My journey with the Samyang 135mm

[RolandKol]

48 minutes ago, Vixen4eva said:

Bought this bracket for my Samyang. Works a treat on my GPDX. Fantastic quality.

Alan

 

Nice!
But I Would not like to leave camera hanging like this... Especially ASI+EWF... 

[Space Oddities]

1 hour ago, Uranium235 said:

Sure, later on i will kick off another thread for people to share their experiences with this brilliant but of kit. 

Not sure about remote focus though, perhaps someone else has figured out a belt type system? But I found that manual works fine - and it saves a couple of hundred quid   

Rob,

Apparently it's possible to use a belt system to focus this lens. I found one using a Robo focus motor (found on the Deep Sky West remote observatory website):

 

The Samyang/Rokinon 135mm also exists in a video version (135mm T2.2), which is the same as the f/2 optically, but with a different focusing system. It might be easier to interface the lens with a focusing motor.

However, I believe the aperture ring is clickless, like most video lenses. I'm not sure that's a good thing for astro?

 

[Uranium235]

2 minutes ago, Space Oddities said:

Rob,

Apparently it's possible to use a belt system to focus this lens. I found one using a Robo focus motor (found on the Deep Sky West remote observatory website):

 

The Samyang/Rokinon 135mm also exists in a video version (135mm T2.2), which is the same as the f/2 optically, but with a different focusing system. It might be easier to interface the lens with a focusing motor.

However, I believe the aperture ring is clickless, like most video lenses. I'm not sure that's a good thing for astro?

 

Is that a 683WSG? I never managed to get a bayonet adaptor short enough due to the ridiculous backfocus requirement of the camera...lol.

 

[Space Oddities]

Very cool images everyone! This Samyang was my first astro lens, and it's a great performer. For beginners like me, with a standard camera, it's the perfect way to get into astrophotography!

I did this picture 1 year ago, with just a tripod and my Fuji X-T1. I think I stacked a lot of 1 second frames, somewhere between f/2 and f/2.8. It's heavily cropped, but when you start AP, it's the kind of picture than encourages you to progress!

 

Also, for those who do daytime photography, it's a fantastic portrait lens! Here's an autoportrait I did with this lens wide open 

 

[Space Oddities]

9 minutes ago, Uranium235 said:

Is that a 683WSG? I never managed to get a bayonet adaptor short enough due to the ridiculous backfocus requirement of the camera...lol.

 

According to their website, it's the QSI 583 WSG-5 with a Nikon adapter  

[Uranium235]

11 hours ago, Space Oddities said:

According to their website, it's the QSI 583 WSG-5 with a Nikon adapter  

Just noticed the camera in those pics... see the reinforcement/support added to the camera itself? That is exactly what I did with the Atik 383L+ so both lens and camera are supported - when operating at f2 any compression of the bayonet adaptor will cause tilt in the field, so its best to take all potential strain out of that weak spot. Getting all four corners perfect is the first essential step if youre thinking about putting a mosaic together.

Probably not an issue with a light DSLR, but if youre sicking a big CCD or FW on it - then support will be required.

[Davey-T]

14 hours ago, Uranium235 said:

Is that a 683WSG? I never managed to get a bayonet adaptor short enough due to the ridiculous backfocus requirement of the camera...lol.

Remember I've got the spare front cover without the built in guider if needed 

Dave

[RolandKol]

 

19 hours ago, Space Oddities said:

Rob,

Apparently it's possible to use a belt system to focus this lens. I found one using a Robo focus motor (found on the Deep Sky West remote observatory website):

The Samyang/Rokinon 135mm also exists in a video version (135mm T2.2), which is the same as the f/2 optically, but with a different focusing system. It might be easier to interface the lens with a focusing motor.

However, I believe the aperture ring is clickless, like most video lenses. I'm not sure that's a good thing for astro?

My motor is Nema17PG27, which is a bit smaller and I hope I will manage to place it under the lens.

By the way, while adjusting the lens holding bolts, - how do you know you do not introduce any tilt?

[Uranium235]

2 hours ago, RolandKol said:

 

By the way, while adjusting the lens holding bolts, - how do you know you do not introduce any tilt?

I did mine very, very carefully

What I did was to sit the whole thing vertically, so the back of the camera is on a flat surface and the lens is pointing upwards. Then tighten up the bolts one by one until the barely make contact... just until you feel the smallest amount of resistance. They neednt be done up tight - the guidescope ring is just there to stop the lens flopping about under its own weight and compressing the bayonet adaptor (even though any movement is tiny, its enough to upset an f2 field).

The 3d printed bracket looks like a good solution to that (I would probably add felt to the rings), but I would also want the camera braced.

[RolandKol]

yep... this is what I want to avoid with my All in One bracket...

but I afraid I may tilt it with the motor belt

Anyway, I am sure I will fail from the first attempt

[Andywilliams]

On ‎05‎/‎04‎/‎2019 at 04:59, Uranium235 said:

Hmmm.... Im thinking that there may be enough users of this particular lens to start a showcase thread (similar to the 130pds or 80ED thread).

A definate yes please from me......I look forward to seeing more of you guys images with this lens.

Cheers,

Andy

[Uranium235]

19 hours ago, Andywilliams said:

A definate yes please from me......I look forward to seeing more of you guys images with this lens.

Cheers,

Andy

Already done mate, it's in the getting started with imaging sub forum (since its am option that would be great for beginners as well). 

https://stargazerslounge.com/topic/333381-imaging-with-the-samyang-135mm-f2/

[Tarun]

3d printed this for Rokinon 135 last fall. I plan to add follow focus gear controlled by motor at some point.

 

[Adamar98]

On 26/03/2019 at 16:05, kirkster501 said:

I recently bought Geordie's 135 to add to my 14mm and it is sublime lens.  I am getting started with wide-field.  It is on my 1100D at the moment but I am looking at fittign my Atik 460 to it.

Adamar98, how did you connect your Atik 460 (with filter wheel?) to the lens?  Is it canon fit?  Mono?

I use the geoptik canon fit adapter. 

[Adamar98]

On 03/04/2019 at 22:23, Andywilliams said:

Hi Rob,

Is this imaged through a Samyang f2??

Is so, its fantastic.

Just one question. The stars are showing quite pronounced diffraction spikes (I personally really like them). Is this a quality of the sheer length of the integration time here? or is it a quality of this lens?. I wouldn't have  expected to see spikes like this off of a camera lens ?

Many thanks,

Andy

The diffraction spikes are caused by the blades in the lens.

[Philippe LECA]

On 05/04/2019 at 11:16, RolandKol said:

Nice!
But I Would not like to leave camera hanging like this... Especially ASI+EWF... 

See this version of bracket with 3 rings

http://www.astrokraken.fr/soon-available-bracket-for-samyang-135-coldmos-qhyccd-a158427790

[kirkster501]

Here is my guided autofocus rig - Samyang 8300 with Moravian 8300 camera.  It works brilliantly with SGP and I get perfect V curves.

A Skywatcher motorfocus unit and a DC focus HiTec Astro.  Available as bundle from FLO, about £120 I seem to recall.  Add to that a 3d printer pulley wheel and a belt from Amazon.

 

[kirkster501]

On my AF rig above this is the pulley wheel:

https://www.amazon.co.uk/gp/product/B0723HRQK4/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

And this is the belt:

https://www.amazon.co.uk/gp/product/B07D916D4T/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

The pulley wheel had to be bored out very slightly - about 1/2mm I seem to recall - to fit on the SW motor spindle.  2 minute mickey mouse job with a bit and a drill.