Fujifilm X-S10 - how to focus on the night sky?

Hi everyone... Sorry newb question here. I have used my Canon G7X for years and never had a problem photographing the sky. But with my Fuji it just wouldn't focus on it. And when I got a photo the stars came out as out of focus blobs. How do I rectify this?

Also any tips regarding how to photograph the galactic core? Any good apps for finding it and figuring out when it will be visible in the sky? And ideal settings to use? I have the 15-45mm lens. Thank you

Check out the astrophotography forum:

https://www.dpreview.com/forums/1059

What I have done in the past is set it to manual focus, magnify the EVF view, and focus on a bright star until it looks sharp, and then take several photos adjusting the focus slightly. Shoot Raw and look for tutorials videos on how to post-process for the night sky.

roshank wrote:

Hi everyone... Sorry newb question here. I have used my Canon G7X for years and never had a problem photographing the sky. But with my Fuji it just wouldn't focus on it. And when I got a photo the stars came out as out of focus blobs. How do I rectify this?

Also any tips regarding how to photograph the galactic core? Any good apps for finding it and figuring out when it will be visible in the sky? And ideal settings to use? I have the 15-45mm lens. Thank you

Well, AF is always tricky when it comes to stars or most anything astro. There simply isn't a lot of light for the AF system to work with and to achieve critical focus. No experience with the X-S10, but I have had some luck aiming at the brightest objects out there (the moon if it's visible or perhaps one of the brighter planets, like Venus or Jupiter). at least on my X-H1, I've found that there is often just enough light for AF to engage, and most often, I've been able to AF accurately. Your 15-45 is frankly pretty slow at f/3.5 for astro work. You can definitely capture some stars, but the problem you'll run into is both the aperture being a bit too small and also 15mm being sort of long. Both will require a long-ish exposure to capture any stars, and that will result in star trailing. The only real solution is to get a faster lens -- preferably an ultrawide... say 12mm or so and f/2.8 or faster. Probably the best solution for that is the Rokinon 12/2.0, which is one of the most popular astro lenses out there. It's also quite reasonably priced at around $250 USD new and under $200 USD used.

There are a ton of sites and apps out there that can provide star charts for your area. You can start here: https://skyandtelescope.org/interactive-sky-chart/ and then use Google to find other tools that can help.

roshank wrote:

Also any tips regarding how to photograph the galactic core? Any good apps for finding it and figuring out when it will be visible in the sky? And ideal settings to use? I have the 15-45mm lens. Thank you

Stellarium (desktop or mobile app). Find where and when the MW core rises and sets.

PhotoPills app or PlanIT Pro app. Helps in planning foreground and also shows best time of the month to shoot MW core.  In my location the MW core is only visible from March to September.

Timeanddate DOT com find the moon phase. Ideally best to shoot MW core during new moon phase or few days either side.

Atmospheric app (predicts clear skies for your location)

Darksitefinder DOT com (shoot away from city light pollution)

Suggested camera settings: 15mm, f/3.5, 20 seconds shutter speed and ISO 4000

There are no ideal settings.   For the 15-45mm I would start with 15mm, f/3.5, 20 seconds shutter speed and ISO 4000.

Good luck.

roshank wrote:

For the focusing, should I just figure out how to put my lens on infinity focus and then stick to that?

You can try that and see how it works.  Frankly, I follow one of the fairly simple processes for achieving critical focus at the start of the evening and I’m good to go.  Again, infinity may not always yield proper focus.  Most photographers I know simply go thru a simple process for achieving focus and then stick with that throughout the session.