Solar imaging often involves long focal ratios, which can limit the field of view available. We offer a range of focal reducers to increase the field of view to better match your eyepiece or camera.
Visual Focal Reducer
The Visual Focal Reducer screws in between the QUARK filter and the eyepiece drawtube. The focal length is reduced by a factor of approximately 0.8X, allowing a wider view, or allowing use of shorter than normal eyepieces. This also increases the brightness of the sun, which can make it easier to see faint prominences or increase the visible extent of a prominence.
$199
0.6x Tilt Reducer
The 0.60X Tilt Reducer includes optics to reduce the focal length by a factor of 0.6x, allowing smaller image sensor cameras to capture more of the sun in the field of view. It is also designed for T mount 17.5mm backfocus cameras, or 12.5mm in combination with the included 5mm spacer. It also brightens the image, allowing shorter exposure times that do a better job of freezing the seeing, which can then be sorted for best sharpness with software. Exposure times will be approximately one third as long as without the reducer.
The Daystar 0.60X Tilt Reducer also includes the tilt feature to help remove any interference fringes.
$299
0.33x Tilt Reducer
Our most powerful focal reducer, the 0.33X Tilt Reducer allows smaller image sensors to still fit the maximum field of view possible. Depending on telescope focal length, full disk imaging may by possible even with small sensors. Exposure times will be approximately one ninth as long as without the reducer. Due to the faster focal ratio, the interference fringes are reduced, so little to no tilt may be required.
The Daystar 0.33X is also designed for T mount 17.5mm backfocus cameras, or 12.5mm in combination with the included 5mm spacer.
$349
Imaging Focal Reducer
DayStar’s Imaging Focal Reducer can give you more field of view in your images. 2″ to T mount, with included T extension tube for even more reduction.
With a T-mount camera connected directly to the reducer, the focal length is cut in half – 0.5X. Add the 20mm extension tube for 0.33X. Even better is to combine the T-thread Interference Eliminator (sold separately) with the reducer for an interference-free 0.38X effect.
Please note that the obtainable field of view is usually limited by the etalon clear aperture; Quantum filters will result in a larger usable field than Quark.
Allows full disk imaging with SR127 and 2/3″ monochrome CCDs such as ICX625, ICX655, IMX250, IMX264.
$285
