I learned about the differences between HD dSLR and 35mm film from two sources: Ken Rockwell who used to work in Hollywood before focusing on digital photography and an interview with Greg Yaitanes who recently directed the season finale of House. The episode was filmed entirely with the Canon 5D Mark II. They're coming from a professional, Hollywood studio perspective, but I think much of the discussion is still relevant to amateur filmmakers.
Pros of HD dSLR
- No film and processing to pay for (that same advantage that digital still cameras have over film still cameras) - this will save you tons of money. According to Ken Rockwell, an hour of film costs a Hollywood studio $10,000 - for the film itself and all the processing.
- Since HD dSLR is already digital, you can take advantage of an all-digital workflow. This can save you lots of time and money since you can do all your post-production with your own team of people, in-house. The same advantage that digital still cameras have over still film cameras.
- You can shoot at ISO 1600+ and do amazing low-light video, which is not possible on film.
- The dSLR is tiny compared to the 35mm film camera, so you can record video in very tight spaces and not have to remove walls in your set in order to film from different angles
- There are tons of fast lenses available already for still cameras. You can shoot with an f/1.2 lens and get amazingly shallow depth-of-field. Or better yet, use a macro lens! According to Greg Yaitanes, they shot the House episode mostly with the 50mm f/1.2 and 85mm f/1.2 Canon lenses, and they also used the 24-70mm f/2.8, 70-200mm f/2.8, and 100mm macro lenses somewhat. Yaitanes claimed that he could get depth-of-field on the Canon 5D Mark II that was one quarter smaller than film.
- Or heck, imagine shooting video with a tilt-shift lens or fisheye! So many creative possibilities open up when you can use still camera lenses.
- The dSLR full frame sensor (24mm x 36mm) is larger than the 35mm film frame (approximately 18mm by 22mm). APS-c sensors are comparable in size to film (approximately 16mm x 23mm). So you'll always get shallower depth-of-field with full frame dSLR sensors. This is the reason why Greg Yaitanes chose to use the full-frame Canon 5D Mark II over the APS-c Canon 7D and APS-H Canon 1D Mark IV.
- In general (at "normal" ISOs), film simply has better image quality than HD dSLR video. This is the big issue. Film has a much better response to highlights whereas CMOS/CCD sensors blow out highlights very easily. However, if you are very good at lighting, you can probably use HD dSLR video and get around it somewhat. As Ken Rockwell says, you cannot do HDR with HD dSLR video. At least not right now.
- Manual focus on HD dSLRs is very difficult. Since the exciting part of shooting with HD dSLR is the potential for super shallow depth-of-field, that makes focusing even more difficult. But this should change as camera manufacturers get feedback from film makers and they improve the technology. Zeiss recently came out with fast, manual-focus prime lenses, designed specifically for HD dSLR video.
- Hollywood studios have been working with film forever, so they know how to use it. HD dSLR video is a new technology and film crews have to learn how to use it.