What is the purpose of the Baader M68 Field Flattener?
The Baader M68 Field Flattener is an optical accessory designed for astrophotography. It corrects for field curvature, a natural aberration in refracting telescopes that causes stars at the edge of the field of view to appear out of focus. By inserting this flattener into the optical path, you can achieve sharp, pinpoint stars across your entire camera sensor.
Can I use the Baader M68 Field Flattener with any telescope?
No. This field flattener is specifically designed and optically matched for use with the Baader APO 95/560 Travel Companion and Zeiss APQ apochromatic refractors. Using it with other telescopes will not provide the correct optical correction and will likely result in poor image quality.
Why does the Baader M68 Field Flattener use M68 threads?
The M68 thread provides a larger clear aperture than more common M48 or M42 threads. This is critical for preventing vignetting (dimming at the corners of the image) when using cameras with large, full-frame sensors. The larger thread also creates a more rigid and stable connection for heavy imaging trains.
Is the Baader M68 Field Flattener suitable for visual observing?
While you could technically place an eyepiece behind it, this accessory is designed purely for photographic use. Field flatteners are not necessary for visual observation, as the human eye is much more tolerant of field curvature than a camera sensor. Its primary function is to create a flat focal plane for imaging.
How does the Baader M68 Field Flattener perform with a full-frame camera on the Baader APO 95/560?
The Baader M68 Field Flattener is engineered to provide excellent correction across large sensor formats when paired with the Baader APO 95/560. The M68 connection is specifically intended to support full-frame sensors, ensuring the telescope's high-contrast, apochromatic performance is maintained to the corners of the frame for objects like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000).
What adapters are needed to connect my camera to the Baader M68 Field Flattener?
The required adapters depend on your specific camera and the necessary back focus distance. Baader Planetarium offers a comprehensive system of M68 adapters and extension tubes to achieve the correct spacing for various DSLR, mirrorless, and dedicated astronomy cameras. You will need to consult the flattener's documentation for the precise back focus requirement and select the appropriate adapters from the M68 lineup.
