Re: Vertical Limit
Porfin nos deja su configuración personal "Aussie Bob", uno de los grandes genios de los filtros en AVS, para q todos podamos disfrutar del Pana lo mejor posible.
<blockquote>
Quote:<hr>
Experiments with projector tuning filters
My first "by eye" choice was correct: Lee Filters "Light Salmon", catalog number #109. Since guessing the filter by eye (and using the Lee Filters swatch for samples), I've evolved a technique for using a Nikon D100 ("Overcast" -2 white balance setting, 6400K) to photograph the screen as 50% gray is projected onto it, entering the RGB numbers of the resulting "gray" image (actually "gray" plus some unwanted cyan "haze" or bias illumination, the result of imperfections in the optics of the projector) into an Excel spreadsheet and coming out with the best "neutralizing" filter to get the "no-signal blacks" as achromatic (and hence as dark) as possible: in other words, a filter that filters out the haze.
This technique has been mentioned in a previous post, and it's a lot more involved than I thought, necessitating an understanding of how gamma curves and densities are calculated and transferred back and forth between Photoshop, the D100 and Excel (plus a "fudge-factor" column to make everything "right"<img src=https://www.mundodvd.com/forum/emoticons/wink.gif ALT="

"> . Many happy hours of Googling and reading technical PDFs right there...
A bonus to my research was an augmentation of the Excel spreadsheet I figured out for use with my flatbed scanner. As Lee Filters don't publish the Color Correction values of their filters - they just name them subjectively e.g. "Light salmon", "Flesh Pink", "Sunset Red" etc. - I figured out a way to scan them and then to turn the RGB values obtained into Color Correction factors (hint: start with ND filters... the Rs, Gs and Bs should all be equal.. if they're not, start using fudge-factors until they are... after that, everything else should come out correct, too). Each Color Correction unit equals 1/30th of a stop, by the way. It was only when I did this that I discovered that the "Light Salmon" filter was the closest Lee filter to my calculated, theoretically "ideal" filter for tuning the AE-700. The fudge-factor inputs are unique to each scanner and scanner gamma setting, but apart from that, all the other Excel calculations are based on rigorous theory, properly and soberly applied (I think).
To celebrate my (seemingly correct) decision to go with "Light Salmon", I went to the local Panavision shop (in McLachan Ave., Artarmon, Sydney for Aussies reading this) and shelled out $19 for a one-metre sheet of the stuff, plus A$85 for a 77mm mount "Clear Glass" filter. Geez, they know how to charge! No wonder movies cost a squillion dollars to make... at those prices!
Are Lee Filter sheets curly, or what? They're rolled up so tightly that it's impossible to flatten them out without "special" measures. Cutting a bit out and sticking it inside a book for 24 hours didn't even touch the sides. I swear I heard the Lee Filters wallahs laughing from afar at my pathetic attempts to tame their cursed gel. Eventually I applied the blowtorch to the belly and gave it The Treatment using a very low iron. Stick the gel between two sheets of printer paper, iron on a low heat for ten seconds and then stick it between the pages of a heavy book while still warm. Wait ten minutes and, voila!, a big sheet of Lee Filter bent (or rather, flattened) to my iron will. For some reason this gave me immense satisfaction: a backyard Aussie showing the mighty Lee Boys that we don't take no s--t Downunder.
For the final, finishing touch, I cut out a circular piece of this flattened gel (72mm diameter, slightly smaller than the filter diameter), bevelled off the top and bottom edges and stuck it to the back of the clear glass filter with sticky tape. After screwing the filter onto the AE-700, I now have a dust-proof filter assembly. All I need to clean is the glass front of the filter. The rest is sealed. This is also pictured in the jpgs.
Well (I hear you ask), is there an improvement? The answer is an emphatic "Yes". Blacks are richer, achromatic and contrast is vastly improved.
OK, what about the downside? Well, the "Light Salmon" filter modulates the lumen output of the AE-700 by just over 2/3rds of a stop: 23 Color Correction units (i.e. it nearly halves the PJ's brightness). Also, despite the blacks being now achromatic, the lighter tones are decidedly pink; so this needs to be compensated for.
Cine4Home picked "VIDEO" mode as their choice of mode to support the increased PQ that filtration provided. I went all the way and settled on "DYNAMIC" to increase brightness.
"DYNAMIC" is a wild beast: sharpening, contrast and brightness are wound out to the max to give the absolutely brightest "light cannon" output the projector is capable of. In short, it's horrible! But it can be tamed.
The basic approach I took was to never increase any BRIGHTNESS slider in ADVANCE set-up mode. I took out my pinks by reducing RED contrast and brightness, leaving BLUE and GREEN at "0" or less. As long as you don't increase brightness, then the no-signal blacks will stay at their darkest possible. Reducing brightness will not appreciably make the no-signal black any darker, or change its color temperature (because, by definition, it's as black as the projector can go, it's the "all pixels absolutely OFF" black level). But increasing brightness - any brightness - just adds numbers to all pixel levels that the slider affects, including no-signal black. So avoid the temptation to brighten your image with the "brightness" sliders (funny, eh?). It only makes the image less contrasty, and more muddy.
<span style="text-decoration:underline">My "final" settings</span> (always, of course, subject to change according to film transfer quality and personal whim) were:
PICTURE MENU
PICTURE MODE: DYNAMIC
CONTRAST: +4
BRIGHT: 0
COLOR: -4
TINT: 0
SHARP: -4
COLOR TEMP: 0
DYNAMIC IRIS: ON
ADVANCE MENU
GAMMA HIGH: 0
GAMMA MID: +3
GAMMA LOW: +3
CONTRAST R: -10
CONTRAST G: 0
CONTRAST B: 0
BRIGHT R: -5
BRIGHT G: 0
BRIGHT B: 0
with the Sony DVD player in either "Dynamic #1" mode or "Cinema #1" modes (both slightly "punchy"<img src=https://www.mundodvd.com/forum/emoticons/wink.gif ALT="

"> . To taste, reduce overall CONTRAST (the one in the PICTURE menu), even down to negative numbers, depending on the gamma of the film you're watching. But the above settings are my "basic" ones, committed to MEMORY-1 of the AE-700. You can also fool around with Color Management settings, mainly to reduce "yellowness" in flesh tones. But this is a matter of personal taste.<hr></blockquote>
Y alguna foto que otra q nos muestra su intalación:
Un saludo <img src=https://www.mundodvd.com/forum/emoticons/hola.gif ALT="

">
</p>
Editado por: <A HREF=http://p216.ezboard.com/bmundodvd43132.showUserPublicProfile?gid=gn0m4>Gn0m4</A> fecha: 4/12/04 14:27