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Anthony RS

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  1. Hello! I bought the HPS 2 inch coma corrector https://www.highpointscientific.com/telescope-accessories/focal-reducers/high-point-2-newtonian-coma-corrector-photo-visual and I thought it would at least come with it's own manual showing the correct spacing etc.. but apparently it doesn't. I checked some forums, and they are comparing it to the GSO CC on which I found a huge thread and it requires 75mm of spacing. The problem is that I haven't had success with 75mm spacing and I don't have enough spacers to try different spacings. So is there anyone using this specific CC with good results? and what's the spacing you're using? Using an 8 inch Netwonian F5 btw. Thanks! Anthony
  2. That's what I though but I'm trying to eliminate any other possible causes and I thought collimation might be one. I think my main issue is focuser sag. Maybe tilting is caused by the focuser sagging when I change focus with the DSLR attached. Do you think that could be the problem?
  3. I already have a thread regarding the issue basically it's offcentered coma, so I' have coma more pronounced in one corner than the others.
  4. I did not know that about the star test. Thank you! I'll try that. As for the offset, I'm only talking about the offset towards the primary not away from the focuser. Here's what I mean: I've been reading that there are 2 ways of collimating the secondary. The first way is by actually centering the Secondary mirror in the focuser tube so that it's dead center. This will result in the REFLECTION to be offset (which is the way my scope is currently collimated). The other way is by offsetting the actual mirror towards the primary which should result in the reflection to be centered. I just want to know if the second method might yield better results for AP and if using the first method might be the reason I'm having the offset coma in my images.
  5. This is where I'm having problems, star test. After collimating and doing a star test, I tried to center the black dot however the results were terrible which leads me to my other question! If the seconday is offset so the relfection isn't actually at the center, doesn't this mean that when I do a star test, the black dot should also be offset and centered?
  6. I have a celestron 8 inch C8N (the one with the AVX mount). I know the offset is created automatically once I center the seconday in the focuser but my questions are: 1- Could that offset result in an offset coma while using a coma corrector? 2- Is it better if I move the secondary mirror inwards towards the primary so that the secondary mirror is offset but the reflection is actually centered? would that produce better images?
  7. I don't really know much about offset. All that I did is center the secondary mirror in the focuser and collimated but I've been reading that a fast newtonian will automatically have the secondary mirror offset if collimated properly. So now I have 2 choices, either leave it as is with the reflection offset, or move the secondary mirror a bit towards the primary which would offset the actual secondary mirror, but the reflection should appear centered and not offset. This is too complicated for me and I don't know which method to follow. Apparently centering both the secondary mirror and the reflection is impossible with my newtonian?!
  8. Hello! I've been having some offset coma issues with my f5 Newtonian so I've been trying to eliminate some elements that might be causing the issue so for now, just to remove collimation out of the equation, I need advice on whether or not my secondary appears to be well in place (not forgetting offset). Below are some images I took, my question is should the black outer ring(pointed by the red lines) be concentric with the rest of the rings? if yes, how do I go about fixing that? is it by adjusting the tilt or moving the secondary inward or outwards (towards primary) or moving secondary away or towards focuser? I also have another image with a crosshair which might help letting me know if the secondary is accurately positioned. Edit: It's not apparent in the image but the crosshair in the image is pointing right on the primary center marker. Thanks!
  9. Anthony RS

    Off Centered Coma

    Ok, would appreciate if you let me know if you've figured it out. I'm not sure also if it's due to spacing or some tilt.
  10. Anthony RS

    Off Centered Coma

    I'm having the same issue. Did you figure it out?
  11. Anthony RS

    Help! Is it my DSLR or Newtonian?

    I would've never thought that the adapter might be tilted. Variables keep on increasing instead of decreasing lol. I'm using a Canon M48 t ring but I've never thought it could be the one causing the tilt.
  12. Anthony RS

    Help! Is it my DSLR or Newtonian?

    I do travel to do imaging and it's a bumpy road! My aim is to figure out what's causing this so if it's due to disturbing the reflector's setup, then I'd try to fix that every time i get to the location before starting to image. What's frustrating is the process of figuring out what the issue is. I wish I could afford a decent refractor but it's my next target for sure.
  13. Anthony RS

    Help! Is it my DSLR or Newtonian?

    Last time I tried my best to square the focuser and collimate the scope and I got the result i nthe image below which is much better than before (at least the stars on the left arent way out of focus). I also think it could be a combination of problems which would be really hard to point and test. I'm trying my best but this is really frustrating and demotivational
  14. Anthony RS

    Help! Is it my DSLR or Newtonian?

    I'll try that and let you know.

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