FocusTwist: Focus-Controllable Images with the iPhone

FocusTwist Logo (copyright, FocusTwist)

Logo Courtesy of Arqball

When you think of controlling the focus of images after the fact, you probably think of the Lytro camera; a clever little device (one is tempted to say prototype) that shows us one way of gaining different info from a shot, instead of spending all our pixels on increased resolution. But now there is an iPhone/iPad app (I’m tempted to think of this as a prototype as well) which allows you to perform a similar trick with your phone photos.

With Arqball’s FocusTwist  app, its time, not resolution reduction, that is used to produce the multiple images. Hold your iPhone still, tap on the foreground element on screen to start the focus process, and in a couple of seconds the FocusTwist app will have captured multiple images with different focal planes; starting with the foreground element you selected. Take a look at this example, which I shot with FocusTwist to include in this article.

FocusTwist Image Example

The process is something of a gimmick, in that the resulting photo can’t be used as a standard image, since there is no current format for “multiple focal plane images”. The other “gimmicky” factor is FocusTwist’s expectation that the foreground object be three to five inches from the lens. This is a great range for macro shots with recent iPhone models, and it shows off the focal plane change function clearly. But it also makes all photos taken with FocusTwist rather similar. The term “meme” comes to mind.

But there are other issues than the “one trick pony” aspect of the application. Note that, while the iPhone was carefully placed and oriented for several seconds before the shot was taken, that FocusTwist failed to orient the image correctly; it appears to be a one-orientation pony as well. And if one wished to adjust the exposure or other factors of the image, say to lighten the tub handles in the foreground? Since this is not a standard image it cannot be edited in a standard image editor, so rotation, lightening, cropping, or other adjustments are not possible. Please recall my “prototype” comment above.

Will FocusTwist images make the rounds as the next phone photo fad? Will such images be passé in a few months? Or are the capabilities of this App perhaps a bit deeper than the directions and marketing video imply? One further dimension that immediately comes to mind is time: it would be possible to capture boughs waving in the breeze, cars moving on the road, or a dancer spinning on the floor in the multiple frames of a FocusTwist image; particularly if Arqball chose to extend the App’s capture capabilities.

How much further will Arqball move with features and functionality? Will they add an option to render out to video, or animated GIF, so that the results of their app can be widely used, instead of trapped in the snowglobe of their own application and website? Will they see this as a beginning of a category, or a parlor trick? Only time will tell…

Credits: C. David Tobie, Copyright 2013. Website: Return to Blog’s Main Page

Adobe Lightroom 5 Beta for Datacolor Users


This week Adobe released a beta version of Lightroom 5. Here is my initial report on what Lightroom 5 Beta means for those using Datacolor products:


Lightroom, while it has added many printing conveniences over the years, has always lacked certain desirable functions for color managed printing. Black Point Compensation is always on when printing from Lightroom; Adobe invented BPC, and is very proud of it, but there are legitimate reasons for choosing not to use it, and the lack of a checkbox for this feature makes Lightroom printing less robust. And while there are four (or at least three and a half) rendering intents in ICC printer profiles, Lightroom chooses to only offer two of them to users. So those who prefer Saturation intent when printing using Datacolor’s SpyderPrint profiles, will have to continue using the SpyderPrint Preference option to switch the Saturation and Perceptual intents to create a version of their profile for printing from Lightroom using the Saturation intent (accomplished in Lightroom by then selecting Perceptual, and the special version of the profile with the switched intents).  None of this has changed in Lightroom 5 beta; though hope springs eternal. Perhaps Lightroom 6…


The Rendering Engine in Lightroom 4 was significantly different from previous versions, necessitating major changes in how the SpyderCube was used; but providing better controls for working with the Cube in the process. Lightroom 5 has no such engine changes, allowing the same process for using the SpyderCube with LR5 as with LR4.


The lack of Rendering Engine changes, or Color changes, mean that creating Camera Calibrations is done the same way in Lightroom 5 beta as it was in Lightroom 4, and that results are the same as well.

Spyder Display Profiles

How Lightroom uses display profiles does not appear to have changed, so it is not necessary to reprofile your displays to use Lightroom 5 beta. But its still a good idea to recalibrate at least once a month anyways…


Lens Auto-Focus Calibration is a camera firmware function, so does not effect Lightroom, or any application, other than providing sharper images to work with.

A Word on LR5B In General

Most of the changes in Lightroom 5 beta involve allowing it to perform more image editing functions. Some of these are functions that used to require moving the image into Photoshop (and out of RAW) that now can be done in Lightroom; and in some cases more easily and automatically than in Photoshop. And a clever new version of Proxy Editing allows images on drives not currently on-line to be edited using a new, larger preview image. This will have some interesting Cloud implications in the long run.

For me the improved rendering engine was the key feature of LR4, while the softproofing function and its ability to create custom tuned virtual print versions of an image for various papers was the elegant new addition. This time around the off-line editing capability has a similar feel of being the elegant new addition, while the LR5 “engine” changes are limited to added capabilities in the Lens Profile section. I will plan to cover these Lens Profiling changes, and what they mean for advanced users, in a future article.

Credits: C. David Tobie, Copyright 2013. Website: Return to Blog’s Main Page

Using SpyderLensCal for Video Focus Control

Datacolor’s SpyderCheckr is used to check the auto-focus on still cameras, and to micro-adjust the auto-focus on cameras with micro-adjustment controls in their in-camera menu. However, there are other uses for LensCal. This article describes how to use it to assist with focus setting in video, TV, and cinema capture workflows.


SpyderLensCal showing Depth and Center of Focus

Videography is based on manual focus methods, but SpyderLensCal can still be useful for video capture. Lets start by considering how focusing is done with a video camera. Video focus is manual, and occurs by rotating the focus ring on the camera lens, or manipulating a “follow” device connected to the focus ring.


Geared Ring added to a DSLR Lens, Follow Gear on Far Side

The results of these adjustments are viewed on the LCD on the back of the camera, or on a portable video reference display screen attached to the camera framework. These screen range from small to tiny, so it can be difficult to determine focus on such screens. It is possible to zoom the view on the camera-back display, and sometimes on the reference display, to enlarge a small part of the screen to more effectively check focus. A larger video reference display is sometimes used as well, either in real time, or with a delay, but these screens are not available to the cameraman adjusting the focus controls.


Reference Display mounted on a Camera

Here’s how one or more SpyderLensCal units can improve the accuracy of focus with a video camera. Lets envision a shot where the camera remains stationary, no pan, no zoom, but the focus moves from a glass with lipstick on it in the foreground of the shot, to the face of a woman wearing the same color lipstick in the middle ground. This configuration simplifies the description, as other adjustments to the lens or camera are not needed in this scenario.

To determine the ideal focus for the beginning of the shot, a LensCal is placed on the table next to the glass, and its target plane is aligned with the surface on the glass with the lipstick stain. The camera is is then focussed on the LensCal target, and can be checked, either at full size on a large remote reference display, or by zooming in on the small target bullseye and sloped scale on the camera LCD. The sweet spot in the intentionally shallow focal range will register on the LensCal scale, and the sharpness of the focus will be clear on the target. Adjustments can be made as needed. This position can then be marked on the follow-focus device, or noted on the focus ring. Cinema lenses, with their longer throw, will increase the level of precision possible.

Next a LensCal unit on a light stand beside the actress in the middle ground will be focused on, repeating the process of checking the focus, and marking the correct location. An advanced follow-focus tool with hard stops available at each end would make this process even simpler. Now both LensCal units are removed from the set, and the shot is made, using the start and finish references to assure accurate focus at each end. This technique can also be used for single focus shots, but is particularly useful when there are multiple functions occurring in the shot; being able to remove two variables allows the cameraman to “focus” on the other functions.

So, don’t leave your SpyderLensCal in the dark when shooting video, get it out and put it to use checking the focus on your shallow-focus shots, and improve the sharpness of your video.

Credits: C. David Tobie, Copyright 2013. Website: Return to Blog’s Main Page

WEBINAR: Exploring Architectural Photography, Today 3PM EDT


This webinar will be an unscripted discussion of the concepts and techniques used in architectural photography, sponsored by Datacolor. David Saffir and I will be discussing a range of sample images, chosen for their value in illustrating architectural concepts and the techniques used to shoot them. Please join us for what we hope will be an interesting discussion on this very challenging theme. And stay tuned, as there will be a Datacolor Spyder product given away to one attendee at the end of the session, plus some excellent discounts for all attendees.

Sign up now at :

Credits: C. David Tobie, Copyright 2012. Website: Return to Blog’s Main Page