filter

[brrttpaul]

along with the guider and finder scope I was also advised to get a good filter, I was looking at this one but how does it connect? telescope is an equinox ED80 with a field flattener which is attached to a nikon dslr im guessing it goes between the nikon and flattener? this is the filter

http://www.firstlightoptics.com/light-pollution-reduction-imaging/baader-neodymium-filter.html

[Oddsocks]

Unfortunately for your combination of scope, flattener and camera there are no suitable LP filters on the market AFAIK.

The flattener to chip spacing distance is critical and inserting the 2" m48 threaded filter cell between the Nikon DSLR coupler and the flattener will extend the flattener-to-chip distance by at least 6mm, the tolerance on spacing is less than 1mm, you would re-introduce coma into the image.

For historical reasons Nikon DSLR cameras are poorly supported in the astronomy market and there are virtually no internal clip filters specifically for them.

If you had a different make of scope and flattener it would be relatively easy to introduce a LP filter somewher in the chain without upsetting the flattener distance but the ED80 and dedicated SW flattener is a bit of a swine.

TBH you might be better off reviewing how you do astrophotography given the bad LP that you report elsewhere in the forum,  possibly looking for a S/H CCD with filter wheel and narrow band filters? Even second hand this would be a serious financial investment, or else look to buy a cheap S/H Canon DSLR, (or an astromodified version with the internal IR filter modification), plus the M48 Canon "T" adaptor, and then you have the option of one of the Canon clip-in LP filters that will not upset the flattener spacing.

[brrttpaul]

Thanks for the reply and the explanation, I,m glad you told me before I went ahead and bought one. I do have a CCD (starlight OSC)  but atm i just wanted to concentrate on dslr side of things, 

thank you

Paul             EDIT just a thought but can you get them for a standard nikon lens? im thinking for widefield images?  I would imagine so but the one lens I have and use often is a 11 mm superwide lens (tokina) which looks more like a fish eye lens 

[Oddsocks]

Hi Paul,

I haven't seen any clip filters for the Nikon bodies for a long while, I think the problem is the lack of space and the very crowded body-lens aperture, there is just too much going on just behind the lens mount to allow clip-filters to fit without fouling some part of the mechanics or electronics.

Since you have the SX OSC you could look at a S/H wide field lens for that, there are plenty to choose from with M42 threads that would allow you to put a filter between the lens and the body of the SX camera with a suitable M42 adaptor.

Bit of a long shot, but if you measure the throat aperture of your M48 Nikon "T" adaptor on the camera body side and email Baader or Astronomik and ask them what is the diameter of the 2" LP filter unmounted, they should be able to supply the filter unmounted without the screw-in cell, if it fits inside the throat of the Nikon 'T" adaptor you could fix it in the throat with black silicone rubber around the edge to hold it in place, it would be straight forward to do and not need any special tools....I'm guessing it would be too large but you never know.....

[wuthton]

Can't you screw a 2" filter into the end of the nosepiece? 

[Oddsocks]

6 minutes ago, wuthton said:

Can't you screw a 2" filter into the end of the nosepiece? 

Hi Matt,

The scope that Paul is using is the ED80 with the Skywatcher dedicated flattener and that screws directly to Nikon DSLR "T" ring, there isn't a nosepiece...

[wuthton]

Ahhh! I thought I must be missing something obvious. 

[Thalestris24]

On ‎19‎/‎02‎/‎2016 at 15:25, brrttpaul said:

along with the guider and finder scope I was also advised to get a good filter, I was looking at this one but how does it connect? telescope is an equinox ED80 with a field flattener which is attached to a nikon dslr im guessing it goes between the nikon and flattener? this is the filter

http://www.firstlightoptics.com/light-pollution-reduction-imaging/baader-neodymium-filter.html

Hi

Other field flatteners will give you more backfocus i.e. for adding a filter holder, and/or have a 2" filter thread at the front

Louise