[Windows Central Question]

it makes sound like shutter closing while closing camera rear camera app.

[anon9169769]

Sounds like a focus issue which is mechanical. Did you drop it at any point?

[SpiDe1500]

This is normal due to the focus mechanism.

[EBUK]

My L735 does this. I thought it was a sound effect!

[Marquis de Faux]

My 521 does it as well. Perfectly normal

[xandros9]

A slight click?

It is likely normal.

My sister's 521 makes that noise. My 920 does it, albeit either much more softly, or much less frequently.
I presume its the camera returning to a default state since it has some moving parts in there.

At least, I believe it is normal, since either phone works flawlessly otherwise for the most part.

[SyaifulArif]

Dont worry, my 720 like that too.