[Screwdriverone (Chris)]

Hi Paul,

Dont confuse eye relief with Field of View (FOV).

Eye Relief is basically how close you need to have your eyeball to the glass on the eyepiece to get a full view of what is coming through the eyepiece.

FYI, Large Focal length eyepieces ie 20-30mm and bigger generally have more eye relief than smaller EP's. The smaller the eye relief, the closer you need to get to the eyepiece and generally the less comfortable it is to take in the view. This is especially important for eyeglass wearers where longer eye relief is generally a must.

Now Field of View, is how WIDE the image you see is when you get to the optimum eye relief position. Easy way to think of this one is looking through a small hole in a fence, you have to get up close to see anything (Eye relief), and then because of the restricted field of view, you dont get to see much anyway. Compare this to a soccer ball hole, the eye relief is great and the field of view is huge because you can put your head through it and look around.

Its a bit simplistic and (possibly a bit technically wrong) but I am just trying to explain what the difference is when it comes to comfort and enjoyment of eyepieces.

Generally, for the price, a 68 degree FOV EP with about 15-20mm of eye relief is going to be comfortable and "widescreen" enough to look through for just about everyone. Sure, you can pay $800-$1000 for a Televue Ethos 100 degree "PORTHOLE" view into space, but for your scope, i would suggest some standard ED type eyepieces from Andrews Comms or similar which are about $60 each and are great performing general purpose eyepieces.

For your FL length of the 6" scope of 750mm, and with Jeff's excellent suggestion of 50x , 100x and 250x (probably the highest limit of that size scope, then the FL EP's for these mags are (in order) 15mm, 7.5mm and 3mm. (to work out the magnifications you divide the FL of the scope by the Eyepiece FL, ie 750 / 15 = 50 x)

Using your 2x Barlow also doubles the magnification, but keeps the Eye Relief of the original FL Eyepiece so you could use a 6mm eyepiece (125x) and then add the barlow to get 250x rather than buy a 3mm and suffer from small FOV and potentially restricted eye relief.

Hope this helps

Chris