Prior to getting into the night and the review of the eyepiece, I thought I would share a few things about the eyepiece. First, is the box. The box is extremely large and there is a reason for that. Here is an image of just the box. That is a medium size Sharpie and a normal size orange to give you size comparisons on the box.
This next picture shows the lid of the box off, the top layer of foam removed and the eyepiece revealed. Yes, this is a massively large eyepiece!
This next image will show you the viewing glass on the top with the eye cup curled down. In speaking of the eye cup being down, I found with this eyepiece I could view with the eye cup down using my glasses, but the best views came with my glasses off. Luckily, I don't need my glasses while looking through an eyepiece, I just need it to view the sky and the constellations.
Here you can see the height of the eyepiece when compared to a regular, medium point black Sharpie pen. I assume that most who are here will know from other reviews that this eyepiece is both large and heavy. For weight I get this eyepiece at coming in around 3.02 pounds vs the 2.2 pounds on the Explore Scientific site.
Now comes the one negative aspect of this eyepiece that I am disappointed in. It started on CloudyNights at this thread. Then on the first night of using the eyepiece I was not able to put a Lumicon OIII 2 inch filter or an Orion Ultrablock NB 2 inch filter. I sent this report in to Explore Scientific:
"I tried the ES 30mm 82 degree eyepiece last night for the first time and both a Lumicon OIII 2 inch filter and an Orion Ultrablock NB 2 inch filter would not fully screw on to the threads at the bottom of the eyepiece. Both filters easy went in on my Paracorr so I could use them, but I would think that for the money, and for an eyepiece that has a wonderful reputation in the past, that the filters would easily thread on. I have no problem with the 20mm 68 degree ES I own nor on the 4.7 ES 82 degree eyepiece I tried (and have on order). As you can see from that thread and from my personal experience, you do seem to have a quality control issue with this eyepiece right now on the threads on the use of filters. If you want, I'd be happy to film putting the two filters on and sending it to you. Just thought you would be interested in this."
I then received this reply:
I have seen the thread. However, you are one of the 1st to bring this issue to our attention and like I said before, I have put filters on this exact eyepiece before with no problems. There is a possibility the the threading in your eyepiece could be either dirty or have some type of damage to them. Have you tried to unscrew the silver barrel and then screw it on backwards, meaning the collared end would then be on the bottom of the eyepiece? Then you could try those threads as they shouldn't have the black paint on them (which could also be giving you issues."
As you can see in this image, my eyepiece as held by my son, Nathan, does not have any black paint on the bottom threads. If you do not have a filter slide or wheel like my friend Mat does (Mat has his own ATM filter slide on his 16 inch) and you need to screw a 2 inch filter on, please be aware that some of the newer Explore Scientific 82 degree 30mm eyepieces do NOT, I repeat DO NOT thread several key 2 inch filters into their grooves. IF you don't have a filter wheel and use a Paracorr Type I with the white lettering or a Type II Paracorr you can screw the filter into the Paracorr and that will serve you well. As I stated, based on the reputation of this eyepiece, the current $250.00 price tag, I would expect the threads to work. Since this has happen to me and to a couple of people on Cloudy Nights, the conclusion has to be made that some of this otherwise terrific eyepieces may have some flaws on the filter threads.
Now for reports on the glass in the eyepiece. I did not write down in order all of the objects we viewed that night, but here are some. Mat used the 30mm 82 degree in his 16 inch f5.6 dob and we observed many objects with it. It picked up Messier 11 revealing the Wild Duck or Borg Cube with in its entire field of view, and it was a marvelous view. We examined Messier 17 the Swan or Omega and without a filter in place it was a grand view, but sliding the OIII filter in showed far more structure of the nebula than the without it. The Orion Ultrablock really extended the nebula far behind the Swan. Stars were crisp to the edge in Mat's scope. Mat used it for M51, the Veil Nebula which showed tremendous views of the Veil. We also took in the Double Cluster, M31 and its two companions. The Cocoon Nebula showed my favorite view of the night in Mat's 16 inch scope and it was easily seen.
In my 10 inch I looked at several other objects and some of those listed above. In my 10 inch F4.7 dob the entire Double Cluster fit beautifully, and M31 was also terrific, though it was higher up in the sky and thus showing the dark lanes. NGC 457 was framed nicely as was M103. There were other objects but that is enough to give a review of the eyepiece.
The Explore Scientific 30mm 82 degree eyepiece is a tremendous eyepiece! I waited too long to get one. It gives about 95% of the view of a Nagler 31mm at a much lower cost. Stars on all objects were sharp to the edge, and I did not notice coma in Mat's 16 inch f5.6 dob or in my 10 inch dob with a Type I Paracorr. Nebula were bright as were galaxies and open clusters. As a finder eyepiece it worked really well. Seeing was average and transparency last night was poor and I did learn not to use it to go after fainter galaxies as they don't stick out. They were able to be found, but a trained eye is needed. So here I go.
Astgmatism Correction: A (none seen).
Lateral Color Correction: A
Distoration: A (none observed)
Field Curvature: A+ (none seen).
Lack of Ghosting: A
Field of View: A+
Eye Relief: A
Cost/Benefit Ratio: A
Filter Fit: C
Overall Grade: A- to B+ (the filter issue is holding this eyepiece back).
Yes, this eyepiece is as wonderful as so man have stated. It's a keeper for the cost though I'll have to keep it and transport it in the box as it won't fit in my eyepiece case!