I understand perfectly how it works and is set up.  The problem is that I have a video with light and dark bands that I want to bring to the same level as the rest of the video.  If I create a mask for the video with the light bands I can darken them, but then I can not lighten the dark bands.  I need a second mask for the dark bands.  Yes, I understand that the masks only change the existing track, but I want 2 independent masks for the same track.  Actually I want 3 or more independent masks.

When a mask is created, I have to click on the video track to get at the controls.  A much better scheme would be to have the controls associated with the mask, so I could create 2 masks, then each mask would have separate controls to change the video and they would of course work sequentially top to bottom.  Mask 1 could raise the brightness of dark bands and mask 2 would lower the brightness of  dark bands.

Yes, I could do that sequentially by outputting the results from one mask, and then doing another pass with the second mask.  This is ugly, time consuming, and inevitable mistakes will require doing it again and again because I can not see the final result in 1 pass.

The utility of multiple masks/video track is endless because old videos do not necessarily have uniform characteristics.  One mask could be used to increase the brightness at the edges of a video, while another might just be used to fix the color in one corner.  But then maybe this is available in the higher priced professional editor, which is a bit to pricey.

You didn't state which version of MEP you have or which flavour - regular, Plus or Premium.

In 2014, Plus and Premium, there is an HDR Gamma slider with an associated HDR Blur. This allows you to bring up the darker parts without losing the blacks and without affecting the brighter areas.

There is also the Gamma slider that can be applied to the highs, midtones and lows.

Brightness and contrast should be avoided unless that is the effect that you want. See some of my replies in this thread showing what happens to the blacks and whites when using the different effects.

I have MEP2014 Plus and VideoPro X6, which is the expensive version. There is no way to put the effects on the masks or using the Load mask function to have more than one mask loaded.

I can understand that it would be nice to be able to apply more than one mask and have each one affect something different, it cannot be done.

If you have HDR Gamma, and since your case is a brightness/darkness issue, copy your image onto track 3, assuming you don't have an audio track on track 2. Then drag in (don't use the effects pop-down) an appropriate mask to apply to the lighter area, or create one and drag it onto track 2, between the 2 images. Apply the Chroma key Alpha to the mask. Now solo track 1 and darken or reduce the brightness so that the image is acceptable, the brighter area that is. Now remove solo and click on the track 3 image and use the HDR Gamma to bring up the dark areas and compensate a bit with HDR blur. This will not affect the brights. The black or darker part of your mask should be size/positioned over the bright areas that you reduced on track 1. This will allow these areas to show through. The rest of the mask should be white, to keep the remainder that is on track 3.

If you don't have the HDR Gamma, then you need 2 masks and there are 2 different methods to do this.

First method:

Copy your image to track 4 and move it out of the way for the moment. Apply your effect to track 1, say darken it and then apply a mask from the Load mask function that will have the white part that will cover only the area that you want darkened. Invert the Alpha arrow if necessary. In my example, this is the white oval.

Now drag in a mask onto track 3 that will cover only the area that you want to brighten and place it below the first mask. Give it Chromakey alpha effect. I used a small square. The part that will show the area to be brightened should be white.

Now drag the image on track 4 below the other ones and brighten it. Look at the image below for the final result. The oval mask on track 2 shows the area that I darkened on track 1. The square mask on track 3 shows the area that I brightened on track 4. The rest is the original image.

The other method consists of 3 images and 2 masks.

No time to finish this now. Let me know if this helps.

Thanks, but obviously there is no simple solution to the problem.  I have MEP 2014 plus.  The duplicate copies of the video with blue screen are again a very ugly, time consuming workaround, but not as bad as saving, restoring in terms of time.  I really could use 3 or 4 multiple masks.  The blue screen method would require changing the blue screen mask every time I change the effects mask-UGH.

YES I know that the mask merely defines where the operation is used on the original video, but the operation can and should be associated with the mask track.  That way one can do successive operations with multiple masks.  The association with the original video track is because they didn't think ahead to what might be possible.  Notice that associating the operations with the masks would make the interface much simpler.  At present if you have a mask and with to add an operation to it you have to delete it, do the operation, and then add the mask back in.  Again this is an ugly solution.  With multiple masks each mask would have access to all operations.

Well I have also requested this type of thing for VirtualDub, and that video processor would be able to implement it easily with no fuss.  The big problem with either MEP multiple masks or VirtualDub masks is getting the developers to pay attention and actually implement the idea.  The multiple mask idea actually creates a whole range of effects which are currently very difficult because it allows successive operations in various areas.

I don't understand what you mean about:

1. "The duplicate copies of the video with blue-screen are again a very ugly, time consuming workaround..." There is no blue-screen in what you need, simply copy the video from track 1 to track 3, place a mask between them, give it Chroma key Alpha, and add effects to track 1 or 3.
2. "The blue screen method would require changing the blue screen mask every time I change the effects mask-UGH." Why? The effect is applied to the video, not mask (as you seem to want). If you change the effect on the video you don't have to change the mask. You can keyframe the effect on the video or simply split the video to have a radical change in effect, but the mask can remain.
3. "At present if you have a mask and with to add an operation to it you have to delete it, do the operation, and then add the mask back in." No, you don't. If you add or change an effect to the video where the mask has been added directly to the video, you simply click on the mask checkbox to indicate whether or not the effect should apply to the mask. See  the images below. There is no need to delete the mask then add it back in.
4. "....but the operation can and should be associated with the mask track." There is no specific track assigned to masks. In the case of loading a mask using the effects pop-down, the mask shows up on the track immediately below the image/video to which it is applied. If there is already something there, it will be pushed down one track. If there is an object, say a title on the same track but that does not interfere with the effect, it stays where it is. And I disagree with you about putting the effect on the mask and not the image. The effect should be and has to be assigned and applied to the image, not the mask. I could not imagine telling the mask, which is just a B&W image, that BTW, I want you to make the part of the image on track 1 brighter and blurred in the masked part. You wouldn't even be able to see what the effect is on track 1 when you were doing it. Thus for me, your solution just would not make good sense.

ADDING EFFECTS TO THE UNDERLYING IMAGE WITHOUT TOUCHING THE MASK

First image - only one effect - video on track 1 is darkened but this only shows up within the mask.

Second image - I added the Whilrpool effect to the video on track 1. I did not delete the mask. I simply checked the little box and the effect shows up in the masked area (oval), along with the brightness effect (darkening) that was in the first image above. If I add another effect, then the same thing happens. Simply check the box.

Third image - I unchecked the box and the Whirlpool effect is not masked but shows up within and outside of the mask.

If you want to remove the effect, say the Whirlpool, then simply uncheck the box to the left of Whirlpool. To remove it permanently, right-click on the Whirlpool or effect, and select Delete effect.

So, why do you say that you have to delete the mask in order to change the effect?

Why do you find this process difficult and ugly when I find it easy? I think that you do not understand all of the possibilities and the way it all works, especially when you say that you have to delete and recreate the mask just to change the effect on the underlying image.

MULTIPLE MASKS

Below is another example with multiple masks, not using the Load mask function, just using Chromakey to achieve the same effect that I showed in my other post. All masks were resized and moved to the location where I wanted the effect to occur. The square mask on track 2 will show 2 effects that are on the video on track 1 - brightness (darkened) and whirlpool. The oval mask on track 4 will show 2 effects, brightness (brighter) and a color change to redish-magenta. The image on track 3 is the untouched video that shows up outside of the masked areas. The star shape mask on track 6 will show the effects applied to track 7.

First image - Brightness and whirlpool applied to track 1. The black square on track 2 shows the effects that are on track 1 within the square, and whatever is above it, meaning track 3 is protected by the white part.

Next image - added oval mask to track 4 and a copy of the image from track 3 onto track 5. Brightness and color change applied to the video on track 5 show up due to the white part of the oval mask, with the black part letting show whatever is below track 5, meaning tracks 1 to 3.

Next image - I added a kind of star shape mask to track 6 and a copy of the image from track 3 onto track 7. I applied brightness of 100 to the video on track 7, which results in a bright white star shape due to the white part of the mask on track 6 showing the effect from track 7 in the white part, and letting whatever is below, meaning tracks 1 to 4 show up in the black part.