We love our GH5 cameras, but they aren't the best in low light. Luckily, Panasonic recently released the GH5S, which has almost two stops better ISO performance, and with the right lens, we are finally able to shoot astrophotography.
The average star exposure is around f/2.8, ISO 3200, and 15 seconds. The GH5 doesn't look great at ISO 3200, and shooting with a multi-second exposure makes the noise even worse. Because of this, we had given up on shooting images or time-lapses of the night sky with the GH5 and we resorted to bringing an extra camera and lens along solely for this purpose.
The GH5S was recently released and seems to have around two stops better ISO performance. This means that ISO 3200 on the GH5S looks pretty similar to ISO 800 on the GH5. Normally, we would shoot wide time-lapses with our Olympus 7-14mm f/2.8 lens, but to get cleaner shots, I tested out two new, faster lenses.
The first lens I tested was the Voigtlander 10.5mm f/0.95. This lens is over three full stops faster than an f/2.8 lens, meaning that we would have the opportunity to shoot at ISO 400 or use a faster shutter speed. The lens is incredibly built and the feeling of the focus and aperture ring makes it one of the smoothest lenses I've ever used. It feels like a professional cinema lens. It's not very sharp at f/.95, but if you stop down even one stop, it creates a great-looking image. There are two main problems with this lens: it's not quite as wide as I would like to shoot the stars and it's $1,100. If you're looking for an ultra-fast, manual focus lens for M43, this may be a great option for you, but for stars specifically, it's not perfect.
The second lens that we tested out was the Laowa 7.5mm f/2. When I opened this lens, I laughed out loud at how small and cheap it felt, but in our tests, it performed pretty well. The lens is acceptably sharp at f/2, but it does suffer from pretty significant vignetting. At $500, it's certainly not cheap, but it is much more reasonably priced than the other two lenses we tested.
In the end, my favorite combination was the GH5S and the Laowa 7.5mm f/2. We were able to get great-looking star time-lapses with this setup. I was able to shoot most of our timelapses at f/2, ISO 1600, and 15 seconds or ISO 3200 and 8 seconds. We put a few unedited time-lapses in the video above, and we were very impressed with the end result.
Keep in mind that If your main interest is astrophotography, I wouldn't suggest this system. Most current full frame 35mm cameras still have better ISO and long-exposure performance than the GH5S, and they have more lens options as well. But, if you're like us and you are shooting exclusively video, the GH5S is definitely capable of capturing clean astrophotography and time-lapses, and of course, it also takes incredible footage during the day as well.