CompuServe Thread

toast glitch in blk fade

7 messages in this thread
#47814From: Duncan KruseDec 1, 1992 11:47 PM
I have noticed with my version 2.0 Toaster that, after blacking a tape with black from the Toaster, when I cut in for a fade up there is a small (approx. 1 IRE) shift in the black level-in short I see a jump on the fades. I spoke to someone at customer service who assured me that this was impossible. While I appreciate his confidence, I am a broadcast editor with an engineering background, and I know what I'm seeing. I'm curious if anybody else has noticed the same thing? I have checked all the system timing and since it is not happening on anything other than the blk input, it is not in whatever subroutine runs the dissolves. A puzzlement! Also, my preview output SC is 180 degrees out of phase w/program. I know in Toaster 1 that both PGM and PVW outputs were proc'd, and they appear to be in version 2 as well, so I can't understand the shift. It's not crucial, but I would like to know what I'm seeing. BTW if any NewTek design people are listening it would be great if at some point a version came out that would allow the user to turn off the proc circuitry, or else leave PVW unproc'd. It would make timing a whole lot easier! All replies appreciated. -dk
#47877From: John GrossDec 3, 1992 12:01 PM
Duncan, if you are talking about using Toaster Black from the BKG generator, it is not 7.5 ire. It is actually about 10 ire. If you save a black framestore from ToasterPaint, you will get a black that is about 7.5 — JG <licensed to fly>
#47921From: Duncan KruseDec 4, 1992 8:41 AM
John-Thanks for the info on the Toaster font utilities. As far as my problems with the black go, I am taking black from an external sig generator. It is right on at 7.5 IRE (though I didn't know about the BG black having a level problem) but there is still a when I dissolve up from black. As I can do a series of match-cuts to black with no shifts, I am led to believe that it is something in the dissolve area. However, I'm not seeing a similar hop using sources other than black. BTW, the hop is approx 1-.5 IRE-small but noticeable particularly when dissolving to a bright scene. Anyway, thanks for your response(s). Let me know if you have any other ideas on the diss. problem. -dk
#47933From: Matthew J. W. RatcliffDec 4, 1992 1:35 PM
The jump in balck may have to do with the loading of the lines depending on the configuration of the framestore buffers.. it might be interesting to compare the jump with different combinations of DV1 and @ on PGM and PVW (oops DV2). Also, a good way to get balck that is black is to use an input with nothing on it, rather than the black BKG (10 ire) or the method of creating the 7.5ire framestore
#47953From: Frank VanellaDec 4, 1992 8:37 PM
Duncan, just a thought on your black level problem. Have you checked to see if the video AGC circuit on your VTR is disabled? If the AGC is left in the on position, it will read the preroll video for it's video level, sometimes it won't let your video signal fall below a certain threshhold. I am assuming that you are using a deck that has a switchable agc circuit, most industrial/broadcast decks have it. Regards Frank
#48268From: John MaguireDec 10, 1992 7:43 PM
Duncan, I also have similar problems with the black level shift and phase shift from frame buffer to frame buffer. The degree of glitchy-ness is board dependant. I suspect the tolerance of the components may be the source of the problem. My solution? Get a new board and keep changing until it gets to your tolerance level. As for the 180 phase problem. It could be a hue adjustment done through software. Or ther is a phase lock loop adjustment (trim capacitor) on the board that will need to be tweaked. (Un-Official Procedure – Remove cabinet CAREFULLY. Power up and configure with a STABLE sync source. Adjust trim cap to mid position while viewing a monitor (or waveform) to obtain minimum disturbance in the picture. I found that it needs to be adjusted frequently and drilled a small hole in the cabinet to get access. Feeding Black at 7.5% into the first position is a way to avoid the glitch. Newtek's idea of black level is 10%.
#48534From: Matthew J. W. RatcliffDec 17, 1992 2:39 PM
The background color called Black is about 10.5 IRE, you can get a 7.5 ire balck by making a black screen in TPaint and saving it as a framestore (mine is called 7.5 IRE Black). The 180 degree phase shift you notice is a result of the Toaster and your equipment not agreeing on which field the color frame starts on. The Toaster is always right on the RS-170a spec, since it is digital. Analog equipment is usually tuned to be 'close enough'. A quick way to flop the Toaster by 180 is to adjust the sc/h phase of the source in input one. If you watch the Toaster phase while you are doing this, it will pop over by 180 at some point. You might also try disconnecting and reconnecting the input, hopping it will catch the frame which your other equipment ic calling frame 1.