DaveL59

21 minutes ago, Stu said:

Err hmmm, it’s actually a light thimble, the Telementor is the peashooter 🤣🤣

my bad Stu, the old grey cells don't always play nice, of course I shoulda realised huh, thimble - a kinda teeny tiny bucket... 😄 

Just tried out the barlow combo on a distant (ish) tree canopy that was nice and bright while the sun peeked out. So focuser -> TAL-M x3 barlow -> TAL-1 x3 barlow -> 25mm Plossl. Worked pretty well. OK dim but that's expected with that amount of mag, adjusting focus I was able to see very close into the leaves on the tree as the branch wafted in and out of focus in the breeze. Focus seems soft though, again no surprise.

No idea what mag that actually gave me, the 25mm plossl should give x21 I believe (80/526mm FL) so with x3 barlow that'd make x63. What effect does a barlow in a barlow give I wonder? Would that add another x3 to the first barlow's x63 or be x6 to the EP's x21? So effective result is x189 or x126?

Either way it seems usable as a combo of the 2 barlows and kinda saves me messing about trying to fettle an extension tube. The acrylic tubes would cost around £8 each for the 2 diameters at 100mm length. Not too bad if I do decide to try that one day, easier than trying to work metal with hand tools too 🙂 

was thinking last night about the one missing component (well apart from the spanner) for the optical train on this scope - the "mount" or focuser extension tube (top left) which allows you to reach a higher magnification. Browsing another thread here I found some information as per pic below

Now being 32mm non-standard it's not quite as simple as buying a standard extension tube and possibly modifying it as while it may fit in the focuser the other components won't fit into the 1.25-inch tube without boring it out a little, not simple without a lathe. The spec arrangement is the extension sits before the barlow as below.

Then I remembered, when I bought the TAL-1 for the 32mm eyepiece set it also has a barlow, but I can't use it in the M as it is wider at the nose. Now since I've modded the TAL-1 for 1.25-inch eyepieces and focuser this 32mm x3 barlow is redundant and I wonder if I can modify that to become the missing extension piece.

It'd be a touch longer than the original "mount" tube but if I can remove the nose end carrying the lens it might just work. Problem seems to be that it seems to be machined as a single piece rather than the nose end screwed into the barrel. Even the lenses look to be cemented in place, no regular rings to be able to remove them:

TAL-M barlow internal

TAL-1 barlow internal

Looking like the only way to fettle this from what I have would be to hack the nose end off the TAL-1 32mm barlow and sacrifice a part that is now rare to find, which would be a real shame I think. I was hoping that nose end and taper back to the main body would have just unscrewed but seems not. Anyone have any ideas on how this might dismantle, if at all?

An alternative would be to try make something up. I can find Acrylic tube that has 32mm OD and another OD 38mm & ID 32mm that I guess I could make a stepped tube, flock the internals and it might work ok. Would feel tacky compared to the nice solid metal of the rest of the scope but preserve rather than sacrifice an original barlow at least.

I recall a couple months back using the TAL-1 barlow inserted into the TAL-M barlow and got good views of Venus thru that crazy combo, will have to check that this works or if memory fails me but if it does then perhaps that's a better solution than knocking up a plastic tube solution...?

1 minute ago, JeremyS said:

Refractors count double, of course 🙂

 

ah well, I've now 2 of those 🙂 

or there's a very nice 6-inch frac going in the classifieds section, bargain price too 😉 

Only at 6 here but then not really room to get more. One of them, the TAL-1, was bought just for the 25mm Plossl with 32mm barrel eyepiece it came with in order to complete the set for the TAL-M I already had, figuring I could always sell the scope itself on later. But then I shifted the mirror and replaced the focuser with a 1.25-inch one and it's still here and in use.

Bino's tho, that's a different story, 30+ pairs 😮 

54 minutes ago, Gina said:

Actually, the water surface can be pretty hard unless travelling very slowly.

true but unlike solid ground the water will have some give to aid damping the impact and offer some final deceleration should you not have lost quite enough speed. 

I always felt the Russian dust downs were a greater achievement really, after all sploshing into water is a kinda cop-out in terms of engineering a landing solution. Getting down onto a hard surface and keeping the pod and people intact seems that much harder to do successfully... 

5 minutes ago, markse68 said:

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!

certainly worth a try, I didn't stick the flock, just rolled it with the backing still on and inserted in the tube. Up-side is the flock can then be easily removed if needed later on. Best I could achieve since I still haven't managed to get the objectives out on the Dialyt's. Didn't want to wreck the tubes so I fixed the lens rattle by using some black wax melted into the edges which worked well too 😉 

Was a shame on the Leitz but heck, I'd not long gotten the dialyt's for the princely sum of £14 so can't really complain 😄 

ahh ok, I did wonder as the CZJ's seem to race to silly prices, it's not like they're rare after all. I'd wanted some as a benchmark glass more than anything really but have held off so far. Missed a nice older Leitz Porro too as while I looked up the details on that model someone else hit the buy button, doh! I'd read that some of the russian ones can pong a bit, the case being the prime culprit IIRC, thankfully the Foton 7x35 roof's didn't suffer from that and are solid and very nice to use.

The Audubon HR/5 aren't particularly heavy tho the older larger model 804's are quite a chunk. Having small-ish hands I do find the HR/5 easier to use and a better fit for me. Very nice if you can find a pair at a good price, tho they also climb the price ladder pretty fast. 

I know what you mean re uncoated lenses, but how's the internal baffling and damping in the tubes on the Ross pair? I've an old just post-war Hensoldt Wetzlar Jagd dialyt 6x42 that I got for a song a while back. Paint mostly gone and corrosion, on prism chipped, uncoated lenses so I guess they never got returned to factory for the free update, probably as they'd come to the UK and no longer in Germany to take advantage of that offer. I've refurbed them and blacked the prism chip (didn't affect the view anyway but for completeness) and while they were nice, bright light in the general observing direction would cause internal flare losing contrast. So I popped some flocking inside the objective tubes, wow what a difference! Sharpened up the image beautifully and even aiming close to the sun or at the full moon these now give great views. Worth considering for the Ross pair, perhaps.

to black the edges a sharpie marker pen would work and not be affected by future cleaning in water. Bonus that it won't flake off and drop down the tube as paint might do as it ages.

Can't speak for the 90 but I have a 130/900 on EQ2 and while it can wobble it does a reasonable job of looking at the moon and planets. As steve has said though it's not the most stable and pretty much at the limit for the EQ2 mount. I found in use that you just need to minimise the physical contact with the scope and controls. Having the clockwork drive helps as once you have the target in view the motor will keep track reasonably well, tho you will need to have placed the mount so it is roughly polar aligned for that to work well.

I do find tho that placing a camera piggy-backed on the tube ring seriously affects balance with the one supplied counterweight, so if you plan on doing anything like that you'd want to consider adding an extra weight. 

The russian ones tend to be good optically but more agricultural mechanically, but then they work better in extreme low temps I believe. For the Ross if feeling brave you could separate the objective using boiling water immersion to soften the balsam and then clean them up, can be done from what I've read. You can then reassemble  without a bonding agent or use a modern UV glue to recement them. Downside of the new glue is you won't be able to split them again, where no glue can give moire fringe patterns but do work well. Peter may have experience of doing this, I can only say what I've read so far.

Sounds like me not winning on a couple of old CZJ's was a good thing if you find them not good, tho I have considered going after some BNU's in the 12x40 range.

edit:
I should caveat the above by saying don't drop the lens into boiling water as the thermal shock could prove fatal for it. I have read though that putting them in a steel mesh carrier (chip pan basket or steamer maybe) and immersing in cool water then bringing that to the boil so the lens gradually heats up should work. It takes a while and you can tease the lens sections from each other using a soft tool like a spatula to slide them apart.

one thing you could try... focus on the target then shift the dioptre so only one side is defocused and ideally you should get the two concentric, bright central dot and fuzzy aura around it. If offset them collimation could be slightly out but close enough not to notice once well focused.

Well after clouds earlier when things were better placed, I popped the scope out just a few mins back and could just get Saturn above the fence, Jupiter and moon behind the oak tree so obscured. Tweaked the finder focus and aim which is fun in the dark finding the tiny grub screws, but now they act as expected. Saturn looked as lovely as ever so was a nice target to test against, tho I stayed with the 25mm plossl as time was limited before the oak was again in the way.

So I think I'm now all finished on the refurb, mirrors collimated and finder focus and aim set. Easily able to just pick up and pop out into the garden and enjoy the views, happy days 🙂 

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?

defo keep using it and learning as you go. The scopes I use most I guess are an old russian TAL-M (80mm) and TAL-1 (110mm) being the easiest ones I have to just pop out into the garden and they view the moon, Jupiter and Saturn pretty well. I guess you're using the supplied eyepieces (H20, H12 and SR4? tho you state different so perhaps things have changed) and that's likely going to limit you more than anything else. The barlow is a x3 from the manual I found online? This will only be useful with the 12mm and be pushing the optical limit of the scope.

Once you are happy with using the scope and want to do more, upgrading the eyepieces to something better may well provide a marked improvement, with the benefit that you can retain those for use on another scope if you choose to upgrade after a while. You'd need to determine if the eyepieces are 1.25-inch barrel or the smaller 0.965 inch, if the latter they are hard to find good quality versions these days, being of a time past. For the 1.25-inch eyepieces there's quite a range to choose from without breaking the bank too much and folks here would be happy to suggest options.

wow that's pretty interesting your other hobby 🙂

For the electronics, I guess if they aren't fired up they'd survive, tho I'd wonder about any batteries and electrolytic capacitors in the long haul. As you say they do get warm when running but then they've active cooling to help keep things under control. The scopes are likely a larger capital investment though so priorities were in the right place I'd say 😉 

The scope may well have been fine but electronics perhaps less so. My scopes sit in the conservatory and that hits 45-50+C on a hot sunny day, perhaps slightly less with the door open but not by much. So far they've not suffered any issues, tho I guess the grease will likely need renewing in the mounts sooner than normal. Either way, your gear and what you feel more comfortable doing so rescuing them into a cooler environment isn't a bad thing to do. For me, space is the issue in a small place so they kinda have to live out there and tough it out...

gave a brief test just now but cloud covering the moon part way so used bright stars as alternate. So far the Porro's I tested all bar one showed round fuzzy moon/jupiter/stars, even the HR/5 with the spalled prism which I half expected might show an abberant on the RH side.

Bino's I tried were:

Swift Audubon 8.5x44 HR/5
Swift Audubon 8.5x44 MK2
Old japanese 10x50 JB86/JE54
Old japanese micro/skeleton type 15x50 (well, a LARGE miniature bino lol)
Minolta 10x50 modern
Nikon Micro 7x15 modern model
Old Tasco plastic body 8x30
Halina Sightsetter 8x30

The one that didn't and showed more oval was a pair of Regent compact 10x50 wide angle Empire made. These are shorter 10x50 body (objective tubes that is) so more compromised optically than a regular 10x50 I expect.

sorry to hear of your loss, it's nice tho that you are hoping to press his equipment back into service which I'm sure would have pleased him.

Can you give some more details on the scope and perhaps a picture of the parts you are using?

A 25mm should be fine to look at the moon and find the planets, but perhaps the scope can't achieve the range of movement needed for visual if it was set up for astro imaging.

decided to set up the TAL-M so its ready to pop out in the garden later if the clouds co-operate. Modified a lens cap by trimming away a small section of the edge such that it will sit on the finder objective end and not snag the nitrile cap. Holds fine and a snug fit so I guess that'll do as a solution and no real need to rig a plate to fix the 2 caps together and look tacky (excuse the pun).

Then I pondered - the OTA on this baby scope is 110mm and the TAL100RS is about the same, hmmm so I decided to see what happens...

Not exactly well balanced tho felt quite stable and most likely way too big a load for the mount, but a mod to rig an extra counterweight under the Alt-AZ head and it might almost make an easy transport mount for the big frac. The feet may be a little short to trust tho, wonder if the TAL-1 feet would fit the pier to improve that...?

Wow the wide-angle on this phone and parallax from the angle taken sure makes the old vintage scope look long compared to the TAL, they are in fact around the same at 96-100mm long.

As you can probably tell, the conservatory is the scope store and cats' room 😉 Well the kitties vacate when it gets too hot on sunny days, thankfully as 45-52C is a bit much for anyone.

Of course now I've done all this I see the cloud gods have decided to lob some more cotton wool into the skies, typical huh!

as others have said, it requires a lot of patience. Also for taking pics with the phone, are you a wearer of glasses normally, or for reading? I found that I don't wear mine at the scope and when I get focus for my eyes a phone pic at the eyepiece is always a little out of focus, took me a while to twig to that one. 

heh so know that feeling Mark 😉 I certainly notice mine getting tired after doing a lot of small fiddly works.

As Peter said, if you get a single point star then collimation is probably OK, good to know I'm not the only one not to have noticed, like Peter I just get focus and carry on. Sounds like you'll get a couple feedbacks on testing which is nice.

cloud permitting I'll try have a look tonight and report back, I've a few older pairs and a more recent minolta pair as well as a few roof type to test with.

Could just be a feature of the lenses used or the eyepiece design, prisms I'd hope should be ok as they'd be made with good plain surfaces for the image to be folded accurately.

I'll have to try that next time I'm out with a few and see how they fair but I don't recall any odd star shapes but then to be fair I wasn't really looking for them, just shifted focus to get to pin sharp 🙂