Hello all,
I am about to receive my TEC 140 and field flattener and would like help to see if I am heading in the right direction before placing my order with precise parts. I have purchased a SBIG 8300m with the 8 filter self guiding filter wheel and would like you to see if my calculations are correct before I order the adapter from precision parts if that is OK.
The back focus of the flattener is 85mm sharp. From the SBIG website (I have 2mm thick filters)
http://www.sbig.com/support/product-...ckfocus-table/ it says for the combination that I have the optical back focus of the camera is 52.8mm.
Am I on the right track in thinking that the adapter has to be 85mm - 52.8mm = 32.2mm but then I have to add one third of the thickness of my filters which would be 0.67mm +32.2 which equals 32.866 or 32.9mm.
Do I also have to take into consideration the thickness of any glass that might be covering the CCD chip as I have not been able to find this information. I wonder if that is taken into consideration in the 52.8 they quote.
If you could have a look over what I have said I would be very much appreciated. I have waited so far for 13 months since my order and am so excited and keen to get my scope up and running.
Thank you for any assistance.
Mark Bateman