10" dobsonian suggested eyepieces

[Norfolk star gazer]

So a 6mm is probably the lowest to go then

[urchin]

I use a vixen 6mm SLV as my high power ep in the 250px. In the few sessions I've had with it. I've been able to use it on Jupiter every time to great success.

The image is crisp, and easily tracked by hand even thought it only has 50 deg fov. However the image seems to elongate slightly as it crosses the field stop but a slightly earlier nudge of the scope stops this.

[Qualia]

I've found that as little as 1mm increase or decrease in the magnification - about 10% to 15% difference of magnification - can be quite surprising which is the main reason why I think most planetary observers will have quite a run of high-mag EPs.

I know they're not for everyone: the eye relief is tight, the FOV is quite slight but for sharpness, contrast and price I think Orthos are excellent eyepieces for planetary, lunar and solar work. I use a set of Genuine Baaders but I also think a strong case can be made for saving just a little bit more money and looking at buying something like a Radian secondhand. With that said, I feel that at the end of the day the eyepiece best for planetary is the eyepiece that caters for how you enjoy viewing.

I've been out quite a bit this month and at the end of each session I spend a little while with Saturn. With the 10" f5 I've found that the most used focal length eyepiece has been the 7mm. Stepping to the 6mm has on a number of occassion been fruitful. Nevertheless, although the seeing has been generally good, moving onto the 5mm hasn't  improved on the image in terms of resolution. To my eye, working at 250x with the Genuin Orthos dims the image of Saturn just a little too much to be in control of a workable sketch.

Needless to say, all eyes are different and I'm certainly glad the 5mm is in the box. M3 at 250x is spectacular