Film-Tech Forum ARCHIVE: Reverse Scan vs Foreward Scan on Red Readers on Older Tracks

This is topic Reverse Scan vs Foreward Scan on Red Readers on Older Tracks in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bill Enos (Member # 440) on 01-11-2006, 08:15 PM:

With regard to problems with sound on older films, is red light not as good either way or is reverse scan worse than foreward??
I looked at other posts covering red light on old prints but didn't notice this mentioned, or maybe I missed it.

Posted by Mark Gulbrandsen (Member # 72) on 01-11-2006, 09:35 PM:

Reverse scam is clearly the winner in spite of the lower signal to noise ratio that the red array affords. You still have far lower IM and harmonic distortion, almost zero crosstalk, and things are far more stable over the long term. Need better S/N ratio just slap in an IR LED array. Thats one good advantage of the BACP reader with their user interchangable led heads.

Mark

Posted by Stephen Furley (Member # 1277) on 01-12-2006, 02:32 AM:

Given that reverse scan has been around for many years, long before red readers, and its advantages seem to be just about universally recognised, why did it not become standard long ago on new machines?

Posted by Marin Zorica (Member # 1716) on 01-12-2006, 06:59 AM:

Maybee because today when you buy new machine, the is 98% that you buy DOLBY DIGITAL, DTS or SDDS. And then analogue is only for backup, so maybe because of that analogue is little backwards. But front scan system do work werry well also!

Posted by Louis Bornwasser (Member # 3063) on 01-12-2006, 07:49 AM:

In fact one of the old Western Electric soundheads was reverse scan, long before Century tried it and gave it a bad name. (Lonny Jennings modified several reverse scan Century's and got wonderful results using a BYS bulb (9 volt, vertical).

It is hard to believe (now with many changes happening fast and stupidly) but this industry was a very cautious place in the 1940 to 1985 era. It was felt, then, that optical was bad and that magnetic was good. No Dolby and no digital. So, "good enough" was the operable phrase. Louis

Posted by Mark Gulbrandsen (Member # 72) on 01-12-2006, 08:51 AM:

quote: Louis Bornwasser
In fact one of the old Western Electric soundheads was reverse scan, long before Century tried it and gave it a bad name.

Known as the TA-7400. I have one out in the garage someplace. Aside from having reverse scam it also utilizes a 3450 rpm drive motor. The slit in it is fully adjustable in height, width, and has a neato adjuster for azimuth.

Old audio equipment dealers need not call me on buying this one.... its priced so high that you don't even want to know [Big Grin]

.

Mark

Posted by Bob Koch (Member # 1062) on 01-12-2006, 02:34 PM:

The soundhead{TA 7400 which Mark has is very rare indeed. In 1935-8 Wetern Electric brought out Mirrophonic sound systems. The ones I remember most were the 3m- 86 systems. 3MA86 had the 207-08 reproducer, 3MF86 had that miserable soundhead with no sprocket;209-211,and the 3MG system which had the TA7400 reproducer which Mark has. Were`nt many because the price of the 7400 was so damn much more money that the exhibitors would`nt buy it. They have from that day to this, remained constant in their revulsion at spending any money in the projection room.

Posted by John Eickhof (Member # 323) on 01-12-2006, 02:46 PM:

Hi Bob and Mark! I have a real nice 7400 too! It was well ahead of it's time!! The century was pretty decent but most techs didn't know how to really adjust it! Thus there were constant problems with distortion and lower signal-noise! I'll take ANY modern reverse scan over the forward scan today!!!