Hey Brian,

I picked up a set of Blue Fireball rings from Agena:

https://agenaastro.com/blue-fireball-m54-thread-spacer-set-3.html

They don't have any spanner notches, so occasionally it's difficult to separate two from each other, but otherwise they work well for my imaging train.

-Ken

On Mon, Jan 30, 2023 at 8:55 AM Brian Valente <bvalente@...> wrote:

Hi everyone

I need to adjust my image train backfocus which is M54 all the way through, but spacer tubes at this diameter seem to be hard to find and expensive

Any leads on these?

--

Brian 

Brian Valente

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