How to remove grey spot on lens of camera? 1

[kippie]

I have some shots which have been taken with a grey spot on the lens of the camera. This spot is on all clips on exactly the same place. I cannot make new shots with the camera. Is there a way to remove this spot totally or partially?

 

[Akribie]

You are unlikely to get a perfect result whatever you do, but if the spot isn't too big you might be able to reduce the visual impact by putting something more like adjacent elements of the picture over the gray mark.

One thing you could try is to put a second copy of the video in parallel, apply a fuzzy-edged track matte to cover only he area of the gray spot, and then to use motion on the second video clip to shift an adjacent area into view through the matte area. This will give a variable overwrite of the gray mark, which might be less intrusive than the original spot - or not - depending on scene content.

 

[kippie]

Thanks Akribie,

Sounds great, only what is a matte? Is that a transparant area or so? Do you know where I could learn more about mattes?

 

[Akribie]

To make a matte, export a still frame containing the problem area.

Open this in PhotoShop.

Create a new layer and give it a memorable name (eg Mask).

Fill the new layer with white.

Reduce the opacity of this layer to, say, 50%.

Paint in black with a soft-edged brush to cover the area of interest.

When done, restore the mask layer to 100% opacity.

Save in PSD format.

Import the PSD into Premiere and choose only the Mask layer.

Base video on V1.

Copy of base video on V2 with Track Matte transparency applied.

Mask clip on V3 stretched to match length of affected video clip.

Apply Motion to the clip on V2 to move an adjacent area into the space previously occupied by the gray blemish.

Test by ALT-Scrubbing and adjust as required.

When (if?) it looks OK, render and check on a TV.

 

[kippie]

Thanks Akribie!

 

[Akribie]

You're welcome.

The final bit works for Premiere 6,5 and earlier. Track Mattes are handled slightly differently in Premiere Pro.

Let me know if you have PPro and I'll give you the required instructions.

 

[kippie]

Hi Akribie,

Well I have Premiere 6.5 for Mac and Premiere Pro for Win. Thanks for all your help!

 

[Akribie]

Track mattes in Premiere Pro work like this.

Place the mask clip on any track and turn off that track's visibility (poke the eye). You need to reserve a track for this or you will not see other clips.

Apply track matte transparency (from the effects palette) to the clip to which you wish to apply the mask. Select the target track for the matte from the list.

If you want to move the matte, then apply Motion to the matte clip, but this movement will only work if you then place the matte clip in its own, separate, sequence and use that sequence for the matte itself.