Lumia 830 Camera Quality issue with Windows Camera?

[dhanushcnd]

I am currently using wp10 technical preview with windows camera. recently i figured out when after taking photos automatically add darker layer to the photo. this happens after "adding finishing touches" thing. I have checked both day light and low light, at both time it happens, but in day light it can't see much clear because background light is high. I am adding two photos below to see the difference. is there anyone know about that or anyone has this issue? thanks.