Samyang 135 taking shape.

[ollypenrice]

The story so far. This is a joint enterprise with Paul Kummer, Peter Woods and myself. (Peter, Paul and Penrice. Oh no! A sixties folk group. )

The image train is Samyang 135 - FLO Bayonet replacing adapter from Astro Essentials, and conceived by Rob (Uranium235 on here) - TS variable length M48 extension - TS M48 to M42 adapter - TS 2600 CP OSC camera. This is all held together by a Wega set of bits dedicated to the Samyang and the EAF focus motor from ZWO.  Don't jump out and copy it,  just yet: we don't know if it works! 

What we don't have is any kind of tilt adjustment. Bites fingernails. I suppose there might be room to squeeze one in where the variable extender now lives, I don't know. The other possibility, if necessary, will be to turn  components relative to each other in the hope that different tilts will cancel themselves out. This has worked for us before.

That the Wega assembly is available at all, given the seriously small market for which it caters, is great. At £139, however, it's a bit closer to something from a Christmas cracker than I'd have liked. OK, call that a Fortnum and Mason's Christmas cracker, but still. The finger nuts for holding in the finder guider were regular hex bolts with 3D printed wingnut tops placed over them. One had already fallen off and how long will they last out in the dark?  Since I didn't find a finder-guider shoe in my staggering assortment of bits I couldn't use it anyway and had to make the alloy bridge between the two lens 'tube rings' that you see.

Tomorrow I'll be putting all this on Peter's Avalon M Uno and Paul will be trying to communicate with it via our carrier-pigeon-esque internet connection! The price you pay for a dark site...

Back soon,

Olly

 

[gorann]

Looks promising, but Olly..... you have a floppy adjustable guide-scope-holder there - I don´t know how many times I read you state that they are useless and that guide scopes should be bolted on😁 (yes I guess it does not matter at FL 135mm).

Will it be piggybacking on a RASA8 like my SY135?

Göran

[ollypenrice]

11 hours ago, gorann said:

Looks promising, but Olly..... you have a floppy adjustable guide-scope-holder there - I don´t know how many times I read you state that they are useless and that guide scopes should be bolted on😁 (yes I guess it does not matter at FL 135mm).

Will it be piggybacking on a RASA8 like my SY135?

Göran

 I'm using what we have on site, Goran!  My own guiders have always been bolted down, which I prefer. This one's Peter's. My objection to guide rings is largely that they are an unnecessary complication and expense as well as being less stiff than a fixed mount.

The Samyang won't be piggybacking the RASA, partly because that's on an Avalon Linear and close to its limit already. We mainly want them on different mounts so we can image the Samyang's regions of special interest at higher resolution in the RASA. We'll then blend them into the widefield. I've been doing this for years with the Tak/TEC combination here. I enjoy the processing and the result can be great, all the more so now that we have such control over star sizes. Since the RASA regions of interest will be downsampled to the scale of the Samyang and used only at partial opacity, I can envisage doing a three hour run with the Samyang and 3x1 hours for different ROIs in the RASA (or 2x1.5 hours, etc.)  The Pixinsight developers dismiss such composite imaging as as 'painting,' but I call it a good use of time.

Olly

[Grant]

Looks great Olly - very interested to see how this all works out as we are considering sending one of these lenses over to the setup in Spain for those super widefield constellation shots 🙂

[pipnina]

Looks like a nice little instrument!

As for the wega stuff, indeed it is metal-machined prices for 3D print quality- but I suppose 3D printing has allowed the product to simply exist on the market at all, which can only be a good thing.

I'm getting my own 3D printer (in the post atm) so hopefully when I next get the need for something printed, I can just smash something out in a CAD program and make it myself.

When I first got a wega adapter for my EAF and TS crayford, I over-did the little M3 bolt that held a little clip on and sheered the thread clean off. Thankfully it wasn't important but it let me know just how flimsy this PLA stuff is!

Out of interest, would it be possible to remove the plate joining the guidescope's rings together, and then use the bolts holding the guidescope assembly to the lens rings, to hold the guide scope AND lens in one go? Might improve rigidity, make it a bit lighter/compact, and look a little tidier?

 

I'm looking forward to the results!

[tomato]

Looking good Olly, but how about making it a duel rig, you know it makes sense😉

[ollypenrice]

1 hour ago, tomato said:

Looking good Olly, but how about making it a duel rig, you know it makes sense😉

I does make sense and is on the cards, maybe for next year... Yours looks tasty. Is that a commercial metal ring carrying the ens?

3 hours ago, pipnina said:

 

Out of interest, would it be possible to remove the plate joining the guidescope's rings together, and then use the bolts holding the guidescope assembly to the lens rings, to hold the guide scope AND lens in one go? Might improve rigidity, make it a bit lighter/compact, and look a little tidier?

 

Possibly so, yes, but I like a bit of space around things for cables, dew heaters and general access. 

Olly

 

[gorann]

4 hours ago, ollypenrice said:

 I'm using what we have on site, Goran!  My own guiders have always been bolted down, which I prefer. This one's Peter's. My objection to guide rings is largely that they are an unnecessary complication and expense as well as being less stiff than a fixed mount.

The Samyang won't be piggybacking the RASA, partly because that's on an Avalon Linear and close to its limit already. We mainly want them on different mounts so we can image the Samyang's regions of special interest at higher resolution in the RASA. We'll then blend them into the widefield. I've been doing this for years with the Tak/TEC combination here. I enjoy the processing and the result can be great, all the more so now that we have such control over star sizes. Since the RASA regions of interest will be downsampled to the scale of the Samyang and used only at partial opacity, I can envisage doing a three hour run with the Samyang and 3x1 hours for different ROIs in the RASA (or 2x1.5 hours, etc.)  The Pixinsight developers dismiss such composite imaging as as 'painting,' but I call it a good use of time.

Olly

Mixing with RASA data is also my strategy now for using my Samyang 135 piggybacking on one of my RASA8. I have it on an adjustable holder so I can adjust the framing. The holder is made by SW and actually sold as a "guide scope mount" although is is sturdy enough for the Samyang with IMX571. However, having the Samyang on a separate rig will of course be a bit more flexible. The Samyang do need quite a lot more integration time to get near the depth of the RASA.

Göran

And here is an example of what the triple rig can do.

 

Edited December 2, 2022 by gorann

[Tomatobro]

2 hours ago, ollypenrice said:

Is that a commercial metal ring carrying the ens?

Not commercial. Tomato and I noticed a big difference in the asking price of used lenses between the Sony and Canon versions and that no adapters were available for the Sony so we took a gamble an purchased a Sony to see if it could be adapted for use on ZWO cameras. Picture shows what we did to make it usable

[ollypenrice]

29 minutes ago, Tomatobro said:

Not commercial. Tomato and I noticed a big difference in the asking price of used lenses between the Sony and Canon versions and that no adapters were available for the Sony so we took a gamble an purchased a Sony to see if it could be adapted for use on ZWO cameras. Picture shows what we did to make it usable

I feared as much! Very nice work indeed. So no escape from 3D printed semi-tat for us then! 

Olly

[ollypenrice]

2 hours ago, gorann said:

Mixing with RASA data is also my strategy now for using my Samyang 135 piggybacking on one of my RASA8. I have it on an adjustable holder so I can adjust the framing. The holder is made by SW and actually sold as a "guide scope mount" although is is sturdy enough for the Samyang with IMX571. However, having the Samyang on a separate rig will of course be a bit more flexible. The Samyang do need quite a lot more integration time to get near the depth of the RASA.

Göran

And here is an example of what the triple rig can do.

 

I do have a Cassady TGAD tilt-pan adjuster capable of carrying a 14 inch scope. We used it for the twin Taks and then the twin TECs. It is currently idle and cost a fortune!

Olly

Edited December 2, 2022 by ollypenrice
False click.

[Elp]

I find the Eos to m42 adaptors great mounting points. With the plain one (no filter drawer) I found I could repurpose an old WO telescope tube ring by attaching two rubber o rings around the lens adaptor thus increasing it's OD for the tube ring to clamp firmly onto. No issues with my dual dslr lens rig.

[tomato]

55 minutes ago, ollypenrice said:

I feared as much! Very nice work indeed. So no escape from 3D printed semi-tat for us then! 

Olly

Thanks Olly. I think it's great how 3D printing has made producing bespoke components more readily accessible, but we just happened to have acquired machine tools for a previous engineering intensive pastime, and it's nice not to lose the skills once you have learnt them.

[ollypenrice]

53 minutes ago, tomato said:

Thanks Olly. I think it's great how 3D printing has made producing bespoke components more readily accessible, but we just happened to have acquired machine tools for a previous engineering intensive pastime, and it's nice not to lose the skills once you have learnt them.

It seems to me that, being weak in tension, 3D printed brackets should not be tightened by having one part pulled towards the other, but squeezed, where possible, by a surrounding and constricting metal strap.

 

9 hours ago, Grant said:

Looks great Olly - very interested to see how this all works out as we are considering sending one of these lenses over to the setup in Spain for those super widefield constellation shots 🙂

If/when we get it all going I'll gladly send you a data set from it.

Olly

[900SL]

Good luck with the Wega mount Ollie. Mine was junk, the focus ring retaining pins both snapped, knobs fell off and I didn't trust the lens rings not to break. 

My original review here 

 

 

[Elp]

After experiencing my astro cam slipping within a metal tube ring whilst setting up despite it being tight I would never trust a 3d printed one to hold what is essentially a grands worth of equipment. Nowadays I tend to put in screws as physical stops to prevent the lens/cam from falling back or forward.

3d printing filaments vary so much in quality it's another reason to err with caution. Infil used, layer thicknesses, cooling all play a part in their mechanical strength.

Edited December 2, 2022 by Elp

[Ratlet]

Yeah, I've got to say that the print quality of @900SL's one looks pretty dire as well.  After seeing that and ELP pointing out the risks, I went for a middle ground and used 90mm Skywatcher tube rings with 3D printed spacers that are lined with felt.  The spacers have a wedge cut out of them so that when the tube rings are tightened the compress the 3D prints.  Because of the nature of the 3D print they are not putting force on any weak planes of the part. 

[Elp]

Absolute bare minimum, there should be no sharp edges on the print where two angled faces join. As with general engineering they should be joined with rads for strengthening.

 

[Magnum]

Hi Olly, looking good.

Here is couple of pics of how I have mounted mine, I have an Altair Hypercam - Canon adapter then a guide ring to support the front to prevent any flex.

I don't bother with autofocus as I have such a crazy mixture of 3 scopes ( SCT not in the pics) , 3 lenses ( 2 not in the pic ), 3 cameras, 2 filter wheels 2 OAGs, 2 lodestars and 2 filter wheels which im constantly swapping around each day depending on target, though having a permanent setup only takes me a few mins to get going even if I need to focus so never really considered going down that route. Amazingly Both  my samyang and 80mm triplet were still in perfect focus this week since the last time I used them in September.

Im sure you will agree its crazy setup all mounted on the EQ8 which guides perfect no matter how much stuff I through onto it 🙂

Lee

Edited January 5, 2023 by Magnum

[Ratlet]

Q:  What focal length are you imaging at?

A:  All of them.

[Magnum]

15 minutes ago, Ratlet said:

Q:  What focal length are you imaging at?

A:  All of them.

hahahahah yes that the issue if I wanted to automate it all in NINA or SGP I would need to make huge amount of profiles to cover every combo, and would need 4 auto focusers that would also need profiles and then also different auto guider profiles. its making my Brin hurt , much easier just to do it all manually in MaximDL and the Sky6. Or maybe im too stubborn to learn a new workflow. 😛 

[scotty38]

8 minutes ago, Magnum said:

hahahahah yes that the issue if I wanted to automate it all in NINA or SGP I would need to make huge amount of profiles to cover every combo, and would need 4 auto focusers that would also need profiles and then also different auto guider profiles. its making my Brin hurt , much easier just to do it all manually in MaximDL and the Sky6. Or maybe im too stubborn to learn a new workflow. 😛 

If you created profiles for the scopes, important for the FL and platesolving etc, then you could connect to whichever focuser is powered up/available at the time as you should be able to see them in each of your profiles. I think you could sort it without it needing to be too complex or having too many profiles.

[Elp]

The main issue is getting FOVs to match to centre, any distance difference whatsoever will push your other lenses out. I can mount two SY lenses side by side separated by around 4mm between lens hoods, their FOVs however are not even close so you can't really use them both at the same time. I can only think it will work if one is a reasonable long FL for target detail, and the SY is wide for everything surrounding said target.

Edited January 5, 2023 by Elp

[Ratlet]

Is the 3 point guidescope style ring on the samyang to aid with getting it in line with the other scopes?  I could see that working, but I'm not massivly familiar with the style of lens to camera adapter.  I use my vintage glass with just two guide scope rings holding the lens in place.  I would imagine it would basically need 'collimating' with the other scope that is iamging but would be reasonably straightforward.

[Elp]

With a bit of work you could likely get them to match, but the moment you slew or do a meridian flip you'll have the same issue again. The only time I've managed two to match is using a 200mm lens with my Canon, and 135mm lens with my 183mm, I could then crop down to the 183mm FOV.