The Celestron T-Adapter-Barlow Lens Universal - 1.25'' can be used three ways; as a 2X Barlow for visual use, as a prime focus T-adapter, or as a “Barlowed” T-adapter to double the magnification.

Features:

1. As a 2X Barlow right out of the box. Insert any 1.25” eyepiece into the adapter to double the magnification, while retaining a comfortable eye relief of your eyepiece.
2. For prime focus photography. Unscrew the bottom section (glass element) to remove the Barlow and slide the chrome barrel into the telescope’s 1.25” focuser. Screw a T-Ring to the T Thread on top of the adapter. Attach to your DSLR or SLR camera.
3. As a barlowed T-adapter simply screw your T-Ring (sold separately) directly to the T-Thread and place into focuser. Good for imaging Planets to enlarge image.

Please note that some telescopes, especially “fast” refractors and Newtonians, may not have enough focus travel to allow the photographic image to come to focus when used in prime focus mode. In these instances, adding the Barlow to the T-Adapter will allow the telescope to reach focus.

In “Tele-Extended” mode, the Barlow doubles the focal length and f/ratio of your telescope, resulting in an image on the sensor or film plane that is twice the size of a prime focus image.

Prime focus and tele-extended photography are popular for short exposure images of terrestrial objects as well as celestial objects like the Moon.

Weight = 68 grams;

Length = 74mm;

Made in China.

Two-year manufacturer limited warranty.

Tele Vue Powermate 5x

Unique Benefits and Applications for Powermates™

• Vignetting, edge field aberrations and pupil movement - all introduced when using Barlows with long focal length eyepieces, are minimized.
  
• Telecentric operation (field rays leave parallel to optical axis, unlike Barlow lenses which diverge rays). This is ideal for Hydrogen-alpha filter use such as with Daystar models.
  
• High performance for image amplification, CCD or film (some of the finest Earth-based planetary imaging is being done with Powermates™ ).
  
• Flexible for visual and imaging with all types of telescopes and eyepieces. Essentially Parfocal, and with nearly constant magnification regardless of image distance behind top surface (except 5x model which increases 1x for every 35mm of image distance increase).
  
• Higher magnifications are possible with high optical performance compared to "doubling up" Barlows.
  
• All will reach parfocal point in star diagonals, except for the 2", 2x which comes very close.
  

In addition to full multi-coating, Powermates™ include other Tele Vue special touches such as safety undercuts where practical on the chrome barrel and captive lock screws that can't fall out, and filter threads. Our 100% QC program at f/4 insures that Powermates™ will add dramatic power (and NOTHING ELSE) to your favorite eyepieces.

If, for example, you own a 24mm Panoptic, you'll have the power of a 12mm focal length eyepiece with the 2.0x Powermate™, 9.6mm with the 2.5x Powermate™, a 6mm with the 4x Powermate™, or a 4.8mm with the 5x Powermate™!

Some of the finest Solar System images have been made with Powermates™. Used singly or stacked, Powermates™ help any scope achieve the long focal-length required to image details on Solar System bodies. The increased image scale allows for imaging without an intervening eyepiece -- like in prime focus photography. Powermate T-Ring Adapters fit on the Powermate lens assemblies to allow attachment of your camera's T-Ring or other T-threaded imaging accessory.

For astro-imagers, the above chart indicates the magnification for each Powermate™ (2x, 2.5x, 4x & 5x) as a function of distance from the Powermate™ top surface to the imaging surface (CCD or film).

These models stand less than 3" out of your focuser and the 5x takes 1¼" threaded filters. They are parfocal in ALL 1¼" diagonals and prisms. For this reason, they are highly recommended over standard Barlows for 1¼" diagonals and refractors such as the Tele Vue-60.

The 5x Powermate™ is ideal for long focus CCD and film photography, magnifying about 7.7x. It's an attractive, high performance alternative to eyepiece projection. The 5x is also perfect for slowing down your scope for Hydrogen-Alpha solar observing.

These Powermates™ are a better choice for 2" diagonals than Barlows, since they are nearly Parfocal. They are threaded for 48mm filters and their performance is excellent with every 1¼" and 2" eyepiece we make (yes, even the 31mm Nagler Type 5!). Both the 2" eyepiece holder and the special 2" flat top adapter use our brass clamp rings for secure operation. And, it also has a very unique feature: you can unscrew the 2" eyepiece housing and screw on a special T-ring adapter for solid, compact attachment of CCD or camera equipment.

Excellent with long eye-relief, 2" eyepieces. Using the 4x model, imagine the quality of a 35mm Panoptic at 8.8mm with 25mm of eye relief! The Powermate™ is NOT a Barlow so the Panoptic-Barlow Interface is not needed! The 2" Powermate™ fits all the way into 2" Star Diagonals, requiring minimal refocus compared to a 2" Barlow.

When using Tele Vue's Paracorr coma corrector, the 2.5x or 5x Powermate™ should be inserted into the Paracorr's 1¼" adapter (i.e., between the Paracorr and the eyepiece). For 2x and 4x 2" Powermates™, first insert the Powermate™ into the focuser, then the Paracorr into the Powermates™.

The Tele Vue Powermate 2x is the perfect choice for both imaging and visual use especially if you want to use larger 2" eyepieces.

Unique Benefits and Applications for Tele Vue Powermate 2x

• Vignetting, edge field aberrations and pupil movement - all introduced when using Barlows with long focal length eyepieces, are minimized.
• Telecentric operation (field rays leave parallel to optical axis, unlike Barlow lenses which diverge rays). This is ideal for Hydrogen-alpha filter use such as with Daystar models.
• High performance for image amplification, CCD or film (some of the finest Earth-based planetary imaging is being done with Powermates ).
• Flexible for visual and imaging with all types of telescopes and eyepieces. Essentially Parfocal, and with nearly constant magnification regardless of image distance behind top surface (except 5x model which increases 1x for every 35mm of image distance increase).
• Higher magnifications are possible with high optical performance compared to "doubling up" Barlows.
• All will reach parfocal point in star diagonals, except for the 2", 2x which comes very close.

The Usual Tele Vue Quality

In addition to full multi-coating, Powermates include other Tele Vue special touches such as safety undercuts where practical on the chrome barrel and captive lock screws that can't fall out, and filter threads. Our 100% QC program at f/4 insures that Powermates will add dramatic power (and NOTHING ELSE) to your favorite eyepieces.

If, for example, you own a 24mm Panoptic, you'll have the power of a 12mm focal length eyepiece with the Tele Vue Powermate 2x, 9.6mm with the 2.5x Powermate, a 6mm with the 4x Powermate, or a 4.8mm with the 5x Powermate!

Some of the finest Solar System images have been made with Powermates. Used singly or stacked, Powermates help any scope achieve the long focal-length required to image details on Solar System bodies. The increased image scale allows for imaging without an intervening eyepiece -- like in prime focus photography. Powermate T-Ring Adapters fit on the Powermate lens assemblies to allow attachment of your camera's T-Ring or other T-threaded imaging accessory.

For astro-imagers, the above chart indicates the magnification for each Powermate (2x, 2.5x, 4x & 5x) as a function of distance from the Powermate top surface to the imaging surface (CCD or film).

1¼" Powermates: 2.5x & 5x

These models stand less than 3" out of your focuser and the 5x takes 1¼" threaded filters. They are parfocal in ALL 1¼" diagonals and prisms. For this reason, they are highly recommended over standard Barlows for 1¼" diagonals and refractors such as the Tele Vue-60.

The 5x Powermate is ideal for long focus CCD and film photography, magnifying about 7.7x. It's an attractive, high performance alternative to eyepiece projection. The 5x is also perfect for slowing down your scope for Hydrogen-Alpha solar observing.

2" Powermates: 2x & 4x

These Powermates are a better choice for 2" diagonals than Barlows, since they are nearly Parfocal. They are threaded for 48mm filters and their performance is excellent with every 1¼" and 2" eyepiece we make (yes, even the 31mm Nagler Type 5!). Both the 2" eyepiece holder and the special 2" flat top adapter use our brass clamp rings for secure operation. And, it also has a very unique feature: you can unscrew the 2" eyepiece housing and screw on a special T-ring adapter for solid, compact attachment of CCD or camera equipment.

Excellent with long eye-relief, 2" eyepieces. Using the 4x model, imagine the quality of a 35mm Panoptic at 8.8mm with 25mm of eye relief! The Powermate is NOT a Barlow so the Panoptic-Barlow Interface is not needed! The Tele Vue Powermate 2x fits all the way into 2" Star Diagonals, requiring minimal refocus compared to a 2" Barlow.

Note for Dobsonian/Newtonian Owners

When using Tele Vue's Paracorr coma corrector, the 2.5x or 5x Powermate should be inserted into the Paracorr's 1¼" adapter (i.e., between the Paracorr and the eyepiece). For 2x and 4x 2" Powermates, first insert the Powermate into the focuser, then the Paracorr into the Powermates.

Al Nagler's 4-element concept, continues the tradition of full-field sharpness with optimum aberration control. Like long eye-relief? Retain the eye-relief of long focal length eyepieces, while at high power. Enjoy, for example, the sharpness and comfort of the 32mm Plössl at up to 5 times the power!

Powermate vs. Barlow

To understand the Powermate, we must first understand the Barlow lens. Barlows amplify the power of a telescope. They are essentially "focal reducers" for eyepieces, or "focal extenders" for objectives. Terence Dickenson, in his Barlow test report in Sky and Telescope, July 1997, says: "Technology has erased the old objections. A modern Barlow will not degrade your telescope's optics. Anyone telling you otherwise is using outdated information. Moreover, the highly regarded Nagler eyepieces and their clones have built-in Barlows, ample evidence that the lens is not some detrimental intruder." Thanks, Terence, for laying the myth of the degrading Barlow to rest.

A high quality Barlow, properly designed and manufactured avoids compromising a telescope's colour and spherical aberration corrections. The "invisibility" of Tele Vue's 2-element Barlows is well recognized in test reports in the astronomy magazines. However, by the nature of its negative power lens, a Barlow will do more than just increase magnification, regardless of the number of elements.

The diverging rays leaving the Barlow result in moving the exit pupil further out, thereby extending the eye relief. In short to medium focal length eyepieces the change is not noticeable. However, in the case of long focal length eyepieces, the increase can be significant and not without performance consequences.

Less Vignetting with Tele Vue Powermate 2x

Vignetting can occur due to the altered ray path, when the eyepiece's lenses are not large enough in diameter to allow all the rays to make it through. Shorter Barlows, or ones with too much magnification, only exacerbate the problem because the ray path entering the eyepiece is steeper.

We had to go beyond the Barlow concept to achieve the goal of a compact, high power, fully corrected image amplifier. The Powermate consists of a negative doublet plus a positive "pupil-correcting" doublet. This 4-element system provides the magnifying function of a Barlow without its limitations by restoring the field rays back to their original direction, as if the Powermate were not there. The result is a pure magnification increase.

Tele Vue Powermate 4x - what's all this talk about Powermates?

Unique Benefits and Applications for Powermates

• Vignetting, edge field aberrations and pupil movement - all introduced when using Barlows with long focal length eyepieces, are minimized.
• Telecentric operation (field rays leave parallel to optical axis, unlike Barlow lenses which diverge rays). This is ideal for Hydrogen-alpha filter use such as with Daystar models.
• High performance for image amplification, CCD or film (some of the finest Earth-based planetary imaging is being done with Powermates ).
• Flexible for visual and imaging with all types of telescopes and eyepieces. Essentially Parfocal, and with nearly constant magnification regardless of image distance behind top surface (except 5x model which increases 1x for every 35mm of image distance increase).
• Higher magnifications are possible with high optical performance compared to "doubling up" Barlows.
• All will reach parfocal point in star diagonals, except for the 2", 2x which comes very close.

In addition to full multi-coating, Powermates include other Tele Vue special touches such as safety undercuts where practical on the chrome barrel and captive lock screws that can't fall out, and filter threads. Tele Vue's 100% QC program at f/4 insures that the Powermate 4x will add dramatic power (and NOTHING ELSE) to your favorite eyepieces.

If, for example, you own a 24mm Panoptic, you'll have the power of a 12mm focal length eyepiece with the 2.0x Powermate, 9.6mm with the 2.5x Powermate, a 6mm with the Powermate 4x, or a 4.8mm with the 5x Powermate!

Imaging the Solar System with Powermate 4x

Some of the finest Solar System images have been made with Powermates. Used singly or stacked, Powermates help any scope achieve the long focal-length required to image details on Solar System bodies. The increased image scale allows for imaging without an intervening eyepiece -- like in prime focus photography. Powermate T-Ring Adapters fit on the Powermate lens assemblies to allow attachment of your camera's T-Ring or other T-threaded imaging accessory.

For astro-imagers, the above chart indicates the magnification for each Powermate (2x, 2.5x, 4x & 5x) as a function of distance from the Powermate top surface to the imaging surface (CCD or film).

Powermate 4x with 2" barrel diameter

The Powermate 4x is a better choice for 2" diagonals than Barlows, since it is nearly Parfocal. Threaded for 48mm filters and its performance is excellent with every 1¼" and 2" eyepiece Tele Vue makes (yes, even the 31mm Nagler Type 5!). Both the 2" eyepiece holder and the special 2" flat top adapter use brass clamp rings for secure operation. And, it also has a very unique feature: you can unscrew the 2" eyepiece housing and screw on a special T-ring adapter for solid, compact attachment of CCD or camera equipment.

Excellent with long eye-relief, 2" eyepieces. Using the 4x model, imagine the quality of a 35mm Panoptic at 8.8mm with 25mm of eye relief! The Powermate is NOT a Barlow so the Panoptic-Barlow Interface is not needed! The 2" Powermate fits all the way into 2" Star Diagonals, requiring minimal refocus compared to a 2" Barlow.

Note for Dobsonian/Newtonian Owners

When using Tele Vue's Paracorr coma corrector andPowermate 4x, first insert the Powermate into the focuser, then the Paracorr into the Powermate.

Al Nagler's 4-element concept, continues the tradition of full-field sharpness with optimum aberration control. Like long eye-relief? Retain the eye-relief of long focal length eyepieces, while at high power. Enjoy, for example, the sharpness and comfort of the 32mm Plössl at up to 5 times the power!

Powermate 4x vs. Barlow

To understand the Powermate, we must first understand the Barlow lens. Barlows amplify the power of a telescope. They can be considered "focal reducers" for eyepieces, or "focal extenders" for objectives. Terence Dickenson, in his Barlow test report in Sky and Telescope, July 1997, says: "Technology has erased the old objections. A modern Barlow will not degrade your telescope's optics. Anyone telling you otherwise is using outdated information. Moreover, the highly regarded Nagler eyepieces and their clones have built-in Barlows, ample evidence that the lens is not some detrimental intruder." Thanks, Terence, for laying the myth of the degrading Barlow to rest.

A high quality Barlow must be properly designed and manufactured in order to avoid compromising a telescope's colour and spherical aberration corrections. The "invisibility" of Tele Vue's 2-element Barlows has been noted in test reports in the astronomy magazines. However, by the nature of its negative power lens, a Barlow will do more than just increase magnification, regardless of the number of elements.

The diverging rays leaving the Barlow result in moving the exit pupil further out, thereby extending the eye relief. In short to medium focal length eyepieces the change is not noticeable. However, in the case of long focal length eyepieces, the increase can be significant and not without performance consequences.

No Vignetting

Vignetting can occur due to the altered ray path, when the eyepiece's lenses are not large enough in diameter to allow all the rays to make it through. Shorter Barlows, or ones with too much magnification, only exacerbate the problem because the ray path entering the eyepiece is steeper.

We had to go beyond the Barlow concept to achieve the goal of a compact, high power, fully corrected image amplifier. The Powermate consists of a negative doublet plus a positive "pupil-correcting" doublet. This 4-element system provides the magnifying function of a Barlow without its limitations by restoring the field rays back to their original direction, as if the Powermate were not there. The result is a pure magnification increase.

• Tele Vue T-Ring Adapter - PTR-1250 replaces the eyepiece holder on the 1.25" 2.5x and 5x Tele Vue Powermate Barlows.
• Threads directly onto the chrome barrel in place of the eyepiece holder.
• Tele Vue T-Ring Adapter - PTR-1250 is suited for photography with short focal length refractors capable of using 1.25" visual accessories.
• Allows for the attachment of a CCD camera.

TeleVue T-Ring Adapter - PTR-2200 replaces the eyepiece holder on the 2" 2x Televue Powermate Barlow.

Top of eyepiece screws off and is replaced by the PTR-2200

Threads directly onto the chrome barrel in place of the eyepiece holder.

TeleVue T-Ring Adapter - PTR-2200 is suited for photography with short focal length refractors capable of using 2" visual accessories.

Allows for the attachment of a CCD camera.

Tele Vue 4x Powermate T-Ring Adapter

TeleVue's 4x Powermate T-Ring adapter allows you to unscrew the standard eyepiece fitting of your powermate. With the T-ring adapter installed you have a secure and much more compact connection between your camera and 4x Powermate. It also guarantees perfect camera sensor alignment, a very important consideration when imaging with such high amplification.

Imaging the Solar System with Powermates™

Some of the finest Solar System images have been made with Powermates™. Used singly or stacked, Powermates™ help any scope achieve the long focal-length required to image details on Solar System bodies. The increased image scale allows for imaging without an intervening eyepiece. Powermate T-Ring Adapters fit on the Powermate lens assemblies to allow attachment of your camera's T-Ring or other T-threaded imaging accessory.

Powermate Magnification Chart for Imagers

The above chart indicates the magnification for each Powermate™ as a function of distance from the Powermate™ top surface to the imaging surface. Using the 4x Powermate T-Ring adapter will produce a magnification factor right on the nominated 4x amplification intended.

https://www.youtube.com/watch?v=5wWKjpDR4J8

When inserted between the eyepiece and telescope, this X-Cel 2X Barlow lens doubles the magnification of all your 1.25” eyepieces. The premium apochromatic optics yield high contrast, sharp images, virtually free of false colour.

The black anodized housing with orange highlights matches the eyepieces in the Celestron X-Cel LX line. A centralised rubber grip helps to keep your hands securely on the barrel, even when your fingers are cold or you are wearing gloves. A brass compression ring just inside the top of the X-Cel Barlow grabs your eyepiece gently but firmly when you turn the thumbscrew. Once the thumbscrew has been secured in place, the brass ring keeps your eyepiece in the Barlow instead of relying on the tip of the thumbscrew itself, offering a better grip and protecting the barrel from scratches.

The barrel of the Celestron X-Cel LX 2x Barlow is threaded to accept 1.25” filters, allowing you to change eyepieces without removing and re-attaching the filter from each eyepiece barrel.

The Celestron 2” Luminos Barlow Lens increases the magnification of your 2” and 1.25” eyepieces by 2.5x. The premium 4-element apochromatic optics are fully multi-coated for optimum light transmission and yield high contrast, true colour images.

The beautiful hard-anodized aluminum housing matches the eyepieces in the Celestron Luminos line. A centralized rubber grip helps to keep your hands securely on the barrel, even when your fingers are cold or you are wearing gloves. A brass compression ring just inside the top of the Luminos 2.5x Barlow grabs your 2” eyepieces gently but firmly when you turn the oversized thumbscrew. Once the thumbscrew has been secured in place, the brass ring keeps your eyepiece in the Barlow instead of relying on the tip of the thumbscrew itself, offering a better grip and protecting the barrel from scratches. A matching 2” to 1.25” adapter is included so that you can increase the magnification of all of your eyepieces, both 1.25” and 2”, in this versatile Barlow lens.

The insert barrel of the Celestron Luminos 2.5x Barlow is threaded to accept 2” filters. This is a nice feature, because you can change eyepieces without removing and reattaching the filter each time.

The Sky-Watcher 2-Inch NOMAD 2 2x Tele-Centric Focal Extender is a high-quality optical accessory with a variety of uses and connecting options for visual and imaging use.

VISUAL USE: Used as a Barlow Lens with an eyepiece for visual use, it effectively multiplies the magnification of any eyepiece by five times, allowing for detailed observations of celestial objects such as the Moon and planetary surfaces. Constructed with premium high-index glass elements and multi coatings, it ensures minimal light loss and maximum clarity. Features a self-centering brass compression ring which avoids marring to eyepieces and a captive eyepiece retaining screw.

IMAGING USES: The premium 4-lens design provides images without colour difference as well as providing excellent field collimation. It is ideal for taking spectacular high resolution photos of planetary surfaces or the surface of the Moon without compromising the quality of the telescope. So in other words it will maintain the apochromatic performance of an ED Apo telescope!! A CCD camera can be mounted directly using the supplied CCD adaptor. A DSLR camera can be mounted with the supplied DSLR adapter (camera M48x0.75 ring required).

The NOMAD 2 will be a very useful addition to the toolkit of many an astronomer !

FEATURES

• 2x Magnification
• 4-Element optical design
• Brass, self-centering compression ring to protect your eyepieces from marring
• Proprietary tuned full multi-coatings & high index glass
• Blackened lens edges & Anti-reflective threads
• Compatible with 2″ & 1.25″ Eyepieces (1.25″ Eyepiece adaptor included)
• CCD Adaptor supplied
• DSLR Camera Adaptor supplied (M48x0.75). M48 ring for DSLR required.
• Captive lock screws that can’t fall out
• 2″ (50.8mm) Barrel, Threaded for 2″ filters
• Safety undercut in nosepiece barrel for extra locking security
• Metal body construction

The Sky-Watcher 2-Inch NOMAD 4 4x Tele-Centric Focal Extender is a high-quality optical accessory with a variety of uses and connecting options for visual and imaging use.

VISUAL USE: Used as a Barlow Lens with an eyepiece for visual use, NOMAD 4 effectively multiplies the magnification of any eyepiece by five times, allowing for detailed observations of celestial objects such as the Moon and planetary surfaces. Constructed with premium high-index glass elements and multi coatings, it ensures minimal light loss and maximum clarity. Features a self-centering brass compression ring which avoids marring to eyepieces and a captive eyepiece retaining screw.

IMAGING USES: The premium 4-lens design provides images without colour difference as well as providing excellent field collimation. NOMAD 4 is ideal for taking spectacular high resolution photos of planetary surfaces or the surface of the Moon without compromising the quality of the telescope. So in other words it will maintain the apochromatic performance of an ED Apo telescope!! A CCD camera can be mounted directly using the supplied CCD adaptor. A DSLR camera can be mounted with the supplied DSLR adapter (camera M48x0.75 ring required).

The NOMAD 4 will be a very useful addition to the toolkit of many an astronomer !

FEATURES

• 4x Magnification
• 4-Element optical design
• Brass, self-centering compression ring to protect your eyepieces from marring
• Proprietary tuned full multi-coatings & high index glass
• Blackened lens edges & Anti-reflective threads
• Compatible with 2″ & 1.25″ Eyepieces (1.25″ Eyepiece adaptor included)
• CCD Adaptor supplied
• DSLR Camera Adaptor supplied (M48x0.75). M48 ring for DSLR required.
• Captive lock screws that can’t fall out
• 2″ (50.8mm) Barrel, Threaded for 2″ filters
• Safety undercut in nosepiece barrel for extra locking security
• Metal body construction

Vixen's Erect Image Adapter is designed to fit a 1.25" focuser. This straight through adapter will re-invert and flip the image so it will appear fully corrected. You will see images with the right side up and read right correct. This Image Adapter is a must have for those terrestrial viewers. Usable on both reflectors and refractors. Coated Optics

Specifications