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Do You Have This Eyepiece?

Posted: Mon Oct 07, 2019 8:28 pm
by Refractordude
My GSO 20mm has some kind of chip on the lens. I really like this eyepiece that does well in my f8 scope. Was thinking of giving the Agenaastro SWA 20mm eyepiece a try as a replacement. I own the SWA 15mm that has super clear and sharp glass, but just 13mm eye relief. The SWA 20mm has an eye relief of 16mm, and better reviews than the GSO 20mm. Has anyone compared the two, GSO 20mm Vs Agenaastro SWA 20mm?

https://agenaastro.com/agena-20mm-super ... piece.html

Re: Do You Have This Eyepiece?

Posted: Mon Oct 07, 2019 8:53 pm
by Bigzmey
GSO SV and SWA are of somewhat different designs, but should perform more less on pair. Both are better suited for slower scopes like your F8. From my experience SWA had a bit softer focus but produced cleaner views. SVs were a ted sharper but had more light scatter on stars. In slow refractors and SCTs I would give a slight preference to SWA.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 12:51 am
by Refractordude
Bigzmey wrote: Mon Oct 07, 2019 8:53 pm GSO SV and SWA are of somewhat different designs, but should perform more less on pair. Both are better suited for slower scopes like your F8. From my experience SWA had a bit softer focus but produced cleaner views. SVs were a ted sharper but had more light scatter on stars. In slow refractors and SCTs I would give a slight preference to SWA.
My GSO SV has no light scatter. Maybe a quality control issue. Some times you get a good one, some times you get a bad one. I may buy both for a shootout, then return the least performing eyepiece. Hoping for more replies.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 12:55 am
by notFritzArgelander
Refractordude wrote: Tue Oct 08, 2019 12:51 am
Bigzmey wrote: Mon Oct 07, 2019 8:53 pm GSO SV and SWA are of somewhat different designs, but should perform more less on pair. Both are better suited for slower scopes like your F8. From my experience SWA had a bit softer focus but produced cleaner views. SVs were a ted sharper but had more light scatter on stars. In slow refractors and SCTs I would give a slight preference to SWA.
My GSO SV has no light scatter. Maybe a quality control issue. Some times you get a good one, some times you get a bad one. I may buy both for a shootout, then return the least performing eyepiece. Hoping for more replies.
I'm happy with my GSO SVs also. No inordinate light scatter here. I have them all.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 1:33 am
by Bigzmey
Not to start CN style war, but EP performance is always relative, and all EPs have light scatter, just different amount of it. You try couple of EPs on Jupiter or a tight double and difference in light scatter control become quite obvious.

Well executed orthos have the least amount of light scatter and some badly executed EPs tons of it. SV and SWA are not the worst, but definitely not the best, somewhere in the middle. :)

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 1:44 am
by notFritzArgelander
Bigzmey wrote: Tue Oct 08, 2019 1:33 am Not to start CN style war, but EP performance is always relative, and all EPs have light scatter, just different amount of it. You try couple of EPs on Jupiter or a tight double and difference in light scatter control become quite obvious.

Well executed orthos have the least amount of light scatter and some badly executed EPs tons of it. SV and SWA are not the worst, but definitely not the best, somewhere in the middle. :)
I agree. Hence my use of "no inordinate". I don't use my GSO SVs for situation when freedom from scatter is critical. Not interested in a CN style jihad either. I was surprised that you saw a difference in the SVs and SWAs with regard to scattered light though.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 2:19 am
by Bigzmey
notFritzArgelander wrote: Tue Oct 08, 2019 1:44 am
Bigzmey wrote: Tue Oct 08, 2019 1:33 am Not to start CN style war, but EP performance is always relative, and all EPs have light scatter, just different amount of it. You try couple of EPs on Jupiter or a tight double and difference in light scatter control become quite obvious.

Well executed orthos have the least amount of light scatter and some badly executed EPs tons of it. SV and SWA are not the worst, but definitely not the best, somewhere in the middle. :)
I agree. Hence my use of "no inordinate". I don't use my GSO SVs for situation when freedom from scatter is critical. Not interested in a CN style jihad either. I was surprised that you saw a difference in the SVs and SWAs with regard to scattered light though.
Yes, I would not use them for doubles splitting now, but there was a time when I had just one EP set. :lol: But let's see if we can find some middle ground. In two SV EPs I had the brighter stars were always spikier than in other EPs of similar FL. To the point that it was somewhat annoying. It could be QC issues, but that put me off trying more of SV line. In the SWA I had the stars looked cleaner and I picked a quite few galaxies with it, so the transmittance was not too bad.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 2:33 am
by notFritzArgelander
Bigzmey wrote: Tue Oct 08, 2019 2:19 am
notFritzArgelander wrote: Tue Oct 08, 2019 1:44 am
Bigzmey wrote: Tue Oct 08, 2019 1:33 am Not to start CN style war, but EP performance is always relative, and all EPs have light scatter, just different amount of it. You try couple of EPs on Jupiter or a tight double and difference in light scatter control become quite obvious.

Well executed orthos have the least amount of light scatter and some badly executed EPs tons of it. SV and SWA are not the worst, but definitely not the best, somewhere in the middle. :)
I agree. Hence my use of "no inordinate". I don't use my GSO SVs for situation when freedom from scatter is critical. Not interested in a CN style jihad either. I was surprised that you saw a difference in the SVs and SWAs with regard to scattered light though.
Yes, I would not use them for doubles splitting now, but there was a time when I had just one EP set. :lol: But let's see if we can find some middle ground. In two SV EPs I had the brighter stars were always spikier than in other EPs of similar FL. To the point that it was somewhat annoying. It could be QC issues, but that put me off trying more of SV line. In the SWA I had the stars looked cleaner and I picked a quite few galaxies with it, so the transmittance was not too bad.
I understand the spiky stars bit. That's why I finally got rid of the ES100s I had. It's been a while since I used the GSO SVs but last time I had them they weren't as bad as the ES100s that way (nor the Nagler 11mm T6 which I loathed for the same reason).

The GSO SVs aren't as good as the TV Panopics or the Takahashi LEs or the BCO and KK orthoscopics.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 2:52 am
by Bigzmey
notFritzArgelander wrote: Tue Oct 08, 2019 2:33 am
Bigzmey wrote: Tue Oct 08, 2019 2:19 am
notFritzArgelander wrote: Tue Oct 08, 2019 1:44 am

I agree. Hence my use of "no inordinate". I don't use my GSO SVs for situation when freedom from scatter is critical. Not interested in a CN style jihad either. I was surprised that you saw a difference in the SVs and SWAs with regard to scattered light though.
Yes, I would not use them for doubles splitting now, but there was a time when I had just one EP set. :lol: But let's see if we can find some middle ground. In two SV EPs I had the brighter stars were always spikier than in other EPs of similar FL. To the point that it was somewhat annoying. It could be QC issues, but that put me off trying more of SV line. In the SWA I had the stars looked cleaner and I picked a quite few galaxies with it, so the transmittance was not too bad.
I understand the spiky stars bit. That's why I finally got rid of the ES100s I had. It's been a while since I used the GSO SVs but last time I had them they weren't as bad as the ES100s that way (nor the Nagler 11mm T6 which I loathed for the same reason).

The GSO SVs aren't as good as the TV Panopics or the Takahashi LEs or the BCO and KK orthoscopics.
Speaking about BCOs. Agena has BCO 18mm on sale now for $65. This is the EP I would pick over $47 SWA 20mm or $45 SV 20mm any day (or night :D).

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 2:59 am
by notFritzArgelander
Bigzmey wrote: Tue Oct 08, 2019 2:52 am
notFritzArgelander wrote: Tue Oct 08, 2019 2:33 am
Bigzmey wrote: Tue Oct 08, 2019 2:19 am

Yes, I would not use them for doubles splitting now, but there was a time when I had just one EP set. :lol: But let's see if we can find some middle ground. In two SV EPs I had the brighter stars were always spikier than in other EPs of similar FL. To the point that it was somewhat annoying. It could be QC issues, but that put me off trying more of SV line. In the SWA I had the stars looked cleaner and I picked a quite few galaxies with it, so the transmittance was not too bad.
I understand the spiky stars bit. That's why I finally got rid of the ES100s I had. It's been a while since I used the GSO SVs but last time I had them they weren't as bad as the ES100s that way (nor the Nagler 11mm T6 which I loathed for the same reason).

The GSO SVs aren't as good as the TV Panopics or the Takahashi LEs or the BCO and KK orthoscopics.
Speaking about BCOs. Agena has BCO 18mm on sale now for $65. This is the EP I would pick over $47 SWA 20mm or $45 SV 20mm any day (or night :D).
Well, I've bought 3 of the BCOs. I've kept 2 complete sets of the BCOs and the 3rd set is gifted to my grandson. They're good for a lifetime. One set of the SVs is enough. ;)

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 1:13 pm
by Don Alvarez
Refractordude wrote: Mon Oct 07, 2019 8:28 pm My GSO 20mm has some kind of chip on the lens. I really like this eyepiece that does well in my f8 scope. Was thinking of giving the Agenaastro SWA 20mm eyepiece a try as a replacement. I own the SWA 15mm that has super clear and sharp glass, but just 13mm eye relief. The SWA 20mm has an eye relief of 16mm, and better reviews than the GSO 20mm. Has anyone compared the two, GSO 20mm Vs Agenaastro SWA 20mm?

https://agenaastro.com/agena-20mm-super ... piece.html
Instead of those, I have a 26mm Meade plossl I was going to put up for sale. One of the old pseudo-masuyama "smoothies" that's not really a plossl. In my quest of collecting this series I acquired an extra one, I was gonna sell it to fund something else I want.

Your chance to own a legend!

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 5:16 pm
by Refractordude
Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 5:51 pm
by notFritzArgelander
Refractordude wrote: Tue Oct 08, 2019 5:16 pm Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.
Direct comparison of the internal contrast in the Pleaiades nebulosity among these eyepieces: BCO 18, Panoptic 19mm, TV 20mm Plossl, Vixen NPL 20mm Plossl caused me to go "Wow!" over the BCO! YMMV of course.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 7:41 pm
by Bigzmey
Refractordude wrote: Tue Oct 08, 2019 5:16 pm Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.
The most deciding factor is what works for you. Selecting right EP is very personal. I have purchased quite few EPs based on the feedback on forums, but what stays in my EP case ultimately depends on how they perform for my eyes in my scopes.

Building ultimate EP set is a never ending process and testing EPs is a fun part of it.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 8:29 pm
by Refractordude
notFritzArgelander wrote: Tue Oct 08, 2019 5:51 pm
Refractordude wrote: Tue Oct 08, 2019 5:16 pm Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.
Direct comparison of the internal contrast in the Pleaiades nebulosity among these eyepieces: BCO 18, Panoptic 19mm, TV 20mm Plossl, Vixen NPL 20mm Plossl caused me to go "Wow!" over the BCO! YMMV of course.
Great info to know, but I will still not buy the BCO 18mm due to the short eye relief. Now thinking about getting the BCO 32mm to replace my Meade 32mm plossl that has a few thin chips in the coatings. Have you tried the BCO 32mm? I am thinking the BCO 32mm would step all over a GSO 32mm Plossl.

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 8:43 pm
by Bigzmey
Refractordude wrote: Tue Oct 08, 2019 8:29 pm
notFritzArgelander wrote: Tue Oct 08, 2019 5:51 pm
Refractordude wrote: Tue Oct 08, 2019 5:16 pm Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.
Direct comparison of the internal contrast in the Pleaiades nebulosity among these eyepieces: BCO 18, Panoptic 19mm, TV 20mm Plossl, Vixen NPL 20mm Plossl caused me to go "Wow!" over the BCO! YMMV of course.
Great info to know, but I will still not buy the BCO 18mm due to the short eye relief. Now thinking about getting the BCO 32mm to replace my Meade 32mm plossl that has a few thin chips in the coatings. Have you tried the BCO 32mm?
32mm BCP is a nice EP, but for $65 I don't see the value there. I would either pay a bit more and get older TV Plossl smoothie, or go with Meade 32mm.

Here is my shootout between Meade, BCP and modern TV Plossl

http://www.astronomyforum.net/telescope ... otout.html

I did not have older TV Plossl smoothie 32mm at that time, which is the best 32mm Plossl IMO. :)

Re: Do You Have This Eyepiece?

Posted: Tue Oct 08, 2019 8:58 pm
by notFritzArgelander
Refractordude wrote: Tue Oct 08, 2019 8:29 pm
notFritzArgelander wrote: Tue Oct 08, 2019 5:51 pm
Refractordude wrote: Tue Oct 08, 2019 5:16 pm Bigzmey:

The BCO 18mm is a good eyepiece, but not great in what I like in an eyepiece. The BCO 18mm has an eye relief of 14.7mm. The minimum eye relief for me is 16mm. Also the SWA 20mm and SV 20mm have a 25 percent or greater field of view. I would bet that the BCO 18mm has a clearer image due to less glass and better contrast, but not a wow factor or even very noticeable difference.
Direct comparison of the internal contrast in the Pleaiades nebulosity among these eyepieces: BCO 18, Panoptic 19mm, TV 20mm Plossl, Vixen NPL 20mm Plossl caused me to go "Wow!" over the BCO! YMMV of course.
Great info to know, but I will still not buy the BCO 18mm due to the short eye relief. Now thinking about getting the BCO 32mm to replace my Meade 32mm plossl that has a few thin chips in the coatings. Have you tried the BCO 32mm?
ER is clearly important to you. I'm fortunate to have eyes that are astigmatism free, so I can remove my glasses to observe and correct my near sightedness by using the scopes focuser.

Of course I've used the 32mm. I've read reviews that complain about a blurry field stop. My samples haven't had the problem. Here's the negative review I recall. https://www.cloudynights.com/topic/5749 ... C3%B6ssls/

I'm citing this because while I disagree about the field stop, the review states that the BCO gives darker images. This is true but what the reviewer misses is that internal differences in contrast are greater in the BCOs. My older TV Plossls throw up brighter images and so they get used when I'm trying to find some object at the limit of detectability. The BCOs aren't so good at that task but are superior at revealing subtle internal structure. The difference is in the coatings. More recent TV Plossls are also darker I hear.

The Panoptics and Vixen NPL are in the middle in my set. The images are brighter than the BCOs but not as bright as the TV Plossl. The internal contrast within a nebulosity is greater than the TV Plossls but not as good as in the BCOs.

Brightness and contrast are different. One eyepiece is often not the best for everything.

(BTW, most Plossls are really symmetricals, but although true it's a losing fight against marketing speak. ;) )

Re: Do You Have This Eyepiece?

Posted: Wed Oct 09, 2019 3:29 am
by Refractordude
notFritzArgelander wrote: Tue Oct 08, 2019 8:58 pm
Refractordude wrote: Tue Oct 08, 2019 8:29 pm
notFritzArgelander wrote: Tue Oct 08, 2019 5:51 pm

Direct comparison of the internal contrast in the Pleaiades nebulosity among these eyepieces: BCO 18, Panoptic 19mm, TV 20mm Plossl, Vixen NPL 20mm Plossl caused me to go "Wow!" over the BCO! YMMV of course.
Great info to know, but I will still not buy the BCO 18mm due to the short eye relief. Now thinking about getting the BCO 32mm to replace my Meade 32mm plossl that has a few thin chips in the coatings. Have you tried the BCO 32mm?
ER is clearly important to you. I'm fortunate to have eyes that are astigmatism free, so I can remove my glasses to observe and correct my near sightedness by using the scopes focuser.

Of course I've used the 32mm. I've read reviews that complain about a blurry field stop. My samples haven't had the problem. Here's the negative review I recall. https://www.cloudynights.com/topic/5749 ... C3%B6ssls/

I'm citing this because while I disagree about the field stop, the review states that the BCO gives darker images. This is true but what the reviewer misses is that internal differences in contrast are greater in the BCOs. My older TV Plossls throw up brighter images and so they get used when I'm trying to find some object at the limit of detectability. The BCOs aren't so good at that task but are superior at revealing subtle internal structure. The difference is in the coatings. More recent TV Plossls are also darker I hear.

The Panoptics and Vixen NPL are in the middle in my set. The images are brighter than the BCOs but not as bright as the TV Plossl. The internal contrast within a nebulosity is greater than the TV Plossls but not as good as in the BCOs.

Brightness and contrast are different. One eyepiece is often not the best for everything.

(BTW, most Plossls are really symmetricals, but although true it's a losing fight against marketing speak. ;) )


My preference for good eye relief is not astigmatism, but to enjoy the edge to edge entire view with out struggle. If astigmatism becomes a problem in the future, I am covered.

Re: Do You Have This Eyepiece?

Posted: Wed Oct 09, 2019 3:36 am
by Refractordude
Bigzmey:

Great shootout info.

Re: Do You Have This Eyepiece?

Posted: Thu Oct 10, 2019 5:52 pm
by Refractordude
Don Alvarez wrote: Tue Oct 08, 2019 1:13 pm
Refractordude wrote: Mon Oct 07, 2019 8:28 pm My GSO 20mm has some kind of chip on the lens. I really like this eyepiece that does well in my f8 scope. Was thinking of giving the Agenaastro SWA 20mm eyepiece a try as a replacement. I own the SWA 15mm that has super clear and sharp glass, but just 13mm eye relief. The SWA 20mm has an eye relief of 16mm, and better reviews than the GSO 20mm. Has anyone compared the two, GSO 20mm Vs Agenaastro SWA 20mm?

https://agenaastro.com/agena-20mm-super ... piece.html
Instead of those, I have a 26mm Meade plossl I was going to put up for sale. One of the old pseudo-masuyama "smoothies" that's not really a plossl. In my quest of collecting this series I acquired an extra one, I was gonna sell it to fund something else I want.

Your chance to own a legend!


thanks for the offer