The 1D C line could have bolstered the dominance of Canon in professional video market and been one of their flagship DSLRs for video shooters. A chance to put all sorts of great technology in a small full frame body – full frame 4K, hybrid OLED viewfinder, yes, even focus peaking! Both are full frame and have similar pixel counts, with the EOS RP offering slightly more resolution at 26 megapixels compared to the A7 III’s 24. 1. Shot on Sony A7 III. 2. Shot on Canon EOS RP. 3. Canon EOS-1Ds is the world's highest-resolution professional digital camera, featuring the first-ever full-frame 35mm sensor with 11.1 million effective pixels. The EOS-1Ds captures astounding detail and color, almost doubling the resolution considered state of the art for a digital SLR camera in the world today (September 2002). While the 1D series has always been Canon's flagship line, the 5D series is the camera of most working photographers. The original 5D Classic came out in 2005 and was the first full frame DSLR From a build, function and usability point of view the EOS-1Ds Mark III is identical to the EOS-1D Mark III apart from the full frame (36 x 24 mm) sensor, (naturally) larger viewfinder and UDMA support for Compact Flash cards. Model line history The APS-H sensor sits somewhere in size between full-frame and APS-H. I always loved using my 24-105 L with the APS-H 1D bodies; the ~30-135mm equiv focal length was just right for the work I was doing at the time. Nu7okJ.