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 Post subject: Re: Cleaning the lens
Posted: 30 Nov 2017, 21:56 

This is always a debated topic. The bottom line is you can listen to opinion or follow Pioneer's instructions.

If you are worried just used distilled water. The instructions say do not use alcohol or compound cleaning fluids.

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Posted: 03 Jan 2018, 05:49 

Hey thanks for checking out my podcast! I'm glad someone who uses LDDB is enjoying it because I've used this website frequently for research in creating my show.

The next episode will be released this thursday/friday - an overview of LaserDisc games primarily focused on arcade. I'm hoping to produce 1-2 episodes a month. If anyone has any topics they'd like me to cover or would like to come on the podcast and contribute some information, please let me know! I hope to cover a wide array of subjects related to LaserDisc, all the while touching on all different types of retro topics and movie-related subjects.

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Posted: 20 Feb 2018, 10:23 

Since this question comes back often, here is a sticky/global post to sum them up.
We can update with more error codes (from the DVL, for example) as we go and what has successfully been done to fix some of these in the past.

Taken from the CLD-D925 Service Manual Section 6 because the CLD-D925 User Manual has only a subset of these codes described.

I could simply include the picture of the page but this would make text-based searches impossible.

Julien

(Updated 2018-02-20)

---

SELF-DIAGNOSTICS FUNCTIONS

The self-diagnostic function automatically display an error code on the TV screen and front panel fluorescent display section when there is an error. The customer checks the error code and conveys it to the service personnel to make repairs more efficient.
After an error occurs, even if the error code goes off, you can display the error code again by holding down the [CLEAR] key for 5 seconds (except a loading error [L*] display). At that time, partial error is displayed with the mechanism switch information.

H0 = Spindle overcurrent detection error

In the play state, overcurrent was detected in the spindle motor. Monitoring starts 5 seconds after the start of play or special playback mode, this error is detected if the overcurrent port is "L" for 4 seconds.

Probable cause(s) :

Motor KO
Clamper rubbing

U0 = FG abnormality error


At LD start-up, the rate of rotation is calculated from the FG was less than 15rpm for 5 consecutive seconds from the spindle run command.
At CD start-up, there was less than 1/8th rotation even after 5 seconds had passed since the end of acceleration.
During play search, CD: subcodes are being read / LD: Phillips codes are being read and the spindle is locked, but a state in which the rate of rotation calculated from the FG was less than 15rpm continued for 5 seconds or more. In the above case, it is judged that an abnormality has occurred in the FG sensor and that accurate rotation rate calculation has become impossible.

Probable cause(s) :

FG sensor abnormality, FG signal not coming to mechanism controller
FG sensor clogged
Rubbing between FG sensor and slit
Turntable dropped
FG slit deposition KO

H1 = Partial short error


At LD start-up, the speed did not reach 1,200rpm without a certain time (12 seconds) after the spindle run command
At CD start-up, a certain speed (313rpm) was not reached within 6 seconds from the end of spindle acceleration.

Probable cause(s) :

Spindle motor KO
Commutator KO
Bearing too tight
Power supply KO

H2 or A0 = Power supply abnormality error

-5V power supply abnormality detected.
The power supply abnormality port is constantly monitored and if its signal stays high for about 1 second consecutively, the power supply is judged to be abnormal.

Probable cause(s) :

-5V not fed from POWER SUPPLY assy
Parts shorted

L* = Loading error


When loading operation goes over time (approx. 10 sec.).
When assist at disc sense entry ends and is not tilt neutral.
When assist at set up entry ends and is not tilt neutral

Probable cause(s) :

Tilt switch 1, 2, 3 abnormal, so tilt/loading state not read in correctly
Tilt/loading mechanism mechanically locked
Drive Integrated Chipset KO
Power supply KO

E* = Slider error

During slider movement, a time over-run occurred (track count search 20 seconds, mandatory movement 10 seconds)

Probable cause(s) :

Slider ceased being able to run
The slider mechanism is mechanically locked and can no longer move to its target
Slider position switch KO
Flexible cable pulled out
Drive Integrated Chipset KO
Power supply abnormal

U1 = Miss clamp error


During LD setup, after 1/8th rotation, the track count during 1/8 rotation exceeded 511.
During start-up, the focus was lost once and refocusing was attempted, but the focus could not be locked.
Two FG pulses did not come within 800ms from the start of LD start-up
The disc clamp operation did not end within 5 seconds.

Probable cause(s) :

Disc sandwidched
Disc shifted
Spindle motor KO
Disc scratched or dirty defocused during start-up
Two discs loaded
PU actuator KO
Tilt sensor KO
Tilt neutral KO (tilt base KO)

U2 = Communication error

The mode controller could not communicate normally with the mechanism controller.

Probable cause(s) :

Defective mechanism controller
Disconnected cable

P* = Spindle error


During TOC reading with an LD, the spindle servo was not locked within 60 seconds from the start of the spindle run.
When CAL/CLV determination is not finished within 60 seconds from spindle servo lock.
The codes could not be read from 10~15 seconds consecutively for an LD or 7~10 seconds for a CD/CDV and the spindle servo was not locked.
The speed exceeded 2,100rpm during LD start-up

Probable cause(s) :

P0: PH code, SUB-Q code can not be read
P0: VCO, PLL offset out of adjustment
P0: Disc defect
P5: PAL disc, mirror disc, etc. PLAY
P5: No RF
P6: Spindle servo does not lock
P6: Spindle motor KO

F* = Focus error


In the "no disc" state, a setup command was received from the mode controller.
When LD is out of focus when slider is moved to starting position during set up. In case of CD/CDV, still KO even after three focus tries.
During start-up, the maximum slider servo duty continued for 3 loops or more.

Probable cause(s) :

F5: CD, LD on top of each other
F5: LD scratched or dirty defocused during slider movement
F5: Disc defect
F5: Slider position switch KO
F6: Inner edge of disc scratched or dirty
F6: Slider ran into inner edge mechanical stopper

---

Mechanism mode contents (corresponding to the * for L* etc.):

O : Play
1 : Open
2 : Standby
3 : Clamp
4 : Disc sense
5 : Setup (rotation start)
6 : TOC read
7 : Play
8 : Search
9 : Side A -> B
A : Side B -> A

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Posted: 25 Feb 2018, 04:36 

Good day Confederate, Signofzeta, Takeshi666, Giannis, Van-Dammage, Nissling, Forper, Rein-o, Firehorse_44, Laserdisc_fan, Je280, Xtempo & Blam1

I hope that you are all well and taking good care of yourselves and your Families,

The subject of expensive, extortionately priced beyond 99% of peoples reach is something that I have an issue with regardless of any viewpoint.

On the Lddb Sellers Shops there are titles such as TITAN A.E & THE SIXTH DAY that are ''with an asking price of $5000'' and when I enquired about one of these, the answer was to the effect of (and I shall try and be as accurate here as I can.) the seller replied by mentioning that it's not for sale but they leave this on view just to see if someone is crazy enough to pay and then they may think about it if someone does.

My answer to that is this and please forgive me here but I am just expressing my own personal view: Are you Kidding me! / and I don't think I would ever do business with such people I mean that, just for the shear front and greediness / Call it arrogance / Call it such a Front and so on and so forth..........

If people say they are not selling and are playing games, then they should not have such titles on display PERIOD!

The majority of the membership who are active on this forum come across as fair unique individuals, whose viewpoints that are worthy of reading, weather I agree with what is shared here or not, and that's the beauty and joy of visiting this forum.

As I read the members replies / Comments I am feel honoured in getting to know a little insight into each person's personality Thoughtfulness, care, balanced or unbalanced views, partial or impartial Comments or views.
Reading between the lines with each message read, one discovers that each member is conveying as best they can (myself included) the way they see things at any particular time, or frame of mind.

I reasonably consider each individuals views and why they have posted a comment in such a way, & consider others personal concerns that maybe going on in their personal life, and some show this more than others and I appreciate each that.

Now here is my point Guys with all balance intended here;

I have mentioned the following words before on previous posts, and for those who have not read them I shall try my best to convey here.

I have spent up to $456 for around 6 Laserdisc titles each in my collection, and some I have 2 of, not for profit or to sell one at some point it's just personal.

I do not have money to throw away ''However Laserdisc is a collectors market'' When I personally mention collectors market I personally mean I cherish this format ''it's personal to myself ''

I have been doing business with Nicholas Santini for the last 'let's say' for around 15 years now.

He moved from France to Japan in 2000-2001 roughly and then around three years ago moved to Australia and is still unpacking 10,000 Laserdisc's and with a good deal of Hardware back in Japan in storage.
funds
Nicholas reserved many LD Titles for me around 12 years ago and I sent available funds when I could afford it every few weeks / months and in recent years available funds have become less.

This has been mostly due to other matters going on in my life, The loss of my mother being the one in charge of her savings, then I equally shared the Mums savings to each member of my Family (still settling my twin who has a long time drug related unhealthy dependence,) / car Repairs, Cut in wages and so on.

It's not about me here understand, but for the sake of the subject matter in question so bare with me and thank you for reading.

When I communications with Mr Santini I expressed my apologies for not being able to pay him any quicker than I am able, of which he doesn't have a problem with, and that we have over time garnered ''TRUST'' between us.

Mr Santini knows the kind of person I am and that we understand each other well enough, he has informed me that due to his other business activities and travelling from his Country of dwelling to the next, that I am the only Customer at this time who he is doing LD Business with, due to his priorities with other business ventures.

So here is my Point sorry I will now finally mention, I just thought by giving some personal background we can all find some common Ground on a united front;
I have spent a lot of money on Laserdisc's because I love the format, this has for the most part not been easy.

I have invested heavily into the Format and worked up to 120 hours in the past years from 1998-2003, in order to acquire the software and hardware that one desired of which has also been a journey (one cold write a book, ''no really'' and humbly I mean this, as it's been a journey.)

There is a Title ''Titan A.E'' £100 imported to the UK at the time, to be honest I cannot see myself owning but, came so close just before release However, the seller in London at the time would not take a deposit to reserve of which was sad....... Literally a week or two before release: I purchased The Phantom Menace / Star Wars Remastered box set and then drove home 26 miles away.

A good number of people who have purchased TITAN A.E paid a handsome price, and so they want some profit understandably but not $5000 that to my mind is just Hideous sorry it is.
Truth be known I own this title on US DVD, but has not been released on Blu-Ray as yet I have searched and it has not so on Blu-Ray.com I have registered my interest and for them to inform myself when it may become available if they get enough interest in this title.

I want this title on Laserdisc it's not complicated.

So regardless of any movie weather widescreen or pan and scan, if sellers are trying it on with ridiculous Pricing ''I personally find it hard to ever trust them sheerly because of the greed aspect.

Like Signofzeta has most eloquently mentioned, that Laserdisc was already expensive when in production ''especially but not exclusively coming from Japan''

My desire to spend $1000 on a Laserdisc has in recent years diminished due to the this being ridiculous and certain titles have become unobtainable I have had enough sadly to say but true.
I currently have a new sealed ''The Sixth Day'' reserved at $456 and another approximately 15 titles, of which includes new sealed A Man Like Flint and In Like Flint James Coburn box set around $150?.
Young Indiana Box set x 2 price to be finalised.
T2 with a Black OBI $175? Squeezed I already have the other squeezed T2
There are others to be purchased and mostly 1940-1960's black & white and colour Japanese versions as I love the way the Japanese packaged Laserdiscs / the gatefolds are superb.

Sorry for going on but just wanted to convey a selfless account that we can relate to here Guys.

Thank you for reading my rant and also sharing in my own way your thoughts in some way ''I hope''

Sincerest Regards to everyone

:wave: :thumbup: :wave: :thumbup:

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Posted: 04 Jul 2018, 03:02 

you are welcome !
Have fun ! It is very interesting to try just for the experience !
I do it around twice a year for some covers !
You can use the same product for washing yellowed game system. It doesn't come back to white, but it removes lot of marks, and decrease the yellowing color.

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Posted: 14 Jul 2018, 21:42 

Just released today.... :)



Finally a very well detailed video that let's us see a Muse LD player in action.

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Posted: 25 Jul 2018, 20:29 

I'm very interested in digitizing it :)

This is the guy to do it, no question.
Good enough of a recommendation for me! I'll get in contact with happycube then. Stuff like this needs to be preserved, no question. Looks like I came to the right place. :)

Also as requested, I've submitted the title for cataloging:

https://www.lddb.com/laserdisc/submit/56031/

My first time doing this, so please let me know if anything looks out of whack or I messed something up. :)

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 Post subject: Re: The Matrix LD vs DVD
Posted: 28 Jul 2018, 20:03 

It's so funny how all people are complaining about "history revision" yet have no experience whatsoever in this business. I'm a film restorer and colorist. Here's a little thing for you all to consider before you start yelling how inaccurate modern releases are:

During the 80s and 90s, most TV manufacturers (especially Sony with their Trinitron sets) had such terrible accuracy out of the box with major blue push. We do see this kind of torch mode today of course, but back then there was really not as much interest for consumers to calibrate their displays and as the movie studios have always been interested in making money, most films that appeared on home video and Laserdisc were to a certain point color timed to compensate for these inaccurate sets (hence red push was very common on masters in this era of time). This meant that pretty much every DVD you'll find by MGM released prior to 2005 or such will have an overly reddish tone and all share the exact same characteristic. Only problem however is that most of these films had much more sophisticated color timings than what we saw on VHS and DVD yet people still take this for granted.

And this becomes extremely clear when you start to have a look at the physical films in an archive. Theatrical prints, even though they never tend to have much sharpness, are usually what we go after. And they rarely have much in common with an outdated VHS, Laserdisc or DVD. Of course we can still have a look at a home video release just for the sake of it, but we know that it has been going through way too many compromises to be used as a reference.

For instance, I had the chance to check out Thief on a Swedish 35mm print from the early 80s. I kept the new grade that's used on the Criterion and Arrow releases (Director's Cut only), as people have complained for years for it being inaccurate. Look at this comparison: http://www.caps-a-holic.com/c.php?go=1&a=0&d1=3606&d2=5422&s1=33376&s2=50607&i=6&l=0
And guess what? This scene was so cold and blue, even when only going through a photochemical process, that's it's not even debateable. The MGM was so off you wouldn't believe it, while the restoration by Criterion keeps it all intact.

Many people complained about the Scanners Blu-Ray by Criterion yet relatively few (in contrast) seem to even have seen it. I've got the BD myself and have honestly no doubt that it's an accurate presentation of the films intended look. The entire process was also supervised by David Cronenberg himself and from my experience, both directors and cinematagraphers tend to remember the color timings and gradings that were used for their films.

As a colorist at one the oldest film archives in the world, I have no intention in changing how the films I grade are supposed to look. I can do plenty of research before I settle down with my work, but sometimes you will have to take a chance if it's unclear just how the film was really supposed to look. Then I will have to look at other factors that play in and try to make a decision from there, but I don't go to Blu-Ray.com or this forum to ask for suggestions. I have a very difficult time believing that someone who hangs around there or at this place, who I don't know through my job, would be of any help when I'm facing a problem like that.

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 Post subject: Re: The Matrix LD vs DVD
Posted: 30 Jul 2018, 15:47 

If you go back to my original entry on this tread, I've included my 1999 screen grab of the LD v DVD image.

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Posted: 04 Aug 2018, 23:00 

lol and now I just stumbled into Julien's original post about it!

The 2 biggest threads were split per year

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 Post subject: Re: Worst Laserdisc covers
Posted: 27 Oct 2018, 12:09 

Well now I just had to take a picture of it.

Here's the original poster for comparison.

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Posted: 11 Jan 2019, 01:14 

Found this article in an old issue of Video Magazine of a tour of the Pioneer LDCA Pressing Plant in Carson, California. Scanned it in so you all can read too.

http://img18125.imagevenue.com/loc564/th_165292510_LD_Pressing_Plant_1_122_564lo.jpg
http://img18114.imagevenue.com/loc347/th_165292927_LD_Pressing_Plant_2_122_347lo.jpg
http://img18117.imagevenue.com/loc217/th_165293766_LD_Pressing_Plant_3_122_217lo.jpg

Article confirms what Publius stated in another thread when I asked about what was format was used for the master which they pressed LDs from. At this point it was D-2 Digital Composite tape.

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Posted: 13 Feb 2019, 01:02 

It was supposed to be optimized based on the players, you can check the documentation on page 4/8 here:

http://manuals.lddb.com/AC3RF_Demodulators/Lexicon_LDD-1-EN.pdf

Julien

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Posted: 18 Mar 2019, 18:22 

Hi all, I'm a translator living in Japan, I mainly do programming stuff so I contacted happycube a little while ago to see if there's any translations I could do for free to help out with LD-decode, and he suggested this article. I finished the part he was most interested in (section 4.2), and will probably do the rest of the article sometime soon. Hope you also find it interesting!


------------
http://sts.kahaku.go.jp/diversity/document/system/pdf/085.pdf

"Historical Development of Laser Disc (LD) Technology with Respect to Efforts to Hasten Its Technological Development and Practical Application" by Sumitaka Matsumura

4.2 Element technology in disc production
Section 4.1 noted the basic workflow for the LD disc manufacturing process, but there were a number of element technologies that caused the disc performance or quality to vary in actual production. The following talks about the optimum pit shape, reduction in micro-defects, and reliability (life expectancy) as examples of typical element technologies.

4.2.1 Optimum pit shapes
The most important parameter that caused LD disc performance to vary was pit shapes, particularly in audio/video quality performance. Optimum pit shapes were investigated from a variety of angles for disc production.

(1) Theory and reality
In theory, the ideal pit shape is a "rectangular" type as shown in Figure 4.17 (a). In such cases, when the playback laser wavelength is λ (lambda) and the disc surface refractive index is n, the optimum pit length becomesλ/4n. Whenλ = 632.8nm and n = 1.49, the optimum pit length becomes 106nm.
However, it is almost impossible to make pit shapes where the edges are perfectly perpendicular; in reality they become "mesa" types as shown in Figure 4.17 (b).
Whether pit shapes are good or bad has an effect on playback signal characteristics and manufacturability, and there is a significant amount of tradeoffs for these qualities. For example, it would be better for the playback signal characteristics if the edge angle was as close to perpendicular as possible, but such a pit shape causes a problem where the stampers cannot accurately replicate the pits during the manufacturing process.

(2) Pit shapes and playback signal characteristics
For the playback signal characteristics, the audio/video quality will improve when the signal has more of the AC component (RF signal) and less of the noise component. The size of the RF signal is mainly determined by the pit depth, pit width, and pit length. In principle, the pit depth is determined by the thickness of the photoresist coating, but configurations are made so that the playback RF signal is maximized for discs in consideration of the amount of the coating removed during development and the pit depth reproduction rate during manufacturing. Because the pit shapes are mesa types in reality, the optimum depth for disc pits was deeper than λ/4n, therefore a thickness of 140-150nm was optimal for the photoresistant coating. Similarly, optimization settings are made to the laser power during cutting for the pit width and to the optical modulator duty (duration of the laser being on) for the pit length.

[image omitted]
Edge

(a) Rectangular type pit

[image omitted]
Edge

(b) Mesa type pit

Figure 4.17 Pit shapes (schematics)

In addition, the dimensional accuracy of pits was improved in order to reduce the noise component, requiring a prevention of minor deviations in shapes. To do this, it was important to narrow down the focus point of the laser beam recorder's objective lens as much as possible. Specifically, a laser with a short wavelength (460nm or less) laser was used with an objective lens that had a high numerical aperture (0.9 or greater). Such special lenses were originally for high-power microscopes, and Olympus lenses were used exclusively. Furthermore, a high resolution type photoresist was used to prevent microscopic deviations in shapes.

(3) Pit shapes and manufacturability
Pit shapes needed to be replicated by the stamper as faithfully as possible during the manufacturing process, but there were pit shapes that were easy to replicate as well as pit shapes that were difficult to replicate. Generally, pits with low depths, narrow widths, and rounded edges were easier to replicate.
A stamper that was molded with easy-to-replicate pit shapes had wide margins for the molding conditions, could have short cycle times, and rarely had pit defects upon mold release. The pit defects that occurred upon mold release were called names such as "plowing" and "pit mekure" ("pit curling"), and they occurred when the edges of the stamper's pits scratched the edges of the disc material's pits immediately after molding. With such scratched edges, abnormal waveforms would occur in the playback signal, resulting in a defective disc. To improve mold releasing for such cases, solutions included smoothing the pit edges by controlling the baking temperatures and times when making the disc masters, or putting lubricants into the molding compounds. In addition, if the cycle time was made too short, the pit replication may become softer and the playback signal characteristics may degrade.

(4) Applying Optical Simulations
As previously mentioned, during development trial and error was repeatedly used in a variety of techniques to determine the optimum pit shapes, but computer simulations were also being done at the same time, and these simulations were used in detailed cause analyses and to determine optimal parameters. The paper "Diffraction theory of laser read-out systems for optical video disc", submitted by the British applied physicist H.H. Hopkins in 1972, was the theory that formed the basis for the theoretical analyses related to playback signals from reflective optical discs. Based on this theory and in accordance with the analysis purposes and computing ability of computers, under conditions such as geometrically limited pit shapes or repeating fixed patterns, various analysis methods were developed such as analysis methods for finding solutions in one or two dimensions, using finite element methods or boundary element methods, and methods for finding solutions in three dimensions without limitations on the pit shapes. Various simulations were also done for mesa type pits, and these simulations were used for investigating the optimum pit shapes and cause analysis for problems. Such optical simulation technology was only used by optical device manufacturers in the past, but with the development of optical discs, this technology also became established in electronics manufacturers. This was achieved by electronics manufacturers employing technicians from optical device manufacturers and training their new technicians, in addition to electronics manufacturers and optical device manufacturers working together.

Note: Summary of H.H. Hopkins' simulation technique
By applying a Gaussian distribution function to the intensity of the laser light output from the objective lens as thus:

[image omitted]

The light will reflect off the pit surface and pass through the objective lens, and the intensity of the light that enters the light sensor is represented by the following Fourier series:

[image omitted]

Here, t is time, I0 is the DC component of the detected light, the second and following terms are the AC component (the high-order harmonic RF component), and we get the following:
In addition, R(m,n) is an expression that reflects the pit shape using the reflection coefficient parameter of the pit surface.

Figure 4.18 (a) and (b) show examples of simulation used for cause analyses of color flashes and dropouts.
(a) shows a normal playback waveform, while (b) shows how the waveform changes when the shape of just one pit in the center is molded smaller. (b) is a typical example of symptoms such as "dropouts" and "color flashes", which are discussed in the next section.

[image omitted]
(a) Playback waveform when pits are normal

[image omitted]
(b) Playback waveform when one pit is abnormal
Figure 4.18 Example of a playback waveform optical simulation

In this manner, simulation methods were used to investigate the playback signal wave in relation to various pit shapes (height, width, length, pitch, etc.), and this was very helpful in investigating the optimum pit shapes for obtaining the best playback signal. In addition, by investigating the relationship with pit abnormalities, simulations were used for analyzing quality problems when there were playback signal waveform abnormalities.

4.2.2 Reducing micro-defects
One side of a LD disc has around 14 to 28 billion pits, but it can be said that it is impossible to create a disc that has no pit defects whatsoever. Therefore, cases where there is a defect in a pit and the playback signal becomes abnormal were referred to as "dropouts", and a correction method where the dropout was replaced with the previous line was used (see figure 4.19 (a)). However, if the size of a defect is the same size as a pit or less, or if part of a pit has changed shape, the defect will be reflected as-is in the video signal without dropout correction being used. In such cases, the phase of the playback signal's RF waveform will be out of phase, therefore one pixel and the surrounding area will appear as a bright, differently colored point when looking at the video. This defect is called "color flash noise" and has an appearance as shown in Figure 4.19 (b).
After investigating the causes of color flash noise, the following three factors were almost always reasons:
① Imperfect pit shape: An RF signal was output but the amplitude was insufficient.
② Foreign material inside the plastic layer: When noise occurs due to colored foreign material, the focus is lost due to the different refractive index of the foreign material in the plastic, causing insufficient RF amplitude.
③ Degradation of the reflective aluminum layer: Sub-micron sized corrosion or exfoliation occurs due to the passage of time, resulting in noise.
① and ② do not change over time, and defective products do not normally make it to retail markets normal quality inspections. The cause of ① was determined to be mainly due to micron sized or smaller defects on the glass master surface during the mastering process, ultra-fine impurities (organic materials or particles) in the ultrapure water or chemical solutions used during various processes, etc. Therefore, by using a higher grade for the relevant materials and being thorough in product quality control, it was possible to prevent color flash noise from occurring. Similarly, ② was addressed by mostly eliminating foreign/residual materials with the help of plastic manufacturers, which in turn mostly eliminated color flash noise. ③ is related to reliability (life expectancy), which is discussed in the next section.

[image omitted]
(a) Dropout (after correction)
[image omitted]
(b) Color flash
Figure 4.19 (a) and (b): A dropout and a color flash

4.2.3 Reliability (life expectancy)
LD discs are a "non-contact format", therefore it was often said that one of their qualities is that they are an "almost permanent" storage medium, with hardly any degradation over time. Unlike "contact formats" such as video tape and VHD which had unavoidable degradation due to friction, LD discs were a "non-contact format", qualitatively implying that friction was not a problem for this "almost permanent" medium. Starting from the R&D stages of LD, there were technological development and evaluation testing done in order to preserve the reliability of LD discs, but in actuality, verifiable results could not be obtained until several years had passed since LD products' marketplace introduction.
One factor that had a large effect on the reliability of LD discs was something that was called "snow noise". Snow noise was a type of color flash noise that occurred due to the sub-micron sized corrosion or exfoliation of the reflective aluminum layer over the passage of time. One difference from the color flash noise mentioned in the previous section is that snow noise appears as flickering snow across the entire screen, and another difference is that the symptoms do not appear immediately after production -- rather they increase gradually over a period of months/years. In addition, this defect was bothersome because instead of appearing on all of the discs manufactured in the same line, it only appeared on some discs. Consumer complaints of snow noise occurred through the first half of the 1980's, but the cause was narrowed down and solutions were implemented in the latter half of the 1980's. Meanwhile, testing methods were established and gradually refined. As stated in the previous section, the cause of snow noise was degradation of the reflective aluminum layer over the passage of time. Investigations revealed that the coating of the reflective aluminum layer was improper, and miniscule changes might occur over long periods of time. These miniscule changes refer to compressive stress due to the growth of the oxide coating of the reflective aluminum layer, causing sub-micron sized exfoliation or aluminum oxide crystal growth, resulting in cases where noise would occur during playback. Because these are microscopic changes, a disc would appear unchanged to the naked eye, therefore analyses were performed with optical and electron microscopes. In addition to suppressing the oxide coating growth and relieving the compressive stress that occurs, it was necessary to establish coating guidelines that would increase the adhesion to the plastic base plate in order to stop these microscopic changes from occurring over time.
The coating guidelines for the reflective aluminum layer were optimized by using different guidelines for trial manufacture then repeatedly performing testing by evaluating the life expectancy after exposure to heat/humidity/acceleration. Some of the process guidelines that were most effective were ① the storage environment of the plastic base plate immediately before vapor deposition, ② the degree of vacuum during vapor deposition, and ③ the vapor deposition rate. In addition, ④ using an alloy doped with approximately 1% of other metals was determined to be particularly effective in regards to the vapor deposition materials (aluminum chips).
For the plastic base plate in ①, moisture absorption was performed on the clear base plate after molding for 15 minutes or more in an environment with a relative humidity of 60%, the aluminum oxide coating adjacent to the base plate was sufficiently grown immediately after vapor deposition, preventing successive growth of the oxide coating.
For the degree of vacuum and vapor deposition rate in ② and ③, a high degree of vacuum and a high speed vapor deposition rate resulted in the aluminum oxide coating becoming a single layer of columnar crystals, allowing for compressive stress from successive growth of the oxide coating to easily occur, but with a low degree of vacuum and a low vapor deposition rate, a laminate of fine granular crystals occurred, preventing compressive stress from occurring.
For the alloy used in ④, the materials themselves prevented growth of columnar crystals and were used for creating a laminate of fine granular crystals.
Figure 4.20 shows cross-section images of the reflective aluminum layer before and after the improvements.
Through these improvements, the snow noise problem was solved, allowing for LD disc life expectancy to reach a level where no practical issues should occur.

[images omitted]
酸化被膜
Oxide coating

柱状結晶
Columnar crystals

ディスク基盤
Disc base plate

(a) Structure of the reflective aluminum layer immediately after deposition

酸化被膜の成長
Growth of the oxide coating

圧縮応力
Compressive stress

(b) Growth of the oxide coating after deposition

酸化アルミニウム結晶の成長
Growth of aluminum oxide crystal

剥離
Exfoliation

圧縮応力
Compressive stress

(c) Exfoliation and growth of aluminum oxide crystal

酸化被膜
Oxide coating

粒状結晶
Granular crystals

基板の水分で形成される酸化被膜
Oxide coating formed with moisture on the base plate

ディスク基盤
Disc base plate

(d) Structure of the reflective aluminum layer after improvements
Figure 4.20 Cross-section images of the reflective aluminum layer improvements

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Posted: 20 Mar 2019, 23:33 

Here's the message:

Hello Criterion!

I'm sorry to contact you out of the blue like that but I should have done it a long time ago. :-)

I'm the webmaster of lddb.com (LaserDisc Database) where Criterion original releases are prominently featured:

https://www.lddb.com/

LD Criterion release by:

CC # = https://www.lddb.com/list.php?format=ld&list=crit&sort=ref&max=250
Title = https://www.lddb.com/list.php?format=ld&list=crit&max=250
Spine = https://www.lddb.com/list.php?format=ld&list=crit&sort=spine&max=250

All available covers, in chronological order: https://www.lddb.com/criterion.php

Site's forum section dedicated to Criterion releases: https://forum.lddb.com/viewforum.php?f=13

I know you dropped Laserdiscs decades ago and jumped into DVD, BluRay (no 4K coming?) and soon video streaming.

I have very simple questions/requests for you:

Would you still have people working at Criterion who used to work on the LD packaging/curating that I could interview?

Any left-over material (unused concepts, cancelled releases, etc.) that the fan would love to discover?

Any LD-related archives that would love to get a 2nd youth?

I'm trying to save the very little that remains from the 80's/90's before they completely disappear ^_^;

Thank you for taking the time to read this message!

Regards,
Julien

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Posted: 20 May 2019, 19:08 

I'm tracking 57 "brands". All of the "boutique" players are built off transports from one of the major player companies (Philips, Pioneer, Panasonic)

A&D (Akai)
Aiwa
Amfiton
Aurex
BMB
Bodysonic
Carver
Clarion
Columbia
Curtis Mathes (although I have yet to actually see proof of one)
Denon
DiscoVision
Fujitsu
Funai
Genexxa
Giga Networks
Gradiente
Grundig
Halcyon
Hitachi
ITV
Kenwood
Kolibri
Luxman
Löwe
Magnavox
Marantz
Matrox
Mitsubishi
NAD
NEC
Nikkodo (BMB)
Onkyo
Panasonic
Philips
Pioneer
ProScan
Proton
PVCb
Quasar
RCA
Samsung
Sansui
Sanyo
Setron
Sharp
Sony
Sylvania
Talkan
Tandy Realistic
Teac
Teknika
Telefunken
Thomson
Toshiba
Yamaha
Zenith

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Posted: 24 Jun 2019, 13:59 

I've just discovered this wonderful track by Anders Enger Jensen; "DiscoVision." Thought you'd enjoy.



Features clips from this video:

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Posted: 26 Jun 2019, 11:30 

So before the current kerfuffle there was this:
Favourites are First Contact and Undiscovered Country.

Khan is also great and Khan/Spock/Voyage make a nice sort of trilogy.



Based on your recommendation I pulled out my LD of Star Trek VI yesterday. Never seen it before.

Are you kidding me? You prefer this courtroom procedural that's more like an episode of Murder She Wrote than the epicness of terraforming a whole world, The original Enterprise going down, Spock DYING and coming back to life, Kirk's son dying, meeting God in TMP and time travel in IV?? Huhhhhhhh?????

:thumbdown:

Then soon after this:

I liked Enterprise a lot more than some people.

Glad you said it. Very often underrated imho. Following on from Voyager just showed up so much of that show as quite tired and ordinary. When it was cancelled at Season 4 and they let loose on some pent up storylines it was just so great.

I don’t like DS9 because it’s all about race wars and fighting and crap making it closer to Tolkien than Heinlein IMHO. It needed less NFL and more MIT.
I get that. But the show was al about doing something different as there was the TNG overlap. Star Trek still needed conflict even if not from the main characters; so if from a whole different race from a different sector of the galaxy? The Dominion were the new Klingons?

Have to say that of all the ST shows DS9 had the most fabulous group of regular character actors performing; Gul Dukat, Quark, Garak, Weyoun/Brunt, Grand Negus and many others I failed to mention; though Jeffrey Combs, Marc Alaimo and Andrew Robinson are some personal favourites.

Yeah but you thought Undiscovered Country was better than the first 4 films so all this opinion above, is invalid.

These "conversations" follow a familiar and tired pattern. Best not to take the bait in the first place and give it the attention it deserves.

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Posted: 02 Jul 2019, 18:53 


it could be me and I might be blind but I do like the bottom one from the US since it feels closer to the normal one and slightly different.
I don't know, it looks like 'SDNY' to me...


It was funny the first time I heard Japanese people in Japan saying they wanted to travel TO Asia. I said "good news, you're already there!" The look they give you of complete confusion is priceless.

Seriously in Japanese culture, even though they know the geography, Japan is not part of Asia. Japan is Japan!. Asia is some poor and interesting place you try to conquer or go on holiday to.
In the UK we still go on holiday "to Europe", and we're doing our level best not be a part of it!

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Posted: 02 Jul 2019, 18:54 

Aren't both main protagonists of Star Wars and Gundam blonde?
And I'm sure at one time they both have white shirts........
So another direct rip off :lol:

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Posted: 14 Jul 2019, 01:08 

I don't want to take sides on this oddball argument but I will say that I had no issues regarding any of Vectrex's questions.

In fact, this question about full CAV support was surprisingly educational for many (e.g.: gypsy didn't even know still frame worked on his LD-S1 ;) ) and I ended learning how some of us old timers overlook something we think is very simple and it turns out it's not so obvious to a newbie.

So yes... we do get a lot of repetitive questions but that can't always be helped. How many times have we discussed "replacing a loading belt" and "how to properly use an AC3-RF Demodulator?". It's just endless and even Julian's attempt to create a section on troubleshooting hasn't made it that much easier to search out a particular curiosity.

And let me just add; it's not like these questions are like "someone we know but I won't say" who was asking questions that just had no business being on the forum in most cases. :roll:

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Posted: 18 Jul 2019, 05:04 

Just saw this at planetfitness.



About 1 1/2 minutes in she puts an LD into an LD player

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Posted: 18 Jul 2019, 21:53 

Under the drop down of My Account it will have Submit Title.

Thanks for taking the time to do so.

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Posted: 31 Jul 2019, 13:30 

Don't start tweeking your player to think you can play a rotted disc better, you may be killing your laser so you can play your 2 dollar movie.

There are no parts left and we can't be tweeking these lasers past their factory specs so you can play ALIEN.
Its not like you are trying to watch some important film that is only available on LD and there are no masters around to make a 4K scan.

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Posted: 11 Aug 2019, 11:07 

I've got to agree with Signofzeta in his his Spotify and SACD comparison. If we were talking about a pre 50s film, were many prints were indeed made directly from the camera negative (which is sacrilege), those old theatrical prints on nitrate film that still exist can actually hold up very well. But in this case, without knowing anything really about SW, I believe we are talking about prints that have gone through multiple generations due to optical effects and have most likely been screened many times over so scratches and damages would be very apparent. Color fading will probably also be a problem, depending on the film stock. No official, "serious" restoration would be done with such a source unless there's nothing else available. Sure you can do digital restoration but anyone who've spent hours in Phoenix or DRS Nova knows for sure that those prints are in many cases just like polishing a turd. The end results may admittedly have a certain charm in its visual appearence and the fan work would certainly be appreciated, but still a long way from a "regular" restoration even on a minimum basis.

Also, if you're scanning a theatrical print the results will be highly dependent on your scanner due to the high contrast. The Cintel II, which I'm working with, tend to struggle with shadow details when scannings prints, but duplicate positives/negatives and camera negatives are much easier to achieve good results with. The HDR mode can certainly get the job done with prints but at the cost of taking four times as long to scan the film. Scanity, Scanstation and ArriScan all fare clearly better in this regard but are also much more expensive.

While there may not be an original camera negative left that's actually usable, I'm fairly sure there are still IPs that would still be up to the task. Still, as a film archivist I know for sure you cannot be completely certain about the availability of a specific film. But, in this case... I believe there are still ways for Disney to create an unaltetered version of the film.
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