HyperStar is the easiest, fastest way to capture deep-sky astrophotos.  The HyperStar lens easily replaces the secondary mirror on a Schmidt-Cassegrain telescope, converting the telescope into an incredibly fast f/1.8 optical system!  What does this mean?  That you can take pictures up to 30 times faster than you could with a camera at the back of the scope!  Not only does this mean imaging takes less time, it also means less hassle and less extra equipment.

Advantages of HyperStar

• Ultra-fast f/1.8 imaging

• 30x shorter exposures than at f/10

• 5x wider field of view

• Eliminates the need for equatorial mount

• Eliminates the need for guiding

• Faster results make learning how to image much simpler

• Finding and framing objects is much faster and easier

• Improved star images

Is HyperStar Easy to Set Up?

Absolutely!  See the Setting Up the HyperStar System page for more details, but here's an overview.  The secondary mirror of the telescope is very easily removed by unthreading a retaining ring, just like taking the lid off a jar.  The mirror, attached to a metal plate, comes out and goes into a protective holder.  The HyperStar lens is then threaded onto the telescope's corrector plate in place of the secondary mirror.  Attach the CCD camera and you're ready to go.  The whole process takes just a couple minutes!  Reverse the procedure when you're done imaging to put the secondary mirror back in place.  The mirror is indexed so there is no need to realign (collimate) the optics after using the HyperStar lens.

No Guiding

The advantage of a Schmidt-Cassegrain telescope (SCT) is that it provides a long focal length in a compact package.  But the focal ratio, which determines how long an exposure takes, is quite slow at f/10 or f/11.  This means deep-sky images can require hours to capture.  Also, the long focal length means even the slightest tracking errors can ruin a photograph.  This makes guiding necessary.  A guided exposure involves using a second camera to keep the telescope perfectly positioned on a star to eliminate tracking errors.  Depending on the telescope and camera used this involves extra equipment such as a guidescope or off-axis guider, not to mention the extra work required to find a guidestar and calibrate the guide camera.

With HyperStar, the exposures are so short there is no need to guide the telescope.  The requirements of the mount are relaxed, allowing less expensive systems to capture deep-sky images.  The need for extra equipment and cost is also eliminated.

No Wedge

In the past, long-exposure astrophotography has always required the use of an equatorial mount.  But the most popular telescopes now are the fork-mounted, computerized SCTs.  Thanks to the computer system, these telescopes can track without an equatorial mount.  But during a long-exposure image, the sky will appear to rotate, ruining the picture.  This field rotation can be eliminated by using an equatorial wedge, but this means more expense, more weight, and a lot more setup time in order to precisely polar align the mount.

With HyperStar, the fast exposure time eliminates the need for an equatorial mount.  Incredibly detailed deep-sky images can be obtained with a simple alt-azimuth mount.  This means less equipment, less hassle, and less cost.

Field of View and Image Quality

Another advantage of HyperStar is the increased field of view.  The amount of sky you can capture in an image is dependent on the focal length of the telescope used and the size of the sensor in the camera.  Most deep-sky objects are quite large, so a big field of view is a definite advantage.  One way to enlarge the field of view is to get a camera with a bigger sensor, but this means spending more money.  Another is to use a telescope with a shorter focal length, but this usually means a smaller telescope, such as a refractor.  High quality refractors suitable for imaging can be quite expensive, and their smaller apertures restrict the resolution and limiting magnitude of the system.  Also, the focal ratio of a small refractor is typically f/5 to f/7--faster than a normal SCT, but still long enough to require an equatorial mount and guide camera.

Even with a larger sensor in the camera, there can be potential issues.  Many telescopes do not produce sharp stars very far off axis.  Most SCTs have coma, and all SCTs have field curvature.  While the field of view might be reasonably large with a big sensor, the star images will not be ideal.  The HyperStar lens, however, corrects for aberrations such as coma and field curvature, producing a very wide field with very sharp stars across the entire field.  The result is more sky covered, even with a small camera, and finer star images.

• Field of view is more than 5 times wider (25 times more area) than at f/10 with a given camera

• A given field of view requires a much smaller, less expensive camera

• Star images (spot sizes) are much smaller with HyperStar than at f/10, both on-axis and (especially) off-axis

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