luminosity

ScottP wrote on 6/21/2001, 10:05 AM
I really like VF!

I'm editing old home movies (8mm) which were tranferred to video tape 20 years ago. Even then the film was dark.

In the tranference process to video from film, there is created a luminosity problem with the edges of the film. Specifically, the film was backlit on a viewer and video taped for the transfer. But, because there is a light source centered in the viewer contraption, the center is brighter than the edges.

Here's the question:
Is there a mask that could be applied to the brightness Video FX which allows graduated luminosity?

VF is useful for restoring color and luminosity but a mask would help even more.

Comments

nclark wrote on 6/21/2001, 7:44 PM
Your question intrigued me so I opened one of my projects and figured something out. Find yourself a rendered file with a section of black in it (or make one by selecting a section of the timeline with nothing in it and render it, making sure to check the "render in loop region only" box). Now, take that clip (it doesn't matter how long it is) and drag it to the "video overlay" track. Point to the edge of the clip (pointer should change to look like a cut piece of film)and drag it out so that it covers the entire length of the part you want to "mask". Now point to the top edge of the clip and drag down. A blue line will appear. The position of the blue line is representative of the opacity of the black clip. This will allow you to "darken" the clip in the track below. Now, click on the Event FX button on the black clip and go to the Pan/Crop tab. By dragging the edges of the frame so that it is larger than the black clip, you now have a rectangular "mask" if you look at the preview window. You can change the size, shape, and position of the "mask" by manipulating the frame's size, shape and position relative to the black clip. (If you want to change the shape, you will need to toggle off the "lock aspect ratio" button.) Finally, to eliminate those sharp edges, add the "gaussian blur" plug-in to the black clip's plug-in chain and adjust as necessary.
ScottP wrote on 6/25/2001, 9:39 PM
Your idea an explanation were excellant! I tried it and see that it will work nicely.

I'm going to go another step further by creating a black rectangle mask, with a graduated black to gray color. The graduated shading will be done in a circular pattern to counter the effects of the backlit viewing device.

I'll make it with Corel Draw and save it as a jpg and use as a still media in overlay. Then use it with opacity level adjustment as you suggested. I don't think I would have figured that out without you.
greatfully,
Scott

I think I'm gonna sell a bunch of Video Factory programs to friends whom I tell about it.

nclark wrote on 7/1/2001, 7:57 AM
I'm glad I could be of assistance. I was actually going to suggest that
you draw your own mask, (because I figured the pattern was probably
circular, not rectangular) but thought you would be turned off by the
suggestion because you may have had to purchase more software.
Besides, I discovered that if you "blur" it enough you can hardly tell its
a rectangle anymore anyway.