Why CMOS Sensors Are Changing Medium-Format Photography

June 12, 2014

By Dan Havlik

The Phase One IQ250 digital back was released in January 2014, making it the first imaging product to sport Sony’s 50-megapixel 44 x 33mm CMOS sensor.

This article is part of a series, “The Next Big Ideas: Thoughts on recent trends and innovations likely to influence photography in the year ahead,” which appeared in the June Photo Annual issue of PDN. Use the following links to read other articles in this series: 
Why Social Media Marketing Demands Great Photography
Hackathons: Asim Rafiqui On The Value of Multidisciplinary Experiments
Ivan Sigal on Bringing New Ideas and Underrepresented Voices to Storytelling
The Market for Better-Looking Stock
Picture Editor Mike Davis On Clarity of Voice in Today’s Media Landscape

The digital medium-format photography landscape changed dramatically this year and it was all because of a single chip. Manufactured by Sony, the 50-megapixel, 44 x 33mm CMOS image sensor quickly established itself as a “game changer” in the medium- format world when it first appeared in Phase One’s IQ250 digital back last January. We got our hands on an early IQ250 production unit and put the back and its much-touted chip, which is the world’s first medium-format-sized CMOS sensor, through its paces during a field test. In a nutshell, we were pleased with the photographic results. Extremely pleased, you could say.

Medium-format cameras are great for capturing gorgeous, detail- rich images with massive amounts of resolution and exceptional dynamic range, but they’ve never fared particularly well when shooting at high ISOs in low light. (In fact, many digital camera backs can’t even shoot past ISO 800.) Older digital backs and their CCD sensors have traditionally produced extremely noisy images at higher ISOs that are damn near impossible to clean up in image-editing software. But just as digital SLRs successfully transitioned from CCD sensors to less noisy CMOS chips nearly a decade and a half ago, the new CMOS-powered IQ250 produced remarkably clean images for us all the way up to ISO 6400. Only a few months prior, this would have been unimaginable. But this new medium-format CMOS sensor was not limited to the Phase One back alone. In March, Hasselblad started shipping its new H5D-50c medium-format camera system, which uses the same Sony-made 50-megapixel, CMOS sensor as the IQ250. The chip will also be used in the new Pentax 645Z medium-format model.

Another benefit of using a CMOS sensor instead of a CCD in a medium-format camera is that it allows these camera systems to shoot faster. In the case of the IQ250, it can shoot at 2 frames per second (fps), while the H5D-50c has a 1.5 fps capture speed. No, that’s not close to the speed of a pro DSLR, but with a medium- format sensor that has 68 percent more capture area than 35mm full-frame, that’s exceptional. And as these CMOS chips start turning up in more and more medium-format models, the best could still be yet to come. In the case of the Pentax 645Z, it may already be here. Thanks, in part, to its CMOS chip, the 645Z is the first medium-format camera that can shoot HD video.