.76x CCD Telecompressor Corrector for 155 f/7 StarFire EDF (f/5.3) and 140f/7.5 StarFire EDF (f/5.6). 4" Focuser required (155TCC)
Brand : Astro-Physics
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Application: Digital imaging with CCD and DSLR cameras. Also suitable for video and 35mm film cameras.
The success of the 160TCC Telecompressor Corrector prompted us to offer a version that was designed to work with theand . Since the focal length of these two scopes is fairly close, it can be used with either one, however the resulting compression is slightly different as shown in the specifications below.
Optimal performance depends on these factors:
- The 155TCC must be used with the 4" focuser. If your 155 or 140 StarFire has the 2.7" Focuser, you can upgrade to the 4" version (easy installation that you can do yourself).
- The distance of the back of the housing to the image plane must be within 1 mm of ideal (80.8 mm +/- 1 mm). Astro-Physics produces several adapters (listed below). These adapters, when used with their respective cameras provide perfect spacing. Please review the document "0.76x CCD Telecompressor Corrector Spacing Requirements" for more information. Adapters for other cameras can be custom ordered from PreciseParts.
Important: The distance must be the OPTICAL distance - NOT the mechanical distance. Please be sure that you have accounted for the indexing effects of your filters, sensor cover slips and any other glass in the light path.
- A UV-IR filter must be installed in the luminance channel in order to preserve the best possible image resolution into the corners of the large formats. Without this filter, the distance will be incorrect and the luminance image will have slightly different scale factor from the RGB channels. Therefore, the various channels will not register properly. Also, the IR must be filtered out to prevent elongation in the corners of the STL format due to difference in lateral magnification of the longest wavelengths.
Important: the UV-IR filter must match the other filters being used in terms of is effect on the light path. Please check with your filter manufacturer to confirm.
When used with the recommended custom adapters, the image is fully illuminated with the recommended cameras. Only 2" round filters will present a tiny, insignificant amount of vignetting in the very corners.
Field size for 155 StarFire EDF @ f/5.3:
|Fully Illuminated Circle||2.1" (53 mm)||3.7 degrees|
|KAF-3200||14.9 x 10 mm||1.04 x 0.70 degrees|
|KAF-8300||18.0 x 13.5 mm||1.25 x .94 degrees|
|APS-C||22.4 x 14.9 mm||1.56 x 1.04 degrees|
|16803||36.9 x 36.9 mm||2.57 x 2.57 degrees|
|35 mm Full Frame||36 x 24 mm||2.52 x 1.68 degrees|
Chip not listed? The 155TCC yields 4.185 arcminutes per mm of chip.
Field size for 140 StarFire EDF @ f/5.7:
|Fully Illuminated Circle||2.1" (53 mm)||3.8 degrees|
|KAF-3200||14.9 x 10 mm||1.07 x 0.72 degrees|
|KAF-8300||18.0 x 13.5 mm||1.29 x .97 degrees|
|APS-C||22.4 x 14.9 mm||1.61 x 1.07 degrees|
|16803||36.9 x 36.9 mm||2.65 x 2.65 degrees|
|35 mm Full Frame||36 x 24 mm||2.59 x 1.73 degrees|
Chip not listed? The 155TCC yields 4.308 arcminutes per mm of chip.