Can you help identify this please.

[Guest chaz2b]

I have in my possession, a BAPL activity eyepiece 25mm. I googled it but no luck in finding out what it is. The coating is purple not the usual green and judging by its construction it could be Russian made.

the optics are a good quality and has a cross hair with circle and some numbers 1-5 , on the bottom are the letters BAPL with the number 95 beside it , year of construction?

Anything to do with Rifle sights perhaps?

chaz

[Rob]

Hazarding a guess here. I would suggest maybe a Microscope EP. I agree Very likely Russian. Its a clearly a Plossl 'PL' lens configuration.

Very Interesting!.. where did you get it?.

Rob

[Rob]

You may with great care be able to remove the lenses. You may find its a transfer that sits with producing the scale settings, and remove. You could then clean the lenses. Just take your time, and document with photos & notes on the lens positions. May guess if it IS a plossl will be 1 group with 4 lenses.

[LR Watanabe]

I'd help you, but sadly I'm no professional and so, the best I can do is to hope you have fantasic day and observing/imaging session!

[mikeDnight]

I bought something similar (possibly the same) years ago, probably around 1999. From what I remember it was sold as a measuring eyepiece and I'm pretty sure it is of Russian origin. My memory is a bit foggy about it as i never used it to measure anything, but I'm fairly sure it was 25mm fl and had Activity eyepiece engraved on it. Possibly Tal as it was advertised in the Helios/Tal catalogue of the era. I think it cost around £40.

[Guest chaz2b]

Thanks Mike, I like the cost info, tells me if it’s worth keeping, the more pricier the more I keep it, ‘cos you know it’s a quality eyepiece.

The top lens unscrews from the body easily so I will have a look at removing said transfer.?

 

Now had a look, it’s not on the top group of optics, but on the clear lens in the bottom, think I will leave alone for now. Looked through my Borg 100 APO, very crisp view! Once I focused, the graphics disappeared.

chaz

[John]

I think it's a micrometer eyepiece used with microscopes.

The scale will be engraved on a flat piece of glass at the focal plane of the eyepiece.

[Ruud]

I found this:

https://www.cloudynights.com/topic/654199-look-what-i-just-found-in-my-cupboard/

 

[F15Rules]

Hi Chaz,

That is a Baader Planetarium (BAPL) Activity eyepiece. 

I sold one about 3 years ago, on UKABS. I hope moderators don't mind, but I've found the archived advert and copied it below as it tells you everything I know about it.

I might even have the original box somewhere, I have a feeling I sold it in a bolt case, having forgotten that I had the original box. 

I'm pretty sure it was made in Japan. It was a lovely piece if kit and well made. 

I would hang on to it!?.

Here is the original text of my advert:

For Sale

Status: Active  Advert Category: Eyepiece-Barlow-Diagonal-Reducer  Advert # 109156

Baader 25mm Plossl for measuring position angles etc This very rare Baader Eyepiece is very rare, I have never seen another one. It's been in my garage for a while and I've never used it (it came with a few extras with a previous used scope purchase). I have also found the instructions for use, written by Adrian Ashford and these will be sent with the item. I estimate this is about 20 years old. It was called the Baader Activity Eyepiece, and is very well built with lovely purple coatings and rotating top focusser for adjusting the etched calibration scale to one's own eye. View are razor sharp as you would expect with a good quality plossl. The instructions explain how to measure angles on the Moon, Planets etc and even the distance on a given night! I hope someone can use this interesting item for it's intended use. £45 posted in the UK. I will include a bolt case as this didn't come with end caps. I can send pictures on request from my phone :-). Thanks for looking. Dave

Price: £45 Posted on: 2016-02-24 11:03:43

 

HTH

Dave