ED Barlow imaging question

[Rob]

I'm now thinking about using a barlow for DSO imaging through the 200P.. I have a t ring and will have a 1.25 nose piece (when delivered) next week. I already own a ED shorty Plus barlow in 1.25 + 3 x Vixen. But I'm now thinking about a 2" ED Barlow that I could use with the DMAX SLR adapter I've been using for prime on the 200P.

Whats the advantages of going 2" ED Barlow over the 1.25"?. Will I gain going the 2" route?.

Cheers

Rob

[Rob]

Is it worth the purchase then?

[Ggeo]

Bought a 2 inch Ed Barlow with this in mind too, now all I need is the chance to try it out

[ollypenrice]

If you use a 2X Barlow for DS imaging you will need 4 times the exposure for the same level of signal on the chip. Four times the sub length with attendant guiding problems. Only once or twice a year do we see Barlows in DS imaging on SGL. This is on the brightest targets. Are you sure you want to do it?

Olly

[Rob]

Not sure at all.. so I've dropped the idea now. Thanks Guys