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Suppose I'd better kick this one off then with a few pics   A random bit of Cephus:   CTB1 (Difficult)   Iris nebula (Atik 383L+ Lum, Canon 1000d RGB):

Great for big mosaics too

Mine from my now sold 135.

Posted Images

8 hours ago, AnonymousAnimosity said:

I have just purchased this lens, I intend to use it with a Canon 100D on a Star adventurer (might swap it for an Az-GTI for mosaic automation). 

To mount the lens I will buy the William Optics Redcat ring and a short dovetail. 

https://www.firstlightoptics.com/william-optics/william-optics-redcat-spacecat-single-mounting-ring-black.html

What is the best option for a guidescope? If I'm not mistaken this 32mm guide scope from FLO should be appropriate for my image scale.

https://www.firstlightoptics.com/guide-cameras/astro-essentials-32mm-f4-mini-guide-scope.html

 Is it necessary to also buy the Redcat handle bar (https://www.firstlightoptics.com/dovetails-saddles-clamps/william-optics-cat-series-saddle-handle-bar.html) or can this be attached directly to the top of the mounting ring?

As for the guide camera an ASI120MM should be enough right?

You need to add a compatible finder shoe. The one sold by WO works perfectly of course, but a bit pricey. I use the one that was on my Sky-Watcher Maksutov scope and one or two countersunk screws (I believe it's M4) salvaged from something else. Works great! I believe the spacing needed is 20mm, but I'm not sure and I don't have my scope with me to confirms, sorry :( 

ASI120 or similar works very well for that setup! I use it to guide my Samyang and my RedCat with the same guide scope and that's more than enough :) 

I think the shoe I'm using is this one: https://www.firstlightoptics.com/finders/finder-mounting-shoe.html

And I believe this one would work too if the spacing is indeed 20mm on the tube ring: https://www.firstlightoptics.com/finders/astro-essentials-finder-shoe.html

Sadly both are out of stock at FLO, but surely you can find them somewhere else, they seem quite standard!

 

Edited by Space Oddities
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3 hours ago, Space Oddities said:

ASI120 or similar works very well for that setup! I use it to guide my Samyang and my RedCat with the same guide scope and that's more than enough :)

 

Thank you, since the Redcat ring is out of stock for a while I am looking for some alternatives. Mounting the guidescope to the support ring of the lens seems like the easiest way, but I'm struggling to find telescope rings of the right size, I can only find smooth ones (no holes to screw in a finder shoe). Perhaps drilling a couple of holes in these? I'm not sold on 3D printed PLA ones like astrokraken or astrojolo/

Do you know of any alternatives?

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So I'm now looking at guidescope mounting options for my Samyang setup. I've got the Evoguide ED 50 with Zwo asi 120mm-s. Most of the setups I've seen on this thread are mounted side by side using an ADM Vixen side by side mounting. Is there a reason for this or can I just mount the guide scope on top using this https://www.wega-telescopes.de/shop/Rohrschellen-passend-für-Samyang-135mm-F2-Objektiv-inkl-Sucherbasis-3D-Druck-p258368766  
Also if mounting side by side for whatever reason is better do I need the ADM 7" or 11" mount. 

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Well, after some concern that maybe my new Samyang wouldn’t reach infinity focus, I was finally in a position to test it today. My Williams Optics Bhatinov mask arrived this morning, courtesy of FLO.

I set the camera and tripod up outside, and located a suitably bright star. At first I was a bit miffed, as I’d never used a Bhatinov mask before, but I had seen loads of the diffraction images that they produce. What I hadn’t realised was that those images had all been zoomed in massively. So when I had a tiny star, and a dinky little diffraction pattern around it, my tiny brain was desperately trying to figure out what I could possibly be doing wrong. Then it dawned on me to just simply take a quick snap and then zoom in. Eureka! A diffraction pattern that resembled those that I had seen. And, more importantly, infinity focus is successfully achieved just short of the stop. My big fear was that I was falling just short.

Really happy that I’ve got a properly functioning lens.  Also very pleased with the WO Bhatinov mask. It has three small screws that locate in slots, so that they can be slid in and out to accommodate differing lens sizes. These screws are shrouded with a soft, silicon sleeve which pinches in on the lens quite nicely once adjusted correctly for a fairly secure fit. I think it should serve me well for many moons to come 🙂

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22 minutes ago, Ande said:

Well, after some concern that maybe my new Samyang wouldn’t reach infinity focus, I was finally in a position to test it today. My Williams Optics Bhatinov mask arrived this morning, courtesy of FLO.

I set the camera and tripod up outside, and located a suitably bright star. At first I was a bit miffed, as I’d never used a Bhatinov mask before, but I had seen loads of the diffraction images that they produce. What I hadn’t realised was that those images had all been zoomed in massively. So when I had a tiny star, and a dinky little diffraction pattern around it, my tiny brain was desperately trying to figure out what I could possibly be doing wrong. Then it dawned on me to just simply take a quick snap and then zoom in. Eureka! A diffraction pattern that resembled those that I had seen. And, more importantly, infinity focus is successfully achieved just short of the stop. My big fear was that I was falling just short.

Really happy that I’ve got a properly functioning lens.  Also very pleased with the WO Bhatinov mask. It has three small screws that locate in slots, so that they can be slid in and out to accommodate differing lens sizes. These screws are shrouded with a soft, silicon sleeve which pinches in on the lens quite nicely once adjusted correctly for a fairly secure fit. I think it should serve me well for many moons to come 🙂

Glad it works, just remember to remove it before starting your imaging run. Not that anybody has ever done that ever 

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1 minute ago, geordie85 said:

Glad it works, just remember to remove it before starting your imaging run. Not that anybody has ever done that ever 

Funny you should say that.......  I took a few test images of the Pleiades before I came in out of the cold. Then realised when I got in the warmth of the living room that I needn’t have bothered 😂. At least it wasn’t a proper session.

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On 23/12/2020 at 16:04, Alien 13 said:

Nice pattern and the focus is almost spot on, must try one.

Alan

Almost spot on? So additional fine tuning is still required? Just ordered one from High Point Scientific here in the US William Optics Diffraction Spikes Bahtinov Mask for 75mm-110mm Dew Shields - BM-DS-GR45 (highpointscientific.com)

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3 hours ago, Scorpius said:

Almost spot on? So additional fine tuning is still required? Just ordered one from High Point Scientific here in the US William Optics Diffraction Spikes Bahtinov Mask for 75mm-110mm Dew Shields - BM-DS-GR45 (highpointscientific.com)

That's a bit expensive for a Bahtinov Mask does the fact it'll have WO on the box add 40% to its cost 😁. I think I'll just get one for  £10 as there are quite a few people making these on a 3D printer. 

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1 hour ago, nephilim said:

That's a bit expensive for a Bahtinov Mask does the fact it'll have WO on the box add 40% to its cost 😁. I think I'll just get one for  £10 as there are quite a few people making these on a 3D printer. 

I must admit that I baulked at the cost too. But it was that image of the diffraction pattern that sold me, as it looked  clearer, and more precise than others I had looked at. That, and the fact that it is adjustable, so one mask could cover a few lenses or scopes. But I agree that it is way more expensive than it should be.

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7 hours ago, Scorpius said:

Almost spot on? So additional fine tuning is still required? Just ordered one from High Point Scientific here in the US William Optics Diffraction Spikes Bahtinov Mask for 75mm-110mm Dew Shields - BM-DS-GR45 (highpointscientific.com)

The Mask is fine but I noticed that the image shown didn't quite have pinpoint feint stars and looked like some dimmer ones were about to "blink on" had the adjustment been a tiny tiny bit more.

Alan

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5 hours ago, nephilim said:

That's a bit expensive for a Bahtinov Mask does the fact it'll have WO on the box add 40% to its cost 😁. I think I'll just get one for  £10 as there are quite a few people making these on a 3D printer. 

I believe the price has more to do with the type of material it's made from than what it says on the box. Apparently, it's produced from optical grade acrylic which supposedly has 92% light transmission producing 3x brighter diffraction spikes. However, the 3D printed ones are probably almost as good at only 1/3 the cost 😉

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16 hours ago, david_taurus83 said:

I set it up and ran back inside!

I find a bottle of red wine helps keep out the cold. Unless of course that freezes then it definitely is time to go in.  

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2 hours ago, Stardust said:

First light this week for the Samyang on a new ZWO533, misty night but had to get out there.

Very nice. The square sensor on the 533 looks like a really good match with the Samyang.

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2 hours ago, Adreneline said:

Very nice. The square sensor on the 533 looks like a really good match with the Samyang.

Thanks quite enjoying the set up. For a first light with not a lot of data and no calibration frames I'm pleased.

I've just got 97 x 180 seconds on M45  tonight so  hoping that will come to something

 

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I'm looking at getting the ZWOasi 533MC-Pro to go with my Samyang lens. Can anyone tell me if the M42-48 adapter that comes with the ZWO the correct one for the lens?

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2 hours ago, nephilim said:

I'm looking at getting the ZWOasi 533MC-Pro to go with my Samyang lens. Can anyone tell me if the M42-48 adapter that comes with the ZWO the correct one for the lens?

Hi @nephilim Out of the box, the Samyang lens will have a bayonet connector for the camera manufacturer you select (e.g. Canon).  There is a Canon ZWO adapter that takes this to more traditional M42.  This is 26.5mm in depth so with the 6.5mm distance from camera face to sensor and default 11mm adapter on the camera gives  the default 44mm for lenses.  As discussed in this thread, it's usually a touch more than this, but the camera does come with some slim spacers that would help.

Alternatively you have the M48 bayonet replacement discussed in this thread that FLO stock (again, for the Canon lens).  This changes the lens to an M48 connector.  The ASI533 will have the M42/M48 adapters out the box but it's setup for 55mm backfocus.  To get the ~44mm may require additional tinkering.  I cant remember if removing the 11mm adapter from the camera face lets you then add the included 21mm M42 and then included 16.5mm M42-M48 adapaters.  the ZWO diagram isn't clear - not sure if anyone else has this information until I can take apart my rig and check?

My ASI533 and Samyang (currently using the Canon ZWO adapter until the M48 item arrives) with UV/IR cut filter was just over 45mm IIRC (to get the focus point within the 'L' infinity marking).

Hope this helps. 

Edited by geeklee
Clarified the focus requirement in marking
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1 hour ago, geeklee said:

Hi @nephilim Out of the box, the Samyang lens will have a bayonet connector for the camera manufacturer you select (e.g. Canon).  There is a Canon ZWO adapter that takes this to more traditional M42.  This is 26.5mm in depth so with the 6.5mm distance from camera face to sensor and default 11mm adapter on the camera gives  the default 44mm for lenses.  As discussed in this thread, it's usually a touch more than this, but the camera does come with some slim spacers that would help.

Alternatively you have the M48 bayonet replacement discussed in this thread that FLO stock (again, for the Canon lens).  This changes the lens to an M48 connector.  The ASI533 will have the M42/M48 adapters out the box but it's setup for 55mm backfocus.  To get the ~44mm may require additional tinkering.  I cant remember if removing the 11mm adapter from the camera face lets you then add the included 21mm M42 and then included 16.5mm M42-M48 adapaters.  the ZWO diagram isn't clear - not sure if anyone else has this information until I can take apart my rig and check?

My ASI533 and Samyang (currently using the Canon ZWO adapter until the M48 item arrives) with UV/IR cut filter was just over 45mm IIRC (to get the focus point within the 'L' infinity marking).

Hope this helps. 

Thats great info, thanks for taking the time to reply. My Samyang is a Canon lens so i'll order the M48 replacement bayonet from FLO. 

 

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31 minutes ago, nephilim said:

Thats great info, thanks for taking the time to reply. My Samyang is a Canon lens so i'll order the M48 replacement bayonet from FLO. 

 

No problem 👍  I've had a chance to take my camera off the rig and dismantle the extensions.  From what I can see, it can't make 44mm out of the box as that 11mm extension that sits on the camera by default is just an M42 female ring.  If you have a 10mm M42 extension then I think it could work - you'd have 6.5mm (sensor to faceplate) then the 11mm M42 extension from the box, then add a separate/new 10mm M42 extension and finally the 16.5mm M42-M48 adapter from the box.  This gives 6.5 + 11 + 10 + 16.5 = 44mm... then use any slim spacers to fine adjust if needed.  

Shame the 21mm M42 extension from the box can't be used... from what I can see... 🤔

PXL_20210110_1.thumb.jpg.10e27950eea5e30590c6fa5eacb84c56.jpg

PXL_20210110_2.thumb.jpg.efba471c387cf9bf2c52a01f0179c3ff.jpg

Note: When I use M42 above, I mean M42*0.75 (i.e. T2) as per ZWO's diagram.  Apologies if that's more confusing!

Good diagrams here:

https://astronomy-imaging-camera.com/product/asi533mc-pro-color

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7 minutes ago, geeklee said:

No problem 👍  I've had a chance to take my camera off the rig and dismantle the extensions.  From what I can see, it can't make 44mm out of the box as that 11mm extension that sits on the camera by default is just an M42 female ring.  If you have a 10mm M42 extension then I think it could work - you'd have 6.5mm (sensor to faceplate) then the 11mm M42 extension from the box, then add a separate/new 10mm M42 extension and finally the 16.5mm M42-M48 adapter from the box.  This gives 6.5 + 11 + 10 + 16.5 = 44mm... then use any slim spacers to fine adjust if needed.  

Shame the 21mm M42 extension from the box can't be used... from what I can see... 🤔

PXL_20210110_1.thumb.jpg.10e27950eea5e30590c6fa5eacb84c56.jpg

PXL_20210110_2.thumb.jpg.efba471c387cf9bf2c52a01f0179c3ff.jpg

Note: When I use M42 above, I mean M42*0.75 (i.e. T2) as per ZWO's diagram.  Apologies if that's more confusing!

Good diagrams here:

https://astronomy-imaging-camera.com/product/asi533mc-pro-color

@geeklee That makes sense. Ive just bought the Astro Essentials M48 adapter to make life easier although its on back order. Thanks again mate, this is my first foray into AP with a dedicated camera so i'd like to get everything right as best I can although i'm sure i'll have a fair few questions for this thread at a later date.

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