Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Miscellaneous Techniques › Can the JVC GZ-HD7 produce film-like video?
October 15, 2007 at 7:56 AM #37116noloc4545Participant
I have a JVC Everio GZ-HD7.
The specs are:
– 3 – 1/5" CCDs
– Focal Length: 3.3-33mm
– F Stop: 1.8-1.9
– Filter Diameter: 46mm
– 1/2 to 1/4000
My understanding, is that for film-like production I need a 35mm lens and a 24fps production. What I dont understand is what the difference between the Focal Length and the Filter Diameter measurements are. If I want to buy a 35mm lens, am I buying a 35mm sized lens or is the 35mm referring to the focal length? I was looking at some DIY 35mm adapter projects (which, of course I dont understand too well) and the person doing it, used a Canon F1.8/50mm. Does that mean the actual size of the lens is 50mm and the focal length is 35mm? Im confused!! Any help would do! Also, with the specifications above…do I even need to make an adapter, or are the numbers exactly or somewhere near film-like production material?
October 15, 2007 at 10:04 AM #164511AnonymousInactive
Hollywood movies have typically been made with motion picture cameras shooting 35mm film. The image area of a 35mm frame is huge, compared to the size of the CCDs in a consumer or prosumer camcorder. It’s just a property of optics that you’re going to have shallow depth of field with these large frames. Of course, you can increase the depth of field by increases the light, which allows you to"stop down" the iris in the lens. Shallow depth of field can be used when shooting a romantic close-up of your leading lady. The background with be a soft blur, and only the lady’s face will be in focus. Also, having shallow depth of field allows you to do a "slip-focus" shot. A slip-focus shot is when you start focused on one thing, then change the focus to something else, thus shifting the viewer’s attention from one thing to another.
The 35mm lens adapters are a way to allow small-CCD camcorders to get the shallow depth of field of a Hollywood motion picture camera. Many professional cinematographers prefer to minimize the use of shallow depth of field, arguing that in real life your eye puts into focus whatever you look at. So having the audience look at a big fuzzy blur on the screen just isn’t natural. It comes down to your individual visual style. BTW, Ansel Adams, the famous still photographer, always put everthing in focus (but then he was usually shooting landscapes).
My advice would be to use your camcorder as is. When you need shallow depth of field, zoom to a longer focal length, and if needed, put a neutral density filter on the lens to force the iris to open up more. Granted, this won’t be quite as shallow a depth of field as you’d get with a 35mm adapter, but it sure would be less hassle. Also, I suspect that you might lose some visual quality by adding an adapter to the optical path.
The Canon F1.8/50mm has a focal length of 50mm. Filter size is probably 52mm or 55mm. And, in this context, 35mm refers to the width of the film.
Regarding frame rates: When movies were 1st made, they shot at 16fps, because that seemed fast enough to produce the "persistance of vision" effect (which makes a sequence of still images seem to be in motion). When Hollywood switched to sound movies, they put the sound track along the edge of the film. 24fps was used, since you could get a higher fidelity sound, and also the visuals looked smoother. When Super-8 film was introduced, they used 18fps instead of 16fps for the silent speed, because even that slight rate increase make motion smoother. However, with some camera moves, even 24fps can look just a little jerky. Some experiments were done using higher frame rates, like 48fps. The results looked great, but film stock is expensive. Besides, theaters would have to get new projectors to go at the faster speeds. So 24fps has remained as a standard for sound movies shot on film. But video can do 30fps, for even smoother motion!!! I’ll bet some past cinematographers are turning in their graves at all this talk about slowing down from 30fps to 24fps in order to get a "film look".
( X-D Just my opinion. X-D )
Hope I put things into focus for you! 🙂
October 18, 2007 at 8:14 AM #164512adaptoruserParticipant
FYI you can find everything you need to know about lenses for use with 35mm lens adaptors like the Redrock M2, Brevis, Letus35 etc. at http://www.lenses35.com. This site also has a large selection of mint/near mint moderately priced lenses for sale. They will answer any question you might have.
August 26, 2008 at 11:01 PM #164513
- You must be logged in to reply to this topic.