Imaging with the Samyang 135mm f2

[fireballxl5]

I bought the dewshield version of the mask, together with camera rings from here

http://www.astrokraken.fr/bracket-system-for-samyang-rokinon-135-f-2-telephoto-lens-a183920490

Works well👍

[Space Oddities]

What about this one? The filter thread of the Samyang is 77mm, so I think that mask would be a perfect fit for the lens and its dew shield. 

I find translucid Bahtinov masks much better than opaque ones, like those that are 3D printed. The lines are more visible and it is therefore easier to focus, in my limited experience at least. Especially if you don't have super bright stars available. Plus, the adjustable size makes it versatile, if you own other scopes with a 75-110 diameter (which is quite standard range). 

https://www.firstlightoptics.com/bahtinov-focus-masks/william-optics-bahtinov-mask-for-dew-shield-diameter-75mm-to-110mm.html

[Mick J]

1 hour ago, Space Oddities said:

What about this one? The filter thread of the Samyang is 77mm, so I think that mask would be a perfect fit for the lens and its dew shield. 

I find translucid Bahtinov masks much better than opaque ones, like those that are 3D printed. The lines are more visible and it is therefore easier to focus, in my limited experience at least. Especially if you don't have super bright stars available. Plus, the adjustable size makes it versatile, if you own other scopes with a 75-110 diameter (which is quite standard range). 

https://www.firstlightoptics.com/bahtinov-focus-masks/william-optics-bahtinov-mask-for-dew-shield-diameter-75mm-to-110mm.html

Related product Takahashi FC-76DS f/7.5 Doublet Fluorite APO Refractor,  just add that on...........    sorry but the idea made me smile.

Edited December 23, 2020 by Mick J

[Ande]

3 hours ago, fireballxl5 said:

I bought the dewshield version of the mask, together with camera rings from here

http://www.astrokraken.fr/bracket-system-for-samyang-rokinon-135-f-2-telephoto-lens-a183920490

Works well👍

I have looked at those, but the whole eco-system seems very pricey for 3D prints. Although I have heard that people seem to like them. I’ll put them as a maybe. If I have a lucrative Xmas that is

[Ande]

1 hour ago, Space Oddities said:

What about this one? The filter thread of the Samyang is 77mm, so I think that mask would be a perfect fit for the lens and its dew shield. 

I find translucid Bahtinov masks much better than opaque ones, like those that are 3D printed. The lines are more visible and it is therefore easier to focus, in my limited experience at least. Especially if you don't have super bright stars available. Plus, the adjustable size makes it versatile, if you own other scopes with a 75-110 diameter (which is quite standard range). 

https://www.firstlightoptics.com/bahtinov-focus-masks/william-optics-bahtinov-mask-for-dew-shield-diameter-75mm-to-110mm.html

That does look good. Very pricey for what it is though.  Maybe that’s why there are no reviews. 

[david_taurus83]

The clear acrylic ones do seem to produce very good spikes as I had one with my WO GT71. Dont know if I could stomach paying near 50 quid for a b mask though!

Theres someone on the Facebook selling page selling them for a tenner. Specific for the Samyang.

 

 

I just used the one I was using for my 80mm scope though and it works fine. Just need to zoom in!

Edited December 23, 2020 by david_taurus83

[Ande]

I must confess, I have just googled some images, and the star produced by the WO mask does appear to offer easier precision. I’m quite tempted.
 

[Alien 13]

2 hours ago, Ande said:

I must confess, I have just googled some images, and the star produced by the WO mask does appear to offer easier precision. I’m quite tempted.
 

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

Alan

[geeklee]

Merry Christmas everyone!

The weekend past, I finally got a chance for first light with my new Samyang 135 lens.  It's paired with the Astrokraken rig which made light work of a lot of questions for mounting and focusing.  I'm waiting on the M48 adapter for the lens itself but still had a Canon ZWO adapter, so used this not expecting much.  Surprisingly, the fit seemed very snug and after a little spacer fun I got it showing focus within the infinity marking area.  So far I've only used it with my ZWO ASI533, but want to get my Atik 460EX on it ASAP.

Seems like an obvious question but do you need narrow band filters designed for speed like the Baader F2 ones?  Would normal 7nm ones work with only a little signal loss?

These were all stacked and calibrated in APP and then a quick process in PixInsight.  Some of it will be worth revisiting for processing, some isn't.  All taken wide open @ F2

Here's a quick tour of the easy targets I wanted to see wide field - with varying integration as I pushed through an all nighter.  Click through for a slightly larger view (all 50% IntegerResampled)

Heart & Soul nebula + Double Cluster.  2 pane mosaic, cropped.  Each pane was 60 x 60s (1 hour each).  Interesting comparison on FOV difference between this camera and full frame from @david_taurus83 on the previous page.

M31. 50 x 30s (25 minutes)

M81, M82 and surrounding area. 180 x 60s (3 hours)

Jellyfish nebula, Monkey head nebula and M35.  90 x 60s (1.5hours)

Orion nebula, Running Man nebula, Horse Head, Flame nebula and surrounding area. 45 x 60s (45 minutes) + 15x5s for core (75s).

 

Constellation Lyra. 2 pane mosaic. Each pane ~13 minutes.

I'm pleased with this start and trying out some easy targets to get a feel for the capabilities, signal and framing/mosaic challenges before planning longer projects.  Who am I kidding in UK weather  

Edited December 24, 2020 by geeklee

[david_taurus83]

37 minutes ago, geeklee said:

after a little spacer fun

 

Lol

[Adreneline]

46 minutes ago, geeklee said:

I'm pleased with this start

... and so you should be! - definitely a good start. Stars look good all the way to the corners too.

Adrian

[nephilim]

1 hour ago, geeklee said:

Merry Christmas everyone!

The weekend past, I finally got a chance for first light with my new Samyang 135 lens.  It's paired with the Astrokraken rig which made light work of a lot of questions for mounting and focusing.  I'm waiting on the M48 adapter for the lens itself but still had a Canon ZWO adapter, so used this not expecting much.  Surprisingly, the fit seemed very snug and after a little spacer fun I got it showing focus within the infinity marking area.  So far I've only used it with my ZWO ASI533, but want to get my Atik 460EX on it ASAP.

Seems like an obvious question but do you need narrow band filters designed for speed like the Baader F2 ones?  Would normal 7nm ones work with only a little signal loss?

These were all stacked and calibrated in APP and then a quick process in PixInsight.  Some of it will be worth revisiting for processing, some isn't.  All taken wide open @ F2

Here's a quick tour of the easy targets I wanted to see wide field - with varying integration as I pushed through an all nighter.  Click through for a slightly larger view (all 50% IntegerResampled)

Heart & Soul nebula + Double Cluster.  2 pane mosaic, cropped.  Each pane was 60 x 60s (1 hour each).  Interesting comparison on FOV difference between this camera and full frame from @david_taurus83 on the previous page.

M31. 50 x 30s (25 minutes)

M81, M82 and surrounding area. 180 x 60s (3 hours)

Jellyfish nebula, Monkey head nebula and M35.  90 x 60s (1.5hours)

Orion nebula, Running Man nebula, Horse Head, Flame nebula and surrounding area. 45 x 60s (45 minutes) + 15x5s for core (75s).

Constellation Lyra. 2 pane mosaic. Each pane ~13 minutes.

I'm pleased with this start and trying out some easy targets to get a feel for the capabilities, signal and framing/mosaic challenges before planning longer projects.  Who am I kidding in UK weather  

Wow very nice indeed. I finally made a firm decision to save a little bit longer & go for the 533 over a DSLR, it'll be a steep learning curve as my first dedicated camera but looking at your images it'll be well worth the extra homework once its paired up with my 135. Should be ready to go at the end of Feb.

Edited December 24, 2020 by nephilim

[edjrgibbs]

First light. Loving this lens already! QHY183c. with Altair Triband filter. 

Edited December 24, 2020 by edjrgibbs

[geeklee]

1 hour ago, Adreneline said:

... and so you should be! - definitely a good start. Stars look good all the way to the corners too.

Thanks Adrian.  Yeah, it's looking good in the 533.  I can worry about larger sensor if I ever have that problem!

28 minutes ago, nephilim said:

Should be ready to go at the end of Feb.

Awesome.  Will still be plenty of time left to test it out before summer!

20 minutes ago, edjrgibbs said:

First light. Loving this lens already! QHY183c.

Very nice!  What integration and exposure times were they and what else is in the image train there... filter wise I'm thinking?  Dual band or just the straight OSC?  The smaller pixels seem to be a good match at this focal length.

Edited December 24, 2020 by geeklee

[Ande]

I think I need to send my lens back. As I try to focus to infinity, the stars get smaller and smaller, and then I hit the hard stop. It feels like a hair’s width from where it should be. I was rather hoping that the stars would begin to momentarily grow, and then the hard stop, to give me that fine adjustment. I have read that people have doctored their lens, when encountering the issue, but I’m not comfortable doing that. The lens is being used on an unmodified Canon 80D. No filters in the chain, and nothing removed, so I haven’t created the problem myself.

[Ande]

Oh, and Merry Xmas 😃

[Ande]

On 23/12/2020 at 21:04, Alien 13 said:

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

Alan

It can’t be coincidence that the stocks at FLO have suddenly depleted.  Managed to bag the last one

[nephilim]

32 minutes ago, Ande said:

It can’t be coincidence that the stocks at FLO have suddenly depleted.  Managed to bag the last one

 

6 hours ago, Ande said:

I think I need to send my lens back. As I try to focus to infinity, the stars get smaller and smaller, and then I hit the hard stop. It feels like a hair’s width from where it should be. I was rather hoping that the stars would begin to momentarily grow, and then the hard stop, to give me that fine adjustment. I have read that people have doctored their lens, when encountering the issue, but I’m not comfortable doing that. The lens is being used on an unmodified Canon 80D. No filters in the chain, and nothing removed, so I haven’t created the problem myself.

Unfortunately I'd read about this , I never mentioned it as the complaints all seemed to be around 2018 & I couldn't find anything mentioned after this so I assumed this had been rectified. Apparently it was affecting random lens' not just a specific batch batch, most people were lucky but some were not. There was even a title on one forum titled '3rd time lucky'.

As its a well documented problem there shouldn't be an issue sending it back. I'm hoping mines ok but wont know until I've bought the camera. Whereabouts did you buy yours from? Mine came from Amazon.

[Ande]

Yeah, I’d read some of the reports before I ordered mine. Just figured that the odds would be in my favour.  Fat chance 😂. Ditto, ordered from Amazon. I have one of those posh Bhatinov masks coming soonish. I might just wait until I receive it. Then I can see if infinity is right on the stop, or I’m falling just short. My ageing eyes cannot be trusted without some help.

Edited December 25, 2020 by Ande

[nephilim]

8 minutes ago, Ande said:

Yeah, I’d read some of the reports before I ordered mine. Just figured that the odds would be in my favour.  Fat chance 😂. Ditto, ordered from Amazon. I have one of those posh Bhatinov masks coming soonish. I might just wait until I receive it. Then I can see if infinity is right on the stop, or I’m falling just short. My ageing eyes cannot be trusted without some help.

That is also my way of thinking but no doubt mine will be questionable now 😂 keep us posted on how you get on. My eyes are not the best these days either so I understand where your coming from with that 😂

[edjrgibbs]

On 24/12/2020 at 17:15, geeklee said:

Very nice!  What integration and exposure times were they and what else is in the image train there... filter wise I'm thinking?  Dual band or just the straight OSC?  The smaller pixels seem to be a good match at this focal length.

It was about 2 hours of 5 min exposures with darks and bias frames stacked in Siril. I used an Altair triband filter on the QHY183c.

[AnonymousAnimosity]

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?

[Kyle Allen]

2 minutes 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?

Hi,

I use an 100D and Star Adventurer. That guide scope and camera is also the one that I use - it works perfectly fine. I’d recommend you get Sharpcap Pro (£10 I think) as it makes polar alignment so much easier - you can easily get it to within 1 arc-minute. The Star Adventurer won’t guide in Dec so a good polar alignment is necessary if you want to do longer subs. 

When guiding, try to balance the mount East side heavy. I find this makes a big difference to how well the mount responds to guide commands. 😀

[david_taurus83]

29 minutes 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?

Those mini guide scopes are great value. Though once their sold out they don't get restocked for a while due to supply issues so I'd grab one now if I were you. The mounting ring for the Redcat is out of stock though so might need to wait for that. You don't need the handle for that but it would make things much easier to mount the guide scope..

[david_taurus83]

I've posted this in the deep sky section but its more at home in here. I added another 3 hours of data to my image of the Heart, Soul and Double Cluster. Got this on Christmas Eve, despite a 75% illuminated moon!

63 x 300s ISO 1600 at f4

Canon 6D (modded) and Optolong L Pro clip filter

Had to cropped out the edges on this one but still almost the full frame.

Previous 2 hours and the new 5 hour version.