user3115: I want to change the opacity of the edge of an object so that when I render it and import to After Effects, it would match with the background video and feather at the edge of objects. 
Cant place images yet.

user-1: When you render in 3D Max make sure pre-multiplying is turned off.

Given the situation you want to render an object to be used for post-production within Photoshop, then…

Be sure you set the background to complete black: Rendering > Environment > Background > Colour (click on the colour field and set
red, green and blue to 0)
Set the antialising in your render settings to Blackman - this type of antialising is quite sharp and doesn’t blur the edges. In
V-Ray this is located in Renderer > Image sampler > Antialiasing
Filter.
Set the file type in the common rendering dialog to tga, 32-bit, premultiplied and alpha split off, compress on.
In Photoshop, load the TGA image, double click the layer to convert it from a background layer into a normal layer.
Go to channels, CTRL-select the alpha channel, invert the selection, go back to layers and hit the delete button.


[...]

If you already have rendered your image and your alpha is accidentally
pre-multiplied, you can add a 6th step to the 5 I mentioned above. In
Photoshop go to Layer > Matting > Remove Black Matte. Voilà, you got
rid of the black ‘halo’ again.

Full article:
http://www.onoff.ch/2007/01/04/premultiplied-alpha-problems/

3115: <p>I want to change the opacity of the edge of an object so that when I render it and import to After Effects, it would match with the background video and feather at the edge of objects. </p>

<p>Cant place images yet.</p>
 -1: <p>When you render in 3D Max make sure pre-multiplying is turned off.</p>
<blockquote>
<p>Given the situation you want to render an object to be used for post-production within Photoshop, then…</p>
<ul>
<li>Be sure you set the background to complete black: Rendering &gt; Environment &gt; Background &gt; Colour (click on the colour field and set
red, green and blue to 0)</li>
<li>Set the antialising in your render settings to Blackman - this type of antialising is quite sharp and doesn’t blur the edges. In
V-Ray this is located in Renderer &gt; Image sampler &gt; Antialiasing
Filter.</li>
<li>Set the file type in the common rendering dialog to tga, 32-bit, premultiplied and alpha split off, compress on.</li>
<li>In Photoshop, load the TGA image, double click the layer to convert it from a background layer into a normal layer.</li>
<li>Go to channels, CTRL-select the alpha channel, invert the selection, go back to layers and hit the delete button.</li>
</ul>
</blockquote>
<p>[...]</p>
<blockquote>
<p>If you already have rendered your image and your alpha is accidentally
pre-multiplied, you can add a 6th step to the 5 I mentioned above. In
Photoshop go to Layer &gt; Matting &gt; Remove Black Matte. Voilà, you got
rid of the black ‘halo’ again.</p>
</blockquote>
<p>Full article:<br />
<a href="http://www.onoff.ch/2007/01/04/premultiplied-alpha-problems/" rel="nofollow noreferrer">http://www.onoff.ch/2007/01/04/premultiplied-alpha-problems/</a></p>
