The ASG Photon Cage was designed to provide tilt, backfocus, and removable filter slider capabilities to any telescope.  What started as a RASA specific device has become a useful tool for any telescope, including refractors, reflectors, epsilons, RASA's and others.

Modular Design

The ASG Photon Cage is unique in that it was designed to work on RASA telescopes as well as mount to any electronic filter wheel or optical train.  We now make the Photon Cage with multiple modular bolt patterns; our ASG 5 bolt fitler slider pattern as well as the common 6 bolt EFW bolt patterns.  We also provide M54 female threads for a universal application.

ZWO 2600 Duo Compatibility included

We are now going to include the DUO 2600 compatible ring as part of our standard 90mm cage system moving forward.  This extra feature makes special room for the ZWO DUO 2600 focuser knob.   This also makes a great 90 degree port for OAG users and alignment.  There is no impact here for users with regular QHY, ZWO cameras either, so it makes a good additional feature for everyone.

Main Baseplate Connection Options

The ASG Photon Cage is now shipping with one single modular baseplate that includes a variety of mounting options.

1.  M54 female threads are universal and accept any M54 extension or adapter.  Thread depth is 3mm.
2.  6 bolt EFW pattern to mount to your filter wheel with M2.5 screws.  This is the standard 62mm diameter pattern found on most larger EFW systems.
3.  5 bolt ASG Filter Slider pattern to mount our own standard filter slider holders.

If not using these ports, we offer plugs and set screws to close holes you may not need!  Please note that if you use a 6 bolt EFW, it should have M2.5 screws with it and that are the correct lengths to adapt.  We do not provide the EFW bolts, we only provide the M2.5 6 bolt threaded holes on our end.

Filter Slider features

The Photon Cage is specifically designed with an ultra-thin filter slider system so that it can be cross-compatible amongst RASA 8's and 11's.  Specifically designed so you can take it with you when upgrading from a RASA 8 to a RASA 11 or simply switching between telescopes.  You can even use the entire system on a refractor, SCT, Epsilon, or Newtonians.

We also have a special filter holder for RASA 8 2400/2600 camera users who have 12.5mm backfocus AND want a filter slider that comes out... We unlocked it and here it is.  CNC machined for precision and mounts to our Photon Cage system so you get everything on there in one device.

Lastly, we offer a PRO filter slider system that is capable of bolting to your Photon Cage and provide a wider variety of larger glass.  50mm x 50mm unmounted filters, 50mm unmounted round filters, or 2" mounted filters are popular amongst larger Full Frame camera users.  The PRO filter slider system comes with an M68 baseplate ready to bolt to any M68 x 1mm threaded accessory.

1. Standard Filter slider is great for low cost CNC or 3D printed 2" mounted filters.  Works great on RASA 8, RASA 11, SCT, Epsilon, newts, Refractors and camera sensors up toward the APS-C sensor size limit and some Full Frame setups.  Comes with M42, M48, or M54 baseplates.
2. PRO filter slider is great for higher end Full Frame users needing maximum light gathering and lowest vignetting using 50x50, 50mm round, or 2" mounted filters.  A bit more expensive, but great for RASA 11 + Full Frame users, Epsilon or other users utilizing a Full Frame camera and need a manual filter slider.  Comes with an M68 baseplate.
3. Special RASA 8 filter slider is for those using a RASA 8 + 90mm camera such as 2600mm/mc.  This special setup replaces the lock ring and uses our economical 2" mounted filter sliders.  No baseplate is needed as it threads onto your RASA 8.

We offer our filter sliders in CNC machined aluminum with thumbscrew and set screws OR you can choose the lower cost 3D printed but equally capable filter sliders.  Custom boxes are also available in a variety of custom configurations such as RGB, HOS, LRGBHOS, Photometry UBVRI, or even blanks.  We can even custom engrave the CNC filter sliders with your filter specs on it!

Tilt features

The Photon Cage really excels in replacing the stock tilt plates on many astrophotography cameras with a system that is accessible from the rear.  We use super fine 120tpi thread adjuster screws to give you 4-corner tilt adjustment across all our systems to really get those corner stars flat and round.  Use popular software such as ASTAP or CCD Inspector to calibrate or visually monitor your corner stars and get the flat field you need with easy to access adjustment screws.

Backfocus features

The ASG Photon Cage provides backfocus adjustment with push-pull technology.  Configure your entire optical train to -.5mm or -1mm under specification and then fine tune your backfocus in and out with our outer ring system.  The Photon Cage offers about 5mm or so of total adjustment.  No more adding washers or extra spacers here and there, now you can micro-adjust using fine thread adjustment your backfocus and dial in that perfect shot.

What Do You Need?

It can be confusing trying to add up the adapters and spacing, so we make it modular and easy.

• (SMALL) 78mm Diameter camera bodies include the ZWO 1600mm, 294mm, 294mc, 533m, 533mc, 183mm, and 183mc.  Our small camera system works with nearly any camera that has the 78mm smooth body style.  These cameras typically have 6.5mm backfocus.
• (LARGE) 90mm Diameter camera bodies include the ZWO 2400, 2600, and 6200 series cameras.  Our large camera system works with nearly any camera that has the 90mm smooth body style including QHY cameras.  These cameras typically have 12.5-18mm backfocus, but it can vary.  QHY cameras with dovetails and CAA adapters can have as much as 23mm of backfocus, but still work with the system.

What Size Filter Slider Baseplate Do You Need?

The ASG Photon Cage filter slider baseplate refers to the scope side threads mounted under our filter slider.  42mm, 48mm, or 54mm are offered, and you can even purchase different ones should you need.

• 42mm baseplate - This is stock and necessary for the RASA 8.  You will screw your 42mm RASA 8 camera holder directly into this 42mm baseplate.  On RASA 11's, you have a stock 42mm and 48mm camera holder.  So it can easily work with the 42mm with additional spacers.
• 48mm baseplate - This is stock on the RASA 11 and with the addition of 48mm spacers will give you a full 48mm optical pathway.
• 54mm baseplate - This option is designed to work in conjunction with our custom 54mm RASA 11 camera holder.  It opens up your optical train to allow more light through.  Use 54mm spacers or rotators in various configurations to take up the extra space.  Great for users with up to an APS-C sensor such as the 2600mm/mc or QHY 268M/C or lower.
• 68mm baseplate - This option is only available if you use the PRO filter slider system with PRO filter sliders.  This is the top choice with CNC aluminum sliders up to 50x50 square.  Great for users with Full Frame cameras looking for maximum unobstructed optical path.

Do you need 54mm or 68mm PRO camera holder & baseplate?

This is optional, but highly recommended for any RASA 11 systems or anyone needing the maximum sized filters for your setup.  APS-C sensors and smaller work great with the M54 setups.  The PRO system is designed to get the most out of a fast telescope such as a RASA 11 with really steep light cones and larger filters.  For a full analysis, you can read our RASA 11 + 6200 analysis here.

What about RASA 8 and 2400/2600mm/mc  users?

We offer a special filter holder to fit those big cameras on the RASA 8 WITH a removable filter slider.  Now you can mount our special lockring and filter slider on with 12.5mm of backfocus.  Add 3mm for our photon cage tilt system plus 12.5mm for your ASI 2400/2600 cameras and you have about 28mm of space, perfect for use to adjust backspacing as well.

Filter Slider Options

We offer a variety of bulk filter slider options.  Pick from CNC aluminum laser engraved or our 3D printed options in a RGB, HOS, LRGBHOS, UBVRI, or even blank boxes.  Save when you purchase as a package.  Our filter sliders are specifically engineered for our Photon Cage and will work with any of our devices.  We also offer custom engraving services to mark CNC filter sliders or boxes with your specific filter needs.  Contact us for this service.