markse68

4 minutes ago, DaveL59 said:

You'll likely disturb the collimation tho if you remove the prisms, not sure if these had eccentric rings for adjustment or used shims/prism-tilt screws.

I think i’ll most definitely disturb the collimation if I remove and re-glue the objective Dave  It’s eccentric adjustment. I’ll have to read up on what’s involved in readjusting then before going too far- I guess they used an optical bench in the factory for precision but i wonder if it’s possible without or if it’s plausible to jerry-rig something? 

4 hours ago, CraigT82 said:

Please buy it and save me! 

if I were into photography i might- it does look v interesting! But right now I’m not and too invested in the old fullerscope so sorry Craig- I cant help you this time😉 😂

1 hour ago, DaveL59 said:

Internally those do look in good order, blacked prisms too? Wonder if that was OEM or someone did that later on to improve contrast?

Not sure Dave- they have a close fitting metal plate under the spring clip (which looks like phosphor bronze- nice ) but i don’t know if the prisms are blacked? Is that a good idea or necessary? the prisms should totally internally reflect surely? i guess painting the flat side nearest the objective could help minimise scatter from  the objective? 🤔 Maybe i should paint it all inside with black 3...

7 hours ago, John said:

If you click on the image it takes you to a flickr page by Simon Spiers, who knows a bit about binoculars.

 

What’s in a name? Well apparently very little- Konig was enormously prolific whilst working for Zeiss with a long list of patents but according to this, most modern “Konig” eps were indeed 1-2-1 like this so these ep evolution charts seem a bit inaccurate! 

http://home.europa.com/~telscope/koenig.txt

Interestingly Ross had close relations with  to Zeiss before the war so likely got to share some of his wisdom.

He sounds like a bit of a legendary designer alongside his boss Abbe!

8 minutes ago, DaveL59 said:

am wondering if they repaired the doublet or if it's just separated and left as-was? If there's balsam residue and they are apart, then hot water will soften it and you'd be able to gently scrape it away with a soft-edged tool. Will be a fun exercise being they are small lenses and in hot water so be careful 😮 

You could get some new modern cement (balsam isn't available any more) which would need UV to cure, but you'd need to be very precise with placement of the lenses since once cured you won't be able to part them if you find things out of true. Alternatively you might find that not adhering the 2 lenses will give reasonable results while leaving you the option to glue them later on if you really felt the need.

Bit pricey but seems you can still get it Dave- they use it for microscope slides apparently.

https://www.supremepaint.co.uk/products/canada-balsam-100ml

I do like the idea of it not being permanent  the more i’m thinking about it the more i’m tempted- it would be a fun restoration job and if it works worth it as they’re a very nice binocular potentially.

No it’s definitely been repaired Dave- it’s one piece stuck together but when you catch the light it’s hazy with tiny bubbles and clear cleaning marks from removing the old cement. hopefully they didn’t use araldite! 

This is the back of the objective which looks to be smaller diameter than the front element which will make alignment a bit hit and miss. then there’s the collimation after 😬

I was thinking of painting the inside with black 3 but actually i like they way it looks now even if it’s not ideal so i’ll leave it

Mark

10 minutes ago, John said:

A form of Konig ?:

 

Thanks John, that’s exactly what it looks like but according to that chart a Konig has one fewer element?  Where did you get that image- is it yours?

4 hours ago, CraigT82 said:

I've been very tempted to by the very interesting little scope Ade is selling on ukabs (Celestron Comet Catcher) but have managed to restrain myself, so far! 

That’s an interesting looking little scope! Does the meniscus lens correct for coma so you don’t need a paracorr?

No- not the wrong category as it’s a bino ep

Took my newly acquired ancient Ross binos eps apart tonight to give them a clean as they seemed hazy. Alas it wasn’t dirt that i was seeing (although they did need cleaning) but one of the doublets has been “repaired” and it looks like they used a scourer  to remove the old balsam 🤦‍♂️

Anyway back to the point of the post- what type of ep design is this? 🤔 It doesn’t seem to match any on the ep evolution charts i’ve seen. It has a plano convex eye lens with the flat to the eye followed by a concave convex cemented doublet followed by a field stop and then another plano-convex element with the flat side towards the objective. Any idea? 

Given the separation of the objective already noted and now this poorly re-cemented ep lens and how much i like them as a design I think i might have a go at re-cementing them myself- what could possibly go wrong? 😳

Sounds amazing Chris! kicking myself for not going out with the scope last night now- spent evening playing with old binoculars instead 🤦‍♂️

3 minutes ago, DaveL59 said:

Worth considering for the Ross pair, perhaps.

That’s a very good idea Dave- I’ll use them as an experiment and see if they can be improved. The Leitz porros are meant to be lovely as you’d expect- shame you missed them!

3 hours ago, DaveL59 said:

Sounds like me not winning on a couple of old CZJ's was a good thing if you find them not good,

Oh i’d never diss CZJ Dave 😳 No no no! Only that comparing my particular example against some of the others i have they have more of this issue but they’re 40-+ years old and probably been dropped a few times etc. They’re the 2nd nicest mechanically and way nicer than the russians in “quality feel” though the older BNU4s are quite nice actually. The Ross have the nicest focus feel by far. I think the Tento 8x40 are probably the best for what I want them for- sharp and bright and light. But they’re the nastiest cheapest feeling and they really stink. The Ross are the worst performing- 7x30 uncoated 80 odd year old damaged optics, but they’re the ones I want to use cos they feel the nicest  🤦‍♂️The Optolyths are v nice- V light for 10x50 but that’s too unsteady for handheld in my hands. I should look for some Audubon’s like the ones you’re fixing but they’re a bit heavy too I think? Maybe some Zeiss West 8x30 as they’re air spaced and maybe less likely to have this issue if Peter’s right?  Gonna keep an eye out for some later coated Ross in better condition too  

PS I don’t think i’m brave enough to try fixing the separated lens in the Ross- the glass has deep scratches too so not really worth the bother. I had the obj cell out already and the rear element is smaller diameter than the front by the looks of it so it would be nigh on impossible to realign them and using them glueless wouldn’t work i think. I do plan to open and clean the eps though as they’re a bit hazy. They have a lovely wide easy view but they’re dimmer and suffer way more flare and reflections being uncoated and the separated side is worse obvs.

2 hours ago, DaveL59 said:

ahh can't claim great eyes these days myself, for sure if tired I've a feeling my eyes go out of collimation, vertically to a small degree, which makes bino use "interesting". As Peter says tho, could just the be objectives as binos are fast F4. What makes are you looking at when you checked?

I think it is the binos not my eyes- i swapped eps on the same eye and the directions of the astigmatic defocus changes and swapping the same ep between both eyes it stays the same. Maybe i’m just being too fussy but it does make getting sharp focus a bit tricky. They’re all old market finds/ebay bargains and none especially good. A couple of russians that are are about the best but not quite right either, optolyths which are not too bad, Jenoptems which aren’t good at all and some really old Ross which have a separated objective which doesn’t help. Maybe I should buy something decent  Actually one of the russians arrived today- BNU4s which are very similar to the Jenoptems. Mechanically they’re not as nice feeling but optically they seem better

Getting back to Peters point I wonder if air spaced objective models would fair better?

1 hour ago, Stardaze said:

Nice report Mark. Helpful, I've earmarked a couple of those to have a go at when next out 😀

That’s how I do it too- read about something on here or other forums and add it to the ever growing list

Thanks very much for doing that Dave- I guess that narrows it down to one of two things then- either all of my binos are faulty or probably more likely it’s my eyes 😞 I should probably get them checked I guess...

1 hour ago, JeremyS said:

Interesting @markse68. What was the scope?

My trusty fullerscope Jeremy- 8.75” f7.4ish

1 hour ago, Peter Drew said:

Many focused star misshapes as opposed to collimation issues are caused by strains in the objectives due to the cementing of the lens components.  Notably in the cheaper models.   🙂

It’s not so much the focussed shapes Peter- I find getting eyes in right place seems to resolve quite nice round stars and planets (though rarely perfect) but defocusing it’s not going to nice round blur but weird seagull shapes like you get with astigmatism.

I guess it could be my eyes- they’re quite old now. I do notice some issues with long fl eps in my scope too...

Mark

Cheers Dave

Mark

It’s a shame they didn’t use 1/4” hex drive inputs for the slo-mos as then we could use those magnetic flex screwdriver shafts and not have to bother with the little grub screw

I just remembered it was Jupiter i was noticing it on- a very bright star  

all old style porro prism type and all pretty ancient so quite likely not factory fresh collimation wise but the 2 images merge ok on them.

I liked the final quote- struck a chord with me and my ancient trusty dob 😉

7 minutes ago, Sunshine said:

Very much so! I was in the same position you are in now, if one finds an eyepiece they really enjoy, the next will almost guaranteed be of the same line. Have fun figuring out which one you want next! There’s a reason Pentax eyepieces have the reputation they have.

It’s a shame they’re so expensive but you realise why when you hold one in your hand and more so looking through them. Decent camera lenses aren’t cheap either. I never would have thought i’d buy such an exiensive eyepiece when I started a year+ ago but I convinced myself (rather too easily 😬🤦‍♂️) that if i looked after them it was a lifetime investment in something I love, so why not!

I’ve had a few pairs of old boot fair binos for ages but never really had a use for them until now that i’m discovering their usefulness for astro. But all of them have a similar feature- or rather defect? Either side of focus on a bright star they all show astigmatism rather than the clean diffraction pattern you’d get with quality scope optics. Does this indicate they all have issues with collimation or something? Or is it normal for the folded optical path in binos?

11 hours ago, DaveL59 said:

That finder is quite good too, I've even forgotten to pull it outward in the past and was looking at Venus via the finder instead of thru the OTA, even barlowed up and still getting a pretty good image which was a surprise!

What diameter is the objective Dave? Same optics as the Tal-1 finder? I like my Tal-1 finder very much

Mark