Post by Chicago Astronomer - Astro Joe on May 11, 2011 2:02:01 GMT -6
2 Inch Eyepiece Shoot-out with the Meade 90mm Refractor
I spent the evening doing house and car stuff, concluding around 9:00pm. Looking up, I saw a very nice Moon hovering above my neighbors roof line and it is a sin to waste an opportunity for some scope time. And with a warm south wind blowing...FINALLY...t-shirt weather! ;D
I wanted to compare my new Rini eyepieces with others I have and see if they are worthy of using. But also, how do all my 2 Inch eyepieces compare with one another too. I used the 90mm Meade Refractor for this test, as I haven't tried any 2" eyepieces on it yet. With only a 800 mm focal length, we can play around with magnification and still keep the lunar orb fully in the FOV.
As of now, I have no secure way of attaching a 2" diagonal. I searched my scope parts and nothing was suitable. So, I friction fit the diagonal in the focuser draw tube with a threaded ring coupler...and it seemed to hold ok...sorta....
And also, the following images are all handheld - with camera up to the eyepiece. With just a friction fit, I did not want to place the entire weight of the camera on the frail connection. And to keep exposures short, pushed up the ISO to 800...ergo some grain.
Living on the edge, we commence...
We have several 2" eyepieces to check out and I start out with the 56mm Meade and work my way on up in power -
This is a nice comfortable eyepiece and sharp.
Next we go to the 56mm Russel...
The eye relief is longer in this one and one has to find the "Sweet Spot", but it is a decent one and also sharp. the views are about the same in the two 56mms.
Next, the Celestron 40mm...
First, I like the E-Lux series eyepieces. No messing around, they perform nicely and they are very comfortable to use.
Next the 35mm Rini...
I forgot to take a pic of the eyepiece in the diagonal, but I am beginning to like this eyepiece a lot. It's sharp and easy to look through. Using the camera's zoom, it takes the zooming in well. I also dig the reticle bunches. This one is a keeper and fits nicely in the power train of eyepieces.
Next the 32mm -
Still sharp and plenty of FOV to fit the lunar sphere.
Next the 26mm -
Still holding sharp and yet continue to keep the entire orb within view.
Next, the 10mm Rini -
Here, we push magnification enough to lose the entire lunar globe and zoom in to large regions. The sweet sharp focus in this eyepiece is dead center. Near the edges, the image degrades into a blur and there is also some chromatic aberration noticed. It's not a great eyepiece by far in either the C5 or in this 90mm. I don't have much expectations when I use it in the C11 either. I'll keep it regardless.
To better compare, I have assembled he various views in a montage, keeping the FOVs as close as possible...
I didn't attach the motor drive on the mount for this test, but even so, the 90mm delivered well. But I wondered how a terrestrial object would reflect in the same magnification steps. About a mile or so away, I have the Fisk power plant, whos exhaust serves as my anemometer, telling me if we will get warm southern winds or chilly northern gusts.
That flashing red light...just over there.
I use this stack often to test out optics...and the night was still young, so here we go....
56mm Meade -
56mm Russel -
The 40mm Meade -
The Rini 35mm -
The Celestron 32mm -
The Celestron 26mm -
]The Rini 10mm -
Again, the 35mm Rini is coming out nicely...and I don't know if it's the build in reticle, but I find it easier to focus with this eyepiece.
Neighbors stopped by to see what the astronomer is doing now, and I gladly showed them the Moon...but really wanted to test these eyepieces out alone. Unfortunately, the only place at Joe's estates where it's convenient - is just outside of the garage.
I do need some teen mm eyepiece to fill in the gap. Something in the 17/15mm perhaps.But, the combo of the 90mm refractor and the 2" eyepieces mate well...now, to come up with some sorta 2" adapter...
