New toys - First light!

[Andy01 (Andy)]

Originally Posted by gregbradley

I don't think that is right Andy and it may be why the stars are off.

Per the link the correct metal back distance is 71.5mm,
scroll down the page and you'll see it. Where did you get 83.7mm?
I think there might be more than one TOA reducer, not 100% sure.

https://www.buytelescopes.com/takaha...oa-150b-132837

Now you need to add 1mm due to the thickness of the filters - I assume they are 3mm thick to get the optical back focus distance.

So that is 72.5mm.

From the sensor surface to your outside face of the OAG you say is 65mm.
So your remaining space is 7.5mm.

That sounds about right to me if my flattener was 7.5mm off it would look like that.

Try adjusting it in so you are at 7.5mm and see if that helps.

Usually flatteners are not so sensitive to the spacing, they can be a bit more forgiving.

Hi Greg, This is the exact same reducer I have...
https://www.buytelescopes.com/takaha...for-n-f-models

The backfocus chart is here as well...says 83.7mm
https://www.buytelescopes.com/t/TakahashiBackFocus

= f/5.79 · 780mm · 83.7mm w/TOA Reducer

Thanks again for your input, much appreciated!

[Xeteth (David)]

Andy - that variable spacer seems like it'd make backfocus adjustment much easier than adding spacing rings all the time. Would you mind sharing where I might be able to purchase one of these?

[gregbradley]

Originally Posted by Andy01

Hi Greg, This is the exact same reducer I have...
https://www.buytelescopes.com/takaha...for-n-f-models

The backfocus chart is here as well...says 83.7mm
https://www.buytelescopes.com/t/TakahashiBackFocus

= f/5.79 · 780mm · 83.7mm w/TOA Reducer

Thanks again for your input, much appreciated!

Oh I see. Yes I thought there were several types of reducers.

Greg.

[The_bluester (Paul)]

Originally Posted by Xeteth

Andy - that variable spacer seems like it'd make backfocus adjustment much easier than adding spacing rings all the time. Would you mind sharing where I might be able to purchase one of these?

I believe he had it made to suit but I am not sure who made it for him.

[Andy01 (Andy)]

Originally Posted by Xeteth

Andy - that variable spacer seems like it'd make backfocus adjustment much easier than adding spacing rings all the time. Would you mind sharing where I might be able to purchase one of these?

Hi David,
I had it made by Jim F in Adelaide. He was the original owner of the 'scope and has a complete fabrication workshop. I'll PM you his email address.
Cheers
Andy

[Ant0nio (Tony)]

Lovely image, congratulations on your first light with the Tak Andy
& good luck with sorting out your tilt/spacing issues. The comments relating to this are of great interest to me as I have no expertise in this area.
Cheers,
Tony