Hotech Field Flattner - How to get flat and sharp astro photos up to the edge of the picture ...
Refractors have the property of showing optical errors at the edge of the image. The result is an image field that is not uniformly flat but curved. These field curvatures are unsightly, make the stars float, not appear sharp or distorted. But especially with astrophotography with a refractor, the aesthetics of the image should be in the foreground. Fortunately there is a little helper ...
Same focal length - flat field
Astro images sharp to the edge. Wouldn't that be nice? With the Hotech FieldFlattner you can achieve this plan - quite simply!
Place this small, chic-designed component on your refractor, whether apochromatic or achromatic. Your telescope should have an aperture ratio between f / 5 and f / 8, because that is what the optics were counted on. Many flattner level the picture, but change the focal length. Your great advantage: The focal length of your telescope remains the same.
What is the use of a field flattner that generates errors again simply because it was tilted in the focuser? The trick is often in the details. The Hotech Field Flattner therefore has a self-centering mechanism. Insert the 2 "adapter into the focuser and turn the integrated ring until the mount itself in the OAZ is clamped by compression rings. There is no tilting due to laterally pressing screws and tolerances in the 2" focus are no longer an issue. This brand new mechanical concept has been patented - and your photo will get better quality
The advantages at a glance:
- suitable for refractors from f / 5 to f / 8
- absolutely flat picture, up to the corners of the field
- against reflexes: multi-coating on the optical surfaces
- no tilting: 2 "sleeve with self-centering mechanism
- 2 "receptacle / T-2 thread on the camera side
- requires 55mm distance from the rear stop to the chip level