Planetary/lunar EP options

Sardukar (Tim) · #1 10-10-2011, 01:31 PM

At the moment i have a 10mm plossl that gives 120x with my dob. Id like to go up to around 200 or so for planets and lunar viewing. Eye relief and comfort is a big deal to me aswell.

What would be better, something like the orion edge on 6mm or a televue 2x barlow? what'd provide the clearest image and also be the most comfortable to view through?

Any help appreciated!

Profiler (Profiler) · #2 10-10-2011, 03:37 PM

Unfortunately, a few more parameters need to be clarified in terms of what precisely you are after - such as field of view versus clarity and the real crux issue of price and how much you can/want to spend. A new planetary eyepeice can range anywhere from roughly $60 almost up to a $1000. A good value for money beginners planetary EP are the TMB pieces which have been available new on the classified EP forum here for sometime.

Sardukar (Tim) · #3 10-10-2011, 03:47 PM

Well it'd mainly be for jupiter, saturn and some lunar stuff so im not sure if a wide FOV is that important? am i correct in saying that a 2x barlow would probably cut FOV of an EP in 1/2? also id be happy to spend around $100.

Profiler (Profiler) · #4 10-10-2011, 04:46 PM

Assuming you 'don't' have a dob with automatic tracking I think the key issue with fov is really what magnification you are intending to observe with. As your magnification increases the object will move faster through your fov in the EP unless you have some form of tracking mount to compensate and maintain the object in the middle of your fov. Consequently, if you want to achieve a high mag and not merely look at the object for a few seconds (without having to continuously re-position the dob slightly) you will need to get an EP with a reasonably good fov - at least something around 60 degrees. The tmb's are a good choice/compromise on all variables of quality, fov, mag and price but if you want to go a significant step up in quality then Televue radians are a good option. However, for a Dob probably the very best would be something like a Pentax XW (excellent optical quality with 70 fov) and some folks also like short fl Naglers. Hope this helps.