Product Description
This eyepiece has a very large 6.9mm exit pupil with an f/4.5 scope, larger than some observers' eyes can dilate. That can effectively waste some of the scope's light gathering capacity, as some of the full light cone will fall on the older observer's iris, rather than entering his or her eye. Even so, some observers willingly trade a little light gathering for the immense field of view of this 82° apparent field eyepiece. This eyepiece very much provides a true "picture window of space" view.
You can use the calculator below to see just how wide the field will be with your particular telescope. For example, it will give you a 2.22° field at 37x with a 10" f/4.5 Dobsonian, more than enough to take in all of the Pleiades at one time. This gives you over eight minutes of uninterrupted observing with such a scope while an object drifts from one side of the eyepiece's flat field to the other. That's plenty of time for multiple observers to look at the same object, or for you to absorb as much detail as possible, before having to reposition the scope.
With a factory-specified eye relief of 27mm, the 31mm Luminos will provide fully unvignetted views for most eyeglass wearers. However, since the 82° field is so wide that you can't see the full field without having to move your head from side to side to take it all in anyway, vignetting in the conventional sense is not a problem in any case.
At 40 ounces, the 2" 31mm Luminos is a very substantial eyepiece. Be sure that your star diagonal is very firmly locked in place on your scope before inserting this eyepiece to avoid the chance of the diagonal swiveling unexpectedly and the eyepiece falling to the ground.
The retractable eyeguard raises by turning the broad rubber grip ring around the eyepiece barrel clockwise and lowers by turning the ring back counterclockwise. The eyeguard mechanism may be a little stiff in operation the first time you raise it.
Tech Details
Barrel Size | 2" |
---|---|
Eye Relief | 27mm |
Field of view | 82 |
Focal Length | 31mm |
Number of optical elements | 6 |
Weight | 40 oz. |
Warranty | 2 years |
Reviews
The only real criticism I agree with is the EOFB which is distracting at worse, but easily tolerable; make no mistake, it’s there, but not nearly as bad as everybody makes it to be. For me, the $200 I paid was money well-spent, and I will not be parting with it anytime soon. Paying several extra hundreds isnt worth the gains you’d get from the “top” eyepieces. As far as the heaviness of the Luminos 31mm, it’s nothing even a mediocre counterweight system can’t handle. Sure it’s big and heavy, but for my 12.5 f5, it works well, though I don’t think I’d use it for a faster scope. F/5 is probably the minimum you’d get the full potential of the EP, and f/6 and higher would be perfect. I like to resolve double stars and observe planetary nebulas, so I use this mostly.
For the price of the Luminos line, you’re entering premium territory, so maybe it’s a bit more expensive than what most people start out with. However, the build and optical quality make these a serious contender for best- bang -for -the-buck. An added bonus is that because of the sheer size, they’re a top attraction for outreach events or when friends are over.
Highly Recommended (Posted on 8/1/2020)
You can kill someone with this if needed. For the price I am sure thats its going to be great. (Posted on 12/29/2018)