Incorporating filters into a Canon Lens video setup

[Macavity]

With smaller chips, we video astronomers may need to look beyond telescopes to get

WIDE fields. Anyway, this had to be an excuse for investing in my first Canon Lens.

A basic (no filter) setup is very easily achieved via simple Canon to C-thread adapter! 

http://www.teleskop-express.de/shop/product_info.php/info/p5192_Adapter-von-Canon-EOS-auf-C-Mount---fuer-EOS-Objektive.html

A conundrum for DSO work is how to incorporate filters (H-Alpha for nebulae) into the

imaging train? May this give someone an idea, or save *big* mistakes re. adapters?

Since I am generally not doing planetary imaging (at least with my Video setup) I have

adopted the Telescope Service FILTER SLIDE as the basis for all my filtering setups...

http://www.teleskop-express.de/shop/product_info.php/info/p2159_TS-Optics-Filter-Quick-Changer-incl--1x-2--filter-drawer---low-profile.html

The filter slide is nice -- it has male / female T2 threads and optical length only 15mm.

(At most, standard Canon EF lenses have but 44mm(?) of back-focus to play with...)

ANYWAY (takes breath) ...

I used the shortest (10mm) Canon lens to T2 thread adaptor on one side of the slide:

http://www.teleskop-express.de/shop/product_info.php/info/p6991_TS-CCD-Adapter-for-Canon-EOS-lenses-to-T2---only-10-mm-length.html

On the other side a rather simple again short  (4mm) T2 to C-mount thread adapter:

http://www.teleskop-express.de/shop/product_info.php/info/p2838_Adaptor-T2-female-on-C-Mount-male---only-4mm-length.html

With a few DELRIN shims (see below) it, rather remarkably, still achieves focus.

http://www.firstlightoptics.com/adapters/baader-t2-delrin-spacer-ring-set.html

And I still have a 2-3mm to play with... Maybe to fully optimise performance???

Here's a picture of the full setup with a Watec 902H Ultimate attached. Conveniently,

3 tiny hex bolts allow the possibility to rotate the camera to align with the filter slide.

Now all I need is to buy a Canon BODY to get back into *modest* photography?

(Believe it or not, I will have to save hard for *any* more things from now on!)

[Dom543]

Chris / Macavity,

Have you considered mirrorless Sony E-mount or Oly or Pan micro four-third mount cameras? Their flange-to-sensor distance is only ~18 mm as opposed to 44mm for the Canon. You can still use your filter drawer between the Canaon lens and a mirrorless camera. There are also inexpensive straight-through adapters to fit Canon lenses to those mirrorless cameras, for daylight applications, when you are not using filters.

Clear Skies!

--Dom

[Macavity]

Thanks Dom. I think, basically (financially) I've decided to stick with the "old-style",

C-thread, Watec 910HX, integrating video camera from now on. Probably my main

reason for the messing about (no rocket science) incorporating the filter slide.

I may ultimately buy a Canon body, but I sense for trivial non-Astro photo use.