I have forgotten what they are for

[skyhawk]

I have forgotten what they are for

any ideas

thanks

P1050522.jpg (99.44 KiB) Viewed 2723 times

P1050523.jpg (147.59 KiB) Viewed 2723 times

[David Frydman]

It looks like a type of Barlow lens, maybe for a particular eyepiece.

I vaguely recall that I had one.
Maybe by a British accessory maker.

If it is a negative lens, not giving an image, this is likely.

Regards,
David

[LeoLion]

The first photo is 'barlowish' and from Astro Engineering (UK) and on sale from Astroboot (UK).Here is a copy/paste from the latters website

New item: By Astro Engineering. The AC555 MagniMax 1.25" filter thread fit photo-visual amplifier lens is new but has been removed from it packaging but is otherwise new. The AC555 screws to 1.25" filter threads on eyepieces and camera nosepieces and provides around 1.5x image scale amplification or visual magnification (depending on spacing the effect may be more or less than 1.5x). This is the latest version of the AC555 and has a male 1.25" filter thread on the rear and a female filter thread on the front. An indispensable accessory.

Hope this helps. My best wishes for Christmas and the New Year

[skyhawk]

Thank you