I only have a DSLR, no scope at all yet. Do I still need to take flat frames, and if so, how?
If you’re shooting long exposures for deep-sky images, then yes! It definitely helps the image a lot to use flats no matter what the focal length or FOV of the imaging glass is. To the camera sensor, the focal length does not matter, and most telescopes and lenses will have at least some vignetting or imperfections that shooting flats can fix, dramatically improve the final quality of your image and remove the need for cropping.
For example, see the single exposure below, and then the final processed image, shot with a crop-frame camera and a 200mm lens at f/4. Notice the vignetting and uneven illumination even with a high-quality telephoto lens:
The larger the camera sensor, the worse the vignetting is, because it comes closer to the edges of the lens objective. So, a full-frame sensor will suffer from more vignetting that a crop-frame sensor. That being said, some telescopes are built specifically with larger areas of “flatness”, or you can use corrective elements in the imaging train to fix this as well. BUT, even when using extremely “flat” equipment, your images can benefit from shooting flats.
Co-founder of PhotographingSpace.com, co-owner of several telescopes and mounts, too many cameras, and not enough hard drives, Cory is an American expat living in South Africa with his wife, Tanja Schmitz.
An avid astrophotographer for timelapse, deep-space imaging, lunar, planetary, and star trail imagery, he is an all-around jack-of-most-trades for night-sky photography.
He is also an internationally published and commissioned astrophotographer, where his photos have been used in multiple online and print publications.
Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful, when NOT to show you popups, and tracking our web traffic, etc.
You can adjust all of your cookie settings by navigating the tabs on the left hand side.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
3rd Party Cookies
This website uses Google Analytics to collect anonymous information such as the number of visitors to the site, and the most popular pages.
Keeping this cookie enabled helps us to improve our website.
Please enable Strictly Necessary Cookies first so that we can save your preferences! Otherwise this annoying popup will happen all the time.