Image of the day

Captured by
Yue Ma

Cas A in NIR. RBI mitigated

My Account

New to Astromart?

Register an account...

Need Help?

Coma Corrector Crazy $$$ ???

Started by EdwardTeach, 09/10/2021 09:26AM
Posted 09/10/2021 09:26AM Opening Post
I'm relatively new to astronomy and I'm just setting up my first better than beginner setup based around a Sky-Watcher Quattro 200P. 

I understand the F4 speed is achieved at least partially through the more curved primary mirror and that's why they need a special coma corrector to compensate. But OMG...

Why is the Quattro coma corrector at $375 more than half the price of the entire OTA???
Posted 09/10/2021 10:04AM #1
Originally Posted by Larry Holt
I'm relatively new to astronomy and I'm just setting up my first better than beginner setup based around a Sky-Watcher Quattro 200P. 

I understand the F4 speed is achieved at least partially through the more curved primary mirror and that's why they need a special coma corrector to compensate. But OMG...

Why is the Quattro coma corrector at $375 more than half the price of the entire OTA???
Because it's an imaging newtonian optimized for astrophotography. As such, the corrector provides:
f/4 ED coma corrector
FPL51 and Schott glass
Optimized for Quattro imaging Newtonians
Requires 55mm backfocus
https://www.adorama.com/skws20204.html?gclid=Cj0KCQjw4eaJBhDMARIsANhrQAA-7esEOpH_71nR1w3_dRWD-LpEmP6cp3TT-aO6_muZvJ9mhAK-ye0aAtMHEALw_wcB&gclid=Cj0KCQjw4eaJBhDMARIsANhrQAA-7esEOpH_71nR1w3_dRWD-LpEmP6cp3TT-aO6_muZvJ9mhAK-ye0aAtMHEALw_wcB&utm_source=adl-gbase-p
A possible visual & photographic corrector option:
https://www.highpointscientific.com/baader-planetarium-2-mark-iii-multi-purpose-coma-corrector-mpcc?utm_source=google&utm_medium=cse&utm_term=BAD-MPCC&gclid=Cj0KCQjw4eaJBhDMARIsANhrQAAYr55d-lRTtRNYwtaZvDs7YGX493HkG-AasGbfAxoeCJ0HDXQ8h2saAvhPEALw_wcB
Visually, this MAY work but may not for photographic:
https://www.aliexpress.com/item/32917167365.html?spm=a2g0o.productlist.0.0.3ed77642rn5ljH&algo_pvid=ef2e4e22-011a-49b9-967d-8092ef54280a&algo_exp_id=ef2e4e22-011a-49b9-967d-8092ef54280a-1&pdp_ext_f=%7B%22sku_id%22%3A%2266029924265%22%7D