Founder Optics 48mm Low Profile Wide T-Ring for Sony E Mount Cameras

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Important note:
- Sony E-mount cameras have an FFD (flange focal distance) of 18mm. To couple these with corrective telescope optics (such as flatteners or correctors) with a 55mm back focus requirement, your T-ring should have an optical path length of 55 - 18 = 37mm.
- However, this adapter has a low profile design with an optical length of only 11mm (not 37mm). This allows you to insert additional M48-threaded accessories (such as OAGs or filter wheels/filter drawers) with a total optical path length of up to 26mm.
- You may need to insert additional M48x0.75 spacers (not included) in addition to other accessories between the corrective optics and this T-ring to get to 26mm so that your camera sensor can be placed at 55mm from the corrective optics' male thread to meet the 55mm back focus requirement.
- For example, to use this with ZWO's popular FD-M42-II filter drawer that has an optical length of 21mm, and ignoring the effect of filter thickness on lengthening the back focus requirement marginally, your imaging traing will be:
Corrective optic > M48 thread spacer (5mm optical length) > ZWO filter drawer (21mm optical length) > this T ring (11mm optical length) > Sony E camera (18mm FFD) so that 5+21+11+18 = 55mm.
Description:
- Founder Optics low profile T-Ring to convert your Sony camera's E-mount to a 48mm thread for attachment to various astronomy accessories such as prime focus adapters, corrective optics, guiders, etc.
- For a list of compatible E-mount Sony cameras, please see this link at Wikipedia.
- M48 female thread on T-ring has a nominal diameter of 48mm and a thread pitch of 0.75mm
- Not for use with Sony A-mount cameras
- Compatible with 48mm T-threaded accessories
- Not for use with the smaller, more common standard 42mm T-threaded adapters and accessories which have a male M42x0.75 thread
- High-precision CNC-machined aluminum and black anodized
- Optical path length: 11mm
- Clear aperture: 41.50mm
- Weight: Xg / Xoz
Other Information
- Country of Manufacture: Taiwan
Important note:
- Sony E-mount cameras have an FFD (flange focal distance) of 18mm. To couple these with corrective telescope optics (such as flatteners or correctors) with a 55mm back focus requirement, your T-ring should have an optical path length of 55 - 18 = 37mm.
- However, this adapter has a low profile design with an optical length of only 11mm (not 37mm). This allows you to insert additional M48-threaded accessories (such as OAGs or filter wheels/filter drawers) with a total optical path length of up to 26mm.
- You may need to insert additional M48x0.75 spacers (not included) in addition to other accessories between the corrective optics and this T-ring to get to 26mm so that your camera sensor can be placed at 55mm from the corrective optics' male thread to meet the 55mm back focus requirement.
- For example, to use this with ZWO's popular FD-M42-II filter drawer that has an optical length of 21mm, and ignoring the effect of filter thickness on lengthening the back focus requirement marginally, your imaging traing will be:
Corrective optic > M48 thread spacer (5mm optical length) > ZWO filter drawer (21mm optical length) > this T ring (11mm optical length) > Sony E camera (18mm FFD) so that 5+21+11+18 = 55mm.
Description:
- Founder Optics low profile T-Ring to convert your Sony camera's E-mount to a 48mm thread for attachment to various astronomy accessories such as prime focus adapters, corrective optics, guiders, etc.
- For a list of compatible E-mount Sony cameras, please see this link at Wikipedia.
- M48 female thread on T-ring has a nominal diameter of 48mm and a thread pitch of 0.75mm
- Not for use with Sony A-mount cameras
- Compatible with 48mm T-threaded accessories
- Not for use with the smaller, more common standard 42mm T-threaded adapters and accessories which have a male M42x0.75 thread
- High-precision CNC-machined aluminum and black anodized
- Optical path length: 11mm
- Clear aperture: 41.50mm
- Weight: Xg / Xoz
Important note:
- Sony E-mount cameras have an FFD (flange focal distance) of 18mm. To couple these with corrective telescope optics (such as flatteners or correctors) with a 55mm back focus requirement, your T-ring should have an optical path length of 55 - 18 = 37mm.
- However, this adapter has a low profile design with an optical length of only 11mm (not 37mm). This allows you to insert additional M48-threaded accessories (such as OAGs or filter wheels/filter drawers) with a total optical path length of up to 26mm.
- You may need to insert additional M48x0.75 spacers (not included) in addition to other accessories between the corrective optics and this T-ring to get to 26mm so that your camera sensor can be placed at 55mm from the corrective optics' male thread to meet the 55mm back focus requirement.
- For example, to use this with ZWO's popular FD-M42-II filter drawer that has an optical length of 21mm, and ignoring the effect of filter thickness on lengthening the back focus requirement marginally, your imaging traing will be:
Corrective optic > M48 thread spacer (5mm optical length) > ZWO filter drawer (21mm optical length) > this T ring (11mm optical length) > Sony E camera (18mm FFD) so that 5+21+11+18 = 55mm.
Description:
- Founder Optics low profile T-Ring to convert your Sony camera's E-mount to a 48mm thread for attachment to various astronomy accessories such as prime focus adapters, corrective optics, guiders, etc.
- For a list of compatible E-mount Sony cameras, please see this link at Wikipedia.
- M48 female thread on T-ring has a nominal diameter of 48mm and a thread pitch of 0.75mm
- Not for use with Sony A-mount cameras
- Compatible with 48mm T-threaded accessories
- Not for use with the smaller, more common standard 42mm T-threaded adapters and accessories which have a male M42x0.75 thread
- High-precision CNC-machined aluminum and black anodized
- Optical path length: 11mm
- Clear aperture: 41.50mm
- Weight: Xg / Xoz
Other Information
- Country of Manufacture: Taiwan

Founder Optics 48mm Low Profile Wide T-Ring for Sony E Mount Cameras
