jetstream

Off the 12.5mm mark but if anyone finds a used Zeiss 12.8mm part # 52 80 59- I would consider it, No longer made I missed buying this eyepiece. It will need the Zeiss adapter though. Also known as the 30/40 Diascope eyepiece.

Yes, I like this comparison too and in this case the APM 20mm 100 is so good that any negatives attached to the phrase doesn't apply IMHO. I use a filter slide on my dobs to compare the performance of this eyepiece to the other mentioned.

Very well.

Me neither but I've had a couple of letdowns including a 12.5mm Tak LE, that is softer than a 12.5mm Tak ortho and for me offers zero advantages. My 12.5m Tak ortho is razor sharp and barlows very well.

I have a very good sample of a 4mm UO ortho that gets frequent use. I havnt seen a time where this eyepiece caused thermal issues. Just my experience.

Yes, agreed. And on somethings the APM bests my sample of the 21E ie sections of the Veil under dark skies. A lot of these differences show up under truly good conditions IMHO. at first coma was masking the astig in the 20 APM, but a Paracorr II revealed it to me. The 21E is superb to the edge with the PCII at f4.1. One thing is for sure- we don't need the most expensive glass to get top views IMHO.

I paid 700 odd bucks for my 21E in CDN dollars... I have never heard of the APM 100s having issues. Dont know what to say except I really like the 20mm Lunt/APM I have.

Its been a few months I think- I had it out once? something like that. I use the 10mm Delos a lot and with the VIP. That Nikon HW is vg with the17E also in its nest. I'm just glad I bought all these on sale and with money at par or near. The price of things these days makes me cringe.

@StuartT I will mention another thing. Being able to select an appropriate eyepiece for the target means a lot. An example- I was trying to see a difficult object-HGC 55 in my 15" and used a high contrast hyperwide to get it in view. Knowing these eyepieces lack what it takes on an object like this I switched it up. I tried an extremely good Zeiss zoom, razor sharp on the moon/planets, basically no scatter. Did it work to break up this object? No. I went in and got some orthos to try and success.

This eyepiece is one of the best values for the money there is IMHO, I use it all the time leaving my 21E gently cradled in the foam case to avoid damaging this uber expensive eyepiece.

I love 100 deg eps for fun observing and espc nebula and certain clusters. When doing the thousand yard stare on faint, small DSO I reach for the cheap n cheerful orthos I have...

A diagonal can have a cooldown, espc prisms.

We are lucky- the APM 20mm 100 deg is a very good alternative to the 21E, the difference to my eyes is minor astigmatism at the edge with and without a Paracorr. IMHO, one low power 100 deg EP is nice to have.

I'm at this point in my wifes life that I'm perfectly happy to go with cheaper eyepieces....😀

😀 You know the 10mm Delos would be a great addition, extremely low scatter, very sharp and high transmission. Its a goto eyepiece.

I hold the Televue Plossls in very high regard, you'll see

I forgot what your imaging? Me, I'm looking for a shorter scope that might be easier to control on the mount.

In this aperture class I would never use 10mm more aperture to be the deciding factor. A few avid Tak owners/collectors have said that the TOA130 is a tiny bit better than the TSA120-but- they all said they could be "wishing" it to be better, or "might be thinking" it is better... Either scope is top notch, just pick one based on needs.

I have to say that I feel the same way. To my eyes the TSA 120 offers a truly pure, razor sharp view of the moon and planets. Swing it over to DSO under dark skies and it excels here too. I could rattle piles of DSO off that the TSA120 has shown me- but- out of all my scopes this one shows Barnards Loop -with no filter- the best of them all, and many others. And scatter? what scatter, there is no scatter.

A really mild day today with evening temps of -1c. Nice and clear out there and I managed an averted glimpse of 17 Umi at 6.8 mag, not bad seeing its not near zenith, but its easy to locate. Interesting setting up the Sky Commander- its initially off a fair bit in both truss dobs? The re align on object feature straightened it out but more investigation needed- I think its the operator!lol! So...a quick sky tour including M57's Owl eyes, the ol' Monkey Head and the Eskimo for a warm up. Over to the Leo Triplet with the 14 Nikon HW and then the favourite Needle galaxy. Back into the Ursa Major area and a swing over to M81/M82 -and- this put the idea in my head for HCG 55, but wait I forgot M51 - great compact spirals tonight in the Nikon. Can't leave M101 behind as those delicate spirals are too hard to ignore. I have observed Hickson 55 a fair bit in the 24", getting 4 separated galaxies in direct vision. I figured why not in the 15"? The blurred chain was easily spotted with the 14 HW and with the Sky Commander putting me right on target. After seeing the target so well I figured its ortho time. A Circle T 12.5mm immediately gave a brighter view, so back in the seacan for the beloved 7mm KK ortho. This eyepiece shows the central star in M57 with the 15" and low and behold I got 3 of HCG 55 with this eyepiece! I could hold two in direct vision but the 3rd in averted. The averted view would then make me lose the 2 direct visions and all would become averted at times. It was quite a sight thats for sure. I'm actually really pumped that I got the separations like this with the 15".

Excellent.

Are you sure the SCT's are including the total obstruction including the baffle? I think the Mew180 is 30%.

Diameter.

Off topic but kind of relating as my new upcoming Mewlon will be a "past scope" as soon as I use it?😉 I think central obstruction can be handled in processing but when combined with aberrations composed of who knows what challenges may present? A "good" SCT should handily compete with a Mewlon if you can cool it to the same degree. Of course the Mewlon will have higher transmission, but is this an issue? I cant wait until the Mew 180 is back on the shelves.

Im very interested as well.