Whats wrong with this focusing screen?

<p>I got an AE1P in good condition. It has been overhauled a month ago. Now I Just notice this kind of stain so on the focusing screen. It is brighter on the left side (see picture).<br>

Could you suggest what it actually could be and if there is something I should do ?<br>

thanks for your help and have a nice day<br>

<img src="https://postimg.org/image/guxzs0473/" alt="" /><br>

link: https://postimg.org/image/guxzs0473/<br>

fotos hochladen<br>

</p>

<p>Assuming there's a repair warranty, return it to the repairer.</p>

<p>Ideally, the screen would be replaced: but if you can see what's at the left edge of the finder there's no reason to worry. A focussing screen has no effect on the pictures a camera takes.</p>

<p>Some lubricant used on the mirror mechanism during servicing may have got on to the screen. I have carefully washed them gently using warm water and washing up liquid, rinsed off with clean water, trying not to damage the delicate surface. But it could make it worse, it's your call.</p>

<p>If the screen is soiled, I'll pass along a tip I learned many years ago. Remove the screen and place it in a plastic film container, then add a drop of dishwashing detergent -- ONE drop -- and fill with warm water. Put the cap on the container, shake gently, then remove the cap. Rinse with water until clear, then place the screen on an absorbant surface (I like a clean sponge) and let dry. Reinstall.</p>

 

<blockquote>

<p>"Some lubricant - may have got on to the screen" <em><strong>John S.</strong></em><br>

"Remove the screen and place it in a plastic film container, add drop of dishwashing detergent" <strong><em>Michael McB.</em></strong></p>

</blockquote>

<p><strong>I concur.</strong><br>

These "laser" matte screens are extremely fragile and especially subject to abrasions. <br>

Even a Q-tip will scratch them...</p>