John

"....the undercut nightmare..." 🤣🤣🤣

Oh boy

When I used to do eyepiece reviews for the forum, much of my testing was done with my F/5.3 12 inch dobsonian. I didn't notice too many field edge issues with the various orthoscopics that I used to be honest

The Baader Classic Ortho's do loose sharpness over the final few % of their AFoV in all scopes I used them in but that was, I believe, accepted by Baader when they stretched the field stop to deliver 52 degrees rather than the traditional ~40 degree ortho field.

While I preferred the ergonomics of the classic "Circle-T" ortho design, the HD "flat topped" designs such as the Baader Genuine Ortho, the University Optics HD orthos, the Fujiyama HD orthos and the Astro Hutech HD orthos did seem to me to offer slightly better light scatter control and light throughput over the older, "classic" design, when I was comparing them "back to back". Probably due to more effective coatings:

https://stargazerslounge.com/topic/175014-baader-classics-the-story-so-far/

https://stargazerslounge.com/topic/184935-astro-hutech-orthoscopics-compared-with-baaders-orthoscopics/

The classic "Circle-T" orthos do perform very well though which is presumably why there is still a demand for them at £50 plus on the used market. A few years back you would have struggled to get £25 for one so they are better appreciated today

I rather liked this "short set" that I had a few years back:

7 minutes ago, Alan White said:

.... something that grates and makes your observing less enjoyable had to be addressed.

If it did for me, I would address it. I don't hang on to equipment that annoys me.

1 hour ago, Alan White said:

Have we mentioned Undercuts yet?

Televue have a love of them, I don’t, tried to discuss with David Nagler, but he was not having it that they catch.

I made my mind up then on the spot, a company refusing to listen to customer feedback is not destined for my custom, so my TV eyepieces went except my Nagler Zoom, it’s undercut is Pentax like in proportion.

Yes they have great products, but flawed with the undercut.

 

 

Personally speaking, I have never found undercuts an issue with the dozens of eyepieces (or many brands) that I've owned, used and tested for the forum

I would certainly never allow the presence (or absence) of an undercut to dissuade me from a brand with so many other superb qualites. It's just a non-issue for me.

I realize that others will differ in that though and so be it - many pages of posts on forums have been fueled in the discussion of the things

Over recent years Tele Vue's undercuts have had a taper applied to the top lower edge of the undercut on most of their ranges, so it's not as if they have been totally stubborn over it.

5 minutes ago, IB20 said:

Seeing was OK but not wonderful. 100x required a bit more patience but 80x was lovely. I have full cloud again now and think that’ll be that!

My haze has thickened to the point where Jupiter is the only thing showing. The edge has been knocked off the contrast of the features now so I've packed in as well

Skies are hazy here but I've got a scope out and I'm observing the gas giants again. Seeing a bit variable, "good in parts" like the curate's egg

17 minutes ago, Deadlake said:

The 130 mm is shorter then the 103 mm, makes it less wieldy to get out.

Also works well as an imaging scope if needed. 😃

My 130 F/9.2 is around the same length as my ED120 when it's dew shield and focuser extension are retracted. For some reason I always post pics of it at "full length"

The 130 weighs around 2kg more than the ED120. Not a huge difference.

I'm in the same situation here. I don't image though so I can keep my scope setups very low tech, portable, and with quick setup and tear down times.

My scopes all live in and around our dining room. I observe on the patio which is a short carry out through the french windows.

I have owned more sophisticated scopes in the past but they didn't get used too much after the initial burst of enthusiasm. I've owned a couple of very heavy setups as well with similar results.

I'm glad that I have resisted the lure of imaging (so far) because I think the setting up requirements to get decent results would drive me nuts

2 minutes ago, JeremyS said:

That dawned on me too, John. We do get carried away sometimes 🤣

It's that "R" word Jeremy

I've just re-read the opening post in this thread and realized that it was about imaging scopes. None of mine are optimum for that purpose really

3 hours ago, Deadlake said:

Do you find your 130 F9.2 a little to big to get out most nights? 

Putting it and the T-Rex mount out takes a little longer and a little more effort than my other scopes. It's not massively different though. I just think the ED120 is pretty compact and easy to manage for a near-5 inch refractor. The Tak is the quickest and easiest of all of them though - practically no cool down time needed so you can get observing, even at high powers, straight away.

If you order a new dobsonian from Orion Optics at least you will have plenty of time to research accessories for it before it arrives 

I think I've already posted this but just in case, a LZOS 130 to follow @Deadlake's LZOS 130.

I've not tried licking it but I guess it might be caviar flavour ?

Sounds like a nice session Ian. Ethel seemed to be enjoying herself as well !

For visual observation I find myself reaching for my ED120 F/7.5 refractor an awful lot these days. It's not quite grab and go but it's readily portable and I can carry both scope and mount (usually the Skytee II) around the garden quite easily in one piece.

The scope can show a 3 degree true field at one end and can handle 300x or more at the other. Enough aperture to show quite a lot of deep sky objects, some resolution in globular clusters and good planetary detail. Resolves tough double stars really well too !

43 minutes ago, JeremyS said:

You're right about the weight. This could be a real frustration. I will see how I get on, but still hanker for trying a Tak Erfle 28 (hence my wanted ad)

That is one of the nice things about the 24mm Panoptic - small and relatively light. Pity that you are not keen on the RD.

The comfort of the BST Starguiders compared to using shorter focal length orthoscopics should not be overlooked in my opinion.

I tend to opt for observing comfort over small differences in ultimate optical performance these days - I'm getting old !

Manually tracking with a 40 degree AFoV, small eye lens and tight eye relief, at high power is somewhat harder work than with a nice big eye lens, 60 degree AFoV and reasonably generous eye relief.

Do you wear glasses and, if so, are you likely to need to wear them when observing ?

This will affect the spec of the eyepieces you consider.

I tend to think of "normal" eyepiece fields of view being in the 50-60 degree range, wide angle 65-72 degrees, ultra-wide 76-82 degrees and hyper-wide 90 degrees plus.

With my Orion Optics 12 inch F/5.3 dobsonian (focal length 1600mm) I find that I use eyepieces of the following focal lengths the most:

21mm (76x)

13mm (123x)

8mm (200x

6mm (267x)

4.7mm (340x)

I prefer eyepieces with a very wide angle of view (100 degrees) to maximise drift times of targets in the undriven scope, plus I just like the hyper-wide views

I don't use binoviewers with the scope - if I did I would need to change to eyepieces with smaller fields of view because the hyper-wides would be too fat !

I don't use a coma corrector with my scope but if you go for something that is F/5 or faster (eg: F/4.5) and opt for wide field eyepieces then you may well need to so that coma generated by the scopes mirror does not mar your lovely wide views.

Another nice night with my ED120 refractor !

Slightly hazy conditions but steady seeing and the brighter targets such as Saturn, Jupiter and the Moon showing really well. 5 Saturnian moons (could not quite get Enceladus tonight) then a Great Red Spot transit to enjoy with lots of other disk / belt detail and colour. Found Neptune lurking in the Moonglow and then on to the Moon with the Mare Crisium, Mare Fecunditatis, Petavius and my favourites Messier and Messier A really well illuminated.

Add some nice tight binary stars plus a few planetary nebulae and globular clusters into the mix and the result was a very nice session

The old ED120 is earning it's keep at the moment - 2nd session on the trot with this scope

1 hour ago, jetstream said:

I figure its a to each your own situation, lots of eyepieces to choose from for sure.

Indeed.

I didn't get on with the Leica ASPH zoom when I had one and the VIP barlow, but others feel it's the best eyepiece they have

Tonights star perfomers for me on Saturn, Jupiter and the Moon with my ED120 refractor were the 6mm Ethos and 4.7mm Ethos SX. Wonderful views and relaxing to use as well 

Lovely night here - very thin cloud layer but not enough to spoil the views of Saturn, Jupiter, Neptune and the Moon

I had a look through one of the Zeiss ZAO orthos a few years back, the 6mm. It was clearly a superb performer even from that brief encounter. These days I suspect I would not get on so well with the short eye relief, small eye lens and limited AFoV given that my scopes are all on undriven alt-azimuth mounts

I still have a Fujiyama 4mm HD ortho which I stick in a scope from time to time to remind myself what using such eyepieces is like in practical terms. 

28 minutes ago, Geoff Barnes said:

I've often wondered what eyepieces are used in professional observatory telescopes and are they available to mere mortals like us? 

Would they be likely to use Televue ep's?

Lowell Observatory uses Explore Scientific but that is for outreach rather than research. Research is mostly done with devices other than optical eyepieces.

The Lick Observatory has some Tele Vues for it's 36 inch refractor:

https://mthamilton.ucolick.org/techdocs/telescopes/36inch/telGeneral/

9 minutes ago, Don Pensack said:

.....Here are a couple links to peruse:

https://web.archive.org/web/20110622011950/http://cieletespace.fr/files/InstrumentTest/201102_test_oculaires.pdf
https://web.archive.org/web/20130829052725/http://www.cieletespace.fr:80/files/InstrumentTest/201306__6_oculaires_10mm.pdf

 

Really detailed testing - we so rarely see that in astro eyepieces.