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# Barlowing Leica ASPH Zoom

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YKSE    2,068

Could't do anything about the weather for the moment, I decided to do a summary the barlow combinations with the Leica zoom, mainly with Baader VIP barlow parts, also baader 7.5mm spacing part 1508155.

1. Calculating barlow effect:

1 + (L_FP + added_length)/ VIP_fl

where

L_FP is Leica's focal plan position, it's 4.5mm inside the length (info from Andreas Braun)

added_length is 2" dapter length plus addition adapter length, (the presentAPM 2"T2 adapter is 25mm for by my measurement.

VIP_fl is VIP barlow's focal length, it's 59mm accoring to Baader when I contacted them by mail.

so if only 1.25" barlow scewed in Leica, we get 1+(4.5+25)/59=1,5x, and if we add spacing part 25A from VIP (15mm long) we have a barlow effect 1+(4.5+25+15)/59=1.75x

2. In 2" focuser:

Tthese combinations can be used in 2" focuser directly without hitting the mirror, to have the least leverage on focuser:

2.1

1,5x, and 1.625x are just like using Leica in native 2" mode, about,

2.2

2x, 2.06x and 2.13x, using VIP's flexible combination, it can still be used in 2" focuser: though some 25mm taller than former combinations:

3.

In 1.25" focuser (or 2" to 1.25" reducer), this will be tallest combination, it includes 1.75x, 1.88x, 2.25x, 2.5x and 2.63x

I find Leica in native mode or 1.5x barlowed has enough coverage for my scopes. Others may need different barlow effects.

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YKSE    2,068

Got the idea of replacing VIP barlow's nosepiece with this adapter Baader M43 male - T2 male, it seems work quite well

The barlow lens can be unscrewed from 1.25" nosepiece, then screw into tha adapter, the length is shortened by about 20mm, which means this combination (Leica+15mm ext + 7.5mm+new nosepiece) for 1.88x (9.5mm to 4.7mm) can be used in 2" with the normal Leica length

And it means that all the barlow effects up to 2.63x can be used in 2" focuser too

What about dust cap to the new VIP nosepiece? The original dustcap for Leica just happen to a perfect one

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Roy Challen    633

Thanks for these nice reports. Don't you just love the versatility that Baader (and Borg) components offer?

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Stu    14,821

Looks like a really handy adaptor Yong. Might have to order one next time I buy from TS. Thanks for the link

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YKSE    2,068

Absolutely Roy, the Lego type connections is a fun playground

Stu, I may post some more stuff in the coming days to help you spend your money

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Stu    14,821

Absolutely Roy, the Lego type connections is a fun playground

Stu, I may post some more stuff in the coming days to help you spend your money

Eeeeeek!!

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Dave In Vermont    4,762

Very cool Yong. Thank you for this! I just received my Baader 8 - 24mm Zoom. There goes eating in September.....

More toys,

Dave

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Highburymark    982

Yong/all,

Do you still recommend the VIP as the best Barlow for the Leica zoom? I'm looking to get maximum 2x out of a Barlow - but want something as compact as possible. I've ruled out the Leica 1.8x extender because of price, so presume the VIP is still the best option?

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Stu    14,821

The VIP works very well with the Leica Zoom. It is supposed to degrade a little above x3 but that's not your requirement so will be fine. I also believe the edge performance suffers at x1.5 because it is too close to the first element of the Leica, but again if only using between x2 and x3, or if on axis performance is what's important at x1.5 then the VIP is great.

The Zeiss Abbé Barlow is the only thing that is a little better.

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Highburymark    982

Thanks Stu.

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YKSE    2,068

I've not tested many barlows, so I took my simple appoach by reading a lot before spening the money, comments like BillP did here doesn't sound discouraging to me

Optically, VIP barlow is very good to my eye, as to flexibility it's simply THE best, IMHO.

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Highburymark    982

Useful link and much appreciated advice, thanks Yong.

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YKSE    2,068

Very cool Yong. Thank you for this! I just received my Baader 8 - 24mm Zoom. There goes eating in September.....

More toys,

Dave

Dave,

May I suggest dieting months before Thanksgiving? - Get the VIP barlow

Here's a picture of the modified VIP with MarkIII zoom, can be used in 2" focuser, some 55mm long before the zoom focal plan, it gives 1.9x to the Zoom

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Dave In Vermont    4,762

If I want to Barlow the Baader, I'll make do with my TeleVue's and my PowerMate. Though I'll likely be shunned by some for committing miscegenation. Or they might undergo spontaneous-combustion.

Living dangerously,

Dave

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Highburymark    982

Can anyone advise whether there are any advantages having a 2" nose/adapter for the Leica zoom (ie - from APM or Starlight) rather than the 1.25" (APM) one I have at the moment? I've recently bought my first 2" diagonal. And a Baader VIP Barlow is on the way. But would there be any point in me getting a 2" adapter as well?

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Stu    14,821

Hi Mark

The only reason I can think of is if you are short of in focus. With the 2" 'barrel' you can gain a little by avoiding the need for the 1.25" adaptor. I've used both and can't think of any other issues. In fact I believe the 1.25" is actually 2" at the top so can go straight into a 2" diagonal as well....? Don't quote me on that but it's worth checking out, I can't properly remember!

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Highburymark    982

Hi Mark

The only reason I can think of is if you are short of in focus. With the 2" 'barrel' you can gain a little by avoiding the need for the 1.25" adaptor. I've used both and can't think of any other issues. In fact I believe the 1.25" is actually 2" at the top so can go straight into a 2" diagonal as well....? Don't quote me on that but it's worth checking out, I can't properly remember!

Thanks Stu, really helpful

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YKSE    2,068

Just as Stu has stated, 2" adapters (T2 or M48 from APM) gain some backfocus in most cases.

The only instance I can think of to the advantage of 1.25" adapter is when you want to use Leica in scopes with only 1.25" focuser, e.g. PST, where Leica can't get into focus with 2"T2 adapter barlowed in 1.5x. The big drawback I see with 1.25" adapter is the increased length in 2" focuser when barlowed, you'll get about 30mm higher above focuser(diagonal) for the barlow effect, comparing to a 2" adapter.

I don't know the measurement of Starlight adapter, can't comment on that, but APM's 2"s (at least looking at the T2 I have) seems quite well optimized according to the feedbacks from earlier discussions on CN.

The difference between APM's 2"T2 and 2"M48 is minor, with 2"M48, you can use 2" filters on Leica directly, with T2 on elsewhere(diagonal or extension tube for Newt); for connecting the VIP nosepiece to Leica (use in 2" mode), with 2"M48, you need to use #29(M48 to T2) in VIP for a barlow effect about 1.57x, while with 2"T2, you connect directly for 1.5x.

In short, you'll have new set of Lego to play with

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Highburymark    982

Thanks Yong, you have provided much invaluable info on this eyepiece.

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Piero    2,854
On 29/08/2015 at 22:25, YKSE said:

Got the idea of replacing VIP barlow's nosepiece with this adapter Baader M43 male - T2 male, it seems work quite well

The barlow lens can be unscrewed from 1.25" nosepiece, then screw into tha adapter, the length is shortened by about 20mm, which means this combination (Leica+15mm ext + 7.5mm+new nosepiece) for 1.88x (9.5mm to 4.7mm) can be used in 2" with the normal Leica length

And it means that all the barlow effects up to 2.63x can be used in 2" focuser too

What about dust cap to the new VIP nosepiece? The original dustcap for Leica just happen to a perfect one

Hi Yong,

If you screw this adapter (with VIP lens attached via M34 to the T2 side) to the bottom of the 2"-to-1.25" reducer via T2 connection, is there room to attach a 2" filter to the outer M48 thread of the reducer?

Basically, is it possible to attach

(2"-to-1.25" reducer [T2-]) ([+T2] T2-M43 converter)

[M48-]) ([+M48] 2" filter)

Thanks,

Piero

Edited by Piero

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John    17,555

Has anyone tried the Leica 1.8x Extender for astro-use ?

I seem to recall Gavin / Gavster using one but I've not read any other reports on it

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Highburymark    982
1 hour ago, John said:

Has anyone tried the Leica 1.8x Extender for astro-use ?

I seem to recall Gavin / Gavster using one but I've not read any other reports on it

Two years on from the above thread, I now have the Leica extender. It takes the Leica's range from 8.9mm-17.8mm to 4.9mm-17.8mm. Ergonomically it's compact and elegant, particularly with the Starlight adapter (which can be ordered via FLO) with a bayonet fastener, which makes switching between native zoom and 1.8x magnification fast and simple. I use it with a Baader Zeiss prism or the T2 blocking filter on Lunt solar scopes, so it screws directly on to both diagonals - otherwise the Starlight (or 2" APM adapter) means it would have to be used with a 2" diagonal. Optically I find it just as sharp and pleasing as the VIP. It's just much easier to use.

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GavStar    853

Hi John,

i would echo what Mark says. Convenient, great views and no change in focus position. For lunar, planets and solar it works very well imo.

Mark

i didn't twig that it can screw directly into the Lunt diagonal t2 connection - excellent, thanks for the idea.

Edited by GavStar
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John    17,555

Excellent feedback Mark and Gavin

I really like convenience coupled with performance and it soulds like there is no major focal point change with the 1.8x extender

I do have the APM 2" adapter though but I suspect that I will be using the zoom almost permanently in 9.89mm - 4.94mm mode.

Sounds like I can always order the Starlight bayonet fit adapter if needed.

The VIP barlow is optically excellent but I have to admit that something simpler and as good optically is very tempting

Edited by John
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YKSE    2,068
On 2017-11-07 at 17:23, Piero said:

Hi Yong,

If you screw this adapter (with VIP lens attached via M34 to the T2 side) to the bottom of the 2"-to-1.25" reducer via T2 connection, is there room to attach a 2" filter to the outer M48 thread of the reducer?

Basically, is it possible to attach

(2"-to-1.25" reducer [T2-]) ([+T2] T2-M43 converter)

[M48-]) ([+M48] 2" filter)

Thanks,

Piero

Piero,

I've not used 2" filter directly on barlowed Leica, a filter is always mounted on the diagonal.

For using it as you're thinking, you need to find a adaptor of M43(female thread) to 2" barrel (with M48 female thread).

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• ### Similar Content

• By YKSE
Finally, the zoom and barlow arrived, almost 4 weeks after the order. The delayed was caused by strong sale before Christmas which made the adapter out of stock according to APM.
Anyway here's some pictures:
1. Unboxing:
Well packed zoom and barlow

Leica zoom out of box and case:

Leica zoom and Baader VIP barlow:

2, Some Phisical data:
The Zoom weighs 470/510gram with/without 2" adapter, 115mm long with the adapter, here's a picture together with my other big boys (Skywather AERO 40mm, Baader Aspheric 31mm and Maxvision 24mm)

With the 1.25" VIP added to Leica for 1.5x, the zoom becomes longer than 40mm Aero:

3. Coating:
Very dark, a picture togethere with BCO 18mm:

Looking at a white background, Leica is at least as white as BCO 18mm.
First impression:
The weather forecast pointing to some less cloudy nights towards the weekend, I'm keeping my fingers crossed for that.
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