Its also very short exposure, only 20 minutes worth of data. That’s enough to reveal the galaxy but the image quality is pretty low.
I do plan to re-shoot this one at some point. But until then its my only M33 image so stays on the site as-is.
Update: I did eventually get another image of this galaxy. The link is below. The color difference is between the two images is striking.
Of the two, the CFF version is much more realistic. It's data was color balanced and calibrated against known white stars. It was then adjusted a bit to look better.
Even so, it's not perfect either. The sensor in the camera used for the CFF image tends to the "warm" side of things and most images from it are a bit too red or yellowish.
The D90 used above however, is much further off. When used as an astronomical camera, it really puts in a lot of blue. And I never really understood color balance at the time and certainly didn't bother with it for the original picture. So, the picture above is off-color for sure, and not just a little either. It's way off. But still, the blue is quite "cool" looking so the old image gets to stay on the website anyway.