Do I need a field flattener for the ZWO FF70 APO?
No. The ZWO FF70 APO has a 4-element Petzval optical design with an integrated flattener. This means you do not need to purchase a separate flattener or calculate a specific back focus distance. As long as your camera can achieve focus, the entire field will be corrected and flat.
How does the ZWO FF70 APO perform on the North American Nebula (NGC 7000)?
The FF70's 490mm focal length is exceptionally well-suited for very large targets like the North American Nebula (NGC 7000). Paired with a full-frame camera, you can capture the entire nebula complex, including the adjacent Pelican Nebula (IC 5070), in a single frame with sharp stars across the field.
Is the 6.7 lb. weight of the FF70 APO suitable for a portable star tracker?
Yes, but only for the most capable models. While the 6.7 lb. optical tube weight is very low, you must also account for the weight of your camera, guide scope, and other accessories. For the best stability, a lightweight harmonic drive mount or a mid-range equatorial mount (such as one in the 25-30 lb. payload class) is recommended for serious imaging.
What cameras can I connect to the ZWO FF70 APO?
The FF70 is designed to be compatible with full-frame astronomy cameras and DSLRs/mirrorless cameras. The included photographic extension tube provides standard M48x0.75 and M54x0.75 threads for easy connection to most dedicated astronomy cameras and T-rings.
What is the main difference between the ZWO FF70 and the FF90?
The primary differences are aperture and weight. The ZWO FF90 has a larger 90mm aperture, giving it better light-gathering ability and higher resolution for smaller targets. The ZWO FF70 is significantly lighter at 6.7 lbs. (compared to the FF90's 8.6 lbs.), making it a better choice for more portable setups and wider fields of view.
Does the ZWO FF70 APO work for visual astronomy?
While optimized for imaging, the FF70 is also a capable visual instrument. Its apochromatic optics provide high-contrast, color-correct views of star clusters, nebulae, and planets. You will need to add a 2" diagonal and eyepiece to use it visually.
