SBIG Off-axis guider for use with SBIG ST-8300 and STF-8300 CCD cameras and ST-i planet cam/guider


Availability: More on the way

The SBIG OAG-8300 is a low profile, wide field off-axis guider that provides single-sensor SBIG ST-8300 and second-generation STF-8300 CCD cameras with a self-guiding capability . . .
Our Product #: OAG8300
SBIG Product #: OAG-8300

Product Description

The SBIG OAG-8300 is a low profile, wide field, off-axis guider that provides the single-sensor SBIG ST-8300 and second-generation STF-8300 8.3 megapixel CCD cameras with a self-guiding capability, just like SBIG's more costly ST and STL dual chip cameras. The OAG-8300 uses an economical optional SBIG ST-i planet cam to do the guiding.

The SBIG OAG-8300 has a small first surface pick-off mirror positioned at a 45° angle to the light path located just outside the field of the imaging sensor in the STF-8300 and ST-8300 cameras. The pick-off mirror views the sky through your main scope optics, just as the camera does. It picks up a star field for guiding that is located just outside the camera's imaging area. A 7-element relay lens system in the guider transfers the image from the pick-off mirror to the optional ST-i guide camera, which is positioned to the side of the main camera and filter wheel. This minimizes the impact on overall back focus, adding only 0.75" (19mm) of back focus to the camera and filter wheel.

The same 7-element relay lens system also acts as a 0.7x focal reducer that doubles the field of view of the guide camera compared to a typical off-axis system. This increases your ability to find and track suitable guide stars.

The guide camera can be rotated in 90° increments to position it in any of 4 positions around your ST-8300 or STF-8300 without impinging on the main camera's field of view. This is convenient for running cables, reducing the likelihood of bumping the guider in the dark, and reducing the clearance requirements as the system tracks across the sky.

The SBIG OAG-8300 can be used on both mono and color ST-8300 and STF-8300 cameras. Color and monochrome cameras used without a filter wheel will need an optional spacing adapter to simultaneously focus the guider and camera. A monochrome camera used with a filter wheel will not need the adapter. Since the guider is positioned in front of the filter wheel, filters will not attenuate the light hitting the guider. You can confidently self-guide with narrowband or photometric filters in use.

The OAG-8300 guider is also available in a number of STF-8300 packages at special money-saving package prices.

Tech Details

Warranty 1 year


Review by:
This off-axis guider will really improve your imaging. I went from using Orion 80mm short-tube and mini auto-guiding kits to this. I could never manage to get rid of flexure issues. The first night I installed the OAG-8300, I could take exposures as long as I wanted with my "1 minute" polar alignment (I setup and tear down an Orion Atlas nightly). I even took a 60 minute exposure and ended up with round stars. Before this, I would get flexure elongation after 5 minutes.

The only negative on this is that it would be nice to have some kind of focusing mechanism for the OAG camera. Even the ST-i doesn't fit snuggly in the holder and you have to move it up and down while viewing a screen to get it focused (not real critical for guiding but a pain none-the-less). I just leave my ST-i attached so this is a one time annoyance.

Note that I could not get this OAG working with Orion SSAGs. My guess is that they aren't sensitive enough. (Posted on 8/4/2017)
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