Astro_Chroma

This thread has been SO HELPFUL for me. THANK YOU. I am currently putting together my Samyang 135mm for wide field astrophotography as well. I purchased the Hyperpod. While it is a great design, the guide shoe mounts are not sturdy and both snapped while I was barely tightening the screws to hold my guide scope and ASIAir Plus. To fix this issue with the guide shoe mounts for the guide scope, and ASIAir Plus, I used the guide shoe from the ASIAir Plus and EAF bracket that came with the EAF to secure it to the HyperPod. It works flawlessly (see attached pictures). You can still use the screws that came with the HyperPod. For the EAF bracket, you will the need a medium size washer to secure one screw to one end of the HyperPod mounting rings. Same thing for the ASIAir guide shoe mount, but no need for a washer to secure the guide shoe to one end of the mounting rings. The EAF bracket used with the ASIAir secured to the HyperPod mounting ring clears the large gear on the lens, and it is very sturdy once every thing is tightened up. Regarding the EAF backlash, I currently have my set at 150; step limit is 6900; course step is set at 50 (will decrease this to 20-25 for fine step). To ensure the larger gear on the lens doesn't hit the EAF bracket, first adjust the lens so that infinity simply is 90 degrees and perpindicular to the large gear (and vise versa). Set the lens to infinity and EAF "current position" to zero. Run the EAF (starting at zero). Pay attention to the large gear and watch it approache the side of the EAF mounting bracket. Be sure to immediately stop the EAF before it hits the bracket. When stopped, jot down the EAF position, and set the position as your limit to ensure the large gear on the lens never hits the EAF bracket and cause the gear to skip. The way I have my EAF positioned on the Hyperpod, I run the EAF in reverse (as suggested by Adrenaline). See attached pictures. Regarding OSC spacers/adapters, I really like the Play One Poseidon-C Pro (IMX 571 sensor). Though, I would be switching to NINA to use this camera as it is not compatible with the ASIAir (duh...🙄). If I were to go with a ZWO camera, I think either the 533 but more so the 2600mc pro (which is comparable to the Poseidon) would be best as I want to utilize a large fov for widefield imaging. This dilemma is driving me crazy as I am also considering an astro-modified Canon RP. Any input would be helpful. Regarding back focus (44mm required for the Samyang): For the Asi533mc pro : 6.5 (camera) + 11mm (adapter) + 26.5 (ZWO t2 thread to canon eos ef mount (without 5mm spacer) + .67 (2" filter -1/3 of the filter) =44.67 back focus. For the Asi2600mc pro or Player One Poseidon: 17.5(camera)+ 26.5 (ZWOt2 thread to canon eos ef mount without 5mm spacer) + 2" filter = 44.67 If you decide to use a filter wheel with any OSC (such as asi533 or 294) with a 6.5 back focus to sensor I believe it replaces the 11mm. I think you're able to go over the standard back focus of 44mm with the Samyang by bit, as the ZWO t2 adapter for the lens intended for users to use a 2" filter. I hope this helps.