Orpington Astronomical Society

Astronomy => Technical => Topic started by: Tony G on Jul 23, 2010, 21:32:51

Title: Filter step up ring
Post by: Tony G on Jul 23, 2010, 21:32:51
Does anyone know where I can get a filter step up ring for fitting my 2" CLS to my Canon lens (58mm),
I want to possibly take some long exposures with the Canon but with the CLS filter attached due to living in Mottingham where the sky is more orange at night, than it is when the sun is setting.

Tony G
Title: Re: Filter step up ring
Post by: The Thing on Jul 23, 2010, 21:43:55
Try here SRB Griturn (http://www.srb-griturn.com/stepping-rings-361-c.asp), they can always make you one.
Title: Re: Filter step up ring
Post by: Mac on Jul 23, 2010, 23:40:20
Amazon.

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=step+up+rings&x=0&y=0&ih=3_6_2_1_1_0_0_0_0_1.12_85&fsc=-1 (http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=step+up+rings&x=0&y=0&ih=3_6_2_1_1_0_0_0_0_1.12_85&fsc=-1)

you just need to know how big your 2" is mm and you might be able to get just one ring, or failing that two.

Mac
Title: Re: Filter step up ring
Post by: mickw on Jul 24, 2010, 00:31:22
Not being picky but I think you need a step "down" ring.
Stepping down from 58mm to 2" (about 51mm)

I would be tempted to bodge it - use a 58 to 52 ring and hold the filter in place with tape  :oops:
Title: Re: Filter step up ring
Post by: RobertM on Jul 24, 2010, 09:41:02
Look down towards the bottom of this page http://www.baader-planetarium.de/sektion/s44/s44.htm (http://www.baader-planetarium.de/sektion/s44/s44.htm)
Title: Re: Filter step up ring
Post by: Fay on Jul 24, 2010, 12:28:23
Tony, I have a, is it a "T" ring that screws into the front of the Canon & it has an extension tube on the end, that goes into the 2" opening at the back of the scope, 2" CLS will screw into that. That is how I did it before getting the clip in
Title: Re: Filter step up ring
Post by: Tony G on Jul 24, 2010, 13:19:30
Quote from: Fay on Jul 24, 2010, 12:28:23
Tony, I have a...................................................., is it a "T" ring that screws into the front of the Canon & it has an extension tube on the end, that goes into the 2" opening at the back of the scope, 2" CLS will screw into that. That is how I did it before getting the clip in

Talk about keeping you in suspense. Fay what is it you have.......... :-?

Tony G
Title: Re: Filter step up ring
Post by: Fay on Jul 24, 2010, 16:37:14
Well Tony, I am somewhat lacking in techincal words.

Perhaps Mark or Robert will know what it is called, I am sure it is T Ring
Title: Re: Filter step up ring
Post by: Carole on Jul 24, 2010, 17:46:12
Fay/Tony, I think the ring that screws directly onto the Canon is called a T adapter.  Then the thing you describe as an extension that goes into a 2" opening on the scope is called a T piece.  

I don't have a T piece (I use a 2" flattener) but assuming the T piece has a thread then the CLS filter should screw on the end.

Or if you've only got a 1.25" telescope opening, there are 2" to 1.25" T pieces as well.  

i.e. http://www.scopesnskies.com/prod/astro-engineering/astro-camera-adaptor/2inch%20to%20T/camera.html

there's a few on Ian King's website as well.
http://www.iankingimaging.com/show_products.php?category=19

Give Ian King or Bernard (Modern Astronomy) a ring, they will tell you what you need.

Carole
Title: Re: Filter step up ring
Post by: Fay on Jul 24, 2010, 17:54:08
|I have mailed Tony already
Title: Re: Filter step up ring
Post by: MarkS on Jul 24, 2010, 18:52:36

This might also help:
http://ukastroimaging.co.uk/forums/index.php?action=printpage;topic=22617.0
Title: Re: Filter step up ring
Post by: mickw on Jul 24, 2010, 20:21:14
I think what Fay and Carole are talking about a "prime focus camera adapter" with a Canon T ring attached.
The prime focus adapter is the tube you shove up the bum of a telescope that replaces the eyepiece.  On the camera end of the tube is a thread, this is what a "T Ring" screws to that converts the tube thread to the bayonet fitting of the Canon - so you can attach the camera to the focuser of the scope.

All you need is what you said - a step down ring from 52mm to 2".
Roberts or Marks link or Ian King or Bernard should have what you want.

Or you could move in with Mac or Chris and sod the CLS
Title: Re: Filter step up ring
Post by: Tony G on Jul 24, 2010, 20:46:04
Thanks for all your replys, but Mark's and Robert's are I think the one's I'm after, as I already have the T-thread Adapter which Fay and Carole are suggesting, which I have and used (not to many times) with the WO66, but was looking to use the CLS filter directly on the end of any of the 58mm Canon lenses I have, and save me the price of a clip-in one.

http://www.baader-planetarium.de/sektion/s44/s44.htm#filterhalter (http://www.baader-planetarium.de/sektion/s44/s44.htm#filterhalter)

Tony G
Title: Re: Filter step up ring
Post by: Tony G on Jul 24, 2010, 20:52:02
Quote from: mickw on Jul 24, 2010, 20:21:14
Or you could move in with Mac or Chris and sod the CLS

The rings are Cheaper. ;)

Tony G
Title: Re: Filter step up ring
Post by: Mac on Jul 24, 2010, 21:41:46
QuoteOr you could move in with Mac or Chris and sod the CLS

Mates rates. :D
or you can bed down for free in the observatory.
Free electricity.

Mac
Title: Re: Filter step up ring
Post by: Fay on Jul 24, 2010, 21:50:09
I also have one of those small cls adaptors for front of lens


ps just corrected spelling, as did not make sense
Title: Re: Filter step up ring
Post by: Rocket Pooch on Jul 27, 2010, 10:26:20
I like the adaptor from Baader for putting a 2" on the front fo a lens, even though it would slow some lenses down.

:-)
Title: Re: Filter step up ring
Post by: Tony G on Jul 27, 2010, 23:31:11
Quote from: Space Dog on Jul 27, 2010, 10:26:20
I like the adaptor from Baader for putting a 2" on the front fo a lens, even though it would slow some lenses down.

:-)


Chris,

That's the one I've gone for, but it was the adapters for this to the 58mm lens that I was trying to source, and hopefully that all sorted now....................... like I said hopefully. ;)

Tony G