Those long exposure photos of the night sky that capture details of our galaxy invisible to the naked eye come at a cost. The longer a camera's sensor is active, the warmer it gets, adding unwanted electronic noise to an image. You can go shoot in the freezing temperatures of the arctic to solve the problem, or grab this custom sensor-cooled Nikon D5500. That massive box hanging off the back of the D5500 above, which essentially doubles the size of the camera, serves just a single purpose: It guarantees the DSLR's sensor always remains at a constant preset temperature, no matter how long you leave the shutter open for a long exposure photo.
The left side of this image was captured with the sensor cooler turned on, while the right side had it turned off.
To clearly demonstrate the advantages of this upgraded Nikon D5500, which boosts the cost from $900 to over $3170, not including a lens, I've brightened the results of this before and after image that PrimaLuceLab has on its website.
The left side shows a long exposure photo with the cooler switched on, while the right side has it switched off. The results are definitely subtle, but there is clearly more noise on the right side of the image. When you're trying to capture small pinpoints of light in the night sky, that noise can really mess up your long exposure photos.
There are some obvious trade-offs to using the upgraded camera. The D5500's touchscreen can't be folded away, you'll need a tripod that can handle the extra weight, and access to an external power source since the cooling mechanism would drain the DSLR's own battery in no time. So get ready to haul around a big clunky battery if your astrophotography hobby requires you to escape the bright lights of the city, but even if you manage to capture a single image like this, it all seems worth it.
Photo by Filippo Bradaschia via PrimaLuceLab