Meade off axis guider question

[samir_ansari]

Hi everyone, I recently bought one of these:

However I've found that in order to connect my DSLR to it I have to remove the nose piece and instead just screw the t ring straight in. This is a problem for me as I have screw on filters which I plan to use.

Is there some sort of adaptor I can get to be able to screw on my 1.25" filters?

Thanks very much,

Samir

[BlueAstra]

You could get something like this for the camera: Adaptors - FLO 1.25-inch T mount camera adapter

Then get a matching drawtube for the OAG.

Alternatively mount the DSLR on the OAG with its Tmount adapter, Then fit a nosepiece+filter to the other side of the OAG. It can then be inserted into the drawtube of the telescope.

[Ludd]

I would in most cases say that the way forward would be to fit the filter (assuming it's a 2" filter) in a push-fit nosepiece that has an SCT thread on the back to fit into the front of the OAG, and then connect the back of the OAG direct to the T-ring on your DSLR. However, if you're using narrow-band filters to cut through the Bayswater orange soup, you may have difficulty guiding with the guide cam behind the filter.

Is there a Van Slyke filter slot with T2 threads on both sides? That could then sit between the OAG and the DSLR, letting the pick-off prism get unfiltered light for the guide cam.

[Merlin66]

Gerd Neumann also does T thread filter holders.

Which scope are you using the OAG on?

[samir_ansari]

In the end I've decided to just bite the bullet and buy an EOS CLS clip filter and take nosepiece filters out of the chain completely.

I think further down the line I will move on to separate narrowband clip filters when I'm more comfortable with the longer exposure times

Thanks again for all your advice!

[Merlin66]

The meade OAG has a SCT threaded nosepiece - are you using this on an SCT????

If not you can use a 2" > SCT male thread adaptor; these usually have a 2" filter thread.

[samir_ansari]

Yep I've already bought the SCT to 2" pushfit adaptor but it didn't seem to have a thread at the end of it (atleast I didn't see one). I must say I do prefer the clip filter route though as it will allow me to use my non EF-S canon lenses. Also it's far cheaper than 2" filters

[Merlin66]

Gerd Neumann also does a 2" to 1.25" filter adaptor;)

Remember you also probably need an extension to get the guide camera in focus.

[samir_ansari]

I was planning on just using a barlow to help with the focus for the toucam but I was a bit worried that my DSLR and webcam would need independent focus adjustments - would this be the case?

[Merlin66]

Basically yes.

The DSLR has to be brought to a focus first; then the guide camera focused to suit. That way they work together.

[samir_ansari]

what would I need to do to focus the webcam separately? the OAG has a small allen key head screw poking out the side of the webcam input which I assume offsets the cameras field of view but I didn't see any way to focus the tube independantly

[Merlin66]

The guide camera nosepiece just slides in and out of the guide tube to achieve focus. There's no helical or other focusing device on these.... trial and error.

(BTW the little grub screw just holds the pick-off prism in place - doesn't do anything else)

[samir_ansari]

ah ha, that makes sense. Thanks very much for the help once again Merlin!