Here is one more leaked image from Lumia 1020 camera and this one is a 5 MP image.
Exif data of this image and the 3.7 MP image show that Lumia 1020 will have F/2.2 camera aperture which is bigger than F/2.4 aperture of 808 PureView’s camera.
So, what this means is that Nokia has improved the low-light and Macro imaging on Lumia 1020 compared to 808 PureView, which due to its smaller F/2.4 aperture was not the best camera to capture macro images, unless one used the lossless zoom to go closer. The F/2.2 aperture looks like the best balance between big F/2.0 aperture on Lumia 920 and its Lumia 92X siblings and F/2.4 on 808 PureView.
While daylight images will be awesome due to oversampling, F/2.2 aperture along with OIS should provide Lumia 1020 great low-light imaging as well. In case you want to know how camera aperture impacts imaging read our article,
Have a look at the 3.7 MP image once again. Apart from the amazing details and clarity, you can see the “Background blurring” or “Bokeh” effect as well, which is hallmark of macro photography.