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View Full Version here: : Stratus 13mm: the perfect EP in your Dob for public viewings


janoskiss
05-02-2006, 02:56 AM
I had the chance to show some newbies a few things through my f6 8" Dob. (Moon, Saturn, and a bit of Orion Neb before Earth-clouds got it.)

Having used orthos and plossls for this sort of thing before and always having to explain that yes there really is something to see in there, how to look into the EP etc, I thought I'd give the 13mm Stratus a go.

Success!! It is perfect! No one had any problems looking through the EP. For most showpiece DSOs like Orion Neb, the big globs, the true FOV of the EP is excellent. (we only got to look at m42 though.) And for planets, it especially works a treat in a 2" barlow. And very easy to look through for everyone. Glasses or not! But you do need to fold the rubber guard down for glasses. (I've had the Stratus 5mm and 8mm out for newbies in the past and they were not so user friendly. Too much false colour that only goes away if eye placement is just right, which it will not be if you are not used to the EP.)

Barlowed in the UO 2", it gives a sharp image all the way across the 68 degree FOV (bit of CA at the edges but trust me no-one will notice ;)), and in my scope it gives a magnification of 200x (yes bit more than double, i've measured this quite precisely before). This was just great in my non tracking Dob, because I could place Saturn on the very edge of the field so that it would float across to the other side, taking about 1+1/2 minutes to do so.

I'd set up the scope and say: just watch as Saturn floats across from left to right. From one person, after 30 seconds of viewing I got this question: "how many rings does it have? I can see bands between the rings." This complete newbie obviously saw Cassini without even trying. Ahhh, it's moments like these... :astron:

RAJAH235
05-02-2006, 04:35 AM
Gives you a little 'tingle' doesn't it? For a first timer to see the Cassini div. Great. Sounds like you've found a nice all round E/Pc, Steve. :D L.

Starkler
05-02-2006, 01:18 PM
Sounds a bit like the Pentax XL's I have. Generous eye relief and forgiving eye placement characteristics make for a 'picture window' type experience.

As a contrast, I had a look through Daves set of orthos last night, and the 18 and 25mm UO orthos are very sensitive to eye placement, get it wrong and you see nothing.