ZWO OAG-L Large Off-Axis Guider with 1.25" Holder
Ships by Next Business Day
Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.
US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.
International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.
- Lightweight and 17.5mm thick
- Prism size: 12x12mm
- The effective light-passing aperture is 11.7mmx8.3mm
- Can be used to connect the main camera and guide camera simultaneously. No guide telescope required.
- Packaged with an M48 sensor tilt plate (5mm)
- PLEASE READ: Visit the compatibility section below carefully to make sure the OAG-L is right for your imaging train. This item is often ordered by mistake because LARGE is not necessarily better. The OAG-L is not necessary for 4/3" or smaller sensor cameras and the standard ZWO Off-Axis Guider with 1.25" Holder and M48 / M42 Threads # OAG may be a better choice for you. Please vist ZWO's webpage Best Solutions for 55mm Back Focus for examples of various imaging train setups using ZWO gear.
The ZWO OAG-L is short for off-axis guider - large and is designed specifically for ZWO full frame and some APS-C sized cooled cameras. The ZWO OAG-L is the ideal choice for serious astrophotographers who need the most sensitivity they can get for detecting guide stars.
The OAG-L features an increased prism size of 12x12mm, giving a wider field of view for detecting a guide star than ZWO's standard OAG. The OAG-L is best paired with ZWO's top end guide camera, the ASI174MM Mini (PAIC-ZW-ASI174MM-MINI), which has a similar sized sensor as the prism on the OAG-L. The large pixels on the ASI174MM Mini paired with the OAG-L's large prism essentially guarantees you will be able to find a guide star, even when imaging in heavy light pollution, using a slow focal ratio telescope, or both. As an upgrade over the standard ZWO OAG, the OAG-L features a helical focuser built in to the design, making it easy to focus your guide camera. Hence, you do not need to buy ZWO's 1.25" helical focuser separately for this OAG-L.
Off-axis guiders offer better performance over traditional guide scopes when used on longer focal length systems for three main reasons:
- Allows you to guide at the same focal length of your telescope which is critical for systems over 1000mm in focal length
- No guide scope means less weight riding on the telescope, which provides better tracking performance.
- Eliminates the possibility of flexure (slight sagging of the guide scope caused by gravity, which negatively affects guiding)
ZWO OAG-L Compatibility
The OAG-L is currently natively compatible with the following cameras without the need for any additional adapters. Please see the product images at the top of this page for how to configure it with your camera.
- ASI6200MM-P & ASI6200MC-P
- ASI2400MC-P
- ASI2600MM-P & ASI2600MC-P
ZWO OAG-L with Smaller Format Cameras
The ZWO OAG-L is not compatible with ZWO's M42 Filter Drawer, meaning it is not usually practical for most astrophotographers using smaller sensor cameras. For those users, we recommend ZWO's regular OAG (PAPI-ZW-OAG) and the helical focuser (PAF-ZW-HF1.25) to go with it. However, for those users who just want to use the ZWO OAG-L without a filter drawer, this is possible with the addition of ZWO's M54 15mm Adapter (PAPI-ZW-D70-M54F). Please see the product images at the top of this page for how to configure it with your camera.
The ZWO OAG-L is not compatible with the Pegasus Astro Indigo Electronic Filter Wheel.
ZWO OAG-L Compatible Guide Cameras
For guiding, the OAG-L can only work with ASI Mini cameras. It is not compatible with ZWO planetary cameras that lack the "Mini" moniker.
- ASI174MM Mini
- ASI290MM Mini
- ASI120MM Mini
How to Connect the ZWO OAG-L
Please see the product images above for full details on how to connect the ZWO OAG-L with your specific imaging train. The ZWO OAG-L is 17.5mm thick, making it easy to connect to other ZWO accessories and retain a standard 55mm back focus. Depending on the size of the rear threads on your telescope or corrector, the OAG-L can use one of three tilt adapters to connect to it:
- M48 tilt adapter (included with OAG-L)
- If the thread on your telescope side is M48, then you don’t need to remove the M48 sensor tilt plate that comes with the OAG-L.
- M54 tilt adapter (included with ASI6200 & ASI2400 cameras)
- If your telescope side threads are M54, ZWO offers an M54 sensor tilt plate (PAPI-ZW-M54-PLATE). This tilt adapter plate is already included with the ASI6200MM Pro, ASI6200MC Pro, and ASI2400MC Pro cameras, so if you have one of those cameras there is no need to purchase the extra tilt adapter. You only need to purchase this tilt adapter plate if you are using the ASI2600MM Pro or ASI2600MC Pro and have a telescope with M54 threads.
- M68 tilt adapter
- Lastly, ZWO also offers a tilt adapter plate with M68 threads (PAPI-ZW-M68-PLATE) for telescopes with larger rear threads.
On the camera side, the ZWO OAG-L features a bolt-on style connection that will bolt directly onto the ZWO 7x2", 5x2", and 7x36mm filter wheels or the ZWO M54 15mm Adapter (PAPI-ZW-D70-M54F) mentioned above.
ZWO OAG-L Additional Info and Tips
- Considering the large prism size, we don’t recommend you use the OAG-L with telescopes whose clear aperture is smaller than M48.
- The major differences between OAG-L and the now discontinued M68 OAG are the prism size and the threads. The OAG-L removed the inner threads so you can directly use the screws to connect it to ZWO 2" and 36mm filter wheels.
- While adding OAG-L into your optical train, please make sure the prism won’t block the camera sensor. You can use the guiding screw to adjust the guiding camera’s focus length. Please make sure the distance from the prism to the main camera and to the guide camera are the same. To ensure the result, it is better to do this at daytime for the adjustment will be very difficult at night.
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
- Lightweight and 17.5mm thick
- Prism size: 12x12mm
- The effective light-passing aperture is 11.7mmx8.3mm
- Can be used to connect the main camera and guide camera simultaneously. No guide telescope required.
- Packaged with an M48 sensor tilt plate (5mm)
- PLEASE READ: Visit the compatibility section below carefully to make sure the OAG-L is right for your imaging train. This item is often ordered by mistake because LARGE is not necessarily better. The OAG-L is not necessary for 4/3" or smaller sensor cameras and the standard ZWO Off-Axis Guider with 1.25" Holder and M48 / M42 Threads # OAG may be a better choice for you. Please vist ZWO's webpage Best Solutions for 55mm Back Focus for examples of various imaging train setups using ZWO gear.
The ZWO OAG-L is short for off-axis guider - large and is designed specifically for ZWO full frame and some APS-C sized cooled cameras. The ZWO OAG-L is the ideal choice for serious astrophotographers who need the most sensitivity they can get for detecting guide stars.
The OAG-L features an increased prism size of 12x12mm, giving a wider field of view for detecting a guide star than ZWO's standard OAG. The OAG-L is best paired with ZWO's top end guide camera, the ASI174MM Mini (PAIC-ZW-ASI174MM-MINI), which has a similar sized sensor as the prism on the OAG-L. The large pixels on the ASI174MM Mini paired with the OAG-L's large prism essentially guarantees you will be able to find a guide star, even when imaging in heavy light pollution, using a slow focal ratio telescope, or both. As an upgrade over the standard ZWO OAG, the OAG-L features a helical focuser built in to the design, making it easy to focus your guide camera. Hence, you do not need to buy ZWO's 1.25" helical focuser separately for this OAG-L.
Off-axis guiders offer better performance over traditional guide scopes when used on longer focal length systems for three main reasons:
- Allows you to guide at the same focal length of your telescope which is critical for systems over 1000mm in focal length
- No guide scope means less weight riding on the telescope, which provides better tracking performance.
- Eliminates the possibility of flexure (slight sagging of the guide scope caused by gravity, which negatively affects guiding)
ZWO OAG-L Compatibility
The OAG-L is currently natively compatible with the following cameras without the need for any additional adapters. Please see the product images at the top of this page for how to configure it with your camera.
- ASI6200MM-P & ASI6200MC-P
- ASI2400MC-P
- ASI2600MM-P & ASI2600MC-P
ZWO OAG-L with Smaller Format Cameras
The ZWO OAG-L is not compatible with ZWO's M42 Filter Drawer, meaning it is not usually practical for most astrophotographers using smaller sensor cameras. For those users, we recommend ZWO's regular OAG (PAPI-ZW-OAG) and the helical focuser (PAF-ZW-HF1.25) to go with it. However, for those users who just want to use the ZWO OAG-L without a filter drawer, this is possible with the addition of ZWO's M54 15mm Adapter (PAPI-ZW-D70-M54F). Please see the product images at the top of this page for how to configure it with your camera.
The ZWO OAG-L is not compatible with the Pegasus Astro Indigo Electronic Filter Wheel.
ZWO OAG-L Compatible Guide Cameras
For guiding, the OAG-L can only work with ASI Mini cameras. It is not compatible with ZWO planetary cameras that lack the "Mini" moniker.
- ASI174MM Mini
- ASI290MM Mini
- ASI120MM Mini
How to Connect the ZWO OAG-L
Please see the product images above for full details on how to connect the ZWO OAG-L with your specific imaging train. The ZWO OAG-L is 17.5mm thick, making it easy to connect to other ZWO accessories and retain a standard 55mm back focus. Depending on the size of the rear threads on your telescope or corrector, the OAG-L can use one of three tilt adapters to connect to it:
- M48 tilt adapter (included with OAG-L)
- If the thread on your telescope side is M48, then you don’t need to remove the M48 sensor tilt plate that comes with the OAG-L.
- M54 tilt adapter (included with ASI6200 & ASI2400 cameras)
- If your telescope side threads are M54, ZWO offers an M54 sensor tilt plate (PAPI-ZW-M54-PLATE). This tilt adapter plate is already included with the ASI6200MM Pro, ASI6200MC Pro, and ASI2400MC Pro cameras, so if you have one of those cameras there is no need to purchase the extra tilt adapter. You only need to purchase this tilt adapter plate if you are using the ASI2600MM Pro or ASI2600MC Pro and have a telescope with M54 threads.
- M68 tilt adapter
- Lastly, ZWO also offers a tilt adapter plate with M68 threads (PAPI-ZW-M68-PLATE) for telescopes with larger rear threads.
On the camera side, the ZWO OAG-L features a bolt-on style connection that will bolt directly onto the ZWO 7x2", 5x2", and 7x36mm filter wheels or the ZWO M54 15mm Adapter (PAPI-ZW-D70-M54F) mentioned above.
ZWO OAG-L Additional Info and Tips
- Considering the large prism size, we don’t recommend you use the OAG-L with telescopes whose clear aperture is smaller than M48.
- The major differences between OAG-L and the now discontinued M68 OAG are the prism size and the threads. The OAG-L removed the inner threads so you can directly use the screws to connect it to ZWO 2" and 36mm filter wheels.
- While adding OAG-L into your optical train, please make sure the prism won’t block the camera sensor. You can use the guiding screw to adjust the guiding camera’s focus length. Please make sure the distance from the prism to the main camera and to the guide camera are the same. To ensure the result, it is better to do this at daytime for the adjustment will be very difficult at night.
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
ZWO OAG-L Large Off-Axis Guider with 1.25" Holder # OAG-L