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I am wondering if I can mount an ASI120MM Mini camera to the Orion finder scope that came with my telescope for guiding?
It's an Orion 8x40. Looks like the crosshairs may come out easily, but I haven't done anything dumb yet.
I have a wood lathe so I could turn a plastic adapter if needed.
What do y'all think?
Thank you!
Please stay safe out there.
It all depends on what you're going to use for your imaging scope and imaging camera. You try to have no greater than a factor of 5 difference in the scale between the imaging setup and the guide setup.
So, for example, if you're guiding set up gives you 5 arcseconds per pixel you wouldn't want your imaging set up to be less than 1 arcseconds per pixel.
Cheers,
JT
∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac ∞ AP Scopes: #1: TPO 6" f/9 RC #2: ES 102 f/7 APO #3: ES 80mm f/6 APO ∞ G&G Scopes: #1: Meade 102mm f/7.8 #2: Bresser 102mm f/4.5 ∞ Guide Scopes: 70 & 80mm fracs -- The El Cheapo Bros. ∞ Mounts: iOptron CEM70AG, SW EQ6R, Celestron AVX, SLT & GT (Alt-Az), Meade DS2000 ∞ Cameras: #1: ZWO ASI294MC Pro #2: 662MC #3: 120MC, Canon T3i, Orion SSAG, WYZE Cam3 ∞ Binos: 10X50,11X70,15X70, 25X100 ∞ AP Gear: ZWO EAF and mini EFW and the Optolong L-eXteme filter ∞ EPs: ES 2": 21mm 100° & 30mm 82° Pentax XW: 7, 10, 14, & 20mm 70°
Searching the skies since 1966. "I never met a scope I didn't want to keep."
The focal length of your finderscope is an unknown. There is a way to figure this out but it would need to be in my physical possession to do this. So I'm guessing it is around 180mm (if it is shorter, this will make the numbers worse). We know your guide camera pixel size is 3.75µm, we know your imaging camera pixel size is 2.4µm and your imaging scope's FL is 1000mm. Throw these numbers into the magic calculator and your imaging scale is 0.5 arcseconds/pixel and your guiding scale is 4.3 arcseconds/pixel (or worse). So your difference in scale is about 8.5X.
This means that theoretically, your finderscope is unsuitable for guiding with that imaging scope. The only way to fix this to get a guide scope with a longer FL. BUT if this is all you have right now, then give it a try and see what you get. PHD2 is supposed to give you sub-pixel accuracy up to a theoretical limit of 1/10 pixel! Give it a go, you might get lucky!
Cheers,
JT
∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac ∞ AP Scopes: #1: TPO 6" f/9 RC #2: ES 102 f/7 APO #3: ES 80mm f/6 APO ∞ G&G Scopes: #1: Meade 102mm f/7.8 #2: Bresser 102mm f/4.5 ∞ Guide Scopes: 70 & 80mm fracs -- The El Cheapo Bros. ∞ Mounts: iOptron CEM70AG, SW EQ6R, Celestron AVX, SLT & GT (Alt-Az), Meade DS2000 ∞ Cameras: #1: ZWO ASI294MC Pro #2: 662MC #3: 120MC, Canon T3i, Orion SSAG, WYZE Cam3 ∞ Binos: 10X50,11X70,15X70, 25X100 ∞ AP Gear: ZWO EAF and mini EFW and the Optolong L-eXteme filter ∞ EPs: ES 2": 21mm 100° & 30mm 82° Pentax XW: 7, 10, 14, & 20mm 70°
Searching the skies since 1966. "I never met a scope I didn't want to keep."
