QUOTE(domo_kun @ Dec 11 2015, 03:23 PM)
Highlighted in red, what were those? Due to the sun? I checked the lens; clean. No particles or whatsoever... It don't show up in all photos, though...

Dust on your front element won't show that easily lol... Heck SCRATCHES on your FE might not even show up UNLESS it's very, very severe. On your back element it would be (comparatively) easier to see on your pics... though it won't be as "well defined" as in the example you gave us either.
But yeah, as many have said already, those look like the most infernal enemy of the Interchangeable Lens Digital Camera: Sensor Dust/Grime/Stains. You can be careful all you want... as long as you change lenses dust/grime/stains WILL get onto the sensor and haunt you.
Fortunately, if its JUST dust, there's a very simple solution: Turn on "CLEANING MODE" on your camera (it's in the settings somewhere), turn it upside down (lens facing ground), take off lens and use a blower (hard) from below to (hopefully) get rid of the dust.
Be careful to pre-blow the blower first to get rid of the crap INSIDE the blower, and try to do this in a (relatively) dust-free area.
With that done, put the lens back, turn to f/11-f/22 and shoot a clear sky... or a torchlight pointed at the lens. If it's still spotty, repeat the cleaning routine a few times and retest.
If you STILL gets spots after a few cleaning rounds, you might just have a bigger issue than JUST dust: Sensor grime/stains.
Reaching that point (which I hope you don't), you basically have 3 options:
1) If you're not that brave (or willing to live with a sensor - or rather, sensor cover glass - scratched by mistake), send it in to Sony for cleaning.
2) Clean it yourself with "dry" cleaners like the SensorKlear lenspen... which might not even work that well against stubborn sensor grime... and might even scratch the cover glass if you're not careful.
3) Clean it yourself with "wet" cleaners like the "gel-stick" or even more scary stuff like the Eclipse liquid sensor cleaners (on a delicate electronic device... GASP!!).
This post has been edited by Eiraku: Dec 12 2015, 05:47 AM