Flash of light
Tuesday, March 23, 2010 at 12:24PM During the past few weeks we began to check and compare the samples that we received from various vendors. Since we discovered many problems with the quality of the files during the first time around, the suppliers reproduced their samples one more time in an attempt to improve the end product.
You can see the flash on the first transferAs part of the process I made a comparison between the first round of samples and the second -- and in so doing, found in one of the files an interesting phenomenon; you could see in the video that a photographer was taking pictures withof a flash. Strangely, this was only visible in one of the transfers, while in another the flash wasn't visible. What makes this even more puzzling was the fact that as the recording went on, one would see the presence of the flash in different files, however, there was no uniformity in which file or which conversion this would be!
The flash on the second transferThe two conversions that you see in the picture are samples recorded by the same vendor. For the moment, we are examining this phenomenon, and are trying to understand whether this has any effect on the quality of the sample, and whether we want to keep the effect of the original, in other words, keep the visibility of the flash, or go for a better quality output whose content would be a little different from the original.
If you know the answer, please share it in the comment box!
Reader Comments (7)
It would appear that perhaps someone "de-interlaced" your footage, and the flash occurred during one of the deleted fields.
Was this a film transfer or something from tape?
It is a VHS tape, transferred to MXF-wrapped DV-50.
Based on my experiences with similar media, I'd venture to say we're looking at a mixed field from an interlaced video. Each transfer is interlacing a different field (meaning every other one). Thus one tranfer shows a single flash, while the other shows a different field.
Strobes on cameras are quite quick... in the 10,000ths of a second sometimes, so you'd only see the flash on one field of NTSC video.
It would be helpful to know what equipment and settings were used in the transfer processes. Too many variables to offer much of an opinion as to what's happening during the transfer.
I feel that on your transfer you should keep to original but on your produced you should correct it as it is disturbing.
I'm with those who think that this a deinterlacing issue, which I think brings up another issue worth thinking about - when footage gets deinterlaced, half of your data is essentially being thrown away. Can these guys really toss half the video information and still give you the best picture quality possible?
You might also check with your vendor; are they using any hardware based restoration software like a Terranex box that might be interpreting this as flicker or dropout?