I recently purchased a Coronado PST telescope.  My primary use will be solar photography.  After purchasing the t-ring and camera adapter for my Nikon DSL I quickly found out that the PST did not have enough focus range to use the telescope as the primary lens.  Instead I had to attach my 50mm lens to the camera, set the lens to manual focus at infinity, and shoot through the key piece.  This worked out ok but hand holder the camera is not what I had in mind.

After many days of research I found that people were adapting webcams instead of using DSLRs and not one explaining how to adapt a DSLR. Using a webcam has some advances over DSLRs, especially when it comes to stacking images since the video camera takes 15 frames per second or more. This translates to hundreds of individual images whereas the DSLR is limited in the number of pictures it can take before writting to disk. The problem with using a webcam is that the newer ones are auto-focus now. Auto-focus may or may not work with your telescope. I went out and bought 2 HD webcams and tried to adapt themto the PST with little limited and disappointing success. Perhaps I could have made it work but the modifications I needed to make just did not seem worth it so I decided to go with the DSLR since I already had readily available access to 3 Nikons.

I continued to research how to adapt a DSLR to a telescope that did not have enough focus range and found "ZERO" articles on the web. That does not mean that they are not out there, just that I could not find any. After having several discussions with my wife, who is a professional phtotographer, I determined that I needed a shorter camera adapter and a 2x barlow lens to compensate for the lack of focusing range in the PST. I describe how to piece together multiple telescope accessories to be able to use the PST as the primary lens.  The key is to get the camera focus point within range of the focusing capabilities of the telescope.  This is what is needed to take solar pictures using the PST as the primary lens and a Nikon DSLR. A plus is that you can use either primary focus or through the lens focusing to take great solar pictures.

Nikon T-Ring (~$30.00)

Orion Camera Adapter 1.25” (~$40.00)

CEMAX 2x Barlow lens(~$110.00)

Screw the 2x Barlow lens to the small tube from the camera adapter as shown

You will need to disassemble the camera adapter and the Barlow lens.  Both pieces have removal parts as shown in the photos. You only need the threaded ring from the Orion camera adapter and the Barlow lens from the CEMAX.

Add the T-Ring and now you have a new short barrel camera adapter that will allow you to use the PST as the primary lens.    The advantage of using the PST is the camera is perfectly centered and you do not need to hold the camera there by eliminating any shaking.

The 2x Barlow lens will thread directly to the supplied Keller 20 mm eyepiece. Now you can go back and forth between shooting through the PST primary lens and using your camera lens with the supplied Keller 20 mm eyepiece and 2x Barlow lens. Below is a comparision shot using both methods. There are trade-off as you can see.