Filter position in imaging train question

[Jm1973]

Hi. I currently have a DSLR attached via T-ring directly to my focusser. I am looking to get a CLS filter or similar. I have seen one for sale which is a 1.25" CLS  filter. I am wondering which is the best way to fit this into my current setup. How do people normally do it? 

Thanks in advance.

[Waldemar]

The best placing is as close to the sensor as possible, to diminish the chance of vignetting, but also to prevent reflections.
That is not so easy with a 1.25" filter for a DSLR... i.m.h.o. the better choice would be a clip-in filter or a 2" one.
In your case a T-ring adapter with an option to mount a 1,25" filter would be the best.
I don't know what brand of camera you have, but something like this would do the job: 

https://www.ebay.co.uk/itm/1-25-t-adapter-Canon-EOS-t-ring-with-filter-thread-For-telescope-Prime-focus/161206445324

Edited November 8, 2020 by Waldemar
typos

[tooth_dr]

I have tried this and came up with a simple solution - a 3D printed filter holder that gets the filter as close to the DSLR sensor as possible.  It doesn’t interfere with the fit of the T-adapter so that can still be screwed directly onto the focuser as before.  The above adapter will place the filter too far from the sensor, and it’s also highly likely you won’t get focus if using a Newtonian, and you lose the security of a fully screwed-on connection of camera to focuser.

Adam 

 

 

Edited November 8, 2020 by tooth_dr

[Geoff Lister]

This is my setup with my Nikon D3200. The nose-piece of the adaptor has an internal thread for standard 1.25" filters.

Geoff