GSO 2" 0.75x Focal Reducer for Ritchey-Chretien RC Telescopes

Stock count is accurate & shown in real time.
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
- This item is out of stock.
- We have no ETA from the manufacturer at this time.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
Lower 48 States:
Orders over $50 ship free within the Lower 48 using a carrier and service we select based on your items and delivery location. Faster shipping options may be available at checkout.
U.S. Outside the Lower 48 (AK, HI, PR):
Free shipping on orders over $50 applies to many—but not all—items. Add items to your cart and enter your ZIP code to see available shipping options and any costs.
International Orders:
Free shipping does not apply to international orders. You’ll see available shipping options and costs during checkout. Some items can’t be shipped internationally due to size or manufacturer restrictions. Duties, taxes, brokerage fees, and tariffs are not included and are the customer’s responsibility.
- GSO 0.75x focal reducer (not a field flattener) for Ritchey-Chretien telescopes
- Enables a wider field of view and shorter exposure times for astrophotography
- Fully multi-coated optical components allow for excellent image color and contrast
- Provides 80mm of back focus
- Ideal for cameras sensors with a diagonal of 15mm or less
- Threads into eyepieces, camera adapters, and other accessories with standard 2" threads, and can be stacked with additional 2" threaded accessories and spacers
Designed for use in GSO Ritchey-Chretien and other compatible RC telescopes, this two-element optical component reduces the scope’s effective focal length by 0.75x. It takes an f/8 scope to f/6 or an f/9 scope to f/6.75, making it easier to capture faint detail in astrophotos with shorter exposure times.
The focal reducer is carefully designed and manufactured with fully multi-coated optics to retain image color, brightness, and contrast. Although it’s not a field flattener, this reducer helps retain the inherent field flatness of an RC scope. It’s ideal for astronomy cameras with sensor diagonals as large as 15mm.
The GSO 0.75x focal reducer provides about 80mm of back focus, enough to accommodate off-axis guiders and filter wheels. The black-anodized body slips into a 2” focuser or adapter, and it secures accessories with 2” barrels using a non-marring compression ring.
On the scope side, the reducer includes a 2” barrel with female M48x0.75 threads. The camera side has a 2” female tube that accepts cameras with 2” nosepieces. The 2” tube can be unscrewed, revealing a male M48x0.75 thread. An M48-M42 step-down adapter is included.
Other Information
- Country of Manufacture: Taiwan
Designed for use in GSO Ritchey-Chretien and other compatible RC telescopes, this two-element optical component reduces the scope’s effective focal length by 0.75x. It takes an f/8 scope to f/6 or an f/9 scope to f/6.75, making it easier to capture faint detail in astrophotos with shorter exposure times.
The focal reducer is carefully designed and manufactured with fully multi-coated optics to retain image color, brightness, and contrast. Although it’s not a field flattener, this reducer helps retain the inherent field flatness of an RC scope. It’s ideal for astronomy cameras with sensor diagonals as large as 15mm.
The GSO 0.75x focal reducer provides about 80mm of back focus, enough to accommodate off-axis guiders and filter wheels. The black-anodized body slips into a 2” focuser or adapter, and it secures accessories with 2” barrels using a non-marring compression ring.
On the scope side, the reducer includes a 2” barrel with female M48x0.75 threads. The camera side has a 2” female tube that accepts cameras with 2” nosepieces. The 2” tube can be unscrewed, revealing a male M48x0.75 thread. An M48-M42 step-down adapter is included.
- GSO 0.75x focal reducer (not a field flattener) for Ritchey-Chretien telescopes
- Enables a wider field of view and shorter exposure times for astrophotography
- Fully multi-coated optical components allow for excellent image color and contrast
- Provides 80mm of back focus
- Ideal for cameras sensors with a diagonal of 15mm or less
- Threads into eyepieces, camera adapters, and other accessories with standard 2" threads, and can be stacked with additional 2" threaded accessories and spacers
Designed for use in GSO Ritchey-Chretien and other compatible RC telescopes, this two-element optical component reduces the scope’s effective focal length by 0.75x. It takes an f/8 scope to f/6 or an f/9 scope to f/6.75, making it easier to capture faint detail in astrophotos with shorter exposure times.
The focal reducer is carefully designed and manufactured with fully multi-coated optics to retain image color, brightness, and contrast. Although it’s not a field flattener, this reducer helps retain the inherent field flatness of an RC scope. It’s ideal for astronomy cameras with sensor diagonals as large as 15mm.
The GSO 0.75x focal reducer provides about 80mm of back focus, enough to accommodate off-axis guiders and filter wheels. The black-anodized body slips into a 2” focuser or adapter, and it secures accessories with 2” barrels using a non-marring compression ring.
On the scope side, the reducer includes a 2” barrel with female M48x0.75 threads. The camera side has a 2” female tube that accepts cameras with 2” nosepieces. The 2” tube can be unscrewed, revealing a male M48x0.75 thread. An M48-M42 step-down adapter is included.
Other Information
- Country of Manufacture: Taiwan
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |

GSO 2" 0.75x Focal Reducer for Ritchey-Chretien RC Telescopes


















