30mm 1rpd eyepiece quick review
Posted 10 July 2005 - 11:24 PM
I've read numerous reviews of this eyepiece and the opinions are all over the map so I had no idea what to expect. But I got it dirt cheap so I figured, what the hey! As it turns out 'rpd' could stand for 'really pretty decent'!
The eyepiece was being used with a Celestron 11 (The Stray Cat) and at f/10, it actually performs quite well. There is some distortion at the outer edge of the field, but the view was no worse than the 32mm TeleVue Wide Field I used to have. The 1rpd has a wider apparent field however (80° vs. 65°). The overall impression viewing objects like The Double Cluster, The Veil, and M-31 was very pleasant.
Six of us - all with many years of experience - had a chance to check out the 1rpd and the general consensus was the eyepiece was "good". I had several offers to purchase it (at my dirt cheap price, of course) that were respectfully declined
Does the 1rpd 30mm perform as well as a 31mm Nagler? Probably not, especially at the edge using a short focal length telescope. However, even at retail price you could buy more than six of the 1rpd's for the price of one 31mm and I doubt that even the Nagler is six times better.
If you ever have a chance to check out a 30mm 1rpd, you might be pleasantly surprised especially if you're using a long focus telescope.
Posted 11 July 2005 - 04:46 AM
You won't be anywhere near remotely close to as pleased with it at f/5, but a Paracorr does make the view look much better. It accomplishes this three ways. The Paracorr flattens the field, clears up the coma, and clips the AFOV down a bit (the 1rpd having a FS of 44mm, and the Visual Paracorr being designed to just permit the rays of the 42mm FS 31mm Nagler to not clip [or vignette]). The Paracorr can't help with the astigmatism of the 1rpd.
Posted 11 July 2005 - 06:01 AM
Posted 11 July 2005 - 11:18 AM
For owners of longer focal length scopes, this EP is a fantastic bargain. At f/9, it performs very, very well. No complaints.
We'll see how it does at f/8, once my AR6 OTA shows up
Posted 11 July 2005 - 11:31 AM
Posted 11 July 2005 - 12:56 PM
One very nice benefit to me: the Televue "B" focal group 1.25" with a 2/1.25" adapter from a WO diagonal is pretty close to parfocal with the 1rpd and the adapter removed. It's the small things that count sometimes...
Posted 11 July 2005 - 04:19 PM
I use it on occasion in the 100mm f/6 achromat and the edges of the FOV leave quite a bit to be desired but that isn't the scope I bought the EP for. And it's fun to look at a 20x 4° TFOV in the southern summer sky.
Posted 11 July 2005 - 04:25 PM
On the f/6 and f/5 setups I start wondering if any doors in the house need stops.
Never thought about using an eyepiece for a door stop. You don't want to dent your door, do you?
Posted 11 July 2005 - 04:36 PM
Posted 11 July 2005 - 07:19 PM
Posted 11 July 2005 - 08:41 PM
Posted 11 July 2005 - 10:17 PM
Posted 13 July 2005 - 08:59 PM
I've found it to be very forgiving on eye position and comfortable to use.
I bought an Astro-Physics 2" visual back (scroll down) to use with it, but careful observation didn't reveal any vignetting with the standard visual back/2" adapter.
If you want to see something ugly, try using it with the 6.3 focal reducer.