Pulled the trigger on the 15mm safety barfed Altair 15mm.

https://www.altairastro.com/Altair-15mm-ULTRAFLAT-Eyepiece-Stainless-Steel.html



I reckon they're the same, and the housings are just cosmetically different.

https://www.apm-telescopes.de/de/fe...a-flat-field-15mm-okular-65-gesichtsfeld.html

 

It's been suspected that the Meade HD and X-Cel are the same eyepiece with different housings for a long time. I'm not absolutely sure though as there seems to be some differences in the series and I don't think they have exactly the same focal lengths. I'm pretty certain the 12mm Meade will be more or less the same thing. I'd bet money the APM and Altair are the same. I'm not the only one to suspect this. The Altair are more convenient to order for me though. I've known their stuff to be delivered to my door the day after ordering.



I'm pretty sure this is the same as the Sky-Watcher 8-24 zoom. But this comes with a groovy plastic tube case. lol

 

Celestron kept the X-Cel name (more or less) and produced these.



The originals were a bit dodgy, although I never owned one. The 'LX' makeover EP's are very good. I think marketing is a thing in itself. Its main function is to separate you from your spondoolies.

Yes, I think these Bresser are the same. My 5.5mm was a borker but I have a bino pair of the 20mm. I also have the 14mm and 9mm.

https://www.bresseruk.com/astronomy...ces/bresser/bresser-pl-20mm-60-1-25-inch.html

I reckon they would be good in the ED80. Speaking of which, I've ordered a visual back with a compression ring for my ED80.



I ordered one for the ED72 as well, you can see it above.


It makes rotating the diagonal a lot easier. Plus, it's cheaper than buying a Moonlite focuser lol.

https://www.firstlightoptics.com/adapters/flo-compression-ring-adapter-synta-skywatcher.html

I'm still waiting on the ED80 one. They have a different thread to the ED72 so aren't compatible.

 

You're probably right, I just don't know. I'll do a shoot-out comparison of them eventually. I don't know about WO, I just thought they sourced from someone who made odd sized objectives lol. Why does my Altair 102mm refractor have exactly 714mm focal length? Apart from the fact it gives it a perfect f/7 focal ratio.


I'm fairly convinced these dielectric diagonals are made by the same OEM. Altair have one without carbon fibre side plates that's more or less the clone of the APM.


I got the Altair a bit cheaper than retail as it wasn't the one I actually ordered. I suppose they just wanted a sale lol.

 

Well, it came today.



Daylight tests in the ED80 seem OK.



The eyeguard rolls down nicely. I'm not so sure of the claimed 16mm eye relief. Seems more like 12-13mm to me. I can believe the 65° AFOV although they may be rounding it up a little.


Similar in overall size and appearance to the 19mm TV Panoptic. I'm still ambivalent about the safety barfs.


Size comparison with 15mm SuperView, TS Planetary HR and Celestron Luminos.

 

Yep, could be identical light trains.


The focal plane seems identical between the two. I reckon I could use them as a bino pair!

 

I'll take your word for it. You know I'm going to ask you to elucidate on this, right? lol

Ordinarily I would have just posted the video of 'Fashion' by David Bowie or something. But admin would remove it as being irrelevant. So you'll just have to sing it to yourself. It's either fashion, marketing strategy or a combination of the two anyway. Or maybe Synta et al got a deal on green anodising. Speaking of anodising, my ED80 visual back/compression ring is being anodised as I write this. I should get it soon.

The safety barfs (kerfs) are just as effective as the Baader ones. No bloody use at all. I've only daylight tested the 15mm ULTRAFLAT but it seems very good. Ergonomics feel right and the image was bright and crisp.

I'm bound to try this at some point lol.

 

I think Gabby's referring to the FPL53 ED glass element in my 102mm Starwave.



I don't know much about this though. I think Japanese FPL53 ED Ohara made glass is as close as you can get to fluorite glass without it actually being fluorite, which is apparently prohibitively expensive. I'm guessing the O'harry chap in Japan knows he's doing. I suppose for doublets with focal ratios greater than f/7 they can use Tesco glass or something. I mean, who'd buy a doublet slower than f/7 anyway lol?



Oh ... that would be me.


According to Sky-Watcher the ED80 has Ohara FPL-53 Extra-Low Dispersion glass as well. So I'm none the wiser.

 

I wish I understood it all lol. Ohara FPL-53 has, of course, become a marketing term now. Has your Orion ED80 got a compression ring in its visual back?



These are made in the UK. Mine should arrive next week. I have one for the ED72. Unfortunately they're not interchangeable with all Synta refractors as the ED72 doesn't have an M56 thread.

https://www.firstlightoptics.com/adapters/flo-compression-ring-adapter-synta-skywatcher.html

 

Thanks Gabby. I guessed it was something like that. I know FPL-53 is an actual 'thing' but it's still used in marketing spiel. I meant it was now effectively a marketing term as it is recognised as being glass of a particular quality. A bit like BAK 4 which I also don't really know anything about lol.



The 12mm EP's do seem to have different coatings, I'll bino them when I get the chance. Meanwhile here's a pointless jpeg of my X-Cel collection.



I was looking at the zenith a while ago with my ED72. I almost dislocated myself trying to use a reflex sight. So I may try this RACI next time. It's only 22mm smaller than the objective lol.