Finding the right spacer between a TOA-Focal reducer and an SBIG-STT 8300M with FW8G-STT

Posted on Updated on

The distance between the reducer and the camera plane is critical. My telescope is a Takahashi TOA-130. I will be matching it with the TOA reducer and SBIG-STT 8300M camera with an FW8G-STT filter wheel.

My Imaging train

train


TOA-130 with The TOA-RF reducer backfocus

TOA-130

The first key number is calculating the backfocus distance.  (more here)

toa

The number I am looking for is 83.7mm, which is the optimal distance from the reducer to the CCD.


SBIG STT8300M and FW8G-STT Spec backfocus

For details go here

fff

I am using 3mm filters so the back focus distance according to the chart is 52.5mm. SBIG technical support advised me to add 3.7mm for the mounting plate, The camera backfocus distance 56.2mm. A spacer is required between the focal reducer and the CCD.

Spacer length = 83.7- 56.2 = 27.5mm spacer.

To build one go here.

spacer

spacer-3 spacer2

One thought on “Finding the right spacer between a TOA-Focal reducer and an SBIG-STT 8300M with FW8G-STT

    Equipment « Cloudbreaker said:
    March 3, 2015 at 4:37 am

    […] Finding the right spacer between a TOA-Focal reducer and an SBIG-STT 8300M with FW8G-STT […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s