Digital Capture with a Better Light Scanning Back


The Scanning Back in Real World Applications

Frequent Questions About Scanning Backs

by Mike Collette, founder of Better Light  
This updated remake of a classic Pinkham & Smith pictorial lens shows off beautifully
in front of a Better Light digital scanning back!

Photography literally means “drawing with light”, and perhaps the greatest influence on any “light drawing” is the lens used to form the image being recorded. Some photographers strive for perfect sharpness throughout their images, while others choose selective focus to express a more abstract view. The well-known Group f/64 advocated sharp, detailed photography – many of its adherents probably knew better than to actually use such a small lens aperture routinely, but the name was antithetical to the wide apertures often used by pictorial photographers to achieve a softer, more impressionistic look. As large-format lens designs improved during the first half of the twentieth century, image sharpness increased as optical aberrations diminished, so some pictorial photographers of the time had lenses designed to yield an intentionally “less than perfect” result for their impressionistic images. A series of such lenses was designed by the Boston optics firm of Pinkham & Smith specifically for pictorial photography, and one of the most notable from this group was the Visual Quality Series IV 9 inch f-4.5 lens, which combined very sharp performance at smaller apertures settings with a wonderful highlight diffusion at wider apertures. This combination of sharpness and softness could be controlled by varying the aperture setting, giving photographers a very interesting tool for their “light drawing ” kit.

UK-based Cooke Optics ( has re-created this legendary optical design in their recently-introduced PS945 soft-focus lens, complete with the original aspheric elements, but with modern coatings to improve color and reduce internal reflections. These limited-production lenses are more expensive than typical large-format optics, but offer some unique options for the discerning photographer. One factor driving price is the relatively large maximum aperture of f-4.5 for a 229mm lens, requiring substantial elements and a Copal 3 shutter. However, examining a few images from this lens quickly renders price secondary to less tangible qualities it offers, quite literally unlike anything one has seen before.

The following is from Cooke’s description of the PS945:  "The original Pinkham & Smith lenses achieve their distinctive soft focus in a manner different from other lenses. Using the traditional glass available at the time, craftsmen hand-corrected multiple surfaces of the lenses to achieve their unique soft focus look. The introduction of aspherical surfaces gave Pinkham & Smith lenses a higher-order spherical aberration that results (when the lens was used fully open) in an image with both very high resolution and a self-luminescent quality. Cooke has reproduced the unique performance of these hand aspherized lenses using modern design techniques that duplicate this unique soft yet high-resolution performance exactly.”

Most photographers understand that the high resolution of Better Light’s large-format digital scanning backs can deliver sharply detailed images, but not as many realize that the wide dynamic range and low noise of these unique image capture devices also make them perfect for rendering softer images with subtle gradations. The combination of a high resolution digital back with a soft-focus lens might at first seem improbable, but in many ways these unique optics have never looked better. Using wide aperture settings also lets more light into the camera, allowing fast scan times at low ISO settings, for optimum results.


After some delay while waiting for another batch of Copal #3 shutters to be produced (!), Better Light recently took delivery of Cooke PS945 serial number 0058. Here are a few initial test shots using this lens at its widest aperture setting, where it produces the most pronounced soft-focus effect. A model 6000-HS captured these images at its full resolution of 6,000 x 8,000 true RGB pixels, generating uninterpolated 274 Mbyte 48-bit files fairly quickly, thanks in part to the wide lens aperture. The examples on this page are each 600 x 800 pixels in size, so the overall 6,000 x 8,000 pixel image would be ten times larger in each direction. On a computer monitor with 100 pixels per inch (a pixel pitch of 0.25mm), each full-resolution image section should be displayed at about the same size that it would appear in a 60 x 80 inch print of the overall image.


“BACKYARD IN RAIN”(at left and below ) was captured during a light rain one evening in January, which is why there are no leaves on the birch trees. The camera’s plane of focus was placed along the foreground light post and nearest corner of the gazebo by using appropriate front swing. Most of the original image (shown at left) was very dark when the light fixtures were properly exposed, suggesting that I missed the optimum time for this photograph. However, I was able to selectively brighten things up by several f-stops without introducing much noise (below). The overall image below exhibits a dreamy softness in its out-of-focus background, with a halo of diffusion around bright objects everywhere in the scene.
Jan 28, 2006 at 5:18 PM;   PS945 at f-4.5; 1/60 sec Line Time at ISO 350;   133 second overall scan time ( original above )

  Below is a full-resolution crop from the image shown above that demonstrates how the PS945 behaves wide open – subjects in the plane of best focus are rendered sharply, but bright subjects have a diffuse halo around them, caused by the intentionally-introduced aberrations in the lens design. Noise in the darker areas is the result of boosting the overall brightness of this image considerably, using an aggressive Curves adjustment in Photoshop.  

  Below is another full-resolution crop from the same image. The PS945 renders the foreground corner of the gazebo roof with good detail, although contrast is reduced in lighter areas, providing a softer appearance. In the distance there’s a redwood light post and fixture just like the one in the foreground (above). The thin vertical lines near the right side of the image section below are caused by falling raindrops, as seen by a scanning back…  

  “WET BRANCH AND WEBS” – (below ) was captured early in the morning after a light rain, while everything was still wet, and the sun was peeking through the clouds to add some sparkle. The camera was set “straight-on” for this relatively close-up photo, and the resulting image certainly shows out-of-focus areas both nearer and farther from the camera than the plane of best focus, but doesn’t particularly demonstrate the soft-focus effect of the PS945. This will change upon closer inspection… Full resolution image available for viewing. Click here.  
Jan. 29, 2006 at 7:38 AM;   PS945 at f-4.5; 1/80 sec Line Time at ISO 809;    100 second overall scan time

Below are four full-resolution sections cropped from the same image shown above that demonstrate the intriguing blend of sharpness and softness that the Cooke PS945 soft-focus lens can create, particularly when combined with a high resolution Better Light scanning back. These image sections are exactly as produced by the lens and digital back, without any subsequent modification.

 BELOW is a comparison showing the adjustable softness rendered by the Cooke PS945 at different aperture settings. These images were captured a few minutes after the “wet branch and webs” image shown above, and the light had already changed considerably. The scanning back’s exposure was adjusted to maintain a constant overall image brightness as the lens aperture was varied.
 CLICK HERE to download the comparison image shown below at full resolution (383 kB JPEG file)
To SAVE images on Windows, right-click on the link to image and then select "Save Target As..." (NOT "Save Picture As...", which only saves
the picture currently displayed). On Macintosh, press Control and Click to reveal menu and select "Download Image to Disk "
 BELOW are 1600 x 1200 pixel images that can be downloaded and used as desktop images for your computer, with our compliments.
To SAVE images on Windows, right-click on the link to image and then select "Save Target As..." (NOT "Save Picture As...", which only saves
the picture currently displayed). On Macintosh, press Control and Click to reveal menu and select "Download Image to Disk".