DaveL59

On my EQ5 the alt adjuster bolts are 8mmx1.25 if that helps. I'd doubt that M6 would be up to the job, but then again on that side it's only really preventing the head tilting downwards as the other bolt is the one carrying the real load.

hi Dave

hope the family is ok, not fun to have to dash off in current times. I put my daughter thru that a couple months ago in fact, gave the family a scare for sure!

The other issue from reading is the E-mount and mirrorless lenses have a very short focus index from the mount to sensor. I'm guessing your astro camera is C/C2-mount? Likely easier to get an adaptor for a more regular SLR/DSLR lens where there's the available length to build an adaptor to suit (44mm vs 15mm) tho I didn't see any for Minolta A-mount (sorry can't bring myself to call it sony, being a Minolta user lol).

33 minutes ago, John said:

You might think that the small plate had never been on Dave's GP. There is no wear mark on the lug which the 12mm bolt would bear against to hold the latitude angle of the mount

 

That was my thought too John, no witness marks from the bolt on the cam so perhaps the offset weight of the head & counterweight was enough to keep things safely in place against the rear bolt, at least for visual.

There was someone selling bits off an EQ5 in the classifieds, ok it'd be white but if its the same size might be a quick cheap option if they still have that bit, unless you already have that kicking around in a drawer/tin somewhere or want to fabricate from scratch.

Assuming it's similar to the EQ5 then yeah it's to tune the polar alignment on the AX axis, acts against a pin in the tripod head. I don't have any spare but could check the thread on the EQ5 if that helps. Could be different in the Vixen tho so hopefully someone who has one can give a more accurate measure.

edit - oops my bad, just re-read and you're after the ones for the 2 empty screw holes. Shouldn't there be a plate there that is bolted by those two and also has a large bolt that acts against the cam to drive the latitude angle?

Like this...

hmm that does seem unavailable as a ready adaptor, found this on DPR
How to attach a Sony E-Mount lens to QHYCCD 183C cooled camera: Astrophotography Talk Forum Forum: Digital Photography Review (dpreview.com)

Is your E-mount lens all electronic control from the camera or has manual controls?  If electronic aperture it sounds like a non-starter as you'd have no control there at all.

surely tho you'd need the sensor to be 2-planar curved? Doesn't mention that in the article and the pic looks like its only curved in one plane.

30 minutes ago, Andy0306 said:

Buy a Pentax camera with their Astrotracer system  

hmmm that does look neat, wonder if Sony will ever do something like that for the Alpha since we also have in-body IS using sensor shift?

On 13/12/2020 at 05:40, gadusmorhua said:

Thanks for your experimentation, I can understand how it works now, to grip a heavy camera and lens requires a big spring to clamp the ball, which requires a similarly matched spring on the lever. In some respects it is more than is needed for lighter loads like my bins.

Until now I've been using my camera gear and the small ball joint  on my monopod was awkward to lock. I find the 222 on the monopod is great in that respect, I just wish the lever was easier.

In fact I'm finding that with the mod I can release with just a little squeeze on the trigger and its much lighter, yet so far still seems to hold well on my A77ii with lens and my bino's. The spring I used is quite stiff tho as it was one of a group I ordered from when I shifted the mirror further up on my TAL-1 reflector. It is set to be slightly longer than the space it fits in by virtue of that bolt so does exert sufficient outward force on the trigger. Its effect is multiplied by the fulcrum arrangement of the trigger mechanism.

I do wonder if the same effect might be had by simply shortening the OEM spring so that it's say 3-5mm longer than the space it fits (casing edge to the internal bore of the plunger). Of course there's no easy way back if that doesn't work tho you could then rig a similar bolt/washer/nut arrangement to increase the effective length.

What bino are you using on this tho, large and heavy, or regular 10x50 type? I can't comment on the bigger version as I tend to use a 10x50 which is fairly light, or Swift Audubon 8.5x44 which are heavier but physically around the same size.

Sounds like you may need one of these:

Adapter Ring for Pentax PK K Lens to Canon EOS EF Mount: Amazon.co.uk: Camera & Photo

There are focus confirm versions too which might be handy if you use the lens for daytime shots. This from a quick google rather than knowing either make. Been a long time since I had a Pentax and never had a Cannon.

21 minutes ago, happy-kat said:

I would avoid fungus

I'd agree with you Kat, fungus will potentially etch the coating and glass and is a fair bit of work to fully dismantle and clean every part of the lens and assembly, then regrease the relevant parts with a modern synthetic lube so focus runs smoothly. Getting the lenses correctly installed and focus correct needs a lot of care and of course the correct tools to carry out the works. Sure if it is slight traces you can treat with a dose of UV/sunlight so it doesn't spread but far better to find one that hasn't been infested already - I'd suggest it to still be worth giving it a UV dose tho as well as exercising the focus/aperture to slow any potential effects later on.

wow, you'll likely need to buy the matched lenses to go with it but an interesting idea I guess. Ain't gonna be cheap for sure.

9 minutes ago, John said:

I don't think I've ever bought a new achromat other than the TAL100R back in 1999 which at £250 with a mount and good eyepieces, delivered from Siberia was quite a bargain I think.

 

I picked up the 100RS on an EQ5 with a set of eyepieces etc for £260 about 18 months back, lovely scope and I believe from the original owner, well cared for too. I consider it to have been a very good buy 🙂 

I have a pair of Charles Frank Nipole miniature bino's in my collection somewhere around the house, obviously badge engineered JPY made and imported so actually not bad 7x23 IIRC. Did bid after one of his small desktop newts a while back but went way over what I was looking to pay.

I think there may be a 2x barlow in the kit? Perhaps not the best quality if it's an all plastic body but worth a try.

A decent quality x2 barlow would be worthwhile depending on what is supplied with the scope and a better short-FL eyepiece as the 10mm's supplied are pretty poor. The 20/25 is generally usable even if not the best but a zoom eyepiece will cover the range and be better than the supplied ones. With a good barlow you'll be able to adjust the magnification to suit the target and conditions and also be able to use them on a future scope if you eventually upgrade. Another option in the zoom range is SVbony 7-21mm which isn't expensive and performs pretty well as does their 8-24mm but that is rather large and heavy.

Hi Adam and welcome aboard.

For focus, you need to adjust until you get the smallest/sharpest image of your target. Going outside of focus you will get a fuzzy ball/disc and racking back you will start to see the black dot in the centre of the disc (the secondary) and the spider vanes. 

Unfortunately at 500mm focal length, your scope with the eyepieces will only give you, if I'm not mistaken:
25mm x20
10mm x50

Did you get a barlow lens supplied with it? That would increase the magnification by whatever factor it has printed on it. x2 or x3 usually. 

If you do a search for the thread "what can I expect to see" on here it'll give you some guidance of what to expect. A 114mm scope will be limited in max magnification, according to specs it says x228 but in reality probably closer to x150 before you lose detail. You'd need shorter FL eyepieces to get up to that and being an F5 scope probably not cheap ones as it is a fast scope. 

Noticed the other night they were real close, could cover both with a fingertip. Sadly they were low behind the treetops so no chance with a scope. Cloudy/rain ever since of course 😞 

There's one listed on the bay from Ukraine at the mo too and only a tenner plus shipping - tho that's just the mountings no TC included

Nikon TC-E2 binocular mount | eBay

they do look nicely put together from the pics. I'm not looking for such a pair but if anyone here is then it seemed a good deal. I recall @markse68 was making a pair and might have been one side short but I could be wrong there.

1 minute ago, Tiny Clanger said:

I will not buy any more toys, I will not buy any more toys ...

I so know that feeling! I was browsing around to see what M42 lenses are around that might interest me, tho I'll likely rarely use them. Must randomly change all by online purchasing passwords I think and let the cards have a breather 😉 

Came across these, not sure if anyone might be interested so posting just in case

Nikon Teleconverter TC-E2 2x with leather case | Oxfam GB | Oxfam’s Online Shop

doh! and of course spell-check won't have picked that up lol

As Girders has said, it's going to be quite limited. You might be able to hand hold it at the eyepiece for snaps and perhaps short video of planets but the extending lens you'd need to be careful of not catching it, so power up and let settle before attempting it. I have the bigger S100FS and that can't be used easily at the eyepiece, too long and bulky.

You might be able to try on a tripod if you can manually focus to infinity, or use the trick method (lens cap on, get it to attempt focus, then switch back to manual focus), at full zoom you could then shoot the moon in video perhaps. For much else you'll need longer exposure or focal length. I gave the S100FS a try briefly as that can do 30s but no longer. It'll mainly only pick out the brighter stars, combination of exposure time and the lens being quite slow zoomed out to 400mm.

So I found a smaller spring that is weaker but a lot shorter and narrower, too short in fact. So with a bolt inserted in the end of it I have it set for the length where the plunger reaches the stop end (bolt end inserted in the plunger to distribute load better).

Reassembled it all and the trigger now needs a bit less effort. No change to the tension on the ball as that is set by the lower spring with the red pointer and the allen screw. Think I'll leave it set up this way rather than mess about trying to get that big spring back in place 🙂 

edit - thinking about it you would have to have a spring with enough stiffness as the trigger is a fulcrum that pushes downward on the yoke that brakes against the ball head. So while you might use a shorter or weaker spring it'd need to be able to apply enough outward pressure on the trigger to force the fulcrum bearing down against the yoke. Perhaps this one I've used while shorter and weaker is enough to succeed.