Where does the filter go for a DSLR?

[Kaptain Klevtsov]

On my Skywatcher, there is a T mount thread on the EP holder, but nowhere to screw a filter. On the Barlow there is a place to put a filter half way down where it unscrews. This is between the Barlow lens and the DSLR so I'm not sure if adjusting this distance is OK. I thought that I could use the outer half of the Barlow without the actual Barlow lens to hold the filter, but it won't fit in the EP holder as the diameter is too big.

Do I need an adapter to hold the filter, (or a damaged EP with the lens taken out) or am I missing something here?

TIA

Captain Chaos

[Kaptain Klevtsov]

I got the recommended light pollution filter to improve the images I get from my DSLR and I don't know where it goes. There doesn't appear to be a thread to fit it except on the EP and this is in a box while the DSLR is mounted on the T mount adapter. If I use the Barlow, there is the facility (don't know if that's what it's for though) to unscrew the barlow half way down and fit the filter between the two sections. BUT this means using the Barlow and I might not want it for some shots.

Ditto with my webcam as it sits inside a converted SLR (see www.gas.uk.net for pictures)

Going to check this out in the daylight to see what I missed.

Captain Chaos

[Ambermile]

CC - are you using a T>1.25" or T>2" adapter? These should be threaded for filters?

Arthur

PS - if not, why not??

[FLO]

He beat me to it

(Was trying to find a link to the Astro-Engineering adaptor)

[Kaptain Klevtsov]

No on both counts. It's the EP adapter that came with the 'scope. One end has a tube that the EP fits inside with thumbscrews to lock the EP in place. this tube is screwed into a boss that goes into the 'scope focusser. The best way that I can think of to describe it is like a round dovetail. The tapered section goes in big end first until it bottoms, then thumbscrews hold it in place. The EP holding tube unscrews from this boss leaving a small raised section which has a thread which fits the T adapter. No provision for a filter.

I have, just now, discovered that the Barlow comes apart in two places, so I can fit the filter AND remove the lens from the Barlow. Woohoo. I was not brave enough to do this at night, as I have a fear of broken glass under my feet if you get my drift.

Thanks for the help guys, it was, as usual, operator error.

Captain Chaos

[Ambermile]

He beat me to it

(Was trying to find a link to the Astro-Engineering adaptor)

Eeek - wash yer mouf owt!!

Arthur

[Kaptain Klevtsov]

Cancel the WOOHOO. The focusser will not go in enough with the bit of the Barlow carrying the filter. I need to get an adapter. Hmmm - now where would I get one of those?

Captain Chaos

[FLO]

Eeek - wash yer mouf owt!!

Arthur

Hey! I like Astro-Engineering products

[OXO]

I got some stuff of them a while back all good

Captain,

Can you not get a T-Adapter with internal thread to take 2" Filters?

James

[Ambermile]

http://www.modernastronomy.com/catalogue.html#adapters

2" to T thread adapter. Can't find a BC+F one.

Arthur

PS - Ambermile also sells them.

[OXO]

[Kaptain Klevtsov]

Might have found a way round it, but I'll have to wait for the stars to come back before I know. In the meantime I need to find a source of a 1.25" to T adapter with filter threads that would work in the Newt.

Arthur, do you do Paypal?

Captain Chaos

[Ambermile]

Umm - yes - but PM me...

[Kaptain Klevtsov]

Thanks Arthur, I will do that if the need arises

Captain Chaos