– what’s the difference

Atticus Webb is fastidious about cameras. Over the years his favourites have been a Hasselblad 500CM, a Rollei 6x7 and a Contax 645, using both film and digital.   He currently shoots with a Phase One 645 medium format camera with an 80 megapixel One IQ180 digital back.

Images in the collection have been taken with the Contax 645 and the Phase One 645.


The Contax 645 and Phase One 645

The Contax 645 was made by Carl Zeiss primarily as a film camera until 2005.   The Contax 645 was regarded by many in the industry as the best medium format camera ever made – even excelling the Hasselblad 500cm.  Since the Contax also accommodated digital backs, many professional photographers and serious amateurs have continued to chase a dwindling supply of these legendary cameras.  As a result Contax 645 cameras have increased in price year on year since production ceased.

Phase One – manufacturers of the Phase One back – also sell Phase One cameras with Mamiya bodies (branded Phase One).  Technically these bodies are more advanced than the obsolete Contax, but many adherents continue to chase the Zeiss product or Hasselblads to mount their digital backs.

The Phase One 645 system finally overtook the Zeiss/Contax combination when Phase One launched Schneider Kreuznach leaf shutter lenses to compete with the Zeiss product in 2012.  At that time Atticus had his Contax 645 stolen in the Paris Underground.  He then switched to Phase One cameras as well as digital backs.

Why Phase One Digital?

The Phase One 80 megapixel back produces the highest resolution currently available from any camera system – over six times more detail than the best 35mm equipment, including Canon’s and Nikon’s flagship cameras.

Firstly, this comes about because of the difference in megapixels. The Phase One IQ180 back shoots 80 megapixels per square inch.  By comparison, the maximum megapixels available from other professional cameras by makers such as Nikon and Canon is approximately 36 megapixels per square inch (and most high end models are typically 18-20 megapixels).

Sensors – size matters

However, the most important difference lies in the area of the digital sensor – an area often overlooked in the fascination with megapixels. (In fact, most cameras do not readily announce the size of the sensor.)

The digital sensor in the Phase One back has an area of 27 cm2 (6cm x 4.5cm) compared with an area of 8.4cm2 (3.5cm x 2.6 cm) for the largest sensor available on digital cameras by makers such as Nikon and Canon.  This means that even if both sensors were shooting with the same megapixels (which they do not) the medium format back would produce more than three times the detail of the smaller sensor.


Atticus Webb uses a full range of Carl Zeiss lenses on the Contax 645.  Together with a small range of other manufacturers (including Schneider Kreuznach, Rodenstock and Leica) these German lenses exceed the quality (and price) of the lenses available on other cameras.

The Zeiss lenses are no longer manufactured for the Contax camera.  Their disappearance coincided with the digital revolution and the introduction of environmental regulations in Europe limiting the use of lead in camera lenses. 

In medium format photography the Zeiss lenses have now been effectively replaced by their long-standing rival Schneider Kreuznach –now supplying Phase One

No effective substitute for the German lenses has yet been found – although modern lens coatings are much better than coatings of 10 years ago.  The Japanese makers produce fine lenses, but they are still no match for hand-made German lenses.   In combination with pixel count and sensor size, the consequences become obvious when images are viewed through large prints.

Taking the Shots

Finally, to get the very best from the equipment, a heavy tripod must be used wherever possible.  There must be no camera movement – the slightest movement will show when the image is enlarged to over a meter across.

Typically Atticus carries 15-20kg of camera equipment in the field.  He finds a market shopping trolley an excellent companion and he looks to his family to help heave it over the bridges of Venice or up countless steps in French villages.

Real Photography

In a commercial world in which photography has become foolproof and easy, the manufacturers have promoted the community belief that light point and shoot cameras (not to mention mobile phones) can hold their own against the best.  And that is true up to A4 size enlargements.

This is reinforced by the fact that cameras with short focal lengths (point and shoots/mobile phones) have significant and inherent depth of field which encourages the photographer to wonder how photography became so easy.

However real photography becomes apparent when the images are significantly enlarged.  Visitors to the Atticus Webb Gallery in South Yarra are impressed by what they see.  By the same token the difference is not apparent on images viewed over the internet.