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StellaLyra RC8 first light with Messier 97 (RGB)


Hughsie

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To say this has been a major source of frustration would be an understatement. After months taking myself off into the garage in all temperatures and fiddling with mirrors, screws and whatnots, Friday presented an opportunity to put the RC8 through its paces. All the usual niggles of finding the focus point, then a bad USB cable stopped images downloading and I managed to get started reviewing collimation under the stars. Having got to where I was with collimation I needed cheering up so pointed it at M97 and snapped away for 3 hours to see what I could capture and produce. So here it is;

M97_RGB.thumb.jpg.de823891d5171b25a0a3dad3fd1fb422.jpg

I wasn't fussed about framing, I just wanted to see something, anything just to assess whether this was a project heading in the right direction.

It's getting there and I feel much better than I did with this scope a few months ago.

Onwards and upwards!

Edited by Hughsie
Wrong Messier number
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  • Hughsie changed the title to StellaLyra RC8 first light with Messier 97 (RGB)

Great image. Seems like your work has paid off.

I hope your issues with the RC8 are not what I have to look forward to.... Mine is slightly out if collimation and I am dreading trying to get it right.

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8 hours ago, Clarkey said:

Great image. Seems like your work has paid off.

I hope your issues with the RC8 are not what I have to look forward to.... Mine is slightly out if collimation and I am dreading trying to get it right.

I had no prior experience with collimating at all never mind with an RC and read so many articles here and on other websites plus YouTube channels. For what it is worth, don’t take your scope apart. First, check the secondary withe a Cheshire to make sure the donut is centred and see if visually your primary mirror looks concentric. Then put it under the stars and see what they look like before making any adjustments to the primary.

If the primary needs adjusting read this article  http://www.deepskyinstruments.com/truerc/docs/DSI_Collimation_Procedure_Ver_1.0.pdf

When you are familiar with the contents and assuming your primary needs tweaking then put the scope under the stars again and adjust the primary using the method above. If you have a long garden you could use an artificial star and make the adjustments during the day. Whatever you have to do, make small adjustments only.

I did none of this and threw myself straight into it and got the pain I deserved. In the end I had to screw down the primary tight then loosen the screws three turns each to ‘reset’ it then collimate it. This could have thrown out the focal length of the scope so after getting what I thought was a collimated mirror I took a quick image, uploaded it to Astrometry.net and held my breath. I was lucky and the focal length was just a few mm out.

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Thanks Hughsie. I have done the reading and I am waiting for a new collimating tool. I have just seen so many 'experts' struggle with these it has made me nervous! I know mine is out of alignment with the mechanical axis although optically it is not too far off. Fortunately I have a long garden😂.

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Great image. I have one basic with RC collimation: Leave one adjuster locked and do all the remaining adjustments with the other two - that way you keep mirror spacing reasonably constant as small changes in separtion of the optics makes a big difference in the final focal length and the position of back focal plane.

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28 minutes ago, fwm891 said:

Great image. I have one basic with RC collimation: Leave one adjuster locked and do all the remaining adjustments with the other two - that way you keep mirror spacing reasonably constant as small changes in separtion of the optics makes a big difference in the final focal length and the position of back focal plane.

Hi Francis, I did read your exploits with your own RC to give myself some inspiration and guidance so thank you for your posts.

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