Northfork Walkabout wrote:
I have a dickens of a time with focus. I set everything to manual, use spot focus and hope it comes out. When it's so dark out, I have trouble with using the LCD screen.
I hear this so often. I am using a Sony and turn on the focus magnifier to full magnification and am able to watch the star diameters on the screen as I focus. And as I get close, fainter stars star appearing, so I turn my attention to a faint star and adjust focus until that faint star is a bright as it can be. When I do this, stars are in perfect focus every time.
Here is the package that can save the day:
http://www.startools.org/Mostly, I see the YouTubes on the web focus on doing galaxies and nebula, and don't really address the simple things like reducing stars, which it can do perfectly. And the trick here is to adjust the star mask smaller by a step or two so the mask disappears from the small stars and then to increase the star mask back to what it was so that only the fatter stars are selected.
If you get Star Tools, the price is about $50.
Here is a post that I used Star Tools to show how to make them round. I didn't have any focus problem and didn't have fat stars. But, when imaging stars, the atmosphere causes the light to twinkle around a bit and the result is that stars don't end up perfectly round if you magnify a lot.
I could make another recipe to show how to make fat stars thinner.
By the way, I tried to download and fix this image, but there is not enough information in this picture to be successful. The download is only 640 x 427 pixels. I had to convert it to TIF, then loaded into Star Tools. My first effort reduced the stars out of existence. The 2nd try was to reduce only one pixel, but it didn't look so good. If you can upload a more suitable file to experiment with, it would be better. Star Tools can't use JPEG, and besides, JPEG throws away too much information. I shoot RAW and convert to TIF and its happy with that.