Siebert Optics - Converters

All these Barlows are Dual Format >>

It uses the best quality optics and is fully coated for maximum light transmission. It also fully corrects for color aberrations.

These Barlows are recommended for eyepieces that are 26mm standard field of view and more powerful. More powerful widefields are fine too.

1.75x Barlows

A) This Barlow sells for $89 .965 inlet w/ .965 outlet (Bar965-1.75x)

B) This Barlow sells for $89 .965 inlet w/ 1.25" outlet (Bar965h1-1.75x)

C) This Barlow sells for $99 Dual Format barlow.(Bar965125h1-1.75x)

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2x Barlows

D) This Barlow sells for $99 .965 inlet w/ .965 outlet (Bar965-2x)

E) This Barlow sells for $99 .965 inlet w/ 1.25" outlet (Bar965h1-2x)

F) This Barlow sells for $99 Dual Format barlow.(Bar965125h1-2x)

Step-Down Adaptor W/ 1.25"OD and .965"ID $15 (125965)

Step-Down Adaptor W/ 2"OD and 1.25"ID $15 (2125)

Want to make sure you are getting exactly the correct item?

#1) This Barlow .965 inlet w/ .965 outlet.

#2) This Barlow .965 inlet w/ 1.25" outlet the 1.25" outlet is for 1.25" eyepieces you might have.

#3) Dual Format. Can be used for 1.25" and .965" eyepieces.

The adaptor W/ 1.25"OD and .965"ID (125965) This adapter is for those who get the #2 model and need the adapter when they want to use their .965 eyepieces. Or want to use their #2 model .965 inlet w/ 1.25" outlet Barlow in a 1.25" focuser and need the adapter to fit the .965 inlet into their 1.25" scope.

Ad #2

For All Telescopes including ratios F3.8 and above.

These are some of the very best barlows available. ED or APO 4-6oz (See also Elite series in Ad#4)

1.25" Original Performance Quality Barlow Lenses

Barlows are 4-6 oz or less and threaded for filters

But you are guaranteed to be purchasing one of the highest quality barlows both in terms of workmanship and optical quality presently on the market. For more information see the information below the Barlow pictures on the right.*

Barlow can be ordered in Brass. Add $50

If one of the barlows below does not come standard with a self centering holder add $50 Click here for details* 1.25" Feather touch but

The barlows below have a standard holder on them of 1 heavy 6-32 thumbscrew.If you need a heavier 3 screw arrangment at 120 deg each please let me know. See image to the right.

If you want a Male T- 2 Tread on top along with the 1.25" holder just say so and it adds NO extra cost.

1.3x Barlow: $159 (BAR12513P)

1.5x Barlow: $159 (BAR12515P)

1.6x Barlow: $159 (BAR12516P)

1.75x Barlow: $159 (BAR125175P)

2x Barlow: $139 (BAR12520P)

2.5x Barlow: $139 (BAR12525P) holder details*

3.0x Barlow.$149 (BAR12530P)

3.5x Barlow.$149 (BARx35P)

4.0x Barlow.$149 (BARx4P)

4.5x Barlow.$149 (BARx4.5P)

5.0x Barlow.$149 (BARx5.0P)

Adaptor W/ 1.25"OD and .965"ID $15 (125965)

Step-Down Adaptor W/ 2"OD and 1.25"ID $15 (2125)

Are all Barlows the same?

The answer is NO! Click here to find out why.

All Balows in this series can come with a T2 top for attaching a camera. Just ask and I will include the T2 top and the barlow will also have a standard top for 1,25" eyepieces.

The performance Barlows are some of the best and you will not find a Barlow that will noticeably out perform them. That said for the ultimate Barlow See the Elite series and the Telecentric series Ads # 3 and 4

If you have questions about the difference between the series of these Barlows Call 919 553 3980 or email harrysiebert@nc.rr.com

You can upgrade the standard barlows

here to a Self Centering holder for $30

Self Centering model shown.

This design makes good baffling possible.

Many Barlows use relatively inexpensive optics that are configured out to about 50% of the total Dia. This is not too bad if you have a slow scope f7 on up. If you have an f6 or lower the light cone is much larger and penetrates a larger area of the optic. Use this area and serious distortion will start to show up. All Siebert optics lens are corrected out to 90% of edge leaving the place for a retainer to hold the optics. That means that the field will remain undistorted in fast scopes.

Siebert Optics does not expect everyone to know many of these things. That is why we have made sure that when you purchase a Siebert optics product you are getting better quality then you might realize. There has never been a cheap Barlow on this page and never will be!

Ad #3

2" and 1.25" Telecentric Ultra Barlows

For All Telescopes including ratios F2.8 and above. Not tested at lower F~

For your most demanding Photographic and Visual Applications.

All Ultra 2" Telecentric Barlows are 10oz or less.

These have a 4 element design similar to the Powermate. Uses larger lens elements than competing models.

Add a self centering holder below - $50 Click here for details* 2" Feather touch

The Barlows below are all made for visual and imaging but you may need the barlow optimized for specific uses. If the important thing is to support a camera imaging train than CLICK HERE

1.37x2"$349 8.5oz (BAR2-1.37XL) Large CA. all uses

1.37x 2"$349 8.5oz (BAR2-1.37XC) Camera version. Chips up to 35mm this is the best for field flatness and coma suppression at F4 and below.

1.5x 2"$349 8.5oz (BAR2-1.5XL) Large CA. all uses

1.5x 2"$249 8.5oz (BAR2-1.5XC) Camera version. Chips up to 35mm this is the best for field flatness and coma suppression at F4 and below.

1.75x 2"$319 8.5oz (BAR2-1.75T) All uses

2x 2"$299 8.5oz (BAR2-2T) All uses

2.25x 2"$299 9.5oz(BAR2-2.25T) All uses

2.5x 2"$299 9.5oz(BAR2-2.5T) all uses

2.75x 2"$279 9.5oz(BAR2-2.75T) all uses

3x 2" $259 9.5oz(BAR2-3T) all uses

3.5x 2"$259 9.5oz (BAR2-3.5T) all uses

4x 2" $259 10oz(BAR2-4T) all uses

4.5x 2" $259 10oz(BAR2-4.5T) all uses

5x 2" $259 10oz(BAR2-5T) all uses

5.5x 2" $259 10oz(BAR2-5.5T) all uses

6x 2" $259 10oz(BAR2-6T) all uses

Below 2" to T2 adaptor $29

Barlow can be ordered Sheathed in Brass. Add $70

Slide in the top of the barlow to connect camera

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For 1.25" Barlows below Add a self centering holder below- $50 Click here for details* 1.25" Feather touch

3.0x 1.25" $229 5oz(BAR125-30T)

2.5x 1.25" $229 5oz(BAR125-25T)

2.0x 1.25" $229 5oz(BAR125-20T)

1.75x 1.25" $229 5.oz(BAR1.25175T)

1.5x 1.25" $249 5.oz(BAR1.25-1.5T)

1.3x 1.25" $249 5.oz(BAR1.25-1.3T)

Adaptor W/ 1.25"OD and .965"ID $20 (125965)

Modular, Zoom and Regular Telecentric Barlows

All the SiebertOptics Telecentric Barlows Barlow are shown with a Feather touch Self-Centering eyepiece Holder. The come standard with Standard thumb screws.

Click here for the New 2" T-2 modular Barlows.

Click here for New Modular Zoom Telecentric Barlow

The Ultra Series are the TV PowerMates counterparts. Our x4 and up optics are the same size as the TV PM Barlows and will illuminate a F.S. up to 65mm if that were possible in a 2" size.

Other then the super high quality Powermates TV makes, these are one of the only other barlows that offer the added benefit of a 4 element Telecentric image. Also maintains the FOV and ER characteristics of your EP's well. The 2" 2x units have a clear aperture and magnification ratio to illuminate a 48mm field stop fully. Will act as a flattener so no Paracorr should be necessary in faster Newtonians. You will not be disappointed if you try one of these. Elements are multicoated. Guaranteed with a 30 day return policy..

For Feather touch 2" Self centering eyepiece model can be applied for $50

Ad #4

1.25" Elite Barlows featuring Super dielectric coated

For All Telescopes including ratios F2.8 and above. Not tested at lower F~

For your most demanding Visual Applications in the fastest scopes.

Barlow can be ordered Sheathed in Brass. Add $70

Aluminum Barlows are 8 oz or less

For 1.25" Barlows below Add a 1.25" Feather touch self centering holder below- $50 Click here for details*

If you need lower power see Ad #3

1.5x $229 (BAR-1.5-E)

1.6x $229 (BAR-1.6E)

1.75x $229 (BAR-1.75E)

2.0x $229 (BAR-2E)

2.25x $229 (BAR-2.25E)

2.5x $229 (BAR-2.5E)

2.75x $199 (BAR-2.75E)

3.0x $199 (BAR-3E)

3.5x $199 (BAR-3.5E)

4.0x $199 (BAR-4E)

4.5x $199 (BAR-4.5E)

5.0x $199 (BAR-5E)

1.25" Elite series BarlowsAre all Barlows the same?

The answer is NO! Click here to find out why.

All Balows in this series can come with a T2 top for attaching a camera. Just ask and I will include the T2 top and the barlow will also have a standard top for 1,25" eyepieces. Also it can have a screw off bottom element section if you like. Just make the request when ordering.

You will not be disappointed if you try one of these. Elements are Dielectric Coated and Guaranteed with a 30 day return policy. The performance Barlows in Ad #2 are great and you will not find a Barlow that will measurably out perform them. But the Elite series Barlows here are made for applications on the highest end of the spectrum and F-ratios down to F2.8 and lower. These are the best Telenegative/APO Barlows available at any price.

Only my Telecentric series in Ad #3 will perfom at this level and are made with the same high cost optics.

The Ultra Telecentric series are TV PM style and are favored for photographic applications.

The Elite series are favored for visual use where the telescope demands the most from the barlow. The Elite series are also a favorite of planetary imagers.

This series uses longer Focal length optics than most Barlows at the same magnification.
(There are no shorty barlows in this series)

For Feather touch Self centering eyepiece model

Ad #5

1.25" and 2" Modular Barlow Lenses all scopes.

Very high quality modular lens systems.

The barlows below have a standard holder on them of 1 heavy 6-32 thumbscrew.If you need a heavier 3 screw arrangment at 120 deg each please let me know. See images on the right.

1.25" Models below First.

Barlows are 5 oz or less and are Filter thread compatible..

Instructions for all the (MB) click here.

A1a) 1.5x - 2.0x - 2.5x Modular. $249 (BAR152025ma1a)

A1b) 1.5x - 1.7x - 2.0x - 2.3x - 2.5x Modular. $279 (BAR152025ma1b)

B1) 2.0x - 2.5x Modular. $149 (BAR2025m)

B2) 2.0x - 3.0x Modular. $199 (BAR2030m)

C)2.0x - 2.5x - 3.0x Modular. $199 (BAR202530m)

E)2.5x - 3.0x - 3.5x Modular $199 (BAR253035m)

F)1.5x - 2.0 - 2.5x - 3.0x Barlow: $279 (BAR15-30m)

G)2.5x - 3.5x - 4.5x Barlow: $229 (BAR253545m)

L1)0.8x - 1.2x - 1.3x - 1.4x - 1.5x - 1.7x Modular. $279 (BAR125-0.817m)

L2)0.8x - 1.2x - 1.3x - 1.4x - 1.5x - 1.7x - 2.0x - 2.5x Modular. $299 (BAR125-0.825m)

Feather touch Self Centering model add $30 Click here for details

Adaptor W/ 1.25"OD and .965"ID $20 (125965)

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2" Models below.

K1) 2.0x - 3.0x This is the same quality Barlow as the seperate Ultra x2 and x3 Telecentric. The difference is it has exchangeable heads at the bottom with male 2" threads to connect to top holder. $399 (BAR2030Tm)

K2) 2.5x - 3.0x Modular. $299 (BAR2-2530m)

K3) 1.5x - 2.0x Modular. $299 (BAR2-1520m)

L1) Model - 0.8x, 1.2x, 1.3x, 1.4x, 1.5x, 1.7x Modular. $349 (BAR2-0817m)

L2) Model - 0.8x, 1.2x, 1.3x, 1.4x, 1.5x, 1.7x, 2.0x, 2.5x Modular. $399 (BAR2-0825m)

Feather touch Self Centering model add $50 Click here for details < NOT AVALIBLE at thie time.

This is the Siebert Optics Modular Barlow Series.

Why buy many eyepiees when you can use your best eyepiece for everthing. These barlows will make your favorite eyepiece the only one you need. Also they will work with any camera. These balows have many other uses as well.

Instructions for all the (MB) click here.

Click on picture for more details.

Here is a multi power Barlow. Uses the best optics and will work in other configurations such as a corrector lens for binoviewers, Camera focus corrector, can also thread into a standard eyepiece since all components have standard filter threads. Can be used in more then one device at a time. etc...... This product has a 60 day money back guarantee.

This design makes good baffling possible.

Instructions for all the (MB) click here.

All barlows have internal baffles including ultra-flat black internal surfaces to eliminate any internal reflections. Lens elements are edge blackened to increase contrast.

Above is the 2x Barlow using all T-6 Aluminum. It comes with bottom threaded for standard light filters.

2/10/02

2" and 1.25" below.

Ad #6

2" to T2(M42) or 2"(M48) topped Telecentric focus adapters.

1.Need help just--

Call 919-614 4297 or harrysiebert@nc.rr.com.

Very customizable.

Adapters are 7 oz or less and are 2" Bottom Filter thread compatible..

A2)1.37x Adaptor. $329 (110-1.37xCA38mm) 98mm in focuser Large CA for camera diagonals over 35mm

A2)1.37x Adaptor. $299 (110-1.37x) 98mm in focuser

A3)1.5x Adaptor. $299 (110-1.5x) 98mm in focuser

B)2.0x Adaptor. $269 (110-2.0x) 77mm in focuser

C)2.5x Adaptor. $269 (110-2.5x) 67mm in focuser

D)3.0x Adaptor. $269 (110-3.0x) 57mm in focuser

E)3.5x Adaptor. $269 (110-3.5x) 47mm in focuser

F)4.0x Adaptor. $269. (110-4.0x) 46mm in focuser

This is the Siebert Optics Focus adaptor series.

The image is projected out from the top 110mm. For H-A/Cameras/CCD/etc.

You fill in the difference. Extention tubes and hardware available if needed.

Telecentric means it is the best there is for photographic use.

Click on picture for more details.

The lower the power the longer the adapter extend into the focuser. The 2.5x is 65mm tall.

Let me know if you need info on the dimention specs

Ad #7

UV+ 1.25" and 2" Focus adaptors for all differnent needs

1.Need help just--

Call 919-553-3980 or harrysiebert@nc.rr.com.

Very customizable.

1.25" 30mm extention tube $30

Or Request optional 2" Add $30

Base models below are 1.25". The Base models are a simple 1.25" format barlow type holder. The optical cell is removable and male filter threaded on both ends to add to customization.

A)1.5x Adaptor. $249. (UV-1.5UVx)

B)1.75x adaptor. $249 (UV-1.75UVx)

C)2.0x adaptor. $249. (UV-2.0UVx)

D)2.5x adaptor. $249. (UV-2.5UVx)

E)3.0x Adaptor. $249. (UV-3.0UVx)

F)3.5x Adaptor. $249. (UV-3.5UVx)

G)4.0x Adaptor. $249. (UV-4.0UVx)

Prices may vary according to your needs.

These are Custom Barlows and Focus adaptors.

These Barlows cover as much of the UV, and Visable light as possible.

They are also very customizable so they can fit into your imaging train in many different ways.

Click Picture.

https://www.siebertoptics.com/SiebertOptics-astrophotos.html

See the links above for more pictures.

Just explain what you are trying to do and I will work with you to find exactly what you need. There is always a way to get the job done.

Call 919-614-4297 or harrysiebert@nc.rr.com.

Here is an Example below. All pictures are clickable.

Ad #8

2" Base.

Optional 2" with 2" top Shown. Optional T2 male top connection.

2" Base model with 2" top 5x-6x model $279 (VarBar2-256)

2" Base model with 2T top 5x-6x model $279 (VarBar2-T256)

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2" Base model with 2" top 4x-5x model $279 (VarBar2-245)

2" Base model with 2T top 4x-5x model $279 (VarBar2-T245)

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2" Base model with 2" top 3x-4x model $279 (VarBar2-234)

2" Base model with 2T top 3x-4x model $279 (VarBar2-T234)

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2" Base model with 2" top 2x-2.5x model $279 (VarBar2-22.5)

2" Base model with 2T top 2x-2.5x model $279 (VarBar2-T22.5)

Variable magnification and focus adapter

FOR Astrophotography.

What this does.

Sometimes you need Super quality magnifier with a very specific magnification at a specific distance. These Focus adapters can create the exact focus you need and can also adjust the magnification up or down within a certain range. Also the amount of space you need in-between the Barlow and Camera. These Magnifierx have a lot of adjustablity built into them.

ex: You have a ADC/filter wheel/Camera combo=100mm and you need to focus at x4 exactly at the camera. This device will do that for you. You want to adjust the magnification to 4.5x no problem. Or you need to keep 4x and add 10mm to your spacing also no problem.You can make some minor adjustments to the corrector. All these have equipment train spacing from 90mm-110mm.

If you have any questions about your specific setup please let me know.

Ad #9

1.25" or 2" 0.6x FOCAL LENGTH REDUCER FOR ALL eyepieces and Binoviewers.

1.25" Barlow type for all eyepieces/binos $129 (looks similar to shorty type barlow. (FLR125Bar)

1.25" Filter cell type for eyepieces/binos $99 (Works similar to a filter cell.) (FLR125cel)

2" models below

2" Cell type with 40mm optics $179 (Works similar to a filter cell.)(FLR2cel

2" Barlow type with 40mm optics $199 (Works similar to a 2" barlow.)(FLR2barlow)

SCT models below.

2" 0.6x SCT type with 40mm optics for Binoviewers and single eyepieces. $199 (Bolts on SCT back.)(FLR2SCT

Eyepieces and binoviewers FOCAL LENGTH REDUCER

FOR SCT'S/MCT'S and refractors.

When you purchase please specify if this is for single eyepieces or for use with a binoviewer.

Have a wider True field with the same eyepieces.

How it works.

This a focal length reducer for your SCT and eyepieces and binoviewers. People need to be warned about these. They can work very well if you don't overdo the focal length reduction. That is why this unit is limited to a 40% reduction which means that if your scope is operating at between f/10 and f/12 you will get a roughly 40% reduction to between f/6-F/7. This may vary slightly depending on a few things including your binoviewer. This is about the maximum that can reasonably be done for two important reasons. 1. Focusing. This unit will focus in virtually any SCT 8" and up with some focusing to spare, 2. By driving down your focal length below f/6 you may introduce so very serious optical irregularities. Call for more information about this. Do not expect an f/10 system to be reduced to f/5 or under f/5 and perform halfway decent. These focal length reducers will maintain excellent image quality and color correction while reducing your scopes magnification. You can use a set of 24mm SWA without apparent vignetting

The SCT model will work by screwing on to the back of the SCT and then threading on your Visual back on to it. The reduction is most with binoivewers because of the extra spacing. Sngle eyepieces will be less magnification You can switch back between mono and bino. Cameras will work with it as well. These are not for low power 2" eyepieces. 2" eyepieces up to 32mm WA will be fine.