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#1 Paul Marschall

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Posted 25 May 2005 - 01:34 PM

So I've been struggling with how to plan post for a feature I will be shooting and am looking for input. I will be shooting S35, 3perf, 2.35. Originally I was looking to do a 2K DI, but I no longer think that is financially realistic. So now I'm considering an HDCam SR DI. If I choose to go that route do you think it would be better/cost effective to transfer dailies directly to HDCam SR or retransfer to it later? Has anyone gone through this process before and can share experiences?

Is this the process Dominion: Exorcist just did? Are there other films that I could refer to see how quality would compare?

Also, should I still consider an optical blow up? Everyone seems to have abandoned ship on blow ups, but are they really that inferior?

Thanks.
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#2 Max Jacoby

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Posted 25 May 2005 - 04:12 PM

Also, should I still consider an optical blow up? Everyone seems to have abandoned ship on blow ups, but are they really that inferior?


No they are not.

Especially if you do not need the extensive color-correction offered by the DI route, an optical blow-up will be much cheaper and will yield excellent results if shot well. The picture quality (sharpness, colordepth, blacks) will certainly be better than with a HD DI.
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#3 David Mullen ASC

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Posted 25 May 2005 - 04:51 PM

A 4:4:4 HDCAM-SR D.I. should in theory look very similar to a 2K D.I., although you're more than likely going to use a Spirit Datacine for the scanning instead of a film scanner like a Northlight, Imagica-XE, Arriscan, etc. I had to do a HDCAM-SR D.I. for "Shadowboxer" -- not my decision, by the way -- and while they haven't done the final film-out, the tests at Technique showed me that the process was comparable to 2K as long as you color-correct for the D.I. (sort of a low-con 10-bit log approach) and not in linear video space like for a home video master.

But in comparison, an optical blow-up will probably look sharper although the grain will be more pronounced (which can be mitigated the old-fashioned way, i.e. shoot a well-exposed negative on a finer-grained stock.) If you don't need digital color-correction tools nor have efx to incorporate, the optical route may be better in most ways except in terms of graininess.
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#4 Brad Grimmett

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Posted 25 May 2005 - 05:37 PM

Is this the process Dominion: Exorcist just did? Are there other films that I could refer to see how quality would compare?

Thanks.

<{POST_SNAPBACK}>


A film I worked on at the beginning of the year is going this route. Unfortuantely, you can't see it yet as it won't be released for a while. I've yet to see any of it so I can't comment. I'll let you know when I see it how it looks.
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#5 Paul Marschall

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Posted 25 May 2005 - 06:15 PM

I know people sometimes rationalize the financial side of DI's by shooting 3perf and putting the savings towards that. Would shooting 3perf offset the costs of an optical blow up? not entirely? Roughly how much is an optical blow up? Is the only added expense the production of the new neg?
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#6 David Mullen ASC

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Posted 26 May 2005 - 02:10 AM

I know people sometimes rationalize the financial side of DI's by shooting 3perf and putting the savings towards that. Would shooting 3perf offset the costs of an optical blow up? not entirely? Roughly how much is an optical blow up? Is the only added expense the production of the new neg?

<{POST_SNAPBACK}>


Well, the problem with a digital or optical blow-up are that they involve costs that may be incurred anyway for any film getting a theatrical release followed by a home video release: the costs of making an IP & IN, the costs of transferring to HD for home video mastering, etc.

Trouble is that most producers only compare these costs to that of making a contact print off of a negative for a screening because they aren't budgeted for all final deliverable costs.

Think of it this way, if you shot in standard 4-perf 35mm 1.85 or 2.39 anamorphic, you eventually have to pay for an IP (for a protection master and for home video transfer, plus to make IN's), plus any IN's for making release prints, plus a final transfer to HD for home video, plus downconversions.

So some of the extra costs of a D.I. or an optical blow-up overlap these costs.

You can figure that if you are doing an optical blow-up for a feature, after cutting neg and answer printing, you'd make a color-timed contact printed IP (maybe $16,000 or so in 4-perf, but it would be cheaper since it is 3-perf). The cost of the optical work is about $15,000, the cost of an IN is about $10,000. So your optical blow-up may cost you about $35,000 or more.

An HD transfer and color-correction may cost you about $50,000 and a laser recorder transfer to film may cost another $50,000. Maybe less for all of that but either way, the optical blow-up is cheaper. EXCEPT that eventually your film would still need an HD master for home video, and you'd be paying for that $50,000 anyway, plus the $35,000 or more you spent for the blow-up. So the D.I. starts to come closer in price once you consider that with a D.I., you are spending the money on both the blow-up and the digital mastering for home video.

Of course, the savings from shooting in 3-perf will come in handy. However, if you had shot in standard 4-perf 35mm 1.85 or anamorphic, you wouldn't have ANY blow-up costs...
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#7 David Cox

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Posted 27 May 2005 - 05:00 AM

Although there are many technical differences between doing a DI at 2K and doing it via HD CAM SR 4:4:4, as long as you are careful about what you do, you shouldn?t really be able to tell any difference and the final release.

There are three issues that govern the image quality in this instance. One is pixel resolution, one is colour depth and the last is compression.

If you are shooting 3-perf, then the resolution between 2K and HD is likely to be just about identical. For example, a 2K frame is normally considered to be 2048 x 1556 pixels. But this accounts for the whole 4-perf-neg frame. It is usual not to have all of the width account for active (visual) film imaging and so commonly the active pixel width is around 1820 pixels. Of course because you are shooting 3-perf, you will not be using the whole frame height either. So your 2k scan might actually mean an active resolution of 1820ish pixels by 1100ish pixels. This compares to a HD resolution of 1920 x 1080 ? pretty close. So there is no reason to believe that the HD route would be any ?softer? than a 2K route.

The second issue is colour resolution, where both HD CAM SR and the 2K file format commonly use 10 bits to describe the images (2K can also be 16 bits linear). However, the 2K 10 bits would use a logarithmic format to make better use of those bits in areas of the range that are more important and so give a better base to colour correct from. It is important to understand the colour depth issue though. There are lots of people who jump up and down saying that everything must be 16bits, 24 bits, 32 bits ? whatever ? with no more knowledge or experience than knowing that 32 is bigger than 16 so ?must be better?. Whilst that is mathematically true, it also should be realised that for each bit you add, you could double any post-processing (computer) time without necessarily seeing a change in the end image. A 16 bit image is desirable if you are taking a neutral scan of the film for digital colour correction later. However, when you view this neutral scan you?ll see hundreds of shades in the ?blacks? ? which are not actually adding to the image since they are just film grain colours. The first thing you would do in colour correction is take these washed out ?blacks? to true black, and this means that actually you don?t need as many bits after you grade as before, because you are now using the bits only to show the colours you want in your final film. So in your case, if you were to be careful with your telecine transfer to HD-CAM SR and make sure that your black and white levels are correctly set at the point you transfer from film, you shouldn?t have too many colour depth issues later down the line, compared to 2K. The benefit you will get is that a HD telecine transfer to HD CAM SR is a real time thing, whereas 2K is rarely anything near real time.

Finally there is the compression issue. HD CAM SR compresses at around 4:1 for 4:4:4 recording. Again this is not mathematically desirable but actually has very little visual affect on the images it compresses ? especially if you?re not going to take the images a very long way from their origins later down the chain ? for example a very extreme grade.

So I guess the moral of the story for your 3-perf shoot is this. 2K is mathematically better but is highly likely to have no (or very marginal) visual improvement by the time you see a bulk print. For that mathematical improvement, your costs will be higher for 2K because it has more data (even if you don?t use all of it) and it will take longer to scan / telecine and import into other devices. So if your budget is tight and you want to have a DI (or a good part of your film has digital vfx), then I would recommend the HD Cam SR route in this case. If you did have more money to spend, then you might want to have a test done between this route and a 4K DI. This will cost more and so you should have a test done to show you what difference you will get for your money.

David Cox
Baraka Post Production
www.baraka.co.uk
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#8 Paul Marschall

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Posted 27 May 2005 - 04:02 PM

Excellent answers David(s). Thankyou very much!
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#9 Dirk DeJonghe

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Posted 28 May 2005 - 04:38 AM

If you are shooting 3-perf, then the resolution between 2K and HD is likely to be just about identical. For example, a 2K frame is normally considered to be 2048 x 1556 pixels. But this accounts for the whole 4-perf-neg frame. It is usual not to have all of the width account for active (visual) film imaging and so commonly the active pixel width is around 1820 pixels. Of course because you are shooting 3-perf, you will not be using the whole frame height either. So your 2k scan might actually mean an active resolution of 1820ish pixels by 1100ish pixels. This compares to a HD resolution of 1920 x 1080 ? pretty close. So there is no reason to believe that the HD route would be any ?softer? than a 2K route.



David,

there is a contradiction here, 3Perf 35 is Super 35 by definition, no sound track involved, so the full picture width would be 2048 pixels wide, not 1820. In my lab 2K S35 is scanned at 2048*1157 pixels if 3Perf (1.77) format.
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#10 David Mullen ASC

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Posted 28 May 2005 - 10:14 AM

David,

there  is a contradiction here, 3Perf 35 is Super 35 by definition, no sound track involved, so the full picture width would be 2048 pixels wide, not 1820. In my lab 2K S35 is scanned at 2048*1157 pixels if 3Perf (1.77) format.

<{POST_SNAPBACK}>


Yes, that should be what Super-35 (3 or 4-perf) is scanned at in 2K. 3-perf is always Super / Full Aperture unless you don't want as wide an image for some reason.

Academy/1.85/anamorphic would be less across, like at 1828 pixels I think.

But if you are scanning on a basic HD Spirit, Super-35 is scanned at only 1920 across and a sound aperture even less.

If you had shot in a sound aperture format (Academy/1.85/anamorphic) then the amount scanned at 2K would be less than 2048 across, more like 1828; therefore 4:4:4 1080P HD is within the same ballpark, resolution-wise, as "2K", at least horizontally.
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#11 Dirk DeJonghe

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Posted 28 May 2005 - 11:45 AM

I just received digital images scanned on a Spirit from S35/3P for output to Cscope on my Lasergraphics recorder.

Compared to my own scanner, the Spirit has noticeably more grain in blue skies etc. I feel that for S35/CScope 2K is not enough vertical resolution, HD is even less. In this case 817 pixels high are resized to 1742 high (2048 wide).

Just last week I finished another job also on S35 (4P) for optical blow up to Cscope. FX were scanned in-house to 3K and resized to 2K for filmout (1850 pixels high to 1742 high). Very big difference in quality and practically undistiguishable from the optical blow up parts (80% of the film).

I always use the full 2048 pixel width even for Academy framing.
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#12 Michael Most

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Posted 28 May 2005 - 04:23 PM

If you had shot in a sound aperture format (Academy/1.85/anamorphic) then the amount scanned at 2K would be less than 2048 across, more like 1828; therefore 4:4:4 1080P HD is within the same ballpark, resolution-wise, as "2K", at least horizontally.


Not really. You can scan any part of the physical image to any resolution, the same way you can resize on a telecine. You can scan the Academy area to full 2K, you can scan the full aperture image (whether it was framed that way or not) to 2K. It's a matter of how you set up your scanner, not numbers defined by the physical characteristics of the film.

You could even scan 16mm to 4K if you really wanted to.
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#13 David Mullen ASC

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Posted 29 May 2005 - 02:02 AM

Not really. You can scan any part of the physical image to any resolution, the same way you can resize on a telecine.

<{POST_SNAPBACK}>


Don't some scanners have a fixed relationship to the film? I was looking at the specs of the Imagica XE scanner and it seems to suggest that you can't scan Academy at the same pixel resolution as Full Aperture. Same with the Kodak Lightning scanner.

http://www.ise.imagi...ifications.html
Film Formats and Resolutions (Full) ? Standard 35mm/4p Gate
35/4p Academy Format 21.936mm × 15.984mm (3656 × 2664 pixels)
35/4p CinemaScope Format 21.936mm × 18.672mm (3656 × 3112 pixels)
35/4p Full Aperture 24.576mm × 18.672mm (4096 × 3112 pixels)

http://www.cinesite.com/?1231&0&1269
KODAK LIGHTNING 35MM SCANNER
The Lightning film scanner, the finest system available for digital imaging, is the cornerstone of Cinesite's scanning capability. Featuring CCD sensor technology with three linear photosite arrays of 4,096 pixels each, the scanner handles the most common 35mm aspect ratios of Full Aperture (1024,2048 & 4096 lines resolution), Cinemascope and Academy (914, 1828 & 3656), and Vista Vision format (6144).
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#14 Dirk DeJonghe

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Posted 29 May 2005 - 03:06 AM

My scanner is like an optical printer, with the projector movement (XY adjustments) on one side, a lens carrier (adjustable in XY axis) and a camera on an optical bench type mount. Very easy to zoom in to whatever framing desired on whatever pixel size desired, mechanical autofocus, camera can be tilted.

If I wanted I could extract a frame smaller than 16mm from anywhere in a 35mm frame and scan it to 2K.

To set up a 1:1 scan/recording I scan a 35mm ruler film (marked in mm/inches) and then record it back to film. I record maybe a hundred frames of this film at slightly different magnifications and then select the one that comes closest to the real mm/inches. This particular frame is then put in the scanner and while looking at a split-screen I zoom in or out on the original ruler film until it matches within one pixel usually. Can't do half-pixels yet.
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