6 replies to this topic

[Macroscopic]

I’m moving over to astrophotography from photography and I’m currently working out what equipment I need and slowly acquiring it. I wondered if you could help me understand if I need anything ‘special’ with regards to guide scope and camera.

 

I’m intrigued by the Zwo AM5 harmonic mount - I seem to be their targeted user. But reading some initial comments I understand it requires at least 2fps (0.5 second) guiding. I’d initially be using a William Optics Zenithstar 73 III.
 

Would something like the William Optics 50mm f/4 scope paired with a ZWO ASI 120MM Mini guide camera be able to achieve this? Or does it need to be ‘faster’?

Edited by Macroscopic, 16 January 2022 - 11:47 AM.

[jonnybravo0311]

I don't use the AM5, but I have a very similar guiding setup with the 50mm f/4 and QHY 5L-II. I use 1" exposures with multi-star guiding and have no issues whatsoever locking on to multiple stars, so I think you'll be fine with that setup. You can always adjust your gain higher if necessary.

[DeepSky Di]

Welcome to Cloudy Nights! I use a WO GT81 (larger scope) with a WO Uniguide 30 (smaller guide scope) and I chose the 290MM mini guide camera because at the time there were USB compatibility issues reported with the 120MM.

[matt_astro_tx]

I think you should be fine with the ASI120MM-Mini.

 

Why a 50mm guidescope?  You can grab the SV165 for $53 (on Amazon, no less) and it'll do the job.

[Macroscopic]

Thank you for the advice in this this thread.

 

If I were to buy an EQ mount I’d simply get the cheapest guiding system I could get away with considering I’d just be doing wide view astrophotography. However, as harmonic mounts are different I wanted to understand if there would be any additional considerations.

 

The Rainbow RST-135 is nearly twice the price of the unreleased AM5 yet that has large PE and requires at least 0.5 second exposures across multi-stars. I worry the AM5 would require even faster guidance…

 

I’m just trying to ascertain whether the following are important guiding variables given the unknown nature of the AM5:

• USB2 vs 3 (for fast frame guiding capture)
• Sensor size
• Scope size

Edited by Macroscopic, 17 January 2022 - 11:55 AM.

[FrostByte]

My little mount is an iExos-100, which needs to be guided aggressively to keep it under control... A ZWO 30mm guidescope and ASI120MM-mini (USB2) work just fine to tame the little beast at 0.5-1 second guiding.

[NoDarkSkies]

USB 2 for Guide Camera and USB 3 for Main Imaging Camera.
I went with the ASI174MM Guide Camera for Guiding.

My Guide Telescopes are WO 50mm and one Guide Star 61
I use the ZWO 1.25" Helical FocuserZWO-HF1.25 on my Guide Scopes as well to make it easier to Focus.

Edited by NoDarkSkies, 17 January 2022 - 12:25 PM.