film lenses on digital cameras

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SALLYNABIL

Guest
i wanna know if i can use the traditional film camera lenses with the digital cameras instead of the zoom lenses
 
With an adaptor like the P&S Technik, sure. There the video camera is rephotographing the image off of the 35mm cine lens as it is being projected onto a groundglass surface.

If you're talking about putting 35mm cine lenses (usually with a PL mount) directly onto a 2/3" CCD camera with a B4 video mount, not so easy.

Besides having to switch out the mount, I doubt there is enough flange depth between the back of the lens and the prism block for many cine lenses, but even if there were, you'd have the problem of needing S16-type focal lengths just to get wide-angle shots.

Also, most pro video lenses are designed to go onto cameras with CCD's on the end of prism blocks, with IR and OLPF filters, so the red, blue, and green wavelengths travel different distances to each sensor and the lens is optimized for that, whereas a cine lens is designed for all light rays to focus on a single plane. So there may be some sharpness and color fringing problems from just sticking a cine lens directly onto a video camera.

There are simple optical relay attachments that allow PL-to-B4 conversions for using cine lenses on a B4 video camera, not the type where you are rephotographing a groundglass as with the P&S Technik-type devices (Redrock, etc.). You don't gain any real depth of field advantages then.

But a true pro HD video lens (zooms or primes) would give you better sharpness on a video camera.

I think the Canon DV cameras like the XL2 and H1XL use a Canon mount that allows ordinary Canon still camera lenses to be put on the camera. Again, the problem is that a 1/3" CCD camera needs very short focal lengths for normal viewing angles, so most people would only use a Canon still camera lens on a Canon DV camera for telephoto photography.
 
S

SALLYNABIL

Guest
thanx for the clarification Mr. David and let me ask u another question; i know that there are digital cameras that work with 24 fps, how can this add to the resolution of the picture ? can this cameras be a real competitor to movie cameras ?
 
24 fps doesn't really describe resolution (but then technically neither do pixels...)

Compared to an interlaced-scan camera (50i or 60i), a progressive-scan camera (shooting like at 24P or any other "P" rate) will have improved vertical resolution when doing any film-out or for display on a progressive-scan monitor because the frame is not made up of sequentially-captured fields as in interlaced-scan camera. When there is any movement of the camera or subject, it occupies a different place on each field when shooting in interlaced-scan mode, so when de-interlacing, you get a sawtooth edge to moving objects because one scan line is from one field capture, then the next scan line is from the other field, and then the next is from the previous field, and so on.

But generally resolution of a broadcast video format is described in terms of whether it is standard def (480/60i or 576/50i) or HDTV (720/60P or 1080/60i for example).

But if you're asking if 24P/1080 has more resolution than 60i/1080, again, it's an issue of vertical resolution only IF you plan on recombining the fields for a film-out or progressive-scan display. Either way, it would be 1920 pixels horizontal resolution.

If you're asking if 24P matches film resolution, it's not really the right way to ask the question. First of all, there is 24P standard def and HDTV. And second of all, film includes everything from Super-8 to IMAX.

For theatrical projection on medium-sized screens, HD photography, even though it does not match 35mm resolution, is generally acceptable in resolution (sharpness, detail, whatever.) 35mm negative is closer to 4K (4000 pixels across) compared to HD (1920 pixels across) but you factor in that the printing process in film (or HD-to-film) loses some resolution. So HD that is digitally projected in HD/2K -- thus no loss in resolution from transferring to film and making dupes and then release prints, and then being projected, etc. -- would seem comparable to 35mm print quality in terms of sharpness, if not better.

But in theory, only the new 4K Bayer-filtered cameras like the RED or Dalsa come close to the resolution of 35mm, although a good 4:4:4 3-CCD camera like the Sony F23, or a 35mm-sized RGB-filtered HD camera like the Genesis, also come close (you figure that a 4K Bayer-filtered camera is practically-speaking more like 3K RGB, and a 4:4:4 3-CCD HD camera is nearly 2K RGB, so they are not far off. Also, many 35mm D.I.'s are only done at 2K RGB resolution, bringing film down closer to HD resolution anyway.)

But you're probably thinking smaller & cheaper than all of those cameras...
 

Taylor Rudd

New member
i wanna know if i can use the traditional film camera lenses with the digital cameras instead of the zoom lenses
The P+S technik is an option, but far from likely for student budgets.

I invested in a Letus Extreme, which I use Nikkor lenses with. While it is definitely not a replacement for a camera that natively accepts cine lenses, it is one step closer in the right direction. Not only do you achieve the shallow DOF of a 35mm-ish frame, you also have to become a pro at pulling focus :)

Personally I use a Canon XH-A1 + Letus Extreme combo. I shot two shorts with this combo and was 1st AC for a feature my school's film department shot in June (we used a Sony EX1 with the Letus Extreme and Zeiss primes).

Lighting still pulls the heaviest load in achieving the cinema look, but these tools certainly allow you more creative control when used properly.


Edit: Here is one of the first lens tests I did with my setup: http://vimeo.com/712895 - my only complaint is that you cannot stop down further than ~f/4.8 on the prime before seeing the pattern of the adapter's ground glass.
 
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