Focusers, Adapters, Extensions and Covers


2.7" and Traveler Focusers and Feather Touch Upgrade and Dedicated Accessories

4" Giant Focusers, Feather Touch Upgrade and Dedicated Accessories

Electronic Focusing Control for Astro-Physics Focusers

Adapters, Extensions and Covers for all Focusers and Related Parts
Custom Adapters
We are continually expanding our selection of adapters. However, there will always be the need for specialized adapters to meet custom requirements. We recommend the company, PreciseParts, for those occasions.

2.7" and Traveler Focusers and Feather Touch Upgrade


Feather Touch Micro Upgrade for Astro-Physics 2.7" and Traveler Focusers (27FTMU)


Achieve very fine critical focus by upgrading your 2.7" or Traveler Focuser with the Feather Touch Micro Upgrade. This dual-speed pinion assembly features a 9:1 speed reduction knob designed and produced for Astro-Physics by Starlight Instruments. The coarse-focus knobs allow you to rack the drawtube out quickly, and the fine knob is used to find and hold the final focus point. Ideal for very high powers with short focus oculars and Barlow amplifiers. It will also allow quick, precise manual focusing with CCD cameras. You'll love the smoooooooth feel and the very cool reflection of the gold anodized knob on the polished aluminum knob.

We highly recommend the dual-speed focuser for both visual and imaging use.  When manually focusing your CCD or DSLR camera, you will see improved accuracy and ease.  Adding the Starlight Instruments’ "Focuser Boss Digital Kit" allows automated focusing using FocusMax or any of the many automated focusing software. 


This upgrade is available for most focusers and refractors shipped since July 2001. This includes scopes purchased from RC Optical, Optical Guidance Systems, Parallax Instruments, D&G Optical and Telescope Engineering Company that have Astro-Physics focusers. In order to determine whether your focuser can be upgraded, please compare the hole pattern on the bottom of the pinion block of your focuser to these focuser block photos. Focusers that can be upgraded must have the current hole pattern (pinion block A1034-A).

If your Traveler was shipped between March - September 2001 and your pinion block looks like this (part # A1034), please give us a call for special instructions.

All other scopes shipped prior to July 2001 cannot be retrofit with this Feather Touch Micro assembly due to the configuration of the pinion block. These early pinion blocks are shown as part # A1004 and look like the photos seen in this link. However, in most cases, complete new focusers can be easily installed onto your Astro-Physics refractor. Please refer to the information regarding the new 2.7" Focuser (27FOC3E-FT) and new Traveler Focuser (TFOC3E-FT), both featuring greaseless drawtubes and the

Instructions: Installing Feather Touch Focuser Upgrade - 2.7" Traveler and 4" Focusers

27FTMU$415.00 in stockAdd 27FTMU To My Cart

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Astro-Physics 2.7" Focuser (27FOC3E)

Our superb Astro-Physics focuser is a very finely crafted unit with several unique features. If you currently own an Astro-Physics refractor with a 2.7" focuser, you may wish to upgrade to this new greaseless version. This focuser is also a first-class choice for the do-it-yourselfer who takes pride in constructing his/her own tube assembly (we no longer offer a separate unengraved focuser for ATMs; you are welcome to use the engraved version). The components are machined to extremely high tolerances, assuring that there is no wiggle between the drawtube and housing. More than a dozen knife-edge baffles are machined into the wall of the drawtube and painted flat black in order to maximize contrast by essentially eliminating any internal reflections. The inside diameter (I.D.) of the drawtube is 2.7" which allows the avid astrophotographer to use a medium-format camera to capture images in a 2.25" x 2.25" format with minimal vignetting. The helical rack and pinion provides smooth motion, free of backlash or wobble, for precision focusing. Our machined aluminum knobs were designed with comfortable, firm handling in mind. The adapter thumbscrews are substantial and easy to grasp.

Brass locking rings are an important feature of our focuser. We realize that many of our customers use a variety of heavy and expensive accessories including 2 lb. eyepieces, 35mm and medium-format cameras, binocular viewers, etc. So, we designed our focuser with recessed brass locking rings at each thumbscrew location. As you tighten the thumbscrews), the brass locking ring clamps onto the part that has been inserted. Consequently, your focuser drawtube, and 2" and 1.25" accessories are held securely in place. As an added advantage, the brass will not mar the surface of your accessories.

Features:

  • Greaseless drawtube.
  • All components are machined of high quality aluminum. Housing is black-anodized .
  • Brass locking rings to secure focuser drawtube, 2" and 1.25" accessories
  • 2" adapter is aluminum, black-anodized, screws into focuser drawtube, brass locking ring and 3 thumbscrews. The extra two thumbscrews provide an extra measure of security for your heaviest and most valuable accessories. If you prefer a single thumbscrew, simply remove the extra ones and store them for later use. Also sold separately as ADA2003. Note: the photo above shows the adapter with a single thumbscrew.
  • 1.25" adapter is aluminum, black-anodized, slips into 2" adapter or 2" diagonal, brass locking ring, thumbscrew, threaded for 48 mm filters. Also sold separately as ADA125.
  • Inside diameter of focuser draw tube is 2.7". The thread pitch is 24 threads per inch.
  • Focus travel with the 2" adapter is 4.4"
  • Focus travel with telecompressor is 5.0"
  • Overall length of the focuser when fully racked in with 2" adapter is 5"
  • Overall length of the focuser when fully racked in with 1.25" adapter is 5.3"
  • Weight of the focuser with the 2" and 1.25" adapters is 5.25 lb. (2.4 kg)

If you prefer the Feather Touch Micro 9:1 dual-speed option, you may wish to consider the 27FOC3E-FT model.

If you have a very early scope with an Astro-Physics cast aluminum focuser (painted black), Jaeger's 2" focuser with red knobs or a 2" Japanese style focuser, please read this link.

Instructions for installation: To substitute focusers, simply loosen the set screw on the underside of the original focuser and thread the focuser from the tube. Do not use the knobs for leverage, or you may bend the pinion gear. Attach the new focuser, position with respect to the finder bracket holes, tighten the set screw and you are ready to go.

You may prefer a sturdier cover than the included plastic plug.  Astro-Physics also offers an optional aluminum cover that will accommodate this part, depending on your storage needs.  Please review the information regarding the Threaded Cover for AP 2.7” Drawtubes and Accessories with 2.7” Female Threads (A1005).  More information can be found on our Accessory Reference Chart for 2.7" Threaded Covers.

27FOC3E$450.00 in stockAdd 27FOC3E To My Cart

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Astro-Physics 2.7" Focuser with Feather Touch Micro (27FOC3E-FT)

The silky smoothness of the 2.7" Astro-Physics focuser and the dual-speed mechanism of the Feather Touch Micro are both realized in this superb focuser. The dual-speed feature is particularly advantageous for critical focusing of scopes with fast focal ratios. Refer to the description and feature list above for dimensions and specifications that are in common with the standard focuser.

 

These are the additional enhancements available for this Feather Touch model:

  • FeatherTouch Micro assembly with 9:1 dual-speed focusing knobs to allow fine adjustments for critical focusing.
  • Focusing scale with mm graduations that will enable you to return to a particular position easily. (Photo at right)

 

 

Who should use this focuser?

  • Upgrade scopes that already have prior version of 2.7" focuser. This focuser is offered to owners of Astro-Physics refractors shipped prior to July 1, 2001 as a replacement for their original focuser. If your scope was shipped later than July 1, 2001, please consider the Feather Touch Micro Upgrade (27FTMU) rather than replacing the entire focuser. Not sure? Please review this focuser block information.

    If you have a very early scope with an Astro-Physics cast aluminum focuser (painted black), Jaeger's 2" focuser with red knobs or a 2" Japanese style focuser, please read this link.

  • Amateur Telescope Makers. This focuser is a great choice for do-it-yourselfers who are constructing their prize scope (we no longer offer a separate unengraved focuser for ATMs; you are welcome to use the engraved version).


Instructions for installation: To substitute focusers, simply loosen the set screw on the underside of the original focuser and thread the focuser from the tube. Do not use the knobs for leverage, or you may bend the pinion gear. Attach the new focuser, position with respect to the finder bracket holes, tighten the set screw and you are ready to go.

You may prefer a sturdier cover than the included plastic plug.  Astro-Physics also offers an optional aluminum cover that will accommodate this part, depending on your storage needs.  Please review the information regarding the Threaded Cover for AP 2.7” Drawtubes and Accessories with 2.7” Female Threads (A1005).  More information can be found on our Accessory Reference Chart for 2.7" Threaded Covers.

27FOC3E-FT$670.00 in stockAdd 27FOC3E-FT To My Cart

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Astro-Physics Traveler Focuser with Feather Touch Micro (TFOC3E-FT)

The Traveler focuser is virtually identical to the 2.7" Focuser described above, except that the focuser body (that houses the drawtube) has an internal thread that attaches to the tube. All other construction features and specifications are the same. The new TFOC3E-FT focuser offers critical focusing and a greaseless drawtube with a mm focusing scale. All of these are attributes that Traveler owners will find appealing.

To replace the focuser, simply thread the original one off (counter clockwise) and the new one on. It's that easy! Be sure that you don't use the focuser knobs for leverage, or you may bend the pinion gear. We suggest that your Traveler be attached to your mounting or have someone else hold the tube as you remove the focuser.

You may prefer a sturdier cover than the included plastic plug.  Astro-Physics also offers an optional aluminum cover that will accommodate this part, depending on your storage needs.  Please review the information regarding the Threaded Cover for AP 2.7” Drawtubes and Accessories with 2.7” Female Threads (A1005).  More information can be found on our Accessory Reference Chart for 2.7" Threaded Covers.

Please notice the drawtube position scale that has been incorporated into all our focusers to help with set up and focusing precision.


If your scope was shipped after July 1, 2001, please consider the Feather Touch Micro Upgrade (27FTMU). If you are not sure, please review this focuser block information.

We are unable to offer this focuser to ATMs since it is specifically engraved "Traveler".

TFOC3E-FT$670.00 in stockAdd TFOC3E-FT To My Cart

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Adapter to use Astro-Physics 2.7" Focuser - 2.7" overall length (A1025-B)

This adapter was designed for owners of our 155EDFS StarFire refractor who are looking more focuser in-travel. It has an overall length of 2.7”. Most of the 155EDFS were originally shipped with a longer adapter.

Additionally, this adapter can used to replace a 4” focuser in a 155EDF or similar Astro-Physics EDF refractor, for those who wish to step down to an A-P 2.7” focuser with an external thread. The collar end bolts into the tube via the six 8-32 tapped holes. Our 2.7” standard and FeatherTouch focusers simply thread into the internal female threads on the eyepiece end of the adapter. Please note this adapter cannot be used for the 130EDF Gran Turismo or 105mm Traveler focusers.

For the amateur telescope builder, this adapter also facilitates adding an Astro-Physics 2.7” focuser to a homemade instrument. Outer diameter of the attachment ring is 5.395”.

A1025-B$95.00 in stockAdd A1025-B To My Cart

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4" Giant Focusers, Feather Touch Upgrade and Dedicated Accessories

Feather Touch Micro Upgrade for Astro-Physics 4" Focusers (4FTMU)

Watch your images snap into focus with this Feather Touch Micro Upgrade. Astro-Physics teamed up with Starlight Instruments to produce this dual-speed assembly, which features a 9:1 reduction knob. The coarse-focus knobs allow you to rack the drawtube out quickly, and the fine knob is used to find and hold the final focus point. Ideal for very high powers with short focus oculars and Barlow amplifiers. It will also allow quick, precise manual focusing with CCD cameras. You'll love the smoooooooth feel. It can be mounted so that the fine focus knob is either on the right or the left side for your convenience.

We highly recommend the dual-speed focuser for both visual and imaging use.  When manually focusing your CCD or DSLR camera, you will see improved accuracy and ease.  Adding the Starlight Instruments’ "Focuser Boss Digital Kit" allows automated focusing using FocusMax or any of the many automated focusing software. 

This upgrade is available for 4 Focusers and refractors shipped since October 2001. In order to determine whether your focuser can be upgraded, please compare the hole pattern on the bottom of the pinion block of your focuser to these focuser block photos. Focusers that can be upgraded must have pinion block A1022-A. If you prefer a total upgrade to the new greaseless version, please refer to the options below.

All other scopes shipped prior to October 2001 cannot be retrofit with this Feather Touch Micro assembly due to the configuration of the pinion block. These early pinion blocks are shown as part # A1022 at this focuser block link. If your scope was produced prior to October 2001 and already has a 4" focuser, you can easily substitute the new version that features the greaseless drawtube and Feather Touch Micro Dual-Speed Knobs. Please refer to this upgrade information regarding the new 4" Focuser (part# S4FOC3E-FT) .

Instructions: Installing Feather Touch Focuser Upgrade - 2.7" Traveler and 4" Focusers

4FTMU$540.00 in stockAdd 4FTMU To My Cart

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Astro-Physics 4" Giant Focuser with Feather Touch Micro (4FOC3E-FT)

The silky smoothness of the robust 4 Giant Focuser and the dual-speed mechanism of the Feather Touch Micro are both realized in this superb focuser. The dual-speed feature is particularly advantageous for critical focusing of scopes with fast focal ratios. This focuser also features our new greaseless drawtube. Refer to the description and feature list above for dimensions and specifications that are in common with the standard focuser. The only difference between the standard focuser and Feather Touch models is the pinion/block/knob assembly.

If you are upgrading an existing 4 focuser and do not wish to purchase the adapters (you already own them), select S4FOC3E-FT. In this case, you may wish to purchase ADA2003 as a separate item, if you prefer the security of the new design with three thumbscrews.

Please notice the drawtube position scale that has been incorporated into all our focusers to help with set up and focusing precision. (2.7" focuser shown)

Who should choose this focuser?

  • Upgrade scopes that already have prior version of 4 Focuser. These scopes include the Astro-Physics 155 f7 StarFire EDF, 180 f7 StarFire EDF and 206 f8 StarFire EDF. It may also include instruments that were manufactured by other telescope makers using our 4 Focuser or instruments crafted by amateur telescope makers (assuming that the original 4 focuser was not modified in any way). To upgrade, simply remove the six screws that hold the original one in place. Slip the focuser out and insert the new one. Replace the screws and you are ready to go. It couldn't be easier.


  • Upgrade Astro-Physics 155 f7 StarFire EDF refractors originally sold with the 2.7 focuser. Choose this option if you plan to purchase the 4 Field Flattener for the 155 (S155EDFFF) or if you like the feel of an excellent large focuser. To upgrade, remove the six screws that hold the 2.7 focuser and the adapter piece ahead of it. You will notice that the new 4 Focuser is the same length as these two components together. Bolt the new 4 Focuser into place and you are ready to go. There are no collimation issues to consider.


  • Amateur telescope makers. This focuser is also a first-class choice for the do-it-yourselfer who takes pride in constructing his/her own tube assembly (we no longer offer a separate unengraved focuser for ATMs; you are welcome to use the engraved version). If you are showcasing a fine large lens, this focuser is particularly suitable given its proportions and weight. You will need to offset the weight of the lens with comparable weight in the rear of the tube assembly in order to achieve a balance point near the center of the tube.


If your Astro-Physics refractor with the 4 Focuser was shipped later than October 1, 2001, you may wish to consider the Feather Touch Micro Upgrade (4FTMU) rather than replacing the entire focuser. Not sure? Please review this information.

4FOC3E-FT$995.00 in stockAdd 4FOC3E-FT To My Cart

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Astro-Physics 4" Giant Focuser with Feather Touch Micro, without the Adapters (S4FOC3E-FT)

What if you already own one of our 4" focusers, but want the new greaseless drawtube and Feather Touch Micro features? This option is for you. We offer S4FOC3E-FT, which is the new assembly without the adapters (2.7", 2" and 1.25") or focuser extension. After all, you already own these parts from your previous focuser. Please refer to the description of 4FOC3E-FT for a description of this focuser and ignore the information regarding the adapters. Keep in mind that all of the adapters can be purchased as a separate item, if you need a replacement. You may want to consider the newer version of the 2" adapter that has 3 locking screws (ADA2003).

Please notice the drawtube position scale that has been incorporated into all our focusers to help with set up and focusing precision. (2.7" focuser shown)

Who should choose this focuser?

  • Upgrade scopes that already have prior version of 4 Focuser. These scopes include the Astro-Physics 155 f7 StarFire EDF, 180 f7 StarFire EDF and 206 f8 StarFire EDF. It may also include instruments that were manufactured by other telescope makers using our 4 Focuser or instruments crafted by amateur telescope makers (assuming that the original 4 focuser was not modified in any way).

    To upgrade, simply remove the six screws that hold the original one in place. Slip the focuser out and insert the new one. Replace the screws and you are ready to go using the adapters that you already have. It couldn't be easier.

S4FOC3E-FT$869.00 in stockAdd S4FOC3E-FT To My Cart

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Focuser Boss II Electronic Focusing Control Kit (FB2HSM30KIT)

We are pleased to be able to offer the Starlight Instruments Focuser Boss II Electronic Focusing Control Kit for digital focusing of our telescopes.  This wonderful system allows computer controlled focusing to be added to our 2.7” (27FOC3E-FT and TFOC3E-FT ) and 4” (4FOC3E-FT)  focusers that are fitted with the Feather Touch Micro.  It is also compatible with the Riccardi-Honders 3.5” Focuser.  This superbly CNC-machined, all aluminum kit is a worthy addition to your Astro-Physics scope.

The kit consists of a Control Hub, a Hand Controller, a high-torque HSM Motor and the required cables.  Your choice of AC transformer or 12 volt DC power connector is also included.

The ergonomic Hand Controller is convenient, whether you’re at the eyepiece, or choose to manually focus your imaging.  Intuitive software works invisibly with your autofocus programs, such as FocusMax™, when you want to sit back and let the computer do the work.

The HSM (Handy Stepper Motor) motor takes motorized focusing to a new level.  Its radical design allows you to switch from motorized to hand focusing by a simple twist of the motor housing.

The high-torque motor provides all the power needed to lift the heaviest camera / filter wheel combos.   Each unit incorporates a built-in temperature sensor. 

Included with kit:

  • Control Hub
  • Hand Controller
  • HSM Motor (choose one)
    • AP 2.7” focuser (FB2HSM30KIT)
    • AP 3.5” or 4” focuser (FB2HSM35KIT)
    • HSM custom for Takahashi and other scopes (FB2HSMCKIT)
      Note: must confirm compatibility with your scope.
  • Power Choice (not shown): AC transformer or 12 volt DC lighter plug
  • Cables (not shown): 10’ cat 5 cable and USB to Serial / RJ11 adapter

Optional upgrades and extras:

  • Additional HSM Motor
    • Select an additional motor for your other telescopes.
      • FB2HSM20 for 2" Starlight focuser
      • FB2HSM30 for AP 2.7” focuser
      • FB2HSM35 for AP 3.5” or 4” focuser
      • FB2HSMC  for Takahashi and other scopes  Note: must confirm compatibility with your scope.
  • Wi-Fi board with Antenna (FBWIFI)
    • The Wi-Fi upgrade is a wireless option that allows you to use your Smart Phone or IPAD (examples) to control the focuser without a need for the hand controller.  Note: must be ordered at time of Kit purchase to allow installation.
  • Control board for 2nd focuser (FBCB2F)
    • This upgrade allows you to control 2 focusers simultaneously.  Note: must be ordered at time of Kit purchase to allow installation.



Links to software:
http://optecinc.com/astronomy/software/download/Setup_FocusLynx_Starlight(1.2.5).zip
and USB to serial driver downloads:
http://starlightinstruments.com/downloads/USB_to_Serial_Converter_Driver.exe

FB2HSM30KIT$680.00 in stockAdd FB2HSM30KIT To My Cart
FB2HSM35KIT$680.00 in stockAdd FB2HSM35KIT To My Cart
FB2HSMCKIT$730.00 in stockAdd FB2HSMCKIT To My Cart
FB2HSM20 $339.00 in stockAdd FB2HSM20  To My Cart
FB2HSM30$339.00 in stockAdd FB2HSM30 To My Cart
FB2HSM35 $339.00 in stockAdd FB2HSM35  To My Cart
FB2HSMC $389.00 in stockAdd FB2HSMC  To My Cart
FBWIFI$145.00 in stockAdd FBWIFI To My Cart
FBCB2F$40.00 in stockAdd FBCB2F To My Cart

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2.7" Adapter for 4" Focuser (A1024)

This adapter is provided with the complete Giant 4"; Focusers described above - 4FOC3E-FT and 4FOC3E. The tapered end slips into the 4.3"; drawtube and the brass locking ring of the drawtube holds it securely in place. When you loosen the thumbscrews of the drawtube slightly, this part can rotate allowing you to position your film, CCD or video camera to frame your objects.

The threads of the opposite side are the same as our 2.7"; drawtube (24 threads per inch), which allows you to use our 0.75x Telecompressor (27TVPH) alone for film or with our various threaded extensions (A3503, A3504-A, A3502-A) for CCD imaging. The 2.7" to 6x7 Outer Bayonet Adapter (ADA2767) can be attached here, and the 2" Adapter (ADA2003) threads in here, as well.

The length that extends from the 4.3"; drawtube connection is 1"; the overall length of this part is 1.6";. It is machined from aluminum and black-anodized. If you have this adapter, but find you need just a little more in-focus travel, consider either the shorter version of this part (A1024-A) or our Thin 2" Adapter (ADA20132).

This adapter has a net spacing distance of 1.0" (25.4 mm).

A1024$45.00 in stockAdd A1024 To My Cart

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Short 2.7" Adapter for 4" Focuser (A1024-A)

If you need just a little more in-travel to reach focus, consider this shorter version of A1024, described above. It is constructed in the same manner with the tapered portion on one end and threads to accept 2.7" accessories on the other, however it is shorter. The length that extends from the 4.3" drawtube is 3/8" long, so you will gain 5/8" more in-travel with this adapter compared with the one above.

This adapter has a net spacing distance of 0.35" (8.9 mm).

A1024-A$45.00 in stockAdd A1024-A To My Cart

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Extension with Brass Locking Ring for 4" Focuser (4FOCEXT)

This accessory provides 2.2" of extension with an overall length of 3". It is typically used in lieu of a diagonal when straight-through viewing is desired. The extension features our brass locking ring and two large thumbscrews. Slip it into the drawtube of the Giant 4" Focuser, then insert one of our 4" to 2.7" adapters or any other accessory that you produce. The ID of the extension is 4.3", the same as our 4" focuser drawtube. Note the tapered barrel of the focuser end. This tapered profile assures a secure connection as the brass ring of the drawtube grabs the taper at the narrow diameter.

This extension is provided when the 4" Focuser is shipped on our refractors, however we offer it as a separate item when the 4" focuser is purchased separately.

This part was previously sold as S40FOCUET. We simplified the part number, but the design itself is unchanged.

This extension has a net spacing distance of 2.2" (55.9 mm).

4FOCEXT$95.00 in stockAdd 4FOCEXT To My Cart

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Adapters and Extensions for all Focusers and Related Parts

1.25" Adapter (ADA125)

The 1.25" adapter is included with our focusers (and refractors); however, we also offer it as an accessory to use with any telescope. It slips into a 2" opening and is used for 1.25" accessories. It features a brass locking ring and is threaded for 48 mm filters. Please note that if you use long-barreled eyepieces, such as TeleVue Radians, you may strike the filter. In this case, we suggest that you add our 2" Barrel Extension w/ 48 mm Threads (A3703) to the bottom of the adapter before installing the filter. Alternatively, install the 48 mm filter on our 2" MaxBright Diagonal (PMDMAX).

ADA125$40.00 in stockAdd ADA125 To My Cart

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2" Adapter With 3 Large Thumbscrews (ADA2003)

Use this adapter for critical applications and heavy loads, i.e. to center your CCD camera securely for an imaging run. Threads into our 2.7" and 4" focusers. If you prefer to use just one thumbscrew on occasion (perhaps if you are interchanging accessories frequently), simply remove the extra 2 thumbscrews for that session.

This adapter is also perfect with our ADASCTLM27 Adapter for large Meade SCT's and our ADASCTLC27 Adapter for large Celestron SCT's.

The 2" adapter version ADA200 with a single thumbscrew is no longer available.

This adapter has a net spacing distance of 0.77" (19.6 mm).

ADA2003$50.00 in stockAdd ADA2003 To My Cart

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2" Thin Adapter with 3 Thumbscrews (ADA20132)

Use this adapter for critical applications and heavy loads where more in-travel is required. This adapter is 11/32" thinner than our regular 2" Adapter. It threads into our 2.7"and 4" focusers. If you prefer to use just one thumbscrew on occasion (perhaps if you are interchanging accessories frequently), simply remove the extra 2 thumbscrews for that session. The overall length of this adapter is 0.880", but the amount of backfocus it takes up is 0.430".

This adapter has a net spacing distance of 0.43" (10.9 mm).


ADA20132$50.00 in stockAdd ADA20132 To My Cart

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2.7" Thread-On Extensions for Astro-Physics Focusers and
Accessories
(A3502-A, A3503-A, A3504-A, A3505, A3506, A1008-A)

This series of extensions is designed to utilize the robust 2.7” Astro-Physics thread size, while providing a variety of lengths for use with barlows, telecompressors and camera systems. These extensions can be used in various combinations to achieve the perfect spacing distance for your system.

These extensions thread directly into the drawtube of the 2.7" focuser and into the 4" to 2.7" Adapter (A1024), or its shorter version (A1024-A), which fit the 4" focuser. They feature knife-edge baffles and an interior that is painted flat black to eliminate internal reflections.  Accessories with 2” nosepieces can easily be attached by using the ADA2003, ADA20132, ADA200 (discontinued), or ADA2013 (discontinued) 2” Adapters with Thumbscrews.

The re-design of these extensions include a lip on the outer diameter to prevent the extension from being racked inside the focuser housing.


This extension has a net spacing distance of 0.60” (15.2 mm).


A3503-A
2.7" Thread-on Extension

This extension has a net spacing distance of 0.75” (19.1 mm).

A3503-A$42.00 in stockAdd A3503-A To My Cart


A3506
2.7" Thread-on Extension

This extension has a net spacing distance of 0.90” (22.9 mm).

A3506$42.00 in stockAdd A3506 To My Cart


A3504-A
2.7" Thread-on Extension

This extension has a net spacing distance of 1.25” (31.8 mm).

A3504-A$46.00 in stockAdd A3504-A To My Cart


A3502-A
2.7" Thread-on Extension

This extension has a net spacing distance of 1.75” (44.5 mm).

A3502-A$46.00 in stockAdd A3502-A To My Cart


A1008-A
2.7" Thread-on Extension

This extension is provided with Astro-Physics refractors that have the 2.7” focuser. It is for use when observing straight-through without a diagonal or when imaging without a prime focus field flattener. [Note that this extension may be too long except for special applications.]

This extension has a net spacing distance of 2.55” (64.8 mm).

A1008-A$50.00 in stockAdd A1008-A To My Cart

You may prefer a sturdier cover than the included plastic plug.  Astro-Physics also offers an optional aluminum cover that will accommodate this part, depending on your storage needs.  Please review the information regarding the Threaded Cover for AP 2.7” Drawtubes and Accessories with 2.7” Female Threads (A1005).  This part can also accommodate the Threaded Cover for AP 2.7" Field Flatteners and Accessories with 2.7" Male Threads (A1225). More information can be found on our Accessory Reference Chart for 2.7" Threaded Covers.


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2" Extension - Length 1.75" (ADA202)


This extension slips into a 2" opening and can be used with 2" accessories or the 1.25" adapter. It features our brass locking ring to hold your accessories firmly. The overall length is 3" and it is threaded for 48 mm filters. This extension is included as part of our Convertible Barlow.

This extension has a net spacing distance of 1.75" (44.5 mm).

ADA202$50.00 in stockAdd ADA202 To My Cart

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2" Extension Length 3.6" (EXTTLR)

Use this extension when you require additional length. It slips into a 2" opening and can be used with 2" accessories or the 1.25" adapter. It features our brass locking ring The overall length is 4.8" and it is threaded for 48 mm filters.

This extension has a net spacing distance of 3.6" (91.4 mm).

EXTTLR$70.00 in stockAdd EXTTLR To My Cart

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2" Adapter for 2.7" Focuser to use SCT Accessories (ADA204)

If you have thread-on accessories for an SCT and own one of our refractors, a Ritchey-Chretien with an Astro-Physics focuser or built your scope with our 2.7" focuser, you will appreciate this item. This adapter threads into our drawtube and has SCT threads on the accessory side.

For owners of larger Meade SCT's with the 3.25" rear cell, simply thread this adapter into our ADASCTLM27 or ADASCTLC27 and you no longer need your Meade or Celestron 2" visual back.

The ADA204 is also popular with owners of Finger Lakes Instrumentation CCD cameras. It can be used with several configurations of Astro-Physics CCD Adapters and 2.7" Extensions to reach proper backfocus distances for the particular combination of components you are using.

This adapter has a net spacing distance of 0.3" (7.6 mm).

ADA204$40.00 in stockAdd ADA204 To My Cart

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2" Adapter for 9.25" SCTs and under, with Brass Locking Ring (ADASCT)

This visual back fits rear cells that have a 2" opening with a 24 TPI (threads per inch) male thread. It can be used with the 8", 9.25" (except the 9.25” Celestron EdgeHD) or other SCT with the standard SCT rear cell. It can also be used with the Maksutov-Cassegrain scopes from Telescope Engineering Company (TEC) that have this specification.

This visual back allows you to use 2" accessories that slip in, i.e. 2" diagonals, Barlows, 2" eyepieces or CCD camera. Starting in late August 2009, we added a third thumbscrew to the two existing thumbscrews and brass locking ring to securely hold your expensive accessories with ease. Also fits DayStar T-Scanner cover that has male T-thread.

This adapter has a net spacing distance of 2.1" (53.3 mm).

ADASCT$40.00 in stockAdd ADASCT To My Cart

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2" Adapter with Brass Locking Ring and 3 Large Thumbscrews - for larger SCTs with 3.25" Rear Cell, (ADASCTLC and ADASCTLM)

This 2" visual back threads onto the rear cell of 10" to 14" SCTs with 3.25" male threads on the telescope's rear cell. It provides a full 2" unobstructed opening (unlike most visual backs). Use with 2" accessories that slip in, i.e. 2" diagonal, Barlow, 2" eyepiece or binocular viewer. It features our unique brass locking ring design and 3 large thumbscrews to hold your accessories securely and squarely; ideal for critical applications. If you prefer to use just one thumbscrew on occasion (perhaps if you are interchanging accessories frequently), simply remove the extra 2 thumbscrews for that session.

We offer two models with slightly different thread specifications. Please verify that your instrument has a 3.25" male thread on the rear cell before ordering. This adapter does NOT fit the 16" or 20" Meade telescopes with 4" rear cells.

Note: Celestron Edge HD scopes have a restricted rear cell that may not allow accessories with a long nosepiece to fully seat in this adapter (the AP Maxbright diagonal will not seat). It is recommended to choose the ADASCTLC27 and ADA2003 (or ADA20132) as an alternative when using the Edge HD scopes.

ADASCTLC - for 11 and 14" Celestron SCTs
ADASCTLM - for 10", 12" & 14" Meade SCTs. Adapter cannot be used when the Microfocuser is attached to the LX200GPS.

This adapter has a net spacing distance of 1.5" (38.1 mm).
It has a safe nosepiece insertion depth of 1.1" (27.9 mm).

ADASCTLC$60.00 in stockAdd ADASCTLC To My Cart
ADASCTLM$60.00 in stockAdd ADASCTLM To My Cart

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2.7” Adapter Threads onto larger Meade SCT’s with 3.25” Rear Cell – Allows the Use of AP 2.7” Accessories (ADASCTLM27)

This 2.7” threaded back allows the use of Astro-Physics 2.7” accessories with 10”, 12" & 14" Meade SCT’s. The accessory back was designed primarily to accept the popular 0.75x, 2.7” Photo-Visual Telecompressor (27TVPH), but it will also work well with other accessories. Combine it with our 2” adapter (ADA2003) or our thin 2” adapter (ADA20132) and you have an unobstructed 2” visual back. Screw in our ADA204 2.7" to 2" SCT Adapter and you are right back to the standard Meade 2" visual back. Attach our 2.7" to 6x7 Outer Bayonet Adapter (ADA2767) along with either of the STL Adapters for the 6x7 Outer Bayonet (ADA671 & ADA672), and you have the maximum available light path to your STL Series camera, and easy image framing to boot! Virtually any accessory from 2.7” diameter on down in size can be used with this adapter, greatly increasing the versatility of your large Meade SCT.

 

Please verify that your instrument has a 3.25" male thread on the rear cell before ordering. This adapter does NOT fit the 16" or 20" Meade telescopes with 4" rear cells. The adapter is one-piece, machined aluminum and is anodized black. Note: Meade uses a 3.25" x 16 thread.

See SCT System Chart for examples of usage.

This adapter has a length of 2.5" (63.5 mm). To derive the net spacing distance when using an SCT, subtract your male thread depth from the back of your SCT.

ADASCTLM27$60.00 in stockAdd ADASCTLM27 To My Cart

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2.7” Adapter Threads onto larger Celestron SCT’s with 3.25” Rear Cell – Allows the Use of AP 2.7” Accessories (ADASCTLC27)

This 2.7” threaded back allows the use of Astro-Physics 2.7” accessories with 11" & 14" Celestron SCT’s and EdgeHD's and the Celestron 9.25 EdgeHD. The accessory back was designed primarily to accept the popular 0.75x, 2.7” Photo-Visual Telecompressor (27TVPH), but it will also work well with other accessories. Combine it with our 2” adapter (ADA2003) or our thin 2” adapter (ADA20132) and you have an unobstructed 2” visual back. Screw in our ADA204 2.7" to 2" SCT Adapter and you are right back to the standard Celestron 2" visual back. Attach our 2.7" to 6x7 Outer Bayonet Adapter (ADA2767) along with either of the STL Adapters for the 6x7 Outer Bayonet (ADA671 & ADA672), and you have the maximum available light path to your STL Series camera, and easy image framing to boot! Virtually any accessory from 2.7” diameter on down in size can be used with this adapter, greatly increasing the versatility of your large Celestron SCT.

Please verify that your instrument has a 3.25" male thread on the rear cell before ordering. The adapter is one-piece, machined aluminum and is anodized black. Note: Celestron uses a 3.29" x 16 thread.

See SCT System Chart for examples of usage.

This adapter has a length of 2.5" (63.5 mm). To derive the net spacing distance when using an SCT, subtract your male thread depth from the back of your SCT.

ADASCTLC27$60.00 in stockAdd ADASCTLC27 To My Cart

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Threaded Cover for Astro-Physics 2.7" Drawtubes and Accessories with 2.7" Female Threads (A1005)

This versatile cover was designed to protect your focuser from gathering dust when not in use. It has 2.7" male threads and can be threaded into any Astro-Physics 2.7" focuser, as well as the Traveler focuser. The front side of the A1005 bears the Astro-Physics name engraved on the center flat surface.

You can also use it with a variety of focuser adapters and extensions, as well as our 2.7" Photo-Visual Telecompressor (27TVPH). To see if this cover will work with your part, please review the Accessory Reference Chart for 2.7" Threaded Covers.

A1005$35.00 in stockAdd A1005 To My Cart

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RoboBracket™ (JRFBRK)

The RoboBracket™ is a professionally fabricated aluminum bracket for accurately and securely attaching the Technical Innovations Robo-Focus™ remote focus driver to all modern Astro-Physics Focusers. This bracket can be used with all Astro-Physics 2.7" and 4" Focusers that have two 8-32 or two 10-32 tapped holes available on the pinion block. Two 8-32x5/8" sockethead cap screws and two #8 washers are provided. If the enclosed screws do not thread properly, please contact Astro-Physics. It is unlikely that it will work with other focusers since the dimensions are specific to Astro-Physics focusers.

Note: Brackets with longer slots for the motor and motor attachment screws started to ship in March 2012.

Photographs shown:

  • RoboBracket alone
  • RoboBracket attached to the Robo-Focus
  • RoboBracket with Robo-Focus attached
    Astro-Physics 2.7" focuser.

JRFBRK$52.00 in stockAdd JRFBRK To My Cart

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Copyright © 2012, Astro-Physics, Inc. - All Rights Reserved
This page was last modified: September 23, 2014

Astro-Physics, Inc.
11250 Forest Hills Road, Rockford, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847