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Totally blurry FOV even after collimation


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I had a telescope some years ago and recently got back into the game with a 6" Skywatcher.

Attempted some observing a couple of nights ago and could only see a complete blur through my lens. I tried a 10mm, 25mm & 28mm lens. The scope has a sweet focuser with a fine tuning knob to boot; but no matter how much I tried, it was always completely blurry.  I could see Polarise perfectly thought the built in polar aligner on the scope of my mount as I was questioning my own eye sight at one point (still haven't ruled that out).

So I concluded the scope needed collimating (it's a 2nd hand scope). Purchased a laser collimator and completed the alignment. Then took it out in the day and pointed it at some hills about 3 miles away.  Still completely blurry no matter how much I focused.

I don't know if the metal fins at the very front of the scope are meant to be adjusted as part of the collimation, as the laser collimator doesn't cover that. Not touched that part of the scope.

If I take the eye piece out and stand about 8-10 inches away, look into the scope i.e. at the secondary mirror without a lens in, I can see the hills albeit upside down. It's only when I put a lens in, any lens it seems, and adjust the focuser from minimum to maximum, I get a consistent blurry image. You can make colours but that's it.

Stuck now - any advice would be appreciated.

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Thanks for coming back to me Cornelius.

To be honest, I'm not sure. I've attached a picture here which shows (I think) a 28mm lens with the 2" adapter and also a 2" to 1.25" adapter for the 10mm lens. The 28mm just goes straight into the eyepiece of the scope. The other one allows me to swap lenses once the adapter is in place.

IMG_2121.jpg

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that won't work you need the 2" adaptor as well or put the eyepiece into the 1.25" to 2" adaptor that came with the scope as per my previous images.

as per your final image the eyepiece needs to come out approx 40mm so if you have the 2" adaptor then you should achieve focus

Edited by fozzybear
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I think the problem is that the adapters you have are not holding the eyepiece in the correct position to allow them to reach focus within the range of travel that the focuser has.

You need to use adapters like the ones in the photos that @fozzybear has posted. You current 1.25 inch adapter is too short and your 2 inch eyepiece needs to go in a 2 inch adapter. The adapter on the end of your focuser tube is not actually a 2 inch one - it is a little wider to accept the flared ends of the correct adapters that you see in the photos.

 

Edited by John
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Thanks everyone for your help. Absolutely spot on about the adapters. Helps my understanding of a focus point too. Have now worked out both the 2" and 1.25" adapters that needed to be in place first to allow correct distance to eye.  The hills have come into perfect focus. Also I can hold off on the glasses for now as I really did wonder if my sight was going slightly : ) )

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3 hours ago, mattatclc said:

Thanks everyone for your help. Absolutely spot on about the adapters. Helps my understanding of a focus point too. Have now worked out both the 2" and 1.25" adapters that needed to be in place first to allow correct distance to eye.  The hills have come into perfect focus. Also I can hold off on the glasses for now as I really did wonder if my sight was going slightly : ) )

So glad that you have your scope up and running … this is one reason why this forum exists . Everyone on here wants to help and for everyone who is new to astronomy and new to SGL remember that every question is treated the same way with respect and knowledge. In other words NEVER be afraid to ask . :) 

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4 hours ago, mattatclc said:

Thanks everyone for your help. Absolutely spot on about the adapters. Helps my understanding of a focus point too. Have now worked out both the 2" and 1.25" adapters that needed to be in place first to allow correct distance to eye.  The hills have come into perfect focus. Also I can hold off on the glasses for now as I really did wonder if my sight was going slightly : ) )

Glad to have helped you out and now you are on your way :) 

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