Do you have a filter on your lens?
my best guess its the stars lah... their position with reference to the building is always the same... i always get these spots until i realize they are always at the same position with reference to the buildings
wah reflections ah..
any idea did the problem come from the filter or the lens?
edit : nvm i test again soon and post results
If you remove the filter and no more reflections, then it's from the filter loh.. Otherwise there is nothing else left for you to remove already.. ;p
heh got ah...self given excuse to change some glass
But let's be practical, the ultimate best in multicoating I've encountered is able to give a transmission about 99.8% which means which means that 0.2% is lost in reflection or absorption. Let's assume that half is reflected and half is absorbed, the reflection would be 0.1%. That's about 10 stops. So if the background is more than 10 stops darker than the light source, chances is that the background is not able to cover up the reflections from the light sources.
In situations like these, I think might be easier/cheaper to clone away the spots. ;p
yea...true..so might be better to increase iso reduce exposure at the end of the day..
was doing very long exposures some where further back there was intense lightning storm..capturing lightning and saw these.
are the dots on the sky hot pixels?
Long Exposure on D90 on 35mm F2[/QUOTE]
You can check out this site for a program that can help to spot hot or dead pixel. Tested on mine but detected no issue. Check this out if it works for you.
[url]http://www.starzen.com/imaging/deadpixeltest.htm[/url]
Did some again without the filter and no spots at all even at 30 secs exposure.