Video Response vs. Video Format

Here are the specifications for various video formats, rated in 
Horizontal Lines of Resolution.

NTSC Format Comparison, Typical: 

• VHS/VHS-C up to 240

• Video8XR up to 280

• S-VHS up to 400

• Hi8 up to 400

• Laser Disc up to 425 

• Hi8XR up to 440 

• MiniDV up to 500

• Digital 8, up to 500

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FOREIGN COUNTRIES & TV FORMATS

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NTSC Video Response Pictured Below:

0-5 MHz Sweep,

Record and Playback are through same Machine:

How to increase and/or maintain Videotape Response

Formats & Videotape

UVW Betacam

DV Format
(my own 3-Chip SONY TRV-900)

SVHS

Hi8

VHS

Higher performance in smaller formats is a very good thing. But there is one drawback. As recorded wavelengths go down, the potential signal loss caused by small particles of debris goes up. This isn't marketing hype. The signal loss in dB equals (54.6(d))/ lambda, where d is the spacing between tape and head and X is the recorded wavelength. Imagine, for example, particles of 0.1 pm -- just 1/1,000 the diameter of a human hair. On a Betacam SP NTSC recorder, the shortest wavelength, X equals 0.9 pm. So the spacing loss is (54.6(0.1))/0.9 = 5.46/0.9 = 6.1 dB. This demonstrates that even tiny particles of debris can cause dramatic signal losses. 

New formats like DVCAM, Betacam SX, DTRS and ADAT recording are using shorter wavelengths than ever. Which means that debris build-up is more threatening than ever. Which means regular cleaning is more important than ever.

Know the enemy 
Debris accumulation can weaken the signal-to-noise (or carrier-to-noise) ratio, cause drop-outs, degrade picture and sound and ultimately disable playback altogether. But not all debris is created equal. There are different types, and they require different cleaning approaches: 

- Debris on the heads. 
This is usually microscopic debris that results from the various impacts and stresses between the recorder and the tape. It includes magnetic materials, lubricants, binder and even base film. Proper cleaning with the Sony CLQ-30K Cleaning Kit can remove these contaminants and restore high performance. 

- Bonded material on the heads. 
Heat and pressure can fuse debris onto the heads. What's more, varnishing, also called plastic filming, can occur when pieces of polyester begin to adhere. Conventional wet cleaning with chamois and alcohol won't be enough to clean this bonded material. And the material that remains behind after cleaning will tend to scrape additional debris off the tape. The performance problems caused by varnishing are similar to those caused by worn heads. So it's easy to confuse varnishing for worn heads and pay for expensive, unnecessary head replacement. Proper cleaning with the appropriate cleaning cassette usually removes varnishing. Cleaning with the appropriate cleaning cassette often removes these scratches, restoring performance. 

- Tape scratches.  
Build-up of debris on the capstans, tape guides, rotating head drum, pinch rollers and stationary heads can cause subtle injuries to the tape. The tape can be subjected to microscopic scratches and impressions, which can degrade audio/video performance. Cleaning solvents can typically remove the debris and prevent tape damage. 

- Head scratches.  
These are usually caused by environmental dust, which can be a particular problem in camcorder shooting. Often you have no choice but to take your camcorder or portable DAT into dirty, dusty or smoky environments. Mineral particles like aluminum and silica can easily become lodged between the tape and heads, where they can cause superficial scratches on the heads. 

Two types of cleaning 
To maintain the performance of your rotary head recorder, you need to clean it regularly using two different approaches. A format-specific Cleaning Cassette is effective for the rotary heads. The next step is wet cleaning with Sony's CLQ-30K Cleaning Kit. It includes a solvent and cloth that work more effectively than many other wet cleaning methods on the stationary heads, guide pins, pinch rollers and capstans of the tape path. As you can see, each method has its specific strengths. 

When to clean 
Use a Sony Cleaning Cassette once every 50 hours of recording or playback. Wet cleaning, such as with Sony's CLQ-30K Cleaning Kit, should be performed once every 20 to 25 hours of recording or playback. More frequent cleaning may be required depending on temperature, humidity, or dust in the operating environment. In particular, camcorders and portable DAT decks operated in dusty or smoky environments may need more attention. Under most circumstances, you shouldn't use a Cleaning Cassette more frequently than once every 25 hours. 

Using the Cleaning Cassette 
1. When you're cleaning with both a Cleaning Cassette and the CLQ-30K Cleaning Kit, use the Cleaning Cassette first. 
2. Load the cleaning cassette into the recorder. 
3. Push the Record or Playback button. 
4. Stop the Cleaning Cassette after five seconds. This is extremely important. Using the Cleaning Cassette generates heat in the head drum. If you go longer than five seconds, you run the risk of melting the debris and varnishing it more stubbornly onto the head drum. 
5. If problems persist, you can use the Cleaning Cassette for additional five-second bursts, separated by ten-second cool-down periods. Run the cleaning cassette for five seconds. Eject. Wait ten seconds. Reinsert and repeat. Severe varnishing and head scratches may require up to a maximum of five bursts of five seconds. If problems still persist after five bursts, contact your local Sony technical representative for assistance. 

Cautions: 
1. Be sure to read the Recorder's operating manual. If the instructions in the operating manual are different from these procedures, follow the operating manual. 
2. Never leave the Cleaning Cassette in the Standby mode. This will cause undesirable heat build-up and head wear. 
3. Never run the Cleaning Cassette for more than five seconds at a time. Again, this will lead to undesirable results. 
4. The Cleaning Cassette operates in Record or Play mode. Never use it in other modes. 
5. Never rewind a Cleaning Cassette, Since the tape is designed to hold debris, reusing a Cleaning Cassette could contaminate the VTR. After one full pass the Cassette is ready for replacement. 
 

Special directions for digital Betacam VTRs: 
1. Insert the SONY's BCT-D12CL in the VTR. 
2. Press the Eject button and the Play button simultaneously. Head cleaning will start. 
3. After five seconds, the Cleaning Cassette will automatically Eject. Consult the VTR operating manual for more information. 

Cautions: 
1. Be sure to read the Recorder's operating manual, if the instructions in the operating manual are different from these procedures, follow the operating manual. 
2. Turn off the VCR before wet cleaning. 
3. Rotary heads are particularly delicate. Be very gentle and wipe only in the direction of rotation. Never wipe vertically. 
4. Never touch the tape or tape path with your fingers. Even if you've just washed your hands, you'll leave fingerprints residue that can cause substantial spacing loss. 
5. Avoid touching the oiled parts of the recorder. Oil on the cleaning cloth can contaminate the working parts of the recorder. 
6. Avoid using a dirty cloth. 
7. If you're not using the Sony CLQ-30K but using ethyl alcohol instead, be especially certain to wipe all parts dry. Ethyl alcohol evaporates slowly and can leave residue on your mechanism long after cleaning. 
8. Do not apply wet cleaning to the dew sensor on the lower head drum. If the dew sensor gets dirty dry wipe only. 
9. Do not eat, drink or smoke in the cleaning area 
 
Your clean machine 
Follow these instructions and you'll get higher signal-to-noise ratios, fewer dropouts, more robust RF output and more reliable handling of tape. In short, you'll be getting the full performance of your rotary head recorder. 

Videotape

What is the difference in tape from the different professional tape manufacturers?
In some cases none, in other cases there are some. When a tape manufacturer licenses a format from the hardware maker, eg Fuji licenses the right to make Beta SP tape, Fuji has to make the tape within the performance specifications of the hardware as provided by Sony. If not, they would lose the right to make the tape. So all the tape is 'pretty good'. Tape Manufacturers can make the tape much better than the specs, if they choose to.  In other cases consistency is the name of the game. All manufacturers occasionally have a bad batch. Consistently good product is what to look for.

In some cases there is no difference. It was a well known fact, when Panasonic first came out with M2 tape, that the tape was made by Fuji. There are many such OEM arrangements which are not allowed to be disclosed, in which one manufacturer makes tapes for another manufacturer. Reason is, each manufacturer has only so many resources and capacity, and it is often less expensive for them to source the tape from a competitor, and put their name on it, than to manufacturer it themselves. 

What's the difference between DVCPRO, DVCAM, miniDV and DV?
MiniDV and DV are consumer formats that a number of manufacturers agreed on to become the next consumer standard. It has been so good a format that many professionals, and semi-professionals have begun using it. The format uses ME tape. Standard lengths are 30 & 60min for the miniDV and 120min / 180min for the DV. (An 80 min mini version is available from Panasonic in Japan. At slow speed, this can provide 120min on a miniDV cassette).

At the same time Sony & Panasonic brought out their professional versions, named DVCAM and DVCPRO. Sony's professional DVCAM format, although similar to miniDV, runs 50% faster for better quality. So its longest tape in the mini size is 40min. There is a 184min DVCAM tape, which will run 270 minutes in a DV machine! Recognition holes in the tape tell the machine what tape you have loaded. 

Panasonic's DVCPRO runs at the same fast speed as the Sony DVCAM, but its main difference is the use of MP tape as opposed to ME. Panasonic, inventors of miniDV and the ME tape, did not think the tape robust enough for professional use and chose to go with MP tape. The physical cassette size for DVCPRO is also larger than miniDV for the shorter lengths... a kind of a 'medium' size. Long lengths use the same size as DV. MiniDV can be used in a DVCPRO deck, but only with an adapter.

Advanced Metal Evaporated (AME). 
Unlike Metal Particle (MP) tape, AME uses pure cobalt, undiluted by nickel. Unlike MP, AME uses an ultra-fine grain of metal that's vapor-deposited in a vacuum chamber! And unlike previous Metal Evaporated tape, AME protects the magnetic grain with Sony's super-hard Diamond-Like Carbon (DLC) layer. The result is a breakthrough in recording density, retentivity and carrier-to-noise ratio. AME is a key enabling technology behind the DVCAM system.

DVCAM and DV tape compared 
If you're reading this, you probably understand that DV and DVCAM tapes and VTRs are broadly compatible. For example, it is possible to record professional DVCAM signals onto consumer DV tape. It is also possible to play back a consumer DV recording on a professional DVCAM VTR. In a pinch, it is possible to use consumer media in professional DVCAM hardware. But we don't recommend making a habit of it. Here's why: 

Cassette memory. IC-equipped pro models offer four times the memory of consumer models. 

Durability. Pro media has an optimized DLC layer and surface treatment. This improves performance for editing and long-term archiving. 

Dropouts. Controlled surface finishing helps cut DVCAM tape dropouts in half, compared to consumer DV. 

Interchange. Tighter slitting tolerances mean DVCAM tape works almost flawlessly when recorded on one VTR and played back on another. 

Shrinkage. DVCAM tape cuts dimensional shrinkage in half, an important benefit for archival stability. 

Running time difference. DVCAM machines use a transport speed 
faster than DV machines. So you'll experience differences between the marked and actual recording times. For example, a 60-minute DV cassette holds only 40 minutes of DVCAM footage. 

Cassette Memory and Its Uses 
The proliferation of DV and DVCAM models means a growing range of applications for Cassette Memory. Consumer-grade machines can store date and photo data, which do not make intensive use of Cassette Memory. That's consistent with the 4 kb memory Sony builds into IC-equipped consumer tape. Entry-level professional machines also make moderate demands on the memory chip. However, a key feature of Sony's top DVCAM models is ClipLink operation, which makes full use of the 16 kb memory of Sony's IC-equipped DVCAM tapes. 

When to Use Which? 
From this analysis, we can develop a clear direction on choosing tape: 

Consumer hardware. For general shooting, use Sony consumer DV tape. For critical shoots, archival recording, news stringers or wedding videography, choose DVCAM tape with or without cassette memory. 

Entry-level DVCAM equipment. Users of the DSR-200 and DSR-30 should choose Sony DVCAM tape with or without memory. 

High-end DVCAM equipment. If you use ClipLink operation, you 
should choose only Sony DVCAM tape with Cassette Memory. 

What's the difference in Panasonic's new "Master" Series miniDV?
Panasonic's new Master XB series of miniDV uses their S-AME technology (Super Advanced Metal Evaporation) to provide 4 times the magnetic particles by reducing the size. It provides a 1db better output as well as a 1db better C/N ratio than the standard EB series. In addition they claim to have the lowest headwear using their tape.

Why does some Panasonic miniDV look different than others?
The professional series of miniDV tape differs. That's the XB and EB series. Panasonic does make a consumer version, EJ. For best results, always use tape labeled "Professional".

What tape do I use in Digital 8?
Sony's new format DIGITAL 8 uses the same tape as regular Hi8. You can choose to use the MP (Metal Particle) or ME (Metal Evaporative) Hi-8 tape. Because of the properties of ME, Sony suggests this is the better tape to use.... it is rather expensive. An alternative may be Fuji's ME Position (Titanium) tape. But you could even use regular 8mm tape in a pinch.  But don't expect the same quality

Why should I clean my heads before changing to a different brand of tape?
Every different manufactured tape is slightly different (unless it is the same because of an OEM agreement). These differences show up in the wear patterns or the deposits of microscopic dirt (or shedded pieces) on the heads, the rollers, and so on. When a new make of tape is used the first time, it may pick up or disturb previous dirt, because its run pattern is a little different or it may be more. or less abrasive. Many times people will try a new brand, and complain bitterly about the dropout and all the hits. It is often not the new tape, but rather dirt or shedded particle from the earlier tape. So it's a good idea to clean those tape heads with a cleaner when you change to a different manufacturer.