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.

Using the PDFs below
We provide several links to exploded diagrams in the product descriptions below. These files are in PDF format and requires Acrobat Reader v5.0 or above.
Download the FREE Acrobat Reader to view these files.
Hint for two-page diagrams: After Acrobat has opened, click on the page icon at the bottom of the screen and choose "continuous-facing" to view the pages of the PDF side by side. Reduce the percentage to fit both pages on your screen.

Our Advanced Convertible Barlow has a unique design that provides several configurations to increase the focal length of your telescope. It was designed to match the characteristics of small and medium size CCD chips. It is also ideal for high-power visual observation and lunar-planetary-solar photography. This redesigned optic features a flatter field, allowing it to be used for deep-sky photography when increased magnification of smaller objects is desired.

This well-corrected accessory lens preserves the high contrast and superb color correction of the main objective. While the telecompressor flattens the field to a certain degree, you may still notice some slightly elongated stars in the corners. This is less of an issue with CCD imaging when the chip size is smaller than a 35 mm negative. For the very best edge star images, we recommend the prime focus 2.7" or 4" field flatteners, which have been specifically designed for each focal length of our StarFire refractors. If you own one of our 175, 160, 155 or 140 StarFires and plan to take CCD images, we suggest our dedicated CCD Telecompressors that are optimally corrected for these scopes.

Here are a few examples of images from our gallery that were taken with our telecompressor:

M42, 105 mm Traveler at f/4.5 taken by Ray Gralak with an SBIG ST8E.
Gamma Cygnus Region, 105 mm Traveler at f/4.5 taken by Ray Gralak with an SBIG ST8E.
M8, 130 mm StarFire EDFS at f/4.5 imaged by Loke Tan with an SBIG ST10E.
IC 5070 - The Pelican Nebula, 155 mm StarFire EDFS at f/5.2 taken by Ray Gralak with SBIG ST-10XE

We designed the telecompressor so that it threads directly into the drawtube, thus placing the optics forward in the optical system. As a result, the telecompressor can only be used with Astro-Physics 2.7" and 4" focusers and Starlight Instruments 3" and 3.5" focusers that have an end-cap adapter for Astro-Physics 2.7" accessories. In addition to our refractors, Astro-Physics focusers are featured in several popular Ritchey-Chretiens (the telecompressor produces very fine results with these scopes) and are available for telescope makers (27FOC3E and 27FOC3E-FT).

Two additional adapters released in 2007 and 2008 respectively have greatly increased the versatility of this Photo-Visual Telecompressor. The 2.7" Adapter that Threads onto the 3.25" Rear Cell of Larger Meade SCT's (ADASCTLM27), introduced in July, 2007 now makes this telecompressor available to owners of larger Meade SCT's. The 6x7 Outer Bayonet Adapter (ADA2767), introduced in August, 2008 allows larger imaging platforms like the SBIG STL Series cameras or full frame DSLR's to be attached to the Photo-Visual Telecompressor without the vignetting effects of a 2" nosepiece or a T-ring.

The focal length of the Photo-Visual Telecompressor is 27.6" (700 mm). In order to obtain approximately 0.75x, please refer to the exploded diagram for various configurations. Although not shown on the diagram, the telecompressor is threaded for 58 mm filters. To calculate the compression factor and coverage for your particular setup, please refer to our Telecompressor Spacing, Compression Calculation and Coverage document or to the CCDT67 & 27TVPH Telecompression Graph.

The design allows full corner-to-corner illumination of the ST-10 and ST-8300 chips with most catadioptric telescopes. This design does not add coma to the wavefront, and thus can be used with all flat-field and coma-free telescopes such as Maksutov-Cassegrains, Schmidt-Cassegrains, Ritchey-Chretiens and refractors. The inherent resolution of the telescope is not compromised when using this compressor.

Please review the exploded diagram to see how this item will fit into your imaging system. If you want a higher compression ratio, but do not use the color filter wheel, you can add one or more of the 2” Barrel Extension w/ 48 mm Threads (A3703) between the CCDT67 and the nosepiece of your camera. This has the advantage of inserting the CCDT67 foward in the light cone so that in-travel (backspacing) requirements are reduced. An alternative is to use T-2 extension rings that we offer from Baader Planetarium. Threading the 15mm T-2 Extension Ring (part # BP25A) and 7.5 mm Extension Ring (part # BP25C) between the CCD camera and the nosepiece. will approximate the spacing of a color filter wheel. You can also experiment with a single extension or other combinations. Please note that as you increase compression, you decrease the size of the image circle at the focus point. At 0.67x, the CCDT67 will cover the chip of the ST-10 and ST-8300. It can never cover the chip of an STL series camera or the newer large size digital SLR chips, because its clear aperture is no larger than their CCD chips.

• Clear aperture is 1.75", designed to screw into our 2” Tapered Nosepiece (AP16T) or any other 2" nosepiece with 48 mm threads that is designed for CCD cameras. It will not thread all the way into the nosepiece provided with SBIG cameras since the threads of that nosepiece are not deep enough.
• 0.67x Compression ratio for SBIG ST7/8/10 + Color Filter Wheel, when used with refractors. Fully illuminated circle: 29 mm
• 0.75x Compression ratio for SBIG ST7/8/10 (without Color Filter Wheel or T-2 extensions), when used with refractors. Fully illuminated circle: 34 mm
• Approximately 5 inches of back focus is needed to achieve focus on the CCD chip. It will not work with the AO7.
• The focal length of the CDD Telecompressor is 12" (305 mm)

To calculate the compression factor and coverage for your particular setup, please refer to our Telecompressor Spacing, Compression Calculation and Coverage document or to the CCDT67 & 27TVPH Telecompression Graph.

This image of the Ring Nebula was taken with the Astro-Physics 10" f'/14.6 Maksutov-Cassegrain and the CCD Telecompressor using an ST10E with the color filter wheel. Once you receive your CCD Telecompressor, we invite you to submit your images so that they can be featured here, all scopes will be welcome.

We highly recommend our 2" Tapered Nosepiece (AP16T) for your CCD camera. When used with the brass locking ring of most of our adapters, this unique barrel will seat your valuable CCD camera squarely and solidly into place. Even a single thumbscrew interface will be improved. Note: If you are using the older style thin 2" adapter (part # ADA2013), we suggest that you use the 2" nosepiece that came with your camera or the 2" nosepiece from Baader Planetarium (we offer as part #BP16). The current style 2" Thin Adapter (ADA20132) works perfectly with the AP16T.

This 2” x ½” Barrel Extension is a more robust version of T-thread extension tubes. It uses 48 mm threads at both ends (female and male) instead of the smaller 42 mm T-threads. Its internal light baffles are painted flat-black to avoid reflections. Use more than one to increase spacing distance and/or telecompression in 1/2" (12.5 mm) increments. This extension has a net spacing distance of 0.5" (6.35 mm).

Realize the full potential of your Fluorite Flatfield Converter (BPFFC) or 2" Convertible Photo-Visual Barlow (BARCON) when imaging by using this extension. The internal T-thread on this extension allows you to attach your BPFFC, BARCON or other accessory with male T-threads INSIDE the 2.7" extension tube. In this way, the camera, filter wheel, off-axis guider, and/or other accessories are all supported by the much more robust and rigid 2.7" tube system, and the Barlow only needs to support its own weight inside the extension tube. This is particularly important when imaging at some of the higher magnification factors achievable with the BPFFC where over a foot of extension may be used between the Barlow optic and the focal plane. The maximum OD of the T-thread accessory is 2.5". Please see this A3511 System Chart for component options.

This 2.7" extension has a net spacing distance of 0.75" (19.05 mm).
It has a net spacing distance of 0.9" (22.86 mm) for the internal optic.

For Astro-Physics customers who have already purchased our 2.7" field flatteners, we are now offering machined aluminum covers to protect their optics. These covers will fit any Astro-Physics 2.7" field flattener. This will replace the red plastic plugs that were previously shipped with all field flatteners.

You do not need to purchase these covers separately if you are ordering a new field flattener. They have been included with all new 2.7" field flattener purchased since summer 2009.

The set includes one each of the following:

• Felted Cover for AP 2.7" Field Flatteners - Bayonet Side (A1226F)


• Threaded Cover for AP 2.7" Field Flatteners and Accessories with Male Threads (A1225).

The most discriminating CCD imagers with large chips may wish to use our field flatteners for the best possible results at the edge of the field. These adapters will preserve the correct spacing from the field flattener to the focal plane of your CCD camera. Choose the correct length for your system. Spacing distance can be refined by adding one of our many Thread-on Extensions. For owners of the SBIG STL Series of large format CCD cameras, we suggest the special STL Series adapters (ADA671 & ADA672) below for both perfect spacing and minimal vignetting.

Important: There are now a huge variety of CCD cameras, filter wheels and other accessories on the market, and all of them have different dimensions in terms of their optical backfocus or light path distance. Even different filter choices will affect the optical distance because of the indexing effect of the filter itself. It is important that you know the specifications of your own particular equipment before deciding on an adapter. The information below provides guidelines - NOT inviolable laws.

Diagrams and Instruction Sheets:
Astro-Physics Prime Focus Field Flatteners
- Exploded diagram showing these CCD adapters with the field flatteners and a variety of other accessories. Note that this is a PDF file. Read hint for viewing this two-page diagram.
Installing the CCD Adapter to Use the 2.7" or 4" Field Flatteners with a CCD Camera
- Instruction sheet in PDF format.

A1262
CCD Adapter to use our 2.7” or 4” Field Flattener with 2.7” accessories. It is generally used in combination with our 2.7” extensions to match spacing requirements for CCD cameras. ADA2003 or ADA20132 Thumbscrew Adapters can be used to accept the 2” nosepiece of cameras. (Originally intended to use with your SBIG ST-series CCD cameras without a Color Filter Wheel.)

This adapter has a net spacing distance of 1.72" (43.7 mm).

ADA671 – This shorter version, 1.580” in length, was designed specifically for the STL series cameras with the optional FW8-STL, 8-position color filter wheel attached. This preserves the critical spacing of our field flatteners with the larger 8-position wheel. (This would also be the adapter of choice for use with an AO-8 or AO-L Adaptive Optics Unit, along with the ADA2767 adapter, but note that the AO-8 and the AO-L can NOT be used with a field flattener. See Additional Applications below.)

This adapter has a net spacing distance of 1.58" (40.13 mm).

ADA672 - The longer version, 1.930” in length, is the adapter for the STL series camera with the standard 5-position color filter wheel. It places the STL’s CCD sensor at the perfect 3.4” distance from the field flattener for pinpoint stars across the big CCD chip.

This adapter has a net spacing distance of 1.93" (49.02 mm).

(67RT - - -, last 3 letters indicate t-ring)

Use this adapter with the 2.7" or 4" Prime Focus Field Flatteners to obtain the best possible results with your 35 mm camera - pinpoint from edge to edge. I.D. painted flat and threaded for 48 mm filters. See how this part fits into your photographic system in the exploded diagram (PDF file). Read hint for viewing this two-page diagram.

This part can also be used with the 2.7" to 6x7 Outer Bayonet Adapter (ADA2767) if you wish to do so, although the required T-ring for camera attachment will not maintain the ADA2767's wide open light path.

Owners of Canon EOS auto-focus 35 mm and digital SLR's may wish to consider the larger, 1.875" clear aperture adapter below. (67RLEOS)

Purchase the adapter with or without the T-ring. T-rings thread easily into place. If you order your camera adapter with a T-ring, the three dashes in the part number will be replaced by three letters, i.e. 67RTNIK if a Nikon T-ring in included. Please specify the T-ring that you wish to use. Order an extra T-ring if you have two cameras. This part can be used with 2.7" field flatteners shipped after May 1994 and 4" field flatteners from any year.

If you have a field flattener that is an earlier model, please call.

This adapter has a net spacing distance of 1.67" (42.3 mm) with the T-ring.
It has a net spacing distance of 1.24" (31.5 mm) without the T-ring.

The new circular dovetail style was developed to not only provide a secure method of attaching the extra weight of modern CCD camera systems, but to also provide an easy way to rotate them to any position and then to flawlessly lock attachments with zero tilt.

Unlike the Astro-Physics Prime Focus Field Flatteners, there are no critical spacing requirements with this scope.

This adapter has a net spacing distance of 1.41" (35.92 mm).

Note the tapered 2" barrel. When used with our brass locking ring (or any locking ring clamp), this unique barrel will seat your valuable camera squarely and solidly into place. Even a single thumbscrew interface will be improved. Purchase the adapter with or without a t-ring. If you order a T-ring, the three dashes in the part number will be replaced by three letters, i.e. PFCTNIK if a Nikon T-ring is included. Please specify the T-ring that you wish to use. Order an extra t-ring if you have two cameras.

This adapter has a net spacing distance of 1.35" (34.3 mm) without the T-ring.
It has a net spacing distance of 1.78" (45.2 mm) with the T-ring.

To see the nosepiece as used with a CCD camera, review the exploded diagram. Note that this is a PDF file. Read hint for viewing this two-page diagram. If you own an Astro-Physics focuser, you also may wish to consider our 2" Adapter (ADA2003) that features 3 locking screws. The combination of these two accessories will redefine "rock solid."

This nosepiece has a net spacing distance of 1.15" (29.21 mm) when used with the CCDT67.
It has a nose insertion depth of 1.025" (26.24 mm).

Protect and carry your 80 mm x 900 mm guidescope (or an even larger telescope without rings) with this handy case. We designed it to allow our 4.4" guidescope rings to remain in position on the scope. You don’t have to take them off! The case measures 39.25" x 9.5" x 10.25" (exterior) and is built like our refractor cases of quality plywood with a grey vinyl exterior. The inside dimensions are 36.5" x 7" x 6.25" and is lined with 1" foam. It is an essential addition if you transport your guidescope or wish to protect another of your telescopes. [Unfortunately, the guidescopes are no longer available.]

Note that this case would be an excellent carry case for protecting many different telescopes in your collection.