LDW1

18 hours ago, Stu said:

Just to add an image of how I have to attach a second dovetail to allow me to mount the scope far enough forward to reach balance, without fouling the focuser. One day I'll find some suitable spacers to avoid this extra weight, which is one benefit of the Altair version.

Why didn’t you just buy a longer dovetail, say a 13” ? They aren’t that much money. Why does the focuser have to be in that position in relation to that of the dovetail ?

You are probably right, I hope so. Its an interesting conversation ! 

I think most if not all scopes of that class have rotatable focusers, as to balance on an AZ4 or equivalent of which I have 4, balance has never been a problem with those small, rather short, lite scopes, just ensure a long enough dovetail. As well I sometimes use a 2” Luminos ep that is very heavy and balance remains satisfactory, the biggest issue is tightening it down  so that the draw tube doesn’t slip back when the scope points above say a 50° angle. Size / weight is the mentioned issue by the poster with some mention of performance, all that being said, the poster had better weigh / take into account the use of the scope in their own back yard over short distances not just when travelling over longer in order to ensure they get the best overall performer or they may be kicking themselves. There is more than one dimension to consider regardless of what they expressed, it is important. I still think 80mm vs 70-72mm is the key to consider when thinking of the views, the objects to see on those awesome nites when they are all hanging there to be seen, hopefully with the right scope !

In your case it is relevant but in the posters case we aren’t so sure it is, in the same way.  He is basically trying to analyze size that are very close to the same not performance differences. To me it is kind of a strange concern when they are all so close. 

22 minutes ago, Stu said:

I think every situation will be different and there are times when even an 80mm scope is too much to take whereas a 60 or 66mm can be squeezed in. It is correct that every step up in aperture, even 60 to 66mm makes a difference but having a scope with you is better than not. I was surprised how well my 72mm performed under a dark sky, and in that case I didn't have room for anything bigger as I already had a 14" in the car.

There is no question that every case, every situation is different but in your case that rather heavy 14” throws a curve into the mix that can’t really be factored in to the posters concerns. In the posters case we are talking about a number of scopes with, in all honesty, are not much different in specs but could be in performance on those black, star strewn nites when you want to pull out everything you can with a scope that you made a critical decision on, just make sure its the right one as there is no turning back ! I can see if they were comparing 60mm to 80mm or 80mm to 100mm but ........ !    PS:  I would squeeze the 80mm ST in even if I had to jump up and down on it, to get it there, lol !

Are you not splitting hairs when you start talking about 0.5kg +/- weight wise vs losing important, maximum performance b y downsizing the scope ? Every time you look through the smaller scope the ? will always be there, the ? ‘ should I have bought the larger ... ‘ all for a kg. Its your choice but get something that will last a life time !

On 23/09/2019 at 18:54, Paz said:

I've been planning getting a light, small, portable, and easy to use set up for travel and for easy short sessions within walking distance of home where I can fit the whole set up in a smallish rucksack or in a couple of light bags and carry it a fair distance easily.

I have sorted out the mount side of things, a Neewer carbon fibre tripod plus a TS optics AZT6 head, and have had a lot of success testing this with an ST80. I think I have now narrowed the scope side down to a 72mm apo. Here's my rationale and the alternatives I've considered, I'd be interested in any comments on this from those who have used such small scopes.

Equinox ED80 - a great scope and great value second hand  but a bit longer and heavier than I would prefer (370cm and 2.9kg).

80mm ED DS pro - also longer and heavier than I would like (4.1kg).

72mm ED DS pro - light at 2kg but quite long at 420mm. Lowest cost.

72mm TS Optics ED Apo - short (310mm), very light (2.1kg), very good quality all round . Would allow me to mount both an rdf and a raci finder.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8866_TS-Optics-Photoline-72mm-f-6-FPL53-Apo---2-5--Zahntrieb-Okularauszug.html

72mm Altair Astro CNC EDF Apo - short (325mm) , quite light (2.5kg) , good quality with optics report. Also allows an rdf and raci finder set up.

https://www.altairastro.com/Altair-72-EDF-Refractor-Deluxe-CNC.html

I have gravitated towards Altair Astro 72mm because of the optics report that guarantees the quality, it has a rotatable focuser which I use on other scopes to help balance things out, and it has spacers on the dovetail that allow the dovetail to be positioned well back towards the focuser to facilitate balance. The down sides are is it isn't the lightest, it's a bit ugly (call me shallow), and it's relativy expensive.

Would this option or any others be fine in terms of working ok with binoviewers or other light path hungry set ups like Herschel wedges? 

Are there any other alternatives to consider in this area. 

Any general comments or experiences to share on scopes of this size would be gratefully received.

Why would you question the ability / quality of any of these scopes to perform ? As well, with all things being equal, why would you not go with either of the 80mm scopes as normally larger diameter usually wins out ? I own an Equinox and it has everything the others have, this is a solid, well built scope that is at least as comparable to the one you are leaning towards incl. weight with more diameter. You can’t get any better than the Schott / fpl53 glass and you are talking scope weights on average of 2.5kg, no big deal unless some one has a disability. My advise is get the Equinox, it doesn’t matter whether I own one, its a great scope.

Has anyone owned / played around with a Celestron CO-62, f4.8 refractor from the mid 80’s ? They were built by Vixen about the time of Halley’s Comet appearance.

If you don’t already know or just haven’t done it, the next time you go to an optometrist or ophthalmologist have them measure your pupil diameter, they will gladly do it at least where I live. Then you will know, have a base to determine on and have both eyes checked, there are so many floaters in my right eye that I trained myself to view / use my left that has literally no floaters, works well.

For the most part I don’t get too exited about exit pupil, I just point the scope and view, lol ! As I mentioned it is a good guide, a starting point if you will, a quick check when buying a scope or an eyepiece to give you an idea as to what kind of performance you are going to get as a start. Its a good reference.

On 19/09/2019 at 09:08, Rob Sellent said:

Thanks for the reply. I don't get the math . The fl 4" does fine at +50x .  

Google / download the NAA Telescope Calculator, this will give you the best case parameters for any scope based on scope specs and the observers age etc., its a fill in the blanks thing and it calculates the theoreticals but it doesn’t mean a particular situation can’t go above the numbers, if you are lucky I guess ! Thats where the numbers I gave you came from so check it out, I use it all the time to check a scopes characteristics when looking at buying a particular scope to give me an idea as to whether I want it or not or might already have one that is quite similar.

The math says that with that scope, to maximize its performance, you are restricted to eps between 18mm - 36mm so with the 6mm ep the brightness factor should / will be practically at zero, you may just make out a bright DSO, a planet or the moon? You figure it out, is that what you want to spend quite a bit of money on when you already have it in a pretty fair set of eps already ? Clear Skies to you !

They sure are unless you are a perfectionist that just likes to spend money in the pursuit of prestige !  

I have a 2” WO 40mm, 70° ep that I use for low power, wide field views in all my refractors from f6 to f11.4. It puts up some great views when skies are at their best ! I also have 2”, 30, 50, & 65 mm eps as well ! How can you tell I like low power wide views, lol !

If you can move up to a couple of 2” low power, wide field eps in the range of $80 - $120 US ! They are a great compliment to the smaller 1.25” eps ! You sure don’t have to spend too much but they should be a level or two above the ones that come with most scopes !

On 28/08/2019 at 05:59, John said:

I've seen people actually selling empty eyepiece boxes for the premium brands such as Takahashi etc

I have a few eyepieces that don't have the original box but they are in great condition which is all that really matters

Some of the Explore Scientific and Meade eyepiece boxes are huge - they do create a storage issue themselves

The problem is for most, are we collecting boxes or viewing the night sky on those great seeing nites, if its the boxes its the wrong hobby, lol ! If its the nite sky its out of this world, lol !

Many observers keep their eps in either a case or separate bolt cases all the box does is collect dust, lots of it, on a shelf somewhere else never to be used again !

It sure is a keeper, have it mounted on my Twilight I and its pretty stable !

I just got the scope, it was superbly wrapped and is in perfect condition ! I may post a pic when I mount it later today ! Thanx every one for looking / commenting !

27 minutes ago, John said:

I've read a number of reports from different sources that the 105mm F/15 Antares Elite was stopped down to around 95mm but that scope is not the subject of this thread.

I hope you enjoy your Antares 127mm F/6.5 achromat. It should provide a nice balance of unobstructed light grasp and good control of CA for it's focal ratio. For what you have invested, you can't go wrong

I agree ! Its the first refractor that I have owned with a weight of around 15lb ! It will be interesting to see how my AZ4’s / Twilight I perform ! I know one thing, I will never own another EQ mount, one was enough ! I will figure this out as I go !

6 minutes ago, LDW1 said:

It should be in Mississauga now via Canada Post, 200mi south of me, from Montreal I would hopefully expect to get it tomorrow or Tues. at the latest !

Someone mentioned on CN, that Antares scopes weren’t stopped down contrary to some peoples beliefs / statements !

5 minutes ago, John said:

The "Vixen Spec" Antares refractors were longer focal length achromats, dubbed the "Elite" series.

They were achromats as well. The 105mm had a baffle design issue that resulted in it's objective being stopped to around 95mm effective aperture.

Have you actually got your Antares 127mm F/6.5 now or is it still on it's way to you ?

 

It should be in Mississauga now via Canada Post, 200mi south of me, from Montreal I would hopefully expect to get it tomorrow or Tues. at the latest !

1 hour ago, John said:

The scope listed on the Antares website is billed as being an achromatic refractor so it will have a 2 element objective that uses crown and flint glass:

http://www.vectorwarrior.com/antares/1208EQ5.htm

If an ED glass element was used they would certainly say so - ED glass costs a lot more than standard glass and manufacturers and vendors make sure that they emphasise when it is used.

I have heard the term "semi-apo" used over the years that I've been involved in astronomy but I don't think it means much. There was a discussion on the Cloudynights forum last year which might be of interest:

https://www.cloudynights.com/topic/603649-apo-and-semi-apo-difference/

From what I've read, the Antares 127mm F/6.5 achromat seems to be a well thought of scope (though rarely encountered here in the UK) so for your investment ($300 was it ?) you have probably made a sound purchase.

 

 

 

Some of the Antares scopes also reference ‘ Vixen Grade ‘ lens, designed to the specs of the older Japanese Vixen scopes so there appears to be something in their wording / meaning ! My understanding and I read it somewhere, but where, was that they were quite selective in obtaining their lens glass and that they were supplied with ED glass which they used in that line that I reference !

1 hour ago, John said:

Sounds like you already know all about them. Hope you enjoy the scope

I have learned a bit over the years, my only question was where does the word ‘semi’ come in and what does it all mean incl other observers interpretations !  Are you actually getting a little more again for your $ ?

3 hours ago, John said:

Well I hope your expectations are met. I have owned quite a few Antares products and they are decent for their cost but not the very best in their niche.  They do usually offer good value though.

As I understand it, the 127mm F/6.5 Antares refractor was made by Jinghua Optical Electronics Co (JOC) who also made Explore Scientific, Telescope Services, Bresser and I believe some Meade products.

 

 

 

 

I have an Antares 102mm, f6.2 refrac. and had an 80mm, f6 as well ! Both put up great views on those great nights but they weren’t professed to be semi anything just excellent quality achros and they were ! This 127mm if you read the old literature from back in 2005-2007, from the Canadian Company that built / put together these scopes they reference semi ed or apo or both for the 2 127mm and 1 154mm models ! As well the chinese company that you reference built scopes for various scope companies is probably correct but my understanding is, like a lot of others do, is that they are built to specs, requirements, wants of the individual scope companies which means the quality / functional ability of each brand of scope could be more or less than another and my understanding of the Antares scopes is that they are closer to the top end of the scale due to stricter controls / requirements of the company ! I have heard / read that a few times through the years from various sources and witnessed it personally with my two vs the half dozen other brands and sizes that I have owned and operated ! So semi or not I am very sure I will get a good scope for what I paid ie approx $300 C !