The most frequent reason I get photos rejected from the big stock sites is because of noise in my photos. I have used a variety of software to reduce it, but often that isn’t enough.
What is it?
All digital cameras will produce noise, because the sensor is comprised of millions of pixels and at the point of capture it is difficult for all these pixels to configure the light and colour of the photo. It can be really bad or almost invisible. To see any noise you have to magnify your photo to the size it is. You can get colour pixelation ot light pixelation.
How I edit it out?
You can use Photoshop by going to Filters > Noise> Reduce and there is some very good software called Nik which is quite cheap.
I now use Lightroom with the RAW image showing to smooth out noise. Here is a video to show you how to do it.
Ways to avoid noise
Obviously the cleaner your sensor is the better. You might have the tools to do this yourself or you should get it done professionally every few months.
Keep your lenses clean.
Reduce the size of your photo.
Here is a photo I submitted which was said to have lots of noise.
I will be advising you later about how to edit your photos for stock acceptance.