By Chuck Gloman
The best way to get the optimal image from your video camera is to use the best lens possible. Most camcorders do not come with interchangeable lenses, but the British company SG Pro (among others, such as Letus and Redrock Microsystems) offers an adapter to use 35mm still camera lenses on your video camera.
Why would you want a 35mm quality lens on your video camera? There are several reasons: 1. Normally, you get a much higher quality lens with better optics; 2. Your depth of field decreases giving you a more film-like selective focus; 3. If using a prime lens, the sharpness is greater because there are fewer optical elements for the light to pass through; and 4. You have a wide array of focal lengths to choose from, from fisheye and super telephoto.
The SG Pro is an image converter/adapter that attaches to a focusing rail mounted on your tripod or dolly and then to your video camera – in our case, an Panasonic AG-HPX170. The SG Pro lens mount we used converted an SLR camera lens to any video camera and would accept lenses from Nikon, Canon, Olympus, Leica, and several others.
Brian Dieck, a graduate of DeSales University TV/Film Program and an assistant editor and grip for bkk Communications, Inc. (specializing in broadcast and corporate videos) worked with our TV/Film students to utilize the latest in technology on a location shoot. Funded by a grant from the Baker Foundation, professionals in the industry (like Brian) spend the day with students teaching them valuable skills that only those working in the field can provide.
Ray Hoover, the teacher for DeSales’ Cinematography class met his students on our baseball field to shoot a scene with a the HPX170 and SG Pro adapter. Ray and Brian both believe that on-the-job training is essential in a complete education.
Ray and Brian discussed the look of the scene which involved two actors walking along the fence and one of them sitting in the dugout. Thirty feet of dolly track was laid and leveled for the Fisher dolly. Because this would be a tracking/dolly shot, the actors would be recorded in medium close-up as they made the journey.
The Panasonic HPX170 shoots in 720/24p onto a P2 card allowing about 40 minutes of footage. The SG Pro adapter utilizes a spinning ground glass (powered by two AA batteries) that gives the shot image a more “organic” film look according to Brian. The SP Pro adapter screws to the front of the camera and locks into place via Allen screws. A 35mm lens is then chosen, in our case an 85mm Nikkor F2.8 manual-focus prime. This lens allows a very narrow depth of field and is slightly telephoto. (Any 35mm lens is acceptable but Ray happened to have Nikkors.) The camera operator then zooms in slightly to crop the image in the viewfinder so the camera is shooting through the lens. The camera must then be manually focused in macro in order to see the grain in the ground glass. Having shot with 35mm motion picture cameras, I can say with this setup, the image seen through the Panasonic’s viewfinder looks very similar to that of an Arriflex with the ground glass.
One distraction is that the image seen through the SG Pro is upside down. The mirror in a 35mm SLR camera corrects this, but the HPX170 does not have this option — therefore the shoot footage must be corrected in post. This is slightly disconcerting when shooting because you are constantly trying to correct the shot. At least the rest of the crew experienced the same problem. In order to solve this dilemma, we turned our Panasonic flatscreen LCD monitor upside down so we could see the corrected shot.
(Note that SG Pro has recently introduced the add-on FLIPmodule to correct this problem.)
The image in the viewfinder looked as if it were being shot shot with a 35mm motion picture camera. The depth of field is extremely narrow and the 85mm Nikkor was sharper than the factory Leica lens on the HPX170. This is the look we were after and why we wanted to use the SP Pro in the first place.
Before any footage was shot, the action needed to be rehearsed numerous times. Coordinating the speed of the dolly, the panning of the camera, the rack focus of the lens, and dealing with the sun moving from behind the cloud took a lot of planning. Even though we were shooting in video, endless recording of every “practice” take is wasteful.
In a shoot like this, the focus puller has a critical job. By making small markings with gaffer tape on the barrel of the lens, Alex had to determine exactly where each character was at a given time. Unable to see the inverted viewfinder, he had to rely on the actors hitting their marks as well as his own on the lens. The SG Pro adapter and 85mm lens added another foot to the length of the camera but allowed Alex more real estate in which to work.
The mid-autumn sun created a backlight on the talent and large reflectors were placed throughout their route to provide the needed fill light. It was imperative that a lens shade was used because as the afternoon progressed, the sun sunk slowly on the horizon shining almost directly in the lens. Not wanting the F-stop to be changed during the shot, we often had to wait until the sun returned to provide the needed illumination as well as the correct color temperature. Fixing it in post should not always be the solution. When shooting outdoors, the lighting could change between every take and therefore the camera should be white balanced frequently.
Again, the HPX170 was the perfect solution because it is better suited in low light than the HPX200, it also has HD SDI output so numerous adapters are not necessary in the field, a built-in waveform monitor and vectorscope allow problems in lighting or color to be addressed, and the cold weather had no effect on the P2 card.
Both the viewfinder and field monitor were watched. Terrance, behind the camera needed to be concerned with framing the inverted image and Ray, acting as the DP, would ask for another half stop. A well functioning crew is ideal with each person having a role so nothing is overlooked. In bright daylight, the viewfinder can be the best source on the camera to accurately judge framing. All flip out LCD screens tend to wash out in direct sunlight. Always position your field monitor where it has a constant source of power and is shaded from extraneous light.
The end result had a “Hollywood-style” look on a more realistic — and modest — budget. The DeSales students gained valuable knowledge from industry veterans as well as working with some new technology from Panasonic and SG Pro.
Chuck Gloman is program director of the TV/Film Department as well as a member of the faculty of DeSales University. He may be reached firstname.lastname@example.org.