lighter cameras but then they make some statements which appear to be based on a random sample of CSCs.

Particularly, they say that while vibrations caused by mirror-slap are gone [true, compared to SLRs], using a camera at arm’s length exaggerates shake. While true, this is completely artificial considering their definition of CSC requires an EVF and – by the way – DSLRs with Live-View can also be used at arm’s length. Just because they can be used this way, does not mean they have to and it certainly should not be a defining difference since both CSCs and DSLRs can both the used the same way. As a matter of fact, I am seeing more and more photography students who are used to shooting with a DSLR at arm’s length.

Then after saying that CSCs are more prone to vibrations, they say that this is minimized because of image stabilization which is available on most CSC lenses. This is a bogus claim since DSLR also have access to stabilized lens and because most CSC lenses are NOT stabilized. A quick search this morning shows 12 stabilized vs 16 non-stabilized lenses.

The claim that follows is that the speed and accuracy of autofocus is the same on both cameras. While we see no technical reason why it could not be the same, the present state of affairs is that  top DSLRs focus faster than top CSCs while accuracy is equal with a properly calibrated phase-detect autofocus system. On the other hand, as we pointed out yesterday, contrast-detect autofocus does not suffer from calibration issues. Note that if we include all SLDs in the definition of CSCs, the distinction becomes arbitrary since Sony Alpha SLT-series use phase-detection autofocus just like all digital SLR cameras.

Even without using a translucent mirror, there is no reason CSCs have to use contrast-detect autofocus. Fuji has already implemented sensors with built-in phase-detection in their compact digital cameras like the Fuji Finepix F300 EXR reviewed here.

Something similar can be said about sensor size. There presently both DSLR and SLDs with the same sensor sizes and probably even the same sensor. There are no full-frame SLDs yet, but it is highly likely that Sony will produce one since they said all future DSLRs [sic] will have translucent mirrors.

The parts of the Luminous Landscape article about lens design are interesting. The shorter flange-distance required by CSCs has an impact on how lenses are designed and allows for wider maximum apertures for the same focal-length designed for a DSLR. On the other hand, lenses are more prone to vignetting if they take advantage of the shorter flange-distance, so it is a double-edged sword. Keep in mind the if part of this statement, since SLDs can use DSLRs lenses with a simple tube-like adapter.

There is a chart that summarizes Imatest’s findings. The problem is that if you treat this as the current state of CSCs, it is wrong. If you treat it as the potential of CSCs, it is still wrong but for different reasons.

The true difference between SLDs and SLRs is their potential for smaller size and weight, which is very well shown among current-generation models like the tiny Panasonic GF3 or Sony NEX-7. Size has more implications for differences then inherent properties of each system.

Neocamera Blog Neocamera.com © Cybernium

2011.08.29

Micro-Adjusting focus of lenses is tedious and imperfect. A number of commercial products exist to help calibrate lenses but only to validate and check focus.  Because these products are disconnected from the camera, they cannot do anything to set the micro-adjustments. On top of that,  micro-adjustments are incapable of characterizing variations in focus according to focus-distance and focal-length.

Well, there can be a better way, at least for modern DSLRs and Sony SLT-series. Even better, it could probably be implemented via a firmware update. All that is needed is a camera with both Phase-Detect and Contrast-Detect autofocus.  Almost all DSLRs with Live-View can do this now. SLDs, other than those using a translucent mirror cannot but they do NOT suffer from that problem anyway.

The key is understanding the nature of the problem. A contrast-detect system evaluates focus directly from the imaging-sensor, therefore always has the correct focus when it manages to lock. A phase-detect system uses a dedicated AF sensor and that one can be slightly off compared to the actual focus distance. A focus micro-adjustment is simply an offset from the focus measured by the phase-detect AF sensor.

A camera that supports both types of autofocus can therefore simply measure the offset itself. It can do so at various focus distanced and even focal-lengths by instructing the user to move the target or change the focal-length. To ensure accuracy, one would have to use a special focus target, either provided as a solid object or printed from a supplied PDF file.  The firmware necessary to do the adjust would basically instruct the user how to place the focus target, perform measurements and repeat this a few times for each lens. It would then be able to characterize and set focus micro-adjustment curves that follow focus and focal-length variations.

Hopefully we can see this solution implemented soon by at least one DSLR manufacturer. Since service centers often perform micro-adjustment and those have to be repeated each time the camera body gets upgraded, it is in their best interest to provide such a self-service solution.

While we wait for self-adjusting cameras there is a detailed explanation of how to do this manually at the Photography StackExchange site.

Neocamera Blog Neocamera.com © Cybernium

2011.06.02

Pentax O-GPS1Pentax announces today the O-GPS1 unit, a unique GPS add-on for DSLR cameras which adds location data to images, camera direction and helps track movements of stars and planets.

By mounting the O-GPS1 onto the hotshoe of select Pentax Digital SLR Cameras, the user can record the latitude, longitude, altitude, coordinated universal time (UTC) and direction of the camera lens for shooting locations onto the captured images.  The O-GPS1 unit is presently fully supported by the Pentax K-5 and K-r via a firmware update, as well as partially supported the the Pentax 645D.

This GPS unit offers unique functions by taking advantage of the built-in stabilization system (Shake Reduction) of Pentax DSLRs:

  • GPS function records the latitude, longitude, altitude, coordinated universal time (UTC) and direction of the camera lens directly into captured images.
  • ASTROTRACER for effortless astronomical photography. When mounted on a Pentax K-5 or K-r, the O-GPS1 calculates the movement of stars and planets using GPS coordinates and the camera’s tilt and pitch data obtained from its magnetic and acceleration sensors, then shifts the camera’s image sensor in synchronization with the movement of the objects. As a result, stars and planets are captured as solid points rather than blurry streaks, even during extended exposures, up to a certain limit of course.
  • Simple Navigation function which calculates the direction and distance to a given destination from the current position. The user can either locate destinations using location data stored on recorded images. At the time of purchase, the O-GPS1 stores nine Pentax service centers as preset destinations.
  • Electronic Compass which displays the camera orientation on its LCD monitor with great precision. Using geomagnetism measured by its magnetic sensor and GPS location data, the unit indicates direction in relation to true north.
  • Simplified weather-resistant construction for use in light rain.
  • Independent power to avoid draining the camera battery. The O-GPS1 runs on a single AAA battery.

While there are plenty of GPS solutions to geotag images, this GPS unit from Pentax is offering unique capabilities which are only possible be combining the magnetic sensor-shift used to stabilize all lenses on a Pentax DSLR.

The Pentax O-GPS1 is scheduled to be available in July for a suggested retail price of $249 USD.

 

Neocamera Blog Neocamera.com © Cybernium

2011.01.05

Undoubtedly the biggest news today is Fuji’s new EXR BSI CMOS sensor which attempts to bring the best image quality and speed together. For a long time, Fuji had a noticeable lead in image quality thanks to its SuperCCD EXR sensors which work in 3 modes to give high-resolution, low-noise or extended dynamic range.

At one point, several manufacturers started using BSI (Back-Side Illuminated) CMOS sensors to attempt to close the gap. It did not work for catching with Fuji’s awesome quality but it it bring new high-speed capabilties to fixed-lens cameras. Things like 1080p HD video, 1000 FPS high-speed video, 60 FPS continuous drive and sweeping panoramas suddenly became possible.

Fuji experimented with their own BSI-CMOS sensor when the launched the Finepix HS10 one year ago. It turned out to be capable camera but did not match the previous ultra-zoom flagship, the S200 EXR when it came to image quality.

Today’s announcement may be able to merge the benefits of both high-quality imaging and high-speed photography. The new 16 megapixels sensor uses a CMOS process with BSI construction to improve its light gathering capability and the EXR tri-mode design. This time Fuji claims an extra stop of dynamic-range, so 1600% more than non-EXR sensors.

The Fuji Finepix HS20 EXR which showcases the new senor has a 30X ultra-wide angle mechanical optical-zoom lens equivalent to 24-720mm, like the HS10 before it. It can record full 1080p HDTV video at 30 FPS along with 320 FPS high-speed video at lower unspecified resolution. It features full manual controls with exposures up to 30s, full-resolution ISO to 3200, a fly-by-wire manual-focus, a multitude of direct controls and RAW mode, a first among EXR digital cameras. How it delivers remains to be seen. This one is scheduled to be available at the end of March for $499 USD.

Neocamera Blog Neocamera.com © Cybernium

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