DaveL59

so while I'm on "light duties" I thought I'd have a go to age the brass screw head. First try was malt vinegar and salt which had a little effect but seemed to not make much of a change after a few hours in the mix. Perhaps it might if left long enough. Should mention first step was soak in acetone to remove any finish protector. Certainly some effect as the threads turned pink, not the effect I was looking for tho. Then I tried some balsamic vinegar and salt and even heating on the gas flame and hot dipping it. Some effect but not very dark. Read a tip that mentioned flux, of course now I want it I can't find the plumbers flux but I do have a flux pen for electronics work, so try that and see... has made a change but still not quite what I'm looking for: I also swapped out the small steel CSK screw in the leather section for new brass, the M2 holds perfectly tho I might get a M2 cheese/pan head for this one later on. Interested to hear any other thoughts on ageing/patina on new brass. Meantime I've another screw head undergoing just the flux treatment which I'll let age over a day or so and see how it does.

sounds interesting. These Nitrile caps are steel so would take a bit of work to cut. You'd also need to consider how to keep the nitrile secure on the uncut areas I guess, if is loses the bonding. I asked about the ID before buying as I recall, or found a supplier that listed the info. It's a very snug fit on the end of the TAL-M OTA and I use it for the mirror end since mine was missing both caps. The nitrile coating meant it doesn't mark the paint which is handy. Good luck finding a solution and with the project

might have been me Mark as I did get one for the TAL-M a while back. I think they're also referred to as a bearing end cap and are solid. The nitrile helps it grip the tube well too. Only thing I'd ask Chris - out of curiosity, what are you thinking to mount using an end cap?

This morning the postie dropped a couple things off: Many thanks Roy for the 0,965 eyepieces and diagonal which will give the scope a degree of range of magnification without modifications. Well I will need to add a lock screw to the fine-focus mechanism but I'll organise a brass thumbscrew for that so it looks in keeping with the vintage 🙂 The Vivitar lens cap is metal, felt lined on the inner lip and a perfect fit over the brass dew shield, result! Lastly the M2 CSK brass screws - one needed to secure the lens cell parts together. Hopefully it'll age to blend in, or I'll maybe clean and polish up the dew shield to bring it back to its former glory.

some bits for the vintage scope, diagonal and eyepieces courtesy of a member here, many thanks Roy!

I fitted a tripod plate under my little NatGeo which is very similar to your SW pictured. Downside it, not so stable on the Velbon photo/video tripod I have really. partly I think down to not a wide enough area supporting the base. It might be more stable on one of the scope tripods but then that adds bulk to shift. With mine the OTA doesn't have a dovetail, there's a captive bolt that fits into the upright that forms the DEC axis. Not sure what other good options there are other than a tall stool to sit it on, as you have done

Been tempted by a small Cat myself John for the same reason, easy travel esp where mine are all long scopes in the main, just need to build some funds first tho...

yeah that's the problem, swap both or have a mis-match. The drawback of rescuing vintage gear sometimes. I think the ones I have on the spares have a screw on eyecup on the eyepiece body and a couple of those missing. Just loathe to chuck something that may yield spares for something later on hence they're sat in a box upstairs

Hi Mark, they do seem to vary between makers and models even. The there's matching the threads, not sure if those would be imperial and the japanese ones metric, for example, tho a german sounding make could be metric too. I've a few spare zenith 10x ZCF's kicking around spare in various condition so its possible and eyecup from one of those may work, post up the various dimensions and I can take a look at some stage, could be a bit slow on that tho...

tis a shame they don't do the nice wood inserts to hold everything tho like in the boxes of old, Tal and the older japanese scoped. The polystyrene while light and moulded to fit soon falls to bits with regular repacking and removal where the wood only needs the foam/felt renewed and it lasts a good many more years

might as well join in, tho I did collect these certainly the cardboard one would have been the shipping box for the 100RS and from what I've read the TAL wood boxes were used to ship the scopes... so yep, more than 10 years here, the wood box is 1996 and the card one unknown but more than 10 years, I think it was from 2003 or earlier.

yep that sure won't help. If you can get some self-adhesive flocking and stick that around the inside of the dew shield that'll make a big difference in daytime use. At night unless it's the moon you should be ok though, unless there's lights in the area that may reflect.

do you get better views looking at a target with the sun behind you? To improve the light damping inside the scope will mean dismantling it and trying to insert a flocking material which on a narrow tube could be quite fiddly. Also check the eyepiece and diagonal barriers are matt black inside the barrel part or they will add to the reflections. For looking at the stars though, you may be fine as it is so give that a try first.

yep am thinking that too, tho I don't have any BA taps these days and not one that small when I did as those were for car repairs so long since retired and disposed (foolish boy!). I may see how an M2 will hold and if not re-tap to m2.5 or M3 if I can source suitable screws, M3 countersunk have a deeper taper so may not sit well, don't want to lose threads off the inner tube as it's not that thick. On the OTA a dome head would work as it'd still sit below the leather surface, could go brass to highlight or black to blend and disappear I guess. For the shield defo brass so it fits with its surroundings.

Is the direction you are looking toward where the sun is? or in that side of the sky? Could be internal reflection if the tube isn't well flocked/coated to damp down the stray light and it's reflecting around inside the tube. That'll certainly lose contrast much as it does with binoculars or even sunglasses.

+1 also give a try without the diagonal to eliminate that as the cause. A wet tissue isn't ideal, lens cleaner (glasses type even) is much better, but the diagonal definitely not. It'd need the mirror cleaning with mild soapy water and rinsed with distilled water and left to dry to not damage the surface.

Decided it might be smart to secure the lens cell even tho I don't have a suitable brass countersunk at the moment, since they do rotate fairly easily, better safe and all that. So drilled and tapped for M2 and countersunk the brass side a little. I'll order some M2x6mm countersunk brass screws and finish the job later on. The screw that holds the cell to the body could well be an older imperial thread, since the M2 fits, seems to hold but is a touch loose perhaps. That original screw doesn't seem to fit the M2 thread. Pity as I was thinking to make that brass too, as well as replace the one holding the focuser which is a longer M4 ish size. While fiddling, decided to compare the brass eyepiece with the 1.25-inch ones I have, so sat the baby NatGeo 76/350 on the table and swapped them around. Luckily I have a 1.25-0.965 adaptor which made that easy. Seems to give an equivalent view as the TAL 25mm mk2 plossl just a touch narrower, but maybe not as much as the vixen 20mm compared the the TAL 25mm. So I guess that old brass plossl (at a guess, not taken it apart yet) is around the 23-25mm mark, performs very nicely as well as being very nicely made. The more I play about with this old scope the more I'm liking it 😄

yes, watched on the B&W TV in fascination and wonder. I was already interested in the planets but no scope to use. Was beyond our means I expect, being one of 3 kids, plus all the travelling every couple years it'd have gotten wrecked in transit. Pity really as we may well have been able to pick up a quality japanese scope back then being in the far east at the time. And I'll add my birthday wishes to you too Gina, many happy returns! 🙂

perhaps post a picture of the scope and lens and if you can, and the setup you are trying and if possible a pic of the image you see. Are you using a diagonal or fitting the eyepiece directly into the focuser? The diagonal may also need a clean, but being a mirror you need to do that in the correct way to avoid damaging it. Lens cleaner and wiping it will likely ruin it.

last night here there was too much cloud in the area it'd show so I didn't get another look, will try tonight tho before I go to bed, have to get a reasonably early one tonight unfortunately. I guess your camera is an optical viewfinder and no live-view? Would make it harder unless it's naked eye visible as you'd have to take a shot and review and adjust/retry. My bridge is electronic viewfinder so pushing the exposure makes it vaguely visible, but in the end I just zoomed back and took a punt. Well overexposed but then I was playing hand-held leaning against a fence panel, upside tho is it picked out a decent amount of stars too. Can't recall the exposure not but I think that was ISO1600 F4 and around 1/20s A little editing pulling down the brightness etc yielded this version Didn't shoot that raw tho, I'd have tried more and exposure bracketing if I'd have the tripod and remote release, but it disappears behind the roof on the right a little time after so I just enjoyed the view thru the binos after that. It should then become visible from the front of the house but the bright LED street lights make it hard work looking past the glare so I didn't bother 😉

hi Paul ideally you want a target a lot further than 50m to do this, so you may still be a touch out against the stars, but you could always tweak once you've had a chance to try them. Or nighttime using a distant street light if its all clouded over

ack, sounds like seller knew there was a problem and just wanted shot of them Ebay/paypal may still act in your favour tho if the ad says they are correctly aligned, but if there's signs you've tried to adjust that won't help of course. Hope they didn't cost too much if you end up stuck with them. An optical repair shop may be able to collimate them for you tho, give someone like east coast binoculars a shout and see what it'd cost.

sounds like the easiest solution Stu, just say they arrived out of alignment. Unfortunately it's very easy to make things far worse trying to adjust them, takes a LOT of patience and good research beforehand and perhaps a degree of luck. Having tilt screws does make things easier though, first ones I did this with you had to shim the prisms and that took me around 5 hours popping a prism out, adjusting the shim, replace and try again... Rock solid now though and I learned a lot doing that work. Eccentric rings can be fun but quite doable again with patience and the right tools.

you mentioned before some instructions, hopefully they give the information? One of the makers I recall did give instructions on how to align their astro binoculars and that is pretty generic, can't recall which it was now tho. The problem is that the prisms, while set at right angles with respect to each other are not so with regard to the image you see. So each screw will alter the image on the diagonal. The lower prism/screw will shift the image top-right to bottom left and the top prism/screw will shift the image top-left to bottom right, if that makes sense. It's a bit like using an EQ mount or perhaps a better example, collimating a reflector, adjust only one screw and see the effect and if worse back it off to previous and try the other etc.

and after purchase you spend extra buying a shroud or making one, which is better...?