Dichroic Beam Splitter for use with AO7 and a Separate Imaging Camera


Principle of operation (from RCOS web site)

To see the original RCOS web page screen capture click here

My configuration:


First light was August 2, 2003. All that was accomplished was confirming that focus could be reached in both cameras. Then the clouds ("the Seattle Nebula") moved in. Ain't it always the way it goes with new gear...


August 7, 2003 UPDATE:

First images:  backyard in Castro Valley, California.

6 x 10 minutes through Hydrogen Alpha Filter (Custom Scientific, 3nm FWHM).

Conditions were deteriorating from sunset on, but I managed to get 5 decent exposures and one iffy one before the clouds shut me down for the evening. The image below needs more signal, I plan to reshoot using longer frame exposures and hopefully will have clearer skies.

Click on image to enlarge

To see first color image click here

--August 9, 2003 update

Was informed by  Mr. S. Karoussos of Spain that there were three different mirror types used in the RCOS beam splitter, all made by Custom Scientific: the older 2mm thick  DC675SP:

The 675 AR

And the  700AR mirror which is 1mm thick:

Fortunately for me, I have the thinner and more desirable Model 700AR mirror.

August 11, 2003 update:

I collimated the C14 and shot three test images of NGC7331 through a luminance filter with a full moon. The image is not a pretty image: there are numerous array defects and other defects arising from a poor flat field. The stars are getting round. I need to focus better. I found a problem with my Optec focuser and corrected it.

3 x 15 minutes through Luminance filter under a full moon. Poor focus and poor flat-field, but round to near-round stars.

For FIT data of image above right click here and select "save as" from your browser


August 15, 2003 update:

I replaced the ST10XME camera with my ST7E camera (parallel port type). I discovered a ground loop that was causing terrible star tailings in the guide chip. The workaround was to use the SBIG 12V field power supply.

The results (13 x 10minute Halpha) look good to me. I think the system is ready to be released to production.


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