All Farpoint Products are made in the USA at our facilities in Gold River, California.
How to select and fit a focus mask for your telescope:
In 2009, George Carey, an amateur telescope maker and astronomer from the UK, published a modification of previous focus mask designs to make a much more sensitive version of the device. This focus mask allows you quickly, easily and precisely focus your DSLR camera, webcam or CCD camera for astrophotography. The method is simple, very intuitive, and the device has universally been named after the inventor: The "Carey Mask".
Attach your camera to the telescope, center a fairly bright star in your telescope and achieve a rough focus. Then place the mask over the front aperture of your telescope by “hanging” it on the plastic screws from the front dew shield. Take a short exposure. The image of the star will show diffraction spikes.
The Bahtinov Mask requires you to judge when the central spike is midway between the two angle spikes. This is quite easy to do, but there is still a little uncertainty in determining the exact center alignment, especially when viewing in a DSLR viewfinder.
With the Carey mask the central spike idea has been abandoned. The angle between spikes has been considerably reduced. Instead of two sloping sets of slits and one central set, there are four sets of slits, with a small angle difference on each side of the mask as shown in the image below.
The diffraction pattern produced is two overlapping 'X' shapes with slightly differing angles, and at perfect focus the Xs will be symmetrical.
Inside and outside focus the Xs will be displaced. Because the angle of each X is slightly different, it will be easy to spot when out of focus, and also which way focus should be altered.
This animation shows focus being reached.
Farpoint manufactures this "lifesaving" astrophotography tool out of virtually indestructible ABS plastic, which comes in two major types and in a range of sizes. The mask pictured below left is a general purpose mask designed to fit refractors and Newtonian telescopes. The mask pictured below right is designed to fit Schmidt-Cassegrain telescopes. Both types of mask are available in a range of sizes to cover your imaging needs.
ชุด SVbony 68 Degree Eyepieces Set F9152 สำหรับกล้องดูดาวขนาดฟอกัสเซอร์ 1.25"ทุกรุ่น
The Super-wide Angle Eyepiece eyepieces offer a quality 5-element Plossl optical design at a super affordable price. Fixed folding rubber eyecup allows easy use with or without eyewear. Anti-reflection fully multi-coated optics ensure bright and clear high-images at any magnification, with true color rendition.
The ASI2600MC Duo combines imaging and guiding sensor in one compact body. The main sensor is the Sony IMX571 coming with a native 16bit ADC, 14stops dynamic range and 3.76um square pixel array. The readout noise is as low as 1.0e, and the full well capacity reaches an incredible level of 73ke. And it has no amp glow!
The guide sensor is the Type 1/1.8 SC2210 with excellent NIR sensitivity. The sensor size is 7.68mm x 4.32mm. It has 4umx4um pixels with an array of 1920x1080 and a full depth of 8780e.
The stars on the corner of the guide images affected by reducers back focus distance might not be very round. It is not due to the sensor tilt and will not affect normal use.
The stars on the corner of the guide images affected by reducers back focus distance might not be very round. It is not due to the sensor tilt and will not affect normal use.
ZWO has released a brand-new FF65APO 0.75× full frame reducer with a four-element optical design. It has a reduction factor of 0.75x, which gives the FF65APO f/6.4 astrograph a shortened focal ratio of f/4.8 and a shorter focal length of 312mm. This allows for less total integration time and a wider field of view, bringing more convenience and possibilities for your wide-field deep sky imaging. The back focus distance is the standard 55mm. It also comes with two thread adapters of M54 and M48, and a built-in M48x0.75 2” filter thread, which makes the connection work simple and convenient.
Very nice look and good quality red dot finder. Easy to use with hex screws for perfect fine adjustment (very precise pointing).
Well machined and painted, comes with bracket and mount.