TS-OPTICS M68 TILTER March_Madness Watertight rubber seal around the

Watertight rubber seal around the lid

starting with the ASI1600MM Pro

M16 by Stefano Salvi | Quattro 200 f/4

it is used in order to compensate the focus position shifting caused by changes in temperature

Locking system: Ergonomic safety screw

TS-OPTICS M68 TILTER March_Madness Watertight rubber seal around theMany astrophotographers know the problem: after accurate focusing, in one or two corners the stars are not pinpoints. Often, the sharpness of the image is compromise to a level that the image has to be cropped. Some possible causes of this problem are: a tilted camera sensor (fraction of a millimetre are enough) a tilted focuser a tilted focal plane of the telescope (common in Newtonian telescopes) tilted optical accessories by imprecise clamping As