how can i use a light pollution filter with dslr at prime focus

[beamer3.6m]

Hi.

I use my Canon 400d with my explorer 200p and attach it at prime focus using an eos t-ring which screws directly to the scope when I unscrew the 1.25" eyepiece holder.

However I want to add a light pollution filter. Where would I do this. I cannot use a 2" adapter as it stops me achieving focus.

Any ideas?

Ps. the camera is used everyday for normal shots too so cannot do any permanent moss.

Cheers

[Stephen]

You could try and find a t-thread filter (they do exist!) which would then go between the camera and focuser?

(Struggling to think of a way round it. Can you get some form of clip in filter for the body?)

[RikM]

Is the FLO 2" adpator too long to achieve focus? I used the very similar MaxDSLR 2" adaptor with my 150P to hold 2" LPR filters and could still achieve focus. There was only about 7-8mm of back focus left, but it did reach focus.

[studdedsole]

An EOS CLS clip filter would be the most obvious solution

Astronomik filters @ Modern Astronomy

Baader do a T ring with integrated filter but the one in the link is IR and i'm not sure if this then uses the thread you are using to attach it to your scope

Baader Astronomy Products | canon eos dslr t ring ir filter

[angusb1]

What he said ^^

[Stephen]

Is the FLO 2" adpator too long to achieve focus? I used the very similar MaxDSLR 2" adaptor with my 150P to hold 2" LPR filters and could still achieve focus. There was only about 7-8mm of back focus left, but it did reach focus.

Stock 200P struggles to obtain focus unless the cameras natively on the t-thread - any form of extension (I tried the MaxDSLR) and it pushes it out too far (based on my own experience)

[studdedsole]

This is the clip filter in action - simply unclip for normal photographic use

[RikM]

Stock 200P struggles to obtain focus unless the cameras natively on the t-thread - any form of extension (I tried the MaxDSLR) and it pushes it out too far (based on my own experience)

[Black Knight]

If you use the SW coma corrector, a 2" filter will screw into the end of the CC. Of course if you don't have a CC, this doesn't help.