chrisM

DLP front projection in an affordable option, but some of the new LCD's are pretty good too. The Panasonic AE700 is getting good reviews, and seems to be able to achieve 2000:1 contrast with good color. IMHO the best resources on the net for domestic display technology are: http://www.avsforum.com/ http://www.projectorcentral.com/ And for excellent reviews of DVD players, etc. to use with your new PJ you can't beat, http://www.hometheaterhifi.com/main.html(DVD player shootouts) I've got a front projection set-up, with a progressive PAL DVD player and HD STB. It's actually not as expensive as you might think. Mine cost about $3500 Australian dollars all up and the pics are fantastic.

A recent article by John Ives of Sony, recommending that the EBU not "go against the tide" of 1080i has prompted the EBU's David Wood to put forward an alternative viewpoint. Both articles are good reading. Personally, I think the EBU's decision to recommend progressive scan is the right one. Bring on 1080 50P and put interlace out to pasture! http://www.ebu.ch/trev_home.html

The Betacam has about the most unstable tripod plate mount of any camera I've used. It's just plain wobbly, and Sony haven't tried to improve it much. Philips have at least made a much more stable compatible mount. I'd take an SR or an Aaton with a prime over a DigiBeta 790 with a monster wide angle zoom lens anyday, and I've done a lot of handheld on 790's!

That's simple weave deinterlacing. The "frame" mode with a PAL DigiBeta is different. This how I understand it works. In "field" (normal) mode the CCD reads out every photosite every field. Charges from adjacent fields are combined alternately, i.e. for the first field line one is actually 1+2 and line 3 is 3+4 and for the second field line 2 is actually 2+3 and line 4 is 4+5. The limits of electronic shutter in "field" mode is 1/50th of a second. With the camera in "frame" mode, (also EVS and extended clear scan), lines of photosites are read out consistent with field times, i.e. line one is read out first and line 2 is read out 1/50th later. The photosites therefore have 1/25 of a second between "readouts" to accumulate charge. This is why shutter times can be slower than 1/50th in these modes. Also, vertical resolution is higher because photosite charges are not being combined. A mechanical shutter can create a true progressive capture characteristic. I'll try and illustrate why: The top two lines depict the times these photosite lines are accumulating charge. The breaks in the lines represent their "readout" time. They read out alternately every 1/50th of a second, but have 1/25th of a second to collect charge. The bottom broken line depicts the time the mechanical shutter is open, XXXX = closed. Time Line 1 __________ __________ __________ __________ etc Line 2 _____ __________ __________ __________ etc Shutter XXXX _____ XXXX _____ XXXX _____ XXXX (open 1/50th closed 1/50th) The shutter only allows the lines to accumulate charge for 1/2 of the normal time. When it closes one field is read out immediately while the other simply "waits" for the next field readout. Usually this second line would continue accumulating charge, but it can't because the shutter keeps it in the dark. The image you get is, in effect, 576 25 PsF, because the photosite charges where all captured within the same 1/50th exposure time. I hope this makes sense :unsure:

I understood that the transfer of charge from the photosites to the optically masked image storage area occurs simultaneously and almost instantaneously. If the charge transfer was to have any effect on spacial rendering of temporal changes these would most likely manifest themselves as smear and lag. True, the readout takes a while, but the CCD charges travel down the columns and out the amp etc. in the dark, i.e. without accumulating additional charge. If you shutter the image just before readout the characteristics of the CCD don't matter anyway. A mechanical shutter will result in a more "filmic" motion capture than a 25P camcorder.

If it did that it would be a PsF progressive scan camera. The Digi Beta doesn't do it, that's the problem. This is exactly what you need to do, set the camera to "frame" and blank one field time. To prove it works I just shot through the gate of an Eclair ACL with the lens and mag off (and yes, it was a very dark picture with soft edges but it proved the point). A 16SR would work too. To do the test you need the shutter to run at 1/50th synced to black one field. Leave the camera in field mode and just start and stop the shutter until you get maximum flicker, then switch to frame mode via the menu and there it is - no flicker and "film" type movement. The other advantage with a real shutter is that you get the same temporal image capture as film, i.e. each frame blanked by the action of a mechanical shutter rather than an instantaneous electronic readout of all the pixels. By the way, I love the term "progressivization" We could call it the "physical optical path interruptor that offers progressivisation to location interlace aquisition".

Hi Phil, When you put the Digi Beta into "frame" mode it reads out alternate lines to alternate fields, unlike field mode where every line is read out , and alternately combined, every field. In frame mode the vertical res goes up, but so does the blur because each line is now "exposed" for a 25th of a second, and the fields overlap for 1/50th of that time. The electronic shutter (extended clear scan) isn't of use here because that shutters each field separately - it's the 1/50th overlap that we're interested in. To get a 25PsF image out of the Digi Beta you need to capture the frame all at once in 1/50th of a second and then record it as interlace. You can do that by physically stopping any light from reaching the CCD at the point the first field is read out (with the camera in frame mode) by using a mechanical shutter. When the second field is read out it consists of pixels that haven't accumulated a charge since the first field time, they've just been sitting there in the dark. The only down side is you lose a stop. End result, you've got an interlaced image where all the lines were captured together in 1/50th of a second - 576PsF The next question I know you'll have is, "where do I get the shutter?" Unfortunately Sony don't make it. But, it should be possible to put a mechanical shutter in the lens, perhaps in place of the 2x convertor. A simple 180 degree shutter timed to the camera sync would do the job.

PAL Digi Beta is an interlaced format, and its vertical resolution (in Field mode) is about 400 lines PPH on a static subject. A Varicam will shoot 720 progressive, so it's vertical resolution should be much better than Digibeta. There is a way to test this. Shoot a slant edge, or ISO 12233, target and analyse the resulting image via a frame capture with free software, called SFRwin. the resulting spacial frequency response is an accurate way to measure the resolution of the whole camera system. To get a higher resolution progressive picture from a Digibeta, you need to use a mechanical shutter. The shutter would need to be closed for one field time, and the camera set to "frame" (EVS) mode in the menu. The resulting image would be, effectively, a full progressive frame recorded as 576-25PsF, with 100 or so additional lines of vertical res. If you look into the engineering menu section of the Digi Beta manual there is a reference to an item called FRM Shutter. Sony told me they did not end up making this accessory.

He might be a bit technically astute for this but you could give him a monitor and show him how to adjust brightness and contrast. Then tell him anything he can do on the monitor he can do in post. He'll fiddle until he gets the picture he likes, (confident that he can do it later in post) and you can shoot it the way you want it to be. Don't laugh, I've done it and it works.

I can't comment on animation but I've got a bit of a theory regards the temporal video look, (as opposed to video contrast, color etc.) The traditional difference between the film look and video look is the field rate vs the frame rate, (i.e. 60 fields shown once vs 24 frames shown twice). In theory, an HD camera shooting at 24P should look the same as film, but in practice it still has a slight "video" motion look about it. I think this is because a film frame is "wiped" by the shutter at the end of the exposure time, while a video camera switches the whole frame within an instant. This means the leading edge of a moving object is very sharp on video - and this leads to a similar "look" to what you get with an interlace camera. The slightly out of focus film shutter gives a softer "end" to the frame. (hope this makes sense :blink: ) I tried a test with a Digi Beta in frame mode where I mechanically shuttered the lens, so that one field time was black. The end result was very "filmic" motion. So, I think blur has a lot to do with the "film look", but perhaps it's the blur in front of the moving object rather than behind it?

Thanks John, is that article available online?

I don't have access to an HD camera at the moment, I was just interested in people's opinions. I will have access soon and will do my own tests. I shoot mainly on a DigiBeta 790 at present, but a lot of production in Australia is changing over to HD. 1080i is mandated for free to air broadcasts. I'm interested in "real world" resolution to determine display scaling losses etc., i.e. how much res you lose on a projection system that isn't 1080 native. My tests on a PAL Digi Beta really surprised me at how soft the vertical res really is when displayed on a progressive display device.

This article explains the issues regards 720P vs 1080i: progressive vs interlace What is not analyzed in this document is whether 1080 25P (recorded as an interlaced frame) is better than 1080i. Some of the debate about 1080i is based on the resolution lost through interline flicker, i.e. even when the resolution is there in the recording you won't see it because the line flicker obscures it. However, the resolution probably isn't there to begin with if Sony adopt the same process with the HD Cams in interlace as they do for standard def cameras. This article Camera pdf(pg 2) gives a pretty good explanation of the process.

A Sony tech told me today that the vertical resolution in 1080i is less than that achieved with a static subject in 1080P. The tech agreed that in interlace mode the HD cameras did vertical pixel "addition", i.e low pass filtering as I described earlier, to reduce interline flicker. I don't know who is right, the Sony tech wasn't 100% sure. Has anyone done independent tests?

But again, on a still shot, the resolution of both will be the same.

I believe according to a test from *Kodak* (in other words, not Sony; this is sort like Apple running a speed comparison test against a Dell) that the Cinealta had a vertical resolution around 860 lines-per-picture-height (using the ISO 12233 chart)

I have a few questions regarding the VERTICAL resolution of the Sony and Panasonic HD cameras. I am not interested in theoretical resolution, but "real world" resolution gained from shooting a resolution chart and examining it, as you would for film, (perhaps using a chart designed for digital still cameras like the 13A/ISO 12233) My questions are: 1. What vertical resolution can be seen, or measured, in 1080i, 1080p and/or 720p 2. Is there a significant difference between 1080i and 1080 24P on Sony HD with a static test subject? 3. How does vertical res compare to horizontal res, relative to picture height? Also, does anyone know if the Sony 1080i cameras have an optical anti-aliasing filter, or only a "software" filter, and do these cameras combine pixels, (in alternate lines on alternate fields), like a Digi Beta, when in interlace mode? Thanks for your assistance.