Meade Infinity 102

[Mak the Night]

41 minutes ago, Ray of LIght said:

Been thinking about one more eyepiece. The 5mm X-Cel would give me 120x un-barlowed. I have been trying to figure out how to get a decent magnification using a short FL eyepiece and the 5mm makes sense and would be parfocal, I believe, with my 9mm and 18mm X-Cel's. Just a thought, a big thought! Any thoughts Mak?

 

It depends on how useful 120x is to you. IMO, it's too high for most DSO's but not high enough for lunar/planetary. If you had a Barlow element you could get 120x and 192x with it. If you're going to shell out on an eyepiece that gives you effectively one magnification, it needs to be one you'll use a lot, otherwise you are buying something that will gather dust most of the time lol. For example, I have never regretted paying the equivalent of 70 USD on my Baader Neodymium filter as I use it a lot. I'd find an eyepiece that will give you at least 150x un-Barlowed. Something around the 3mm to 3.5mm mark would be a good planetary size.

[Dave In Vermont]

Lordy, MTN! You must have as many Barlow's as I have filters! Praise be to us 'Astrophiles' with an OCD!

Ray - if you don't have a Barlow-lens that you just unscrew from it's barrel - I have one I designated and is permanently separately stored for this use - I'd recommend an Orion(USA) Shorty model:

http://www.telescope.com/Accessories/Barlow-Lenses/Orion-Shorty-125-2x-Barlow-Lens/pc/-1/c/3/sc/41/p/8711.uts

I believe it to be a GSO, branded for Orion. Quite good quality and worthy of use in my bizarre collection of eyepieces & filters.

Nice and clear weather here - so I'm waiting for the unexpected t-storm.....

Dave

[Mak the Night]

26 minutes ago, Dave In Vermont said:

Lordy, MTN! You must have as many Barlow's as I have filters! Praise be to us 'Astrophiles' with an OCD!

Ray - if you don't have a Barlow-lens that you just unscrew from it's barrel - I have one I designated and is permanently separately stored for this use - I'd recommend an Orion(USA) Shorty model:

http://www.telescope.com/Accessories/Barlow-Lenses/Orion-Shorty-125-2x-Barlow-Lens/pc/-1/c/3/sc/41/p/8711.uts

I believe it to be a GSO, branded for Orion. Quite good quality and worthy of use in my bizarre collection of eyepieces & filters.

Nice and clear weather here - so I'm waiting for the unexpected t-storm.....

Dave

I have a few,

Of course, my William Optics bino Barlow elements aren't in the above photo. Those Orion Barlows look good, I think you're right about them being GSO. I think TS Optics have an equivalent.

[Ray of LIght]

So the Orion Shorty has a lens that can be removed and screwed onto the eyepiece? Tte X-Cel comes in a 2.3mm which would be much too high a magnification. What would screwing the barlow onto a 5mm eyepiece do for me? 2x or 1.5x? 1.5 would give me 180x. Can you guys clarify? I do not want to barlow everything if I can help it.

[Ray of LIght]

Oh, the Agena (Barsta?) Starguider comes in 3.2mm for 187.5x. I have the 8mm version right now. Mak, didn't you mention they were well regarded? It is 60 degree AFoV with 16mm ER and ED glass (60 US). Thoughts?

[Mak the Night]

23 minutes ago, Ray of LIght said:

So the Orion Shorty has a lens that can be removed and screwed onto the eyepiece? Tte X-Cel comes in a 2.3mm which would be much too high a magnification. What would screwing the barlow onto a 5mm eyepiece do for me? 2x or 1.5x? 1.5 would give me 180x. Can you guys clarify? I do not want to barlow everything if I can help it.

Basically, threading a Barlow element into a 5mm EP would make it a 3.1mm approximately. I believe the Barlow element on its own magnifies by 1.6x.

[Mak the Night]

6 minutes ago, Ray of LIght said:

Oh, the Agena (Barsta?) Starguider comes in 3.2mm for 187.5x. I have the 8mm version right now. Mak, didn't you mention they were well regarded? It is 60 degree AFoV with 16mm ER and ED glass (60 US). Thoughts?

That sounds like a good planetary magnification for a 102mm scope. The Starguider is Barsta and sold under a variety of names.

http://www.365astronomy.com/3.2mm-BST-Explorer-ED-Eyepiece.html

They're highly rated. My Barsta (Omegon) 2x apochromatic Short Barlow is very high quality, it seems not far off TeleVue to me. I'm guessing the Barsta eyepieces are similar quality optically.

[Dave In Vermont]

So if my maunual on the 102mm Infinity is correct, your scope's FL is 601.8mm. So 120.36X is what a 5mm would do. And one of these Barlow-lens cells would give you either 1.5X or 1.6X. So call it 1.55X:

120.36X X 1.55X = 186.22X

"That's All Folks!"

Dave

 

[Mak the Night]

I've never really known if the element produces 1.5x or 1.6x. I believe any Barlow magnification relies on the distance the element is from the field lens itself. I think Speers Waler eyepieces have extension tubes which can act like Barlows as the eyepiece has a form of Barlow internally, not unlike a Nagler.

Barlow Lens ~ Wikipedia

[Ray of LIght]

8 hours ago, Ray of LIght said:

Oh, the Agena (Barsta?) Starguider comes in 3.2mm for 187.5x. I have the 8mm version right now. Mak, didn't you mention they were well regarded? It is 60 degree AFoV with 16mm ER and ED glass (60 US). Thoughts?

 

8 hours ago, Mak the Night said:

Basically, threading a Barlow element into a 5mm EP would make it a 3.1mm approximately. I believe the Barlow element on its own magnifies by 1.6x.

Got you. Above are my comments mentioning the 3.2mm Starguider as another option. Basically the same result I guess. I wonder which is the better option though?

So I figure it's either get the Orion Shorty and steal it's lens element or get the 3.2mm Starguider. The Starguider solution is cleaner I suppose and would become my high magnification stand alone eyepiece. I can Barlow my other eyepieces for planetary and also will have a good selection for deep sky objects un-barlowed. Am I making sense? Thanks again guys! Hey Dave, thank Porky Pig for me too ??!

[Mak the Night]

3 hours ago, Ray of LIght said:

 

Got you. Above are my comments mentioning the 3.2mm Starguider as another option. Basically the same result I guess. I wonder which is the better option though?

So I figure it's either get the Orion Shorty and steal it's lens element or get the 3.2mm Starguider. The Starguider solution is cleaner I suppose and would become my high magnification stand alone eyepiece. I can Barlow my other eyepieces for planetary and also will have a good selection for deep sky objects un-barlowed. Am I making sense? Thanks again guys! Hey Dave, thank Porky Pig for me too ??!

I think the 3.2mm Starguider makes a lot of sense. Many of the eyepieces I bought over the past year or so were intended to be used without a Barlow with the Big Cat.

[Ray of LIght]

1 hour ago, Mak the Night said:

I think the 3.2mm Starguider makes a lot of sense. Many of the eyepieces I bought over the past year or so were intended to be used without a Barlow with the Big Cat.

Yep, that's my decision. Will order the Starguider next week and it should be a nice and worthwhile addition to my kit, I think. What's the focal length of the Big Cat? 

[Mak the Night]

34 minutes ago, Ray of LIght said:

Yep, that's my decision. Will order the Starguider next week and it should be a nice and worthwhile addition to my kit, I think. What's the focal length of the Big Cat?

The Big Cat has a focal length of 2350mm (f/10).

[Ray of LIght]

46 minutes ago, Mak the Night said:

The Big Cat has a focal length of 2350mm (f/10). 

Sometimes I forget we have over 9000 views on this thread (correct?). So anyway, that is some focal length! Doubt you will need to barlow much! I will do the best I can with what I have. I do love that little refractor though!

[Stu]

Gents, a gentle reminder, no politics please.

Many thanks

Stu

[Mak the Night]

The way I've worked it out, I'll really only need the TeleVue 2x Barlow. It will only be practical on the 19mm Panoptic (247x), 18mm AH ortho' (261x), 18.2mm DeLite (258x), 16mm T5 Nagler (294x), 15mm Antares UPL (313x), and the 14mm Baader (336x). The 2.5x Powermate may be useful with the 24mm Panoptic.

Then there's the bino case with 1.6x and 2x nosepiece Barlows. These will give me a few combinations on some of the pairs of eyepieces:

32mm Baader BCO's

25mm AH ortho's

18mm Baader BCO's

15mm TeleVue Plossls

13mm Celestron (GSO) Plossls

[Mak the Night]

4 minutes ago, Stu said:

Gents, a gentle reminder, no politics please.

Many thanks

Stu

I thought I was subtly within SGL rules.

[Stu]

6 minutes ago, Mak the Night said:

I thought I was subtly within SGL rules.

Well the rule is no politics, so let's stick to astronomy ??

[Mak the Night]

7 minutes ago, Stu said:

Well the rule is no politics, so let's stick to astronomy ??

Sounds like a good rule.

[Ray of LIght]

So trying to order the 3.2mm Starguider now. Gift cards are a pain! Can a bino viewer be used with my 102? Seems maybe large for my scope. That's great kit you have for the Big Cat!

[Mak the Night]

58 minutes ago, Ray of LIght said:

So trying to order the 3.2mm Starguider now. Gift cards are a pain! Can a bino viewer be used with my 102? Seems maybe large for my scope. That's great kit you have for the Big Cat!

I used the bino regularly with my 102mm Mak. As long as your mount is stable it should be fine. I'm guessing there's a bit of weight in that Meade anyway. I reckon you could use the bino on a light alt-az. It's not a large bino unit and the eyepieces I use are not heavy.

I may have a shot at the Martian polar cap tonight with a green #56 filter at 250x. I've also pulled the trigger on a 7mm X-Cel which should give me 257x with a 2x Barlow. I figured as Mars is getting noticeably smaller and starting to phase I'd push the Bazooka as near to its 260x limit as is practical.

[Ray of LIght]

The 7mm looks nice. I'd better get well soon to get some Mars observing in. Diabetics heal very slowly. I will continue to check out bino viewers, they seem awesome!

[Mak the Night]

47 minutes ago, Ray of LIght said:

The 7mm looks nice. I'd better get well soon to get some Mars observing in. Diabetics heal very slowly. I will continue to check out bino viewers, they seem awesome!

I was too knackered to set up last night after two nights in a row of setting up to see nothing. Around midnight Mars and Saturn were quite visible ... Sod's Law lol. You can buy the WO bino without eyepieces. If I could buy a bino for the first time again, that's how I'd do it. There are quite a few reasonably priced bino's out there. You can pay a lot for the ones with bigger prisms. It's best to start off with a pair of the smaller prism ones and then upgrade later I think.

[Ray of LIght]

Quote

 

Don't know what happened above, anyway, Agena has one fairly reasonsble and I put it in my wishlist. I will revisit it and let you know who makes it.

[Mak the Night]

4 minutes ago, Ray of LIght said:

Don't know what happened above, anyway, Agena has one fairly reasonsble and I put it in my wishlist. I will revisit it and let you know who makes it.

Odds are it's made by Kunming United Optics Corporation, regardless of the brand name.