A general Eyepiece question

[jgs001]

All,

is it best to have a 10mm ep, or will using a 2x barlow with a 20mm ep provide the same view ? Is the barlow going to dramatically alter the image brightness ?

[barkis]

There is a small loss of light using a Barlow John, but not enough to matter. The Barlow is a very useful and desirable addition to any astronomers viewing kit.

Ron.

[jgs001]

Ron,

Thanks for that. That's settled things in my mind. I'll put off buying that 10mm LER ep () I saw on the for sale board then, as I'm expecting a tal barlow shortly.

[The Warthog]

Any small loss of light in a Barlow is made up for by the comfort of the larger eye lens and better eye relief of most longer eps. I designed my ep kit with the intention of using a Barlow as an integral part of the setup. I have a 24mm, 7.5mm, and a 4.3mm, which with a 2x Barlow give me most of the eps I could ever want. I am thinking of adding a 35 - 40 mm ep, but I haven't fully made up my mind about that.

[jgs001]

Warthog,

Thanks, With the the Barlow I got from Starflyer and the ep's from Barkis I now have:

32mm, 20mm and 6.5mm plossl's and a x2 Tal barlow. I think this gives me quite a nice range in total from what I have read about others collections.

[The Warthog]

Warthog,

Thanks, With the the Barlow I got from Starflyer and the ep's from Barkis I now have:

32mm, 20mm and 6.5mm plossl's and a x2 Tal barlow. I think this gives me quite a nice range in total from what I have read about others collections.

I would call that a well-selected ep kit!