Exposures of from 1sec to 30sec were taken. The telescope used was a Takahashi FSQ-106 refractor. Only an IR Block filter was used in between the starfish camera and the telescope optics. The images below were dark frame subtracted and then contrast stretched for display. Only a single frame was taken at each exposure setting. The images were scaled down to 683 x 512 pixels for the web page. Remember that the full size images are 2047 x 1536 pixels!
Click on each thumb nail image below to bring up the larger image. I have annotated some star magnitudes in the frame for your reference.
Starfish camera with Micron MT9M001 image sensor:
We were able to test a version of the starfish camera with the Micron MT9M001 image sensor. This sensor is a monochrome imager with 5.2u pixels. The quantum efficiency is 56%. This is more than twice as sensitive as the MT9T001 image sensor. The spatial resolution is 1280 X 1024 pixels but since the pixel size is 162% larger, the optical format is the same at 1/2" giving the same filed of view as the MT9T001 image sensor.
2 second exposure.
30 second exposure.
We used a modest telescope objective size of around 4" at f/5 for the sensitivity tests. This is because most guide scopes will not be much larger than this. Exposure settings for guiding will ideally range from 1 to 5 seconds in order to give the guider software frequent enough guide star position updates. In this exposure range, stars of magnitude 8 or less are readily visible and should provide a suitable star image for guiding. Increasing the image sensor's gain setting can provide additional signal level intensity. The resulting image noise would not interfere at all with guide star position calculations.
Tests with the more sensitive MT9M001 image sensor were very promising. The sensor has a maximum QE of 56% and would provide a broader selection of suitable guide stars in guiding applications. We are currently planning to offer this image sensor in a version of the starfish camera.