Raph-in-the-sky

57 minutes ago, Franklin said:

Hey Ralph, I see you are in Brussels and just remembered that ASTROBOOT have on their Euro site the William Optics 2x Barlow bino-nosepiece @ 24euro. Would give you an extra power and it's the dedicated one for the WO bino's.

I really wanted to get one for mine from them but they have stopped trading to the UK because of all the Brexit nonsense. 😪

Thanks for the tip. I'll have a look!

11 minutes ago, Franklin said:

Yes definately they would work well. But if you use eyepieces with a focal length longer than about 20mm, they will vignette in the WO bino's. Still work but you won't get the full field of view. This is because the WO bino's have an inside clear aperture of around 21mm. 

What do you think of these? https://www.amazon.fr/Svbony-Oculaires-Astronomique-Accessoires-Asphérique/dp/B07TVJC5KR/ref=sr_1_3?__mk_fr_FR=ÅMÅŽÕÑ&dchild=1&keywords=svbony+20mm+oculaire&qid=1629045025&sr=8-3

Hello,

I was thinking buying a couple of these (https://www.amazon.fr/Svbony-Oculaires-Astronomique-Accessoires-Asphérique/dp/B07TVJC5KR/ref=sr_1_3?__mk_fr_FR=ÅMÅŽÕÑ&dchild=1&keywords=svbony+20mm+oculaire&qid=1629045025&sr=8-3) for the WO binoviewer I just got. I intend to use this in a 10' fulltube dob with either the x1.6 barlow provided with the bino or a x2 celestron ultima barlow.

All advice welcome!

Cheers,

Raphael

1 hour ago, Franklin said:

PPS. The WO 20mm 66deg pair work really well and I also use a couple of Baader 10mm BCO's for higher power.

Do you think goldline plossl (also 66°) would do well in this set up? How about the Skywatcher planetary? I'm looking for a cheap option

Hello,

I just bought a WO bino. It came with the x1.6 barlow and I have a x2 Celestron Ultima Barlow. I intend to use the bino on a Skywatcher 10' fulltube dob (So I will have to use it with one of the barlows)

My question is: will the x1.6 barlow give x1.6 and will the x2 Barlow actually give x2?

And which EPs would you go for with such a set up?

Cheers,

Raphael

3 minutes ago, wibblefish said:

I haven't heard of the ET cluster but I have tried the others (oddly the beehive took me a few goes to find!) will add it to the list thank you for the suggestion!

ET cluster is NGC 457 in Cassioppiae... you'll understand the name once you see it. One of my favorite open clusters.

With a refractor open clusters are really great targets. If you haven't already, try and have a look at the pleiades, the hyades, the beehive cluster, the ET cluster...

1 minute ago, Stu1smartcookie said:

Yes its the obvious answer really , but its good to get other Views ( no pun intended) from users . I've just put a Hyperflex 7.2mm-21.5mm Eyepiece  into my basket on the FLO website .. looks like i will start there . 

You can find these zoom second hand quite easily here or on UK astro buy sell. You could definitely save a few quids that way.

5 minutes ago, Carbon Brush said:

When talking FOV. For planetary viewing you don't care.

Actually if you use a manual dob, a widefield EP on planetary allows you to stay longer on the target without having to nudge the scope... I find this valuable.

20 minutes ago, John said:

It's usually the other way around with zooms - wider field at the short focal length and narrower at the longer focal lengths 

 

You re right! I got mixed up... I really don't use my zoom often!

I still find the AFOV too narrow ... now that I got used to 70-80° EPs, it's difficult to use something else.

Just now, Stu1smartcookie said:

Do you lose any clarity with a Zoom EP ?

To me the main issue is the narrow field at high power. For example, my zoom which is a basic Celestron 8-24mm provides only 40° of AFOV at 8mm.

1 minute ago, Stu1smartcookie said:

Well , already some very interesting replies , thank you for those . The BST starguiders certainly seem popular . I also really like the look of the Hyperion Zoom . There is so much choice . For me , this area is a minefield . What about Barlows ?.

 

I also have a zoom EP and to be honest I barely use it. I much prefer fixed focal lengh EPs as most people do. A zoom EP is great for a travel scope as it allows you to have all required focal lengh (might need to add a Barlow) in a very small package. 

And another +1 for BST starguiders (I have the 5mm and the 15mm)

Otherwise you could have a look at OVL Nirvana's (I have the 7mm and 16mm is on its way). Price is not crazy (69£ at FLO), you get a 82° AFOV and the general quality of the image is very good. On the other hand the range is quite limited, only 4mm, 7mm and 16mm. To me those EPs are among the best deals you can get in astronomy.

Up to a 10' dob full tube fits easily on the back seats of most cars (with the base in the trunk)... I know its pushing you budget a bit but a 6' or 8' dob is really really good to start with.

As said an 8' Dob is a big beast but a mighty one! It still fits in most cars if you want to go to a dark site and is relatively cheap for a very nice apperture. 

I fail to see how a 200p on EQ 5 is easier to store/move than a 200 Dob. You could add a couple of straps around the OTA to help. The EQ 5 is heavy and bulky. I would say that if a 200 dob is to big you could get the SW 150/750 flextube which you can carry in one hand and store anywhere.

Thanks for all the replies. I will stay away from those Jones-bird scopes and try to find a classic newtonian optical formula. 

Cheers,

Raph

48 minutes ago, Victor Boesen said:

I had the Pollux as my first telescope so I think I can add to this discussion.

As mentioned by the others, it's a Bird-Jones type of telescope which consists of a spherical mirror and a correcting lens. Without the correcting lens the telescope would work and it's, therefor, not possible to remove. I was happy with my Pollux for about a year until I started to get picky about its optical performance. Having a focal length of 1400mm it isn't that suitable for wide field either.

I remember observing Jupiter, Saturn and Mars through it back in 2015 or 16 and I noticed the rings on Saturn weren't as sharp as I have later observed them. The two main cloud bands were visible on Jupiter together with the great red spot. I don't ever recall observing an eclipse on its surface though. No detail was visible on Mars...

I later upgraded to a 10" dobsonian from Skywatcher, and I noticed that the rings on Saturn were sharper, banding was visible together with the Cassini division. I've observed numerous shadow transits on Jupiter, and the shadow is quite easily visible. Mars also shows albedo features, polar caps and cloudiness/haze on the limb. I know a 10" is a lot larger than the Pollux and the 114/900 you mention, but I think I'd have chosen the 114 instead over the two if I were to start over, although a Heritage 130 would probably be my most recommended option.

I sold the dob not long ago, and I now own a 72mm Skywatcher ED refractor and a 102mm F/7 apo. With the 72mm I've resolved detail on the Martian disk at a size of 8-9 arc seconds at 90X and had the best views of Mars with my 102mm, which I got a couple months ago. My point is, despite comparing the Pollux to a 10" dob, I've still managed to get better planetary views with apertures of 72mm and 102mm. On deep sky the Pollux will win though.

Feel free to ask me more about the Pollux! I don't remember everything that I've observed with it, but I may be able to help anyways!

I just dug out an old video of some videos I took through the Pollux. It looks a little worse in the video than in person, but you can see the planetary performance is lacking...

 

Thanks a lot! That is very helpful. I currently have a SW 250/1200 as my main scope and I had a 130/900 EQ2 in the past so any of those would be a great reference point.

Regarding the Bresser, the one I might buy is an older version which is white... and I beleive shorter thus more corrected. To be honest, I found the pics of Jupiter trully awful (I'm not saying that to be mean, I trully appreciate your help). What did you use to take these pics? Is it a cell phone through one of these nice ES 82° EP? I 'll need to think about it but I may try to source a scope from another place (maybe a heritage 130) and have it shipped there as I can't find anything really satisfactory in the area.

22 minutes ago, Cornelius Varley said:

The "barlow" is an integral part of the optical system in these Jones-Bird telescopes. The lens has two purposes,  the first is to correct the aberrations from the  spherical mirror and the second is to correct the focal length and achieve focus. Without the corrector lthe telescope will be even worse.

Have you used one of these? Are they that bad? Would you go for this and get a 150 apperture or gor for a 114/900 for example?

Hello,

I'm trying to get a cheap scope for when I spend time at my in-laws in Valencia.

On local second hand websites, I see a lot of either Bresser or Seben 150/1400. Those scopes have an integrated barlow which is supposed to be really bad. My question is: for the same price, would you rather go for a classic 114/900 (or 114/500) or 130/900 or would you put more importance on apperture and get the 150/1400 despite the integrated barlow.

Also do you think it would be possible to get rid of the integrated Barlow? Will I still be able to reach focus?

Has anyone already use one of those scopes with integrated barlow? Is it as bad as people make it to be?

Cheers,

Raphael

46 minutes ago, AstroMuni said:

Could you let us know what mount its on and pics would also help.

Here are are a few pics. It came with a viking 77/910 from the 60's (From what I understood its similar to a Royal Astro Japan). I don't know the ref of the mount.

Hello guys,

I just bought a old japanese frac but the counterweight and shaft are missing. I was wondering if I could replace it with the shaft of an EQ2 or star adventurer so if you have one and can tell me the width of the screw part of the shaft that would be very helpfull.

Cheers,

Raphael

Hello guys,

I just bought a old japanese frac but the counterweight and shaft are missing. I was wondering if I could replace it with the shaft of an EQ2 or star adventurer so if you have one and can tell me the width of the screw part of the shaft that would be very helpfull.

Cheers,

Raphael

Hello,

If you go for a full tube 150/1200 dob, collimation should hold pretty well for a few month at a time. If you grandson keeps using it, he will learn how to collimate eentually. Maybe a cheap laser that you collimate yourself beforehand would be a solution that is quite intuitive to use and eventhough it 's not gonna be precise, it should be good enough. Other than that, I think you're left with cheap achro which I wouldn't recommend.

Raph

I have bought a ironing chair like this one 

https://www.leifheit.be/product/details/multi-seat-niveau-chrom.html

It's pretty cheap, comfortable enought and can be adjusted  in height.