New wide angle lens, night sky test

Looks much better, but I don't think I quite nailed focus

30-minute time exposure at f/5.6, ISO 200

The shot above is a 30-minute time exposure. The stars make trails because the earth rotated during the exposure. With a 24-hour day, and 360º per earthly rotation…the star arcs represent 7.5º of the daily rotation.

A 5-second ISO 1600 image at f/5.6

The shot above is the exact opposite: a 5-second exposure to minimize earthly rotation effects. (With 86,400 seconds per day, that is 5/86,400th of a circle, or 1.25 arc minutes of rotation.)

Technical info: both shots are with the 32mm lens/Cambo WRS-500/Phase One digital back IQ3 100. They were taken from my driveway; that’s a nearby house at bottom left (and my wife’s Jeep to the left of that).

There were problems with the first lens I used for night shots (my best guess is that one or more elements in the lens were misaligned), but this lens checks out fine. If you dig in deep enough, you will discover that I did not get the focus right. Long story, that goes like this.

I had planned to shoot at f/11 or f/16, and I set the lens a little off of infinity focus so that the foreground objects would be sharper. But then I decided to test at f/5.6, and did not adjust focus accordingly. (The focus plan is deeper at larger f numbers.) A classic experienced-photographer unforced error; we always think we were smart enough to set the settings right and then don’t verify them. :)

Note: photos on Substack are showing up darker than the way that I have processed them. I hope the stars make it through that. I have an inquiry in to the technical team at Substack to see what they can tell me.