Reducer/flattner and LP filters

[jambouk]

Is it possible to screw a round 2" or 1.25" filter into the light path when using a reducer/flatner with a DSLR, rather than using the EOS filter clip LP filter?

Thanks

James

[red dwalf]

Hi James,

should be fine, my reducer has a 2" filter thread on the end of it which i now use with my Baader LPF, using a dlsr i would think a 2" might be better than a 1.25" version

[markarian]

The filter will be thin enough not to cause any significant change in the light path. Probably the important thing is maintain the correct chip - reducer/flattener distance.

I've used a 2" DS filter with a coma corrector on my DSLR .

Mark

[jambouk]

A 2" filter will only screw onto the back (DSLR end) of the reducer, but in doing so adds an extra 8mm between the reducer and the DSLR.

There is an extension tube which attaches onto the front of the reducer and allows filters to be screwed in pre-reducer; but I wonder if that contributes to greatly worse vignetting...

http://www.firstlightoptics.com/adaptors/flo-adapter-for-skywatcher-focal-reducers.html

James

[jambouk]

Putting the filter between the reducer and the dslr causes artefact at the edges of the field, very unflat i presume. I also cold welded the filter into the eos t ring. So sticking with the extension tube method and will try that out.

James

[wxsatuser]

I had my Hutech lp filter in the FLO adapter with my ED80.

Never noticed any problem apart from a reflection from a very bright star on exposures above 10minute .

[jambouk]

I'm unguided so 10 minutes isn't even remotely on the cards