ZWO OAG-L Large Off-Axis Guider with 1.25" Holder
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- Large 12x12mm guide prism for a wider field of view when hunting for guide stars
- 11.7mm x 8.3mm effective light-passing aperture
- Built-in helical focuser, so no separate 1.25" focuser is needed
- Slim 17.5mm thickness that fits a standard 55mm back focus imaging train
- Ships with an M48 sensor tilt plate (5mm)
- Built for ZWO full-frame and larger APS-C cooled cameras
ZWO Large Off-Axis Guider
The ZWO OAG-L is a large off-axis guider made for full-frame and bigger APS-C ZWO cooled cameras. It pulls a guide star from the same light path your main camera uses, so you can guide at the exact focal length of your telescope. That matters most on long systems, where a separate guide scope struggles to keep up. The "L" stands for large, and the name points to the prism. At 12x12mm, it is bigger than the prism on the standard ZWO OAG. A bigger prism sees more sky, which gives you a better chance of landing on a usable guide star. This is a real advantage when you image under heavy light pollution or run a scope with a narrow field of view. Bigger is not always better here. The OAG-L is often bought by mistake. If you shoot with a 4/3" or smaller sensor camera, the standard ZWO OAG is likely the smarter pick for your setup. Check the compatibility section on this page before you order. Any cameras, telescopes, and other accessories are sold separately and not included in this OAG purchase.
ZWO OAG-L Large Off-Axis Guider Video Introduction
Please enjoy this introduction to the setting up a ZWO OAG-L as it is paired with APS-C camera and 36mm
Highlights of the ZWO OAG-L Large Off-Axis Guider
Larger Prism, More Guide Stars
The 12x12mm prism gives a wider field of view than the standard OAG. More sky in view means you are far more likely to catch a bright guide star, even in poor conditions.
Built-In Helical Focuser
A helical focuser is part of the OAG-L body. You focus the guide camera right on the unit. There is no need to buy the separate ZWO 1.25" helical focuser.
Slim 17.5mm Profile
At 17.5mm thick, the OAG-L slots into a standard 55mm back focus train with room for your other ZWO parts. Less stacking means fewer spacing headaches.
When Off-Axis Guiding Beats a Guide Scope
On long focal length telescopes, a separate guide scope creates problems. An off-axis guider fixes them in three ways. First, it guides at the same focal length as your main scope, which is critical on systems over 1000mm.
Second, it removes the extra weight of a guide scope from your rig, so tracking is cleaner. Third, it kills flexure, the slight sag a guide scope can develop under gravity that throws off your guiding. The OAG-L takes its guide star straight from the main optical path, so what the guider sees is what your camera sees.
Who Should Buy a ZWO OAG-L?
This off-axis guider is designed for ZWO's full-frame and select APS-C cooled cameras. It works natively, with no extra adapters, with the ASI6200MM Pro, ASI6200MC Pro, ASI2400MC Pro, ASI2600MM Pro, and ASI2600MC Pro.
Serious imagers reach for the OAG-L when they need every bit of sensitivity to pull a faint guide star out of the sky. Pair it with a large-sensor guide camera like the ASI174MM Mini, whose sensor roughly matches the prism size, and finding a guide star becomes close to a sure thing.
Guide Camera Compatibility
The OAG-L works with a range of ZWO ASI guide cameras, not just Mini models. The camera side of the OAG accepts full-size ASI cameras, ASI Mini cameras, and other ASI bodies. Since each camera type has a different back focus, the OAG comes with a 1.25" extender and a T2 5mm extender to make up the difference and bring your guide camera to focus. The ASI174MM Mini is a popular pairing, since its larger sensor and larger pixels take full advantage of the wide prism, but it is not your only option.
Cameras sold separately*
Connecting to Your Telescope
The telescope side uses a sensor tilt plate that threads onto your scope or corrector. The OAG-L ships with an M48 tilt plate, so if your telescope threads are M48 you are ready as is. For M54 threads, ZWO offers an M54 tilt plate, which already comes packed with the ASI6200 and ASI2400 cameras.
If you run an ASI2600 with an M54 scope, you would buy that plate on its own. For larger rear threads, an M68 tilt plate is also available. On the camera side, the OAG-L bolts directly onto ZWO 7x2", 5x2", and 7x36mm filter wheels, or onto the ZWO M54 15mm adapter.
Working With Smaller Sensor Cameras
The OAG-L is not compatible with ZWO's M42 Filter Drawer, which makes it a poor fit for many small-sensor color cameras. So if you shoot with a smaller OSC camera, the regular ZWO OAG and the 1.25" helical focuser are the better route.
You can also run the OAG-L without a filter drawer by adding the ZWO M54 15mm adapter. Or you can use a 3rd party filter slider with the appropriate threads. Please also note that the OAG-L is not compatible with the Pegasus Astro Indigo Electronic Filter Wheel.
Setup Tips for Clean Guiding
Because the prism is large, ZWO advises against using the OAG-L on telescopes with a clear aperture smaller than M48. When you build the train, make sure the prism does not block your main camera sensor. Use the guiding screw to set the guide camera's focus, and keep the distance from the prism to the main camera equal to the distance from the prism to the guide camera. This is much easier to dial in during daylight, since fine adjustment at night is difficult.
Specifications
- Prism Size: 12x12 mm
- Thickness: 17.5 mm
- Effective Aperture: 11.7 mm x 8.3 mm
- Sensor Tilt Plate: Built-in M48 sensor tilt plate (5mm)
- Compatible Filter Wheel: 2" EFW, 36 mm EFW
- Recommended Main Camera: ASI cameras with full-frame sensors or APS-C sensors
- Recommended Guide Camera: ASI Mini camera
- Weight (Net): 265 g
Frequently Asked Questions:
1. Does the OAG-L need a separate helical focuser?
No. The helical focuser is built into the OAG-L body. This is one of its upgrades over the standard ZWO OAG, which needs the 1.25" helical focuser bought separately.
2. Will the OAG-L work with my planetary guide camera?
Yes. The OAG-L supports a range of ZWO ASI guide cameras, including full-size ASI cameras and ASI Mini models. The included 1.25" and T2 5mm extenders set the correct back focus for whichever camera you use.
3. Is the OAG-L overkill for my small-sensor camera?
Often, yes. For 4/3" or smaller sensors, the standard ZWO OAG is usually the better choice. Larger is not automatically better, and the OAG-L is frequently ordered by mistake.
4. What tilt plate do I need if my scope has M54 or M68 threads?
ZWO offers both an M54 tilt plate and an M68 tilt plate. The M54 plate ships with the ASI6200 and ASI2400 cameras, so you may already own it.
5. Can I use the OAG-L with a filter drawer?
It is not compatible with ZWO's M42 Filter Drawer. If you want to run it without a drawer, you can add the ZWO M54 15mm adapter.
6. How do I keep the prism from blocking my main sensor?
Adjust the prism position so it clears the main camera sensor, then match the prism-to-main-camera distance with the prism-to-guide-camera distance. Do this in daylight, since night adjustments are hard to get right.
Other Information
- Country of Manufacture: China
ZWO Large Off-Axis Guider
The ZWO OAG-L is a large off-axis guider made for full-frame and bigger APS-C ZWO cooled cameras. It pulls a guide star from the same light path your main camera uses, so you can guide at the exact focal length of your telescope. That matters most on long systems, where a separate guide scope struggles to keep up. The "L" stands for large, and the name points to the prism. At 12x12mm, it is bigger than the prism on the standard ZWO OAG. A bigger prism sees more sky, which gives you a better chance of landing on a usable guide star. This is a real advantage when you image under heavy light pollution or run a scope with a narrow field of view. Bigger is not always better here. The OAG-L is often bought by mistake. If you shoot with a 4/3" or smaller sensor camera, the standard ZWO OAG is likely the smarter pick for your setup. Check the compatibility section on this page before you order. Any cameras, telescopes, and other accessories are sold separately and not included in this OAG purchase.
ZWO OAG-L Large Off-Axis Guider Video Introduction
Please enjoy this introduction to the setting up a ZWO OAG-L as it is paired with APS-C camera and 36mm
Highlights of the ZWO OAG-L Large Off-Axis Guider
Larger Prism, More Guide Stars
The 12x12mm prism gives a wider field of view than the standard OAG. More sky in view means you are far more likely to catch a bright guide star, even in poor conditions.
Built-In Helical Focuser
A helical focuser is part of the OAG-L body. You focus the guide camera right on the unit. There is no need to buy the separate ZWO 1.25" helical focuser.
Slim 17.5mm Profile
At 17.5mm thick, the OAG-L slots into a standard 55mm back focus train with room for your other ZWO parts. Less stacking means fewer spacing headaches.
When Off-Axis Guiding Beats a Guide Scope
On long focal length telescopes, a separate guide scope creates problems. An off-axis guider fixes them in three ways. First, it guides at the same focal length as your main scope, which is critical on systems over 1000mm.
Second, it removes the extra weight of a guide scope from your rig, so tracking is cleaner. Third, it kills flexure, the slight sag a guide scope can develop under gravity that throws off your guiding. The OAG-L takes its guide star straight from the main optical path, so what the guider sees is what your camera sees.
Who Should Buy a ZWO OAG-L?
This off-axis guider is designed for ZWO's full-frame and select APS-C cooled cameras. It works natively, with no extra adapters, with the ASI6200MM Pro, ASI6200MC Pro, ASI2400MC Pro, ASI2600MM Pro, and ASI2600MC Pro.
Serious imagers reach for the OAG-L when they need every bit of sensitivity to pull a faint guide star out of the sky. Pair it with a large-sensor guide camera like the ASI174MM Mini, whose sensor roughly matches the prism size, and finding a guide star becomes close to a sure thing.
Guide Camera Compatibility
The OAG-L works with a range of ZWO ASI guide cameras, not just Mini models. The camera side of the OAG accepts full-size ASI cameras, ASI Mini cameras, and other ASI bodies. Since each camera type has a different back focus, the OAG comes with a 1.25" extender and a T2 5mm extender to make up the difference and bring your guide camera to focus. The ASI174MM Mini is a popular pairing, since its larger sensor and larger pixels take full advantage of the wide prism, but it is not your only option.
Cameras sold separately*
Connecting to Your Telescope
The telescope side uses a sensor tilt plate that threads onto your scope or corrector. The OAG-L ships with an M48 tilt plate, so if your telescope threads are M48 you are ready as is. For M54 threads, ZWO offers an M54 tilt plate, which already comes packed with the ASI6200 and ASI2400 cameras.
If you run an ASI2600 with an M54 scope, you would buy that plate on its own. For larger rear threads, an M68 tilt plate is also available. On the camera side, the OAG-L bolts directly onto ZWO 7x2", 5x2", and 7x36mm filter wheels, or onto the ZWO M54 15mm adapter.
Working With Smaller Sensor Cameras
The OAG-L is not compatible with ZWO's M42 Filter Drawer, which makes it a poor fit for many small-sensor color cameras. So if you shoot with a smaller OSC camera, the regular ZWO OAG and the 1.25" helical focuser are the better route.
You can also run the OAG-L without a filter drawer by adding the ZWO M54 15mm adapter. Or you can use a 3rd party filter slider with the appropriate threads. Please also note that the OAG-L is not compatible with the Pegasus Astro Indigo Electronic Filter Wheel.
Setup Tips for Clean Guiding
Because the prism is large, ZWO advises against using the OAG-L on telescopes with a clear aperture smaller than M48. When you build the train, make sure the prism does not block your main camera sensor. Use the guiding screw to set the guide camera's focus, and keep the distance from the prism to the main camera equal to the distance from the prism to the guide camera. This is much easier to dial in during daylight, since fine adjustment at night is difficult.
Specifications
- Prism Size: 12x12 mm
- Thickness: 17.5 mm
- Effective Aperture: 11.7 mm x 8.3 mm
- Sensor Tilt Plate: Built-in M48 sensor tilt plate (5mm)
- Compatible Filter Wheel: 2" EFW, 36 mm EFW
- Recommended Main Camera: ASI cameras with full-frame sensors or APS-C sensors
- Recommended Guide Camera: ASI Mini camera
- Weight (Net): 265 g
Frequently Asked Questions:
1. Does the OAG-L need a separate helical focuser?
No. The helical focuser is built into the OAG-L body. This is one of its upgrades over the standard ZWO OAG, which needs the 1.25" helical focuser bought separately.
2. Will the OAG-L work with my planetary guide camera?
Yes. The OAG-L supports a range of ZWO ASI guide cameras, including full-size ASI cameras and ASI Mini models. The included 1.25" and T2 5mm extenders set the correct back focus for whichever camera you use.
3. Is the OAG-L overkill for my small-sensor camera?
Often, yes. For 4/3" or smaller sensors, the standard ZWO OAG is usually the better choice. Larger is not automatically better, and the OAG-L is frequently ordered by mistake.
4. What tilt plate do I need if my scope has M54 or M68 threads?
ZWO offers both an M54 tilt plate and an M68 tilt plate. The M54 plate ships with the ASI6200 and ASI2400 cameras, so you may already own it.
5. Can I use the OAG-L with a filter drawer?
It is not compatible with ZWO's M42 Filter Drawer. If you want to run it without a drawer, you can add the ZWO M54 15mm adapter.
6. How do I keep the prism from blocking my main sensor?
Adjust the prism position so it clears the main camera sensor, then match the prism-to-main-camera distance with the prism-to-guide-camera distance. Do this in daylight, since night adjustments are hard to get right.
- 1x OAG-L Main Body with Helical Focuser
- 1x M3 Brass Screw
- 2x M3 Locking Screws (x2)
- 4x M2.5*6mm Socket Head Screws (x4)
- 1x Quick Guide
*Please be aware that the OAG-L does not work with the Pegasus Astro Indigo Electronic Filter Wheel.
- Large 12x12mm guide prism for a wider field of view when hunting for guide stars
- 11.7mm x 8.3mm effective light-passing aperture
- Built-in helical focuser, so no separate 1.25" focuser is needed
- Slim 17.5mm thickness that fits a standard 55mm back focus imaging train
- Ships with an M48 sensor tilt plate (5mm)
- Built for ZWO full-frame and larger APS-C cooled cameras
ZWO Large Off-Axis Guider
The ZWO OAG-L is a large off-axis guider made for full-frame and bigger APS-C ZWO cooled cameras. It pulls a guide star from the same light path your main camera uses, so you can guide at the exact focal length of your telescope. That matters most on long systems, where a separate guide scope struggles to keep up. The "L" stands for large, and the name points to the prism. At 12x12mm, it is bigger than the prism on the standard ZWO OAG. A bigger prism sees more sky, which gives you a better chance of landing on a usable guide star. This is a real advantage when you image under heavy light pollution or run a scope with a narrow field of view. Bigger is not always better here. The OAG-L is often bought by mistake. If you shoot with a 4/3" or smaller sensor camera, the standard ZWO OAG is likely the smarter pick for your setup. Check the compatibility section on this page before you order. Any cameras, telescopes, and other accessories are sold separately and not included in this OAG purchase.
ZWO OAG-L Large Off-Axis Guider Video Introduction
Please enjoy this introduction to the setting up a ZWO OAG-L as it is paired with APS-C camera and 36mm
Highlights of the ZWO OAG-L Large Off-Axis Guider
Larger Prism, More Guide Stars
The 12x12mm prism gives a wider field of view than the standard OAG. More sky in view means you are far more likely to catch a bright guide star, even in poor conditions.
Built-In Helical Focuser
A helical focuser is part of the OAG-L body. You focus the guide camera right on the unit. There is no need to buy the separate ZWO 1.25" helical focuser.
Slim 17.5mm Profile
At 17.5mm thick, the OAG-L slots into a standard 55mm back focus train with room for your other ZWO parts. Less stacking means fewer spacing headaches.
When Off-Axis Guiding Beats a Guide Scope
On long focal length telescopes, a separate guide scope creates problems. An off-axis guider fixes them in three ways. First, it guides at the same focal length as your main scope, which is critical on systems over 1000mm.
Second, it removes the extra weight of a guide scope from your rig, so tracking is cleaner. Third, it kills flexure, the slight sag a guide scope can develop under gravity that throws off your guiding. The OAG-L takes its guide star straight from the main optical path, so what the guider sees is what your camera sees.
Who Should Buy a ZWO OAG-L?
This off-axis guider is designed for ZWO's full-frame and select APS-C cooled cameras. It works natively, with no extra adapters, with the ASI6200MM Pro, ASI6200MC Pro, ASI2400MC Pro, ASI2600MM Pro, and ASI2600MC Pro.
Serious imagers reach for the OAG-L when they need every bit of sensitivity to pull a faint guide star out of the sky. Pair it with a large-sensor guide camera like the ASI174MM Mini, whose sensor roughly matches the prism size, and finding a guide star becomes close to a sure thing.
Guide Camera Compatibility
The OAG-L works with a range of ZWO ASI guide cameras, not just Mini models. The camera side of the OAG accepts full-size ASI cameras, ASI Mini cameras, and other ASI bodies. Since each camera type has a different back focus, the OAG comes with a 1.25" extender and a T2 5mm extender to make up the difference and bring your guide camera to focus. The ASI174MM Mini is a popular pairing, since its larger sensor and larger pixels take full advantage of the wide prism, but it is not your only option.
Cameras sold separately*
Connecting to Your Telescope
The telescope side uses a sensor tilt plate that threads onto your scope or corrector. The OAG-L ships with an M48 tilt plate, so if your telescope threads are M48 you are ready as is. For M54 threads, ZWO offers an M54 tilt plate, which already comes packed with the ASI6200 and ASI2400 cameras.
If you run an ASI2600 with an M54 scope, you would buy that plate on its own. For larger rear threads, an M68 tilt plate is also available. On the camera side, the OAG-L bolts directly onto ZWO 7x2", 5x2", and 7x36mm filter wheels, or onto the ZWO M54 15mm adapter.
Working With Smaller Sensor Cameras
The OAG-L is not compatible with ZWO's M42 Filter Drawer, which makes it a poor fit for many small-sensor color cameras. So if you shoot with a smaller OSC camera, the regular ZWO OAG and the 1.25" helical focuser are the better route.
You can also run the OAG-L without a filter drawer by adding the ZWO M54 15mm adapter. Or you can use a 3rd party filter slider with the appropriate threads. Please also note that the OAG-L is not compatible with the Pegasus Astro Indigo Electronic Filter Wheel.
Setup Tips for Clean Guiding
Because the prism is large, ZWO advises against using the OAG-L on telescopes with a clear aperture smaller than M48. When you build the train, make sure the prism does not block your main camera sensor. Use the guiding screw to set the guide camera's focus, and keep the distance from the prism to the main camera equal to the distance from the prism to the guide camera. This is much easier to dial in during daylight, since fine adjustment at night is difficult.
Specifications
- Prism Size: 12x12 mm
- Thickness: 17.5 mm
- Effective Aperture: 11.7 mm x 8.3 mm
- Sensor Tilt Plate: Built-in M48 sensor tilt plate (5mm)
- Compatible Filter Wheel: 2" EFW, 36 mm EFW
- Recommended Main Camera: ASI cameras with full-frame sensors or APS-C sensors
- Recommended Guide Camera: ASI Mini camera
- Weight (Net): 265 g
Frequently Asked Questions:
1. Does the OAG-L need a separate helical focuser?
No. The helical focuser is built into the OAG-L body. This is one of its upgrades over the standard ZWO OAG, which needs the 1.25" helical focuser bought separately.
2. Will the OAG-L work with my planetary guide camera?
Yes. The OAG-L supports a range of ZWO ASI guide cameras, including full-size ASI cameras and ASI Mini models. The included 1.25" and T2 5mm extenders set the correct back focus for whichever camera you use.
3. Is the OAG-L overkill for my small-sensor camera?
Often, yes. For 4/3" or smaller sensors, the standard ZWO OAG is usually the better choice. Larger is not automatically better, and the OAG-L is frequently ordered by mistake.
4. What tilt plate do I need if my scope has M54 or M68 threads?
ZWO offers both an M54 tilt plate and an M68 tilt plate. The M54 plate ships with the ASI6200 and ASI2400 cameras, so you may already own it.
5. Can I use the OAG-L with a filter drawer?
It is not compatible with ZWO's M42 Filter Drawer. If you want to run it without a drawer, you can add the ZWO M54 15mm adapter.
6. How do I keep the prism from blocking my main sensor?
Adjust the prism position so it clears the main camera sensor, then match the prism-to-main-camera distance with the prism-to-guide-camera distance. Do this in daylight, since night adjustments are hard to get right.
Other Information
- Country of Manufacture: China
- 1x OAG-L Main Body with Helical Focuser
- 1x M3 Brass Screw
- 2x M3 Locking Screws (x2)
- 4x M2.5*6mm Socket Head Screws (x4)
- 1x Quick Guide
*Please be aware that the OAG-L does not work with the Pegasus Astro Indigo Electronic Filter Wheel.
ZWO OAG-L Large Off-Axis Guider with 1.25" Holder