Barry Green
Forum Replies Created
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… soon, Ron promises we will be able to edit posts…
Okay, that was the wrong calculator I posted in the link. That was for the depth-of-field calculator.
This is the one that compares angle of view between different formats:
https://www.panavision.co.nz/main/kbase/reference/tblelenseqvform.asp—————–
Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
[jeremiah black] “Why is the diagonal of the frame smaller (around 25mm by your numbers) on cine cameras? 25mm seems awfully tiny. Also, shocking to think that 35mm cine only has a diagonal four times mini-dv.”
35mm film, as used in a still camera, runs through the camera horizontally. There’s 24mm between the sprocket holes. (the width of the holes, plus the thickness of the film on each side, bring the total dimensions up to 35mm). So on a still camera you get 8 perforations per frame, and the frame size is 36 x 24mm (w x h). The area between the sprocket holes is the height of the frame.
In a movie camera, you use the same (or basically the same) film, but run it through vertically. The area between the sprocket holes is now the width of the frame, not the height. As such, the frame is now a maximum of 24mm x 18mm.
A full-aperture Super35 frame has a maximum possible area of 24mm x 18mm, which is exactly half of the size of a 35mm still frame. Accordingly, lenses look more telephoto on a movie frame.
Now, that’s not where it ends — the actual, usable area of the 35mm cine frame is even smaller, due to two levels of cropping. First, one side is cropped down a couple of millimeters to make room for the optical soundtrack area. And, vertically, a lot gets lopped off to make for the 1.85:1 aspect ratio. So the actual, usable, visible area of a 35mm movie frame is more like 21mm x 11mm. That’s a total area of just 231 square mm, vs. a 35mm still camera’s total area of over 800 square mm.
Of course, it’s different if you’re shooting anamorphic (which uses a much larger 1.2:1 frame size, the full height of the frame and most of the width. And full-aperture Super35 lets you get the full 24mm size.
If you want to compare fields of view among various cameras and formats, the Panavision angle-of-view calculator is a most handy tool, at:
https://www.panavision.co.nz/main/kbase/reference/calcFOVform.asp—————–
Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
For those who may not want to visit the other forum to read the methodology, let me be clear about a few things: 1) this was not, as Luis said, any attempt to compare cameras, and no reasonable conclusion about forthcoming cameras can be drawn from viewing this test. The recording format is just one element in the total image chain. A $25,000 SDX900 can shoot and record on regular 4:1:1 DV, the same DV format as used by a $299 Sharp ViewCam from Circuit City. But there will be a *world* of difference in the images. Cameras are far more than just their formats, and while the format is important, it is by no means the only thing that counts. So looking at this test and trying to extrapolate forward that an HD100 would be better than an HVX, or that an HVX would be better than a Z1, would be completely unsubstantiated speculation. A brilliant camera head, recording to HDV, could probably look much better than a mediocre camera head recording to DVCPRO-HD.
Also, you may ask why, on each picture, there’s only one picture for DVCPRO-HD and there are two for HDV. The reason is that DVCPRO-HD compression is the same no matter what the circumstances — it’s intraframe, and nothing that happens in any other frame has any influence on what happens in the current frame. But with HDV, that’s not the case — frames are dependent on what else is happening within a specific group of pictures. So for testing, I decided to test both extremes: HDV at the best it can possibly be, and HDV at the worst it can possibly be.
For the best, I used a still image for the entire GOP, giving the MPEG-2 compression its easiest task. For the worst case, I took scenes from 15 different productions and scattered one frame from each across the GOP, so that every frame was as different as I could possibly make it.
The truth is, HDV video will almost never look as bad as the “worst” shot, nor as good as the “best”, but somewhere in-between, depending on each scene, the amount of detail, the amount of change per frame, etc.
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
[Julie Marzac] “1. Will it be possible to use a Firestore hard drive AND FCP/POWERBOOK simultaneosly to capture DVCPRO HD from HVX200 (for redundancy)? “
Probably not. Maybe. It’s a stream coming out the firewire port; I don’t know if you could use some sort of firewire hub perhaps; or maybe if the forthcoming HD FireStore offers an output port… for clarification, the existing FireStore products will not be able to capture DVCPRO-HD. They’re limited to about 40mbps maximum throughput, and DVCPRO-HD demands 100mbps, so there will need to be a new type of FireStore developed specifically to support the format.
[Julie Marzac] “2. Will an AVID Express PRO HD system on a notebook computer capture DVCPRO HD from Varicam deck? Will it capture all frame sizes and frame rates from a HVX200? “
Almost certainly. I would say “certainly” except I haven’t used Avid Express Pro HD, but FCP-HD will, so presumably the Avid will as well.
[Julie Marzac] “3. Can someone explain if the HVX200 uses progressive scan CCD’s or is the reported 1080p30 some sort of manufactured progressive signal? “
Newly-designed, 16:9-shaped, genuine progressive-scan high-def CCDs. The CCDs will support variable scanning frame rates (not just 24p and 30p, but as low as 4p and as fast as 60p).
[Julie Marzac] “4. I read something about needing a smart hard drive (if using standalone hard drive) for DVCPRO HD capture. Does this disqualify the use of a PCMCIA to SATA or PCMCIA to Firewire adaptor (and hard drives)? “
No, not necessarily. That remains to be tested. It seems very likely that someone will develop a PCMCIA-to-firewire (or SATA) device that will handle the processing that’s necessary. What Panasonic has clarified is that an off-the-shelf firewire drive may not be able to capture data directly from the firewire port (but then again, no camera can…) There needs to be some intelligence somewhere to handle the file system, etc. If the PCMCIA-to-firewire card handles what needs to be done, then yes you should be able to record directly to a firewire drive, using that adapter. That remains to be tested. Even if current PCMCIA-to-firewire adapters don’t work, it seems exceptionally reasonable that someone will develop an adapter that does provide that functionality.
What Panasonic has also verified is that you can use an off-the-shelf USB2 drive to dub the contents of a P2 card directly to the drive. You may not be able to capture directly to the drive, but you can dub directly to it (so, no laptop computer necessary, and no firestore-type drive is mandatory in that case; you can shoot to the card and dub it directly to any cheap off-the-shelf USB2 hard disk).
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
[jeremiah black] “On a normal lens (53 degree angle of view) focal length is equal to the diagonal of the image area. The diagonal of a 35mm piece of film is 43.27mm. The diagonal of a 1/3 inch CCD is .236 inches (5.9 mm)- yeilding a 22/3 ratio between the two, or 7.33. At 4.5mm (the DVX) at it’s widest point is a 33mm equivalent (4.5 x 7.33). Using the .6x century optics adapter, multiplying the magnification of the lens by the zoom focal length, gives you a 35mm film equivalent of 20mm.
Your numbers would be appropriate for a 35mm still camera, but not a 35mm movie camera, which is what Brian was referencing.
The 7.33 multiplier you used is typically rounded off to 7.2 — you’ll find most manufacturers, when listing a “35mm equivalent” for a 1/3″ camera, will use 7.2x. So the DVX lens, at 4.5 to 45mm, is listed as equivalent to 32.5 to 325mm on a 35mm still camera.
With a cine camera, the frame is much smaller than it is on a 35mm still camera, so you use a smaller multiplier. For cine equivalency, the multiplier is 4.2. A DVX lens delivers the equivalent of 18.9 to 189mm on a 35mm movie camera.
With a .6 wide-angle adapter, the DVX matches the field of view of a 35mm movie camera with about an 11.5mm lens (or a 35mm still camera with a 20mm lens).
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
Excellent! Very well done — simple, elegant, to the point, easy to follow, and you clearly outlined your methodology as well as provided the original source graphic so others could conduct their own tests. Also, excellent choice of codecs, because DVCPRO25 let you choose 4:1:1 vs. 4:2:0 but with the same compression.
Thanks for this very nice work!
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
Actually, the deck *will* record the 1080p signal. The way the 1080p is implemented, it’s carried within a 1080i stream, just like 24p and 30p are implemented on the DVX and XL2. So the firewire data stream coming out of the HVX will be a DVCPRO-HD-compliant 100-megabit 1080i data stream, with flags set for pulldown recognition. The AJ-HD1200A will be able to record it, and any DVCPRO-HD gear would be able to play back those tapes.
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
Well, that I don’t know. Didn’t ask that question. Hopefully Jan can clarify for us.
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
No inches. Just feet.
So you get three readouts: MF00-MF99, meters, and feet.
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a) -
[Guy Bruner] “So, we have a DVCPROHD camcorder that will record to P2 card, to external intelligent hard drive, or to a laptop/desktop in full 1080/60i (100 Mbps) or any mode below that. “
Or to a firewire-equipped DVCPRO-HD tape deck.
The hard disk thing is that to capture directly to the drive, without a card, it needs to be an intelligent firestore-type of device. But you can use a cheap off-the-shelf drive to dub the contents of the P2 card over. So if you had one card you could capture to the card, then between takes you could plug in a cheap drive and offload the card to it. You wouldn’t need a laptop or a special type of drive for that, so you can record all day to a cheap drive, you just apparently won’t be able to capture directly to that drive “live”. And yes, that is how the ipod would work as well — you could use it to copy off the contents of the P2 card.
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Get the most from your DVX camera. The DVX Book and DVX DVD are now available at https://www.dvxuser.com/articles/dvxbook/ and at Amazon (https://tinyurl.com/54u4a)