The first picture was taken at 7:41 in the morning, 35 minutes before sunrise, at ISO 1600, f/2, 1/25s:
The second was taken at 8:10 in the morning, six minutes before sunrise, at ISO 160, f/2.5, 1/45s:
In practice, I took a series of four images in both cases, and then later chose the least blurry of them. That's how I handled the slow shutter speeds without a tripod.
I think most would agree that the first image is the most striking, at least at first glance. It has the deep blue tint associated with the early morning, and there is the contrast with the yellowish artificial lights.
To be able to photograph the first one without a tripod, I needed to push the ISO rather high, at ISO 1600. This is at the border of what the GH2 can handle, and the image quality suffers. Here is a comparison at pixel level between the images shot at ISO 1600 and ISO 160:
Note, though, that this difference is not purely due to ISO differences. The first image also has a slower shutter speed (1/25s versus 1/45s) and a larger aperture (f/2 versus f/2.5), both potentially making the image less sharp. The Olympus 45mm f/1.8 lens is quite sharp, but you'll usually notice that the sharpness increases quite a bit when stopping down from f/1.8 to, say, f/2.8. Despite this, I think the first image could well be printed fairly large without any problems.
The pictures above are from the out of camera (OOC) JPEGs. One could say that the first of the images is rather blue. However, this is not the GH2 auto white balance doing anything wrong, it was quite simply very blue this early in the morning. Opening the RAW image in Lightroom 4, it could be edited to something like this:
I think this edited version is probably a bit more striking.
After having looked at these images, I think it is quite impressive that it is possible to take a handheld image half an hour before sunrise, and even with a tele lens to boot. This shows how far the technological development has come.
Still, the image quality could be improved by using a tripod. If I had a tripod, I could have set the shutter speed to, e.g., 1 second, and used a significantly lower ISO, and a larger aperture for the best image quality.