DF Body AF Accuracy vs Speed

December 7, 2011 | Tech, Tech Features

Background: How do Autofocus Systems Work?

Autofocus systems work by detecting contrast in the image, and measuring how that contrast changes as the lens focuses in and out. When the contrast is high “enough” the autofocus system tells the body it’s ok to take the picture.

Contrast means the difference between the brightest and darkest area of the image. This is why autofocus systems sometimes have problems trying to focus on smooth surfaces; even when in focus the brightest and darkest area of a smooth subject are not that different. Autofocus systems also have a minimum amount of light they can see, which is why autofocus systems can struggle in dark environments and why the DF Body projects a red pattern of light on to the subject.

One Size Does Not Fit All

But how contrasty is contrasty “enough”? For most cameras the manufacturer sets this threshold and you have no control. This one threshold is used no matter what kind of photography is being done. Take two extremes: tripod-based landscape photography and run-and-gun photojournalism, even though the two applications have completely different priorities from the photographers point of view. In slow, precise, diligent landscape photography there is no problem giving the camera as long as it needs to scan through various focus distances to determine the focus with absolute precision. In run-and-gun photojournalism the photographer is very concerned with the camera taking the picture quickly so that they can capture a particular moment, expression, or event; for this kind of photography if the autofocus engine is “pretty confident” it has the right focus it is more important to the photographer that the image is captured immediately than to wait another fraction of a second for the autofocus engine to re-scan the focus-range again to gain higher confidence of focus.

The upshot is that no focus system can perfectly fit every need, especially in medium format where larger sensors, higher resolution, shallow DOF, and sharper lenses demand higher standards of focus accuracy and larger/heavier lenses make it harder to achieve this accuracy.

The Solution? Give the Photographer Control

Phase One and Mamiya worked together to devise a creative solution to this issue and implemented it in the DF Body: the autofocus system can be set (via custom function #19) to either “speed” or “accuracy”. Understanding the advantages of each mode is critical to easily getting consistent focus.

Speed: The autofocus system will allow the camera to fire when it’s “fairly sure” of the focus. It is recommended you use a higher f-stop (e.g. f/8-f/16) when using this mode so that slight variances of focus will be covered by the depth-of-field.

Accuracy: The autofocus system will continue to scan focus back and forth until it is “very sure” of the focus. This can result in some “hunting” especially if the subject is low-contrast. However it provides the highest degree of assurance that the image will be perfectly focused on the intended subject, even when shooting wide-open (e.g. f/2.8)

Which Mode Should You Choose?

The default mode is speed. Whether you should change from the default “speed” to “accuracy” depends on your shooting style. If you’re shooting tabletop, product, landscape, architecture, interiors, etc then the “accuracy” setting will improve your focus accuracy and only cost you a fraction of a second more when the camera occasionally hunts for the perfect focus position. If you’re shooting moving subjects handheld the [Speed] setting will reduce the frequency with which the focus hunts and decrease the time between pushing the shutter release (or starting the focus using rear-button focus method).

Advanced hint: in [Speed] mode you can half-tap the shutter to focus the camera, and then release and half-tap the shutter again to fine-tune the focus. The final effect is similar to using [Accuracy] mode. When making major changes to focus distance (e.g. from infinity to a close-up or vice-versa) this is often needed when in [Speed] mode as the initial focus attempt often comes up a bit shy of moving the focus all the way to the subject.

How Do I Change Modes?

1. Rotate the main body dial  to CF (for “Custom Functions”)
2. Rotate the shutter dial until you are on CF#00 (“SEL”)
3. Rotate the thumb-dial until you’ve selected to use Custom Function Set A, B, or C.*
4. Rotate the shutter dial until you are on CF#19 (“AF_2″)
5. Rotate the thumb-dial until you’ve selected to use Option 0 [Speed] or to Option 1 [Accuracy]
6. Rotate the main body dial back to your desired shooting mode

Users of the Phase One P40+/P65+ can also use the interface on the digital back “DF Setup” to access and change the setting. The Phase One IQ will also allow for control of the DF custom functions on the back’s LCD in a future firmware update.
*When using the [blank] Custom Function Set (rather than A, B, or C) the camera uses all defaults and you cannot change any custom functions. This ensures that any user can pick up any DF and put it on defaults by simply changing CF#00 to [blank].

Note: Error in User Manual

The current Phase One DF User Manual (v1.3 – download) corresponds to the current firmware (1.21 and later); however, on page #99 it misidentifies the default as being [Accuracy]. The actual default is [Speed]. In previous versions of the Phase One user manual and firmware the settings for [Accuracy] and Speed were swapped; using previous user manual versions with the current firmware would lead to setting the body exactly opposite of what you intended.

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Media Pro 1.1 Released – Not Ready

December 1, 2011 | News, Tech

Media Pro 1.1 was released about one month ago with many bug fixes and some performance enhancements. We’ve been testing this release for the previous month hoping we could make a recommendation for Media Pro. So far our position has been that it was a very good move for Phase One to acquire Media Pro from Microsoft, and that the future for Media Pro as a sister product to Capture One was a great strategy that should pay off big for the company and for its customers. However, as expected in any 1.0 release there were bugs that kept us from endorsing it when it launched and at the 1.01 release.

Unfortunately we’ve found this is still the case in Media Pro 1.1. We’re still very optimistic about the future of this product and think it’s the best long-term bet for photographers looking for a cataloging (DAM) system, but we cannot endorse version 1.1. There remain too many bugs and insufficient performance/speed.

We eagerly await being able to test the next release of Media Pro whenever Phase One makes it available.

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Capture One 6.3.2 Released

November 3, 2011 | Capture One, Tech, Tech Features

A minor bug-fix update has been posted for Capture One. It fixes an issue caused by OSX 10.7.2 whereby brushes and mouse cursors would not display properly, leaving many users scratching their heads.We will be testing Capture One 6.3.2 in the coming week to let our users know about it’s stability and real-world performance.

Download Capture One 6.3.2

Other bug-fixes / Improvements

• Fixed an issue causing MobileBackups to show up as a volume in the library tool.
• Improved colors and noise defaults for Samsung NX11
• Both PEF and DNG format for all Pentax models now supported
• Support added for Olympus Pen E-PM1
• Support added for Samsung NX200
• Support added for Pentax Q

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10.7.2 Breaks Brushes in C1 6.3.1

October 13, 2011 | Tech, Tech Features

We have tested the latest version of OSX, released this week, 10.7.2.

In Capture One 6.3.1 this update appears to have broken the brush tool used for spot/dust correction and local adjustment layers. These tools remain useable but the cursor no longer changes to an outline of the brush, and instead remains a standard cursor.

For this reason we’d recommend most Capture One users not to update to 10.7.2 until there is an update to Capture One to address this.

Update: this also applies to other cursors like the white balance cursor (thanks Paul for reporting this).

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New GUI for Mamiya Backs

September 27, 2011 | Tech

Leaf Capture 11.5.2 has been released which includes updates for all Mamiya DM backs to the new Leaf GUI. This new Graphical User Interface allows LCC-in-the-field, hastens boot times, shows 100% views faster, and has an improved interface for use outdoors.

You can download Leaf Capture 11.5.2. Or you can wait for a few weeks for the next release of Capture One which will very likely provide this firmware. If you normally use Capture One 6.3 (or later) but would like to start using this firmware you can download+install Leaf Capture 11.5.2 for free, connect the back to update the firmware, and then resume using Capture One 6.3 (or later); Capture One will not overwrite/revert the new firmware.

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IQ Firmware 1.47

September 25, 2011 | Tech

New firmware has been released for the Phase One IQ. It primarily serves to address an error on Mamiya mount backs that would result in the error “no db” on a Mamiya or Phase One body (typically the mirror on the body would also remain in the up position when the back was mounted rather than dropping into the shooting position).

As always however there are some improvements to situation-specific image quality and general bug fixes and other minor improvements.

Download Latest IQ Firmware

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Capture One 6.3.1 (for OSX 10.5.8)

September 20, 2011 | Capture One, Tech

Capture One 6.3.1 was released today to fix a few crashes/problems in OSX 10.5.8.

It’s good to see Phase One continue to support this older version of OSX but Capture Integration is, in general, strongly recommend 10.5 users upgrade to 10.6 or 10.7 as support for 10.5 from all software vendors will drop off quickly now that 10.7 has been released.

In case you find the cat names easier to remember:
10.5 = Leopard
10.6 = Snow Leopard
10.7 = Lion

http://www.phaseone.com/en/Downloads/CaptureOne.aspx

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DF Body Minor Firmware Update

September 19, 2011 | Tech

There is new firmware for the 645DF that corrects a minor issue with the Schneider Kreuznach 150mm LS. The issue is that if you set the camera body to half step aperture (1/3 steps are default) then sometimes it will jump the setting f/4, and go directly from f/3.5 to f/5.6. Users who do not own and do not plan to rent the 150mm LS can disregard this firmware update.

Download

www.phaseone.com/en/Downloads/Firmware/FirmwareUpdater.aspx

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Capture One 6.3, CI Certified

September 15, 2011 | Capture One, Tech, Tech Features

As usual we have been testing the latest version of Capture One on a variety of Mac machines under both 10.6 (Snow Leopard) and 10.7 (Lion). We test Phase, Leaf, Mamiya, and Canon tethering. We do extensive LCC testing and work with large sessions.

In this case we are happy to report that Capture One 6.3 has passed all of our testing with flying colors. Nothing is perfect, but we have found 6.3 to be rock solid, very fast, and otherwise very polished.

For customers with 10.6 or 10.7 we strongly recommend Capture One 6.3.

The usual caveats apply. See the bottom of the original Capture One 6.3 Release blog post for those caveats.

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Capture One 6.3, Lion Supported

September 7, 2011 | Capture One, Tech, Tech Features

Update: We have now tested Capture One 6.3 for enough time to draw a strong conclusion. Read More.

Capture One 6.3 is now available for download at phaseone.com. If you are upgrading from version 3, 4, or 5 please see our article on Saving 10% on Capture One Pro.

Lion (OSX 10.7) Compatibility

• Lion Style Fullscreen (when using Lion)
• Lion Style Scrollbars (when using Lion)
• OpenCL supported in Lion
• Keyboard Shortcuts now works
• Importer no longer crashes
• Several minor artifacts/issues in Lion

General Enhancements

• Improved Wide-Angle Tech Camera LCC algorithms
• Schneider 150mm LS lens added to Lens Correction

Camera Specific Improvements

• Enhanced support for Samsung NX10 and NX11
• Improved noise defaults for IQ180
• Improved noise defaults for Olympus ZX-1
• Improved default colors for Fuji X100
• Support for Olympus E-P3 and E-PL3
• Preliminary support for Sony NEX-7, NEX-5N, SLT-A77, SLTA65

Bugfixes

Editorial Comments

We believe professional photographers should continue to hold off on adopting Lion as the OS on their production computers (especially if they tether). New Mac OS releases always contain significant bugs (often affecting Capture One users). These bugs often persist for a few months after release. While we have been running release candidates of 6.3 with few, if any, glitches we’d encourage caution when changing your OS. It is easy to consider it “just another upgrade” – you should not; it is a major and fundamental change to the software on your computer.

About Capture One Updates

Capture Integration is constantly testing new releases of Capture One and has many customers who are kind enough to keep us informed about their testing. We recommend a user update critical software or their operating-system only when:

1. The update contains an improvement, new feature or bug fix which is relevant to the user (“if it isn’t broke – don’t fix it”)
2. The update has been out long enough to give a sense of whether it contains any nasty bugs
3. The user has time/desire to do a complete test of anything workflow critical (e.g. tethering, processing, retouching, printing etc)
4. The user has a complete bootable backup of the computer. We recommend SuperDuper.
5. The user has the time to do a clean install. This means removing the previous version before installing the new version in the case of a software update. For an OS that means doing a erase+install.

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Broncolor IR Receivers

August 15, 2011 | Tech

Broncolor power packs with an IR Receiver (identified by the small red dome on the pack which is the IR receiver itself) have a potential problem in studios with new eco-friendly room lights.

These new eco-friendly room lights put off enough IR light to trigger the pack. In other words the pack mistakes the room lights IR flicker as a signal to fire and consequently fires in a stroboscopic manner (several times per second for as long as it sees the room lights). This can be very to misdiagnose as a problematic/defective pack since they user might experience or not experience the issue based on whether the room lights are on, whether someone is standing over the pack blocking the room lights, or bring it into another room to diagnose the issue where it would not happen.

This is not really an issue for usability since almost no one uses IR transmitters for studio packs (instead using radio triggers) but if someone holds down the reset button for 10 seconds the pack resets to factory defaults which on some packs means the IR receiver will be on.

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IQ Firmware: Live Preview & More

July 28, 2011 | Tech, Tech Features, Top Articles

Firmware 1.33 Now Available

Phase One has released firmware 1.33 for the Phase One IQ series (Phase One IQ180, Phase One IQ160, and Phase One IQ140).

Compared to firmware version 1.19 this firmware offers the following improvements:

• Live View is now available on the IQ display
• IIQ Small file format is now available
• New Specific camera mode for Mamiya RZ PRO IID
• General stability improvement

IIQ-Small

IIQ Small (IIQ-S) format is a lossy compressed format. It sacrifices a very small amount of image quality in exchange for a much smaller raw file. It does not change the resolution of the system and can be used in either full-resolution mode or Sensor+ mode. Those seeking the absolute highest image quality will still want to use IIQ Large (IIQ-L) format, which compresses the raw without any loss of quality. However, the IIQ-S algorithm has been greatly improved from the algorithm used in the P+ series, opening the door for photographers and applications where a very minor loss of quality (producing files still far beyond that of almost any other camera system) is acceptable in exchange for increased speed and reduced storage needs.

Live View

The Phase One IQ series is the first digital back in the world to offer Live Preview on the LCD of the back without the need to tether. It’s important to note that the Phase One IQ series uses a CCD sensor so the frame rate and range of acceptable lighting/contrast conditions is well below that of CMOS based dSLRs. However, in conjunction with variable ND filters to control the amount of light hitting the sensor Capture Integration is hopeful that the Live View will offer an extremely useful tool for the composition and focusing of technical cameras such as the Arca Swiss RM3D and Cambo Wide RS. We will be performing extensive tests.

Download Links

• Phase One White Paper on Live Preview
• Download Firmware 1.33

Install Instructions

Update should be performed with the digital back disconnected from the camera, and without FireWire or USB connected. Also make sure you have a fully charged battery in the IQ back.

• Download the latest IQ Firmware from the link above,
• Transfer the .fwr file to an empty compact flash card and insert it into the IQ’s compact flash card slot.
• Select “Update Firmware” from the Firmware menu and the IQ back will automatically detect and implementthe update from the card.
• After upgrade the digital back will have to be rebooted, a full reboot is performed by removing the battery from the IQ back, and reinserting it.
• After rebooting select [Menu > Restore Defaults] to ensure the back is on default settings.

Note: If you have any issues with the update, the “Restore Firmware” option will revert to the factory installed firmware version. If you experience errors you can use the menu “Dump Log” to transfer Log information to the CompactFlash card – this log file you can use to send to support for further analysis

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