Gerd Neumann Aurora 100mm Flat-Field Mask with Inverter for 2x AA Batteries

Product Description

Anyone involved in astrophotography will, sooner or later, inevitably stumble upon the term "flat field." When an image is captured through a telescope, optical artifacts occur that result from uneven illumination of the sensor. To enable image processing software to correct these errors, reference images of a uniformly illuminated surface are required—images that are captured under the exact same conditions as the actual astronomical images. The Aurora Flatfield Illuminator provides just such a surface.

The Advantages of Aurora Flatfield Illuminators:

Completely uniform illumination of the telescope aperture
Full-spectrum light output, making it compatible for use with narrowband filters
Available with power supply options for either 12V DC or standard mains voltage

Aurora Flatfield Illuminators are supplied fully assembled within a plastic frame. The frame is constructed from shatterproof plastic, features rounded corners, and is fitted with protective edge trim; this ensures your Aurora unit remains perfectly protected during transport to your observing site, while the translucent front panel ensures an even more uniform distribution of brightness.

The available diameters have been selected to effectively cover the most common telescope sizes:

100mm Diameter: For instruments up to 4" aperture
160mm Diameter: For instruments up to 6" aperture
220mm Diameter: For instruments up to 8" aperture
315mm Diameter: For instruments up to 12" aperture
420mm Diameter: For instruments up to 16" aperture
590mm Diameter
750mm Diameter

Selecting the Right Size:

To obtain high-quality flat-field data, the *clear aperture* (unobstructed opening) of your instrument must be completely covered. The diameter of the dew shield (or similar accessories) is *not* the deciding factor! For example: For a 6" (15cm) refractor, the 160mm Aurora unit is sufficient—regardless of the diameter of the dew shield. If you are using a Newtonian, RC, ODK, or similar telescope, the Aurora light sheet must be larger than the clear aperture of your optics! As a rule of thumb for a Newtonian, the required size is: Clear mirror diameter + diagonal of your camera sensor. Here is an example: For an 8" Newtonian, a 220mm Aurora is sufficient if you are using a camera with a very small sensor (<14mm diagonal). If you are using a typical DSLR with an APS-C sensor, you must choose a 315mm Aurora.

It is perfectly possible to use a large Aurora with smaller instruments: For instance, if you own a 315mm Aurora, you can use it without any limitations on a 4" refractor or even with your camera lenses.

The brightness of the sheets is ideal for imaging with filters; however, for white-light imaging or imaging using only an L-filter, the brightness must be reduced. The brightness of Aurora flat-field light sheets can be adjusted—within certain limits—by reducing the input voltage (this applies only when using 12V inverters). Additionally, brightness reduction can be achieved very simply and inexpensively by placing one or two layers of white paper inside the frame, between the light sheet and the instrument! For use with very fast optical systems—or with large cameras featuring slow shutters—you will find gray filter sheets in suitable sizes listed under "Recommended Accessories." These filter sheets allow for a very significant reduction in brightness. If you intend to use the light sheet with a fast astrograph, we highly recommend ordering these filter sheets at the same time!

Power Supply: A dedicated inverter is available for every size of Aurora flat-field light sheet. A standard power supply unit cannot be used, as these light sheets operate on high voltage. However, due to the extremely low amperage involved, there is absolutely no safety risk! Please use the light sheets only with the specific inverter recommended for them: While they may technically light up when connected to larger inverters, doing so will drastically reduce their lifespan! Scope of Delivery: Aurora Flatfield Illuminators are supplied as a complete, ready-to-use set. This consists of the illuminator sheet mounted in a frame, the matching inverter, all necessary cables, and printed operating instructions.

Technical Specifications
General
Series
Aurora
Design
Flatfield Mask
Type
Masks
Miscellaneous
Battery Type
AA (LR6) (2 units)


Product Safety
Manufacturer: Dipl.-Ing. Gerd Neumann jr., Neumann-Reichardt-Str. 27-33, Haus 4, 22041 Hamburg, Germany, www.gerdneumann.net