Astro-Physics CCDT67 CCD Telecompressor…
This AP telecompressor will provide full coverage of the ST10E chip with scopes ranging from f/9 to f/18 focal ratio. The 2-element cemented design transmits close to 99% of the incoming light over the range of 420 to 700 nm. The focal length of the telecompressor optics is 12". For refractors, the field is compressed by 0.67x (when using a Color Filter Wheel). If you have a moving mirror system, the native focal ratio will increase.
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 forward in the light cone so that in-travel (backspacing) requirements are reduced. An alternative is to use T-2 extension rings from Baader Planetarium, and thread the 15mm T-2 Extension Ring and 7.5 mm Extension Ring between the CCD camera and the nosepiece. This 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.
- The clear aperture of the AP CCD Telecompressor is 1.75". It is designed to screw into the 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).
- Additional Information
SKU AP-CCDT67 Manufacturer Astro-Physics Barrel Size 2" Warranty Limited Warranty
- Included Items
- Astro-Physics CCD Telecompressor
- Questions & Answers
Product QuestionsI read somewhere that it comes with a step down adaptor to t thread, is that true or is it a separate purchase?Question by: Henry Kwok on Dec 24, 2014 5:55:57 AMThe CCDT67 comes as shown with female M48 threads on the scope side and male M48 threads on the camera side. We do carry step down adapters from M48 to T thread from a couple of manufacturers, but they would be separate accessories. Please contact us if you have any questions.Answer by: Chris (Admin) on Dec 24, 2014 7:44:58 AMYou mention that there is an "exploded view" to a link to which details a variety of hookups between this FR and the scope, but the link is not working--"404" error code....Any other way to access it?Question by: bryan5549 on Jan 5, 2015 12:44:29 PMThe link is to a .PDF file, which may require either Adobe Reader or another .PDF reader to view, especially on a smart phone or tablet. My Android phone requires that I download the file and open in a reader program. The link works just fine on the computer in my office running Win 8.1.
The diagram is also available on Astro-Physics website at http://www.astro-physics.com/products/accessories/photo_acc/ccdt67.pdf, but the same restrictions on file type apply.Answer by: Chris (Admin) on Jan 6, 2015 4:38:35 AMI also have a TPO 6" RC. I typically use an AT2FF for field flattening. Has anyone reported good luck using this reducer with a field flattener?
Question by: Blaine Hebert on May 27, 2015 6:51:00 PMQuestion by: David Meissner on Jul 18, 2017 10:50:00 PMUnfortunately, no. The second reducer would interfere with the back focus and field illumination of the first. If you need greater reduction that 0.67x, we would need to know what telescope system and camera you were trying to adapt. At some point it may be better to consider a fast telescope of a different design, as too much reduction will prevent large sensors or cameras from being used. Please contact us at email@example.com with questions.Answer by: Chris Hendren on Jul 19, 2017 10:20:00 AMWill this work with or is it compatible with the Astro Tech 6RC ?
I'm planning to use it with an ATIK 428 EXM and a Xagyl 5 position motorized filter wheel.Question by: andres noriega on Jun 21, 2016 10:54:00 AMYes, this reducer works on all f/9 and f/8 RC scopes on sensors up to 28mm diagonal. You will have no issues with the combination you are proposing, although you will possibly need spacers to get the correct distance from the CCD to the reducer for the reduction factor you want. Please contact us if you have questions.Answer by: Chris Hendren (Admin) on Jun 21, 2016 5:30:00 PMQuestion by: paulchess10 on Sep 10, 2014 2:26:47 AMYes, the CCDT67 is compatible with the TPO RC6 as it is f/9, however this is just a reducer - not a reducer/corrector - so the corrected field will be smaller when using this on the RC6 - possibly only 15-20mm compared with the ~28mm corrected field at f/9. The amount of reduction and field illumination are related to the distance from the CCDT67 to the camera sensor, with the ideal being 101mm from the lens or 85mm from the M48 thread to the sensor.Answer by: Chris (Admin) on Sep 10, 2014 7:25:44 AM
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