Imaging with the Samyang 135mm f2

[Simon Pepper]

Me again! So I tested out the Sammy the other day with all manor of different spacings, apertures, etc and deduced that the issue is the filter or at least filter holder.  So I need some links please or suggestions what I need. This is what I have or at least the older model and thats my issue. https://www.firstlightoptics.com/zwo-accessories/zwo-adjustable-eos-lens-to-t2-adapter-for-all-asi-cameras.html . So what I need is some other connection to the lens and my ZWO 294, but also somewhere to house a 2" mounted filter. I have the ZWO filter draw, but no obvious connection back to the lens. Has anyone got a recommendations please or pictures of their setup not using the above adapter but using a mounted filter without a filter wheel? 

 

On a positive note the lens is fine I tested it without the filter and stars were pinpoint in all corners

Thanks

Edited October 1, 2021 by Simon Pepper

[powerlord]

so are you using that with the filter drawer ? or screwed into the adapter ? i can't say I noticed any issues when I screwed it into the adapter. maybe just lucky. or blind.

[Simon Pepper]

I am using a t2 canon adapter with a 2 inch filter inside here is a picture. If I take the filter out I don’t have a bad corner… 

[geeklee]

1 hour ago, Simon Pepper said:

I am using a t2 canon adapter with a 2 inch filter inside here is a picture. If I take the filter out I don’t have a bad corner… 

Typically for spacing on this lens, you will need to account for the filter if it's between lens and camera - usually add 1/3 the thickness of the filter like you would on a scope.  I have found these to be very good:

M42
https://www.firstlightoptics.com/adapters/baader-t2-fine-adjustment-rings-aluminium.html

M48
https://www.firstlightoptics.com/adapters/Baader_M48_adjustment_rings.html

You will also have got thin spacers with your ASI camera - one of these might just be thin enough, I can't remember.  Whether you'll still get an iffy corner, I'm not sure  

If you want to break away from that adapter, you could get the Canon Samyang M48 adapter that FLO sell, use your filter drawer and make the rest up with what you have and additional spacers.

[Simon Pepper]

1 hour ago, geeklee said:

Typically for spacing on this lens, you will need to account for the filter if it's between lens and camera - usually add 1/3 the thickness of the filter like you would on a scope.  I have found these to be very good:

M42
https://www.firstlightoptics.com/adapters/baader-t2-fine-adjustment-rings-aluminium.html

M48
https://www.firstlightoptics.com/adapters/Baader_M48_adjustment_rings.html

You will also have got thin spacers with your ASI camera - one of these might just be thin enough, I can't remember.  Whether you'll still get an iffy corner, I'm not sure  

If you want to break away from that adapter, you could get the Canon Samyang M48 adapter that FLO sell, use your filter drawer and make the rest up with what you have and additional spacers.

Cheers Lee I’ll try the latter m48 adapter see if that one works 👌

[Chefgage]

 

IC1318 Gamma Cygni nebula in Ha (also posted in the imaging - deep sky sub forum)

Capture information

HEQ5 Pro mount
ASIAIR Pro
Samyang 135mm lens (at F4)
Canon 200D (modified)
Astronomik Ha filter (12nm)
ZWO ASI120mm mini guidscope

ISO 800
EXP 300s
Lights 25
Darks 0
Flats 20
Bias 20

Moon percentage 61% Moon 103° 39' 29" from target (halfway through imaging)

Stacked in DSS and processed in Pixinsight

 

[Simon Pepper]

1 hour ago, Chefgage said:

 

IC1318 Gamma Cygni nebula in Ha (also posted in the imaging - deep sky sub forum)

Capture information

HEQ5 Pro mount
ASIAIR Pro
Samyang 135mm lens (at F4)
Canon 200D (modified)
Astronomik Ha filter (12nm)
ZWO ASI120mm mini guidscope

ISO 800
EXP 300s
Lights 25
Darks 0
Flats 20
Bias 20

Moon percentage 61% Moon 103° 39' 29" from target (halfway through imaging)

Stacked in DSS and processed in Pixinsight

 

Nice capture! 

[mxcoppell]

Folks,

First post here at Star Gazer's Lounge. 

Recently I started to build my ultra-wide-field rig based on Samyang 135/2. Finally, the pieces come together. And I noticed something unexpected.

The following are some photos of my setup. The payload at camera mount side includes QHY294m, CFW3s-us, CTU M48 and a custom-made CAA. 

If I push the tail of the camera downwards, I can see there is a very small play (flexure) between the imaging payload and the lens. It's not the M48 plate used to replace the bayonet - initially I suspected that and retightened all 3 screws. When I release the pressure from the camera, the tiny play "bounces" back. 

There is a picture with a YELLOW arrow to show where the flexure happens. 

Does anybody experience similar thing, or I got a bad copy?

Thanks in advance! 

-Min from Coppell, Texas

 

[Simon Pepper]

14 hours ago, mxcoppell said:

Folks,

First post here at Star Gazer's Lounge. 

Recently I started to build my ultra-wide-field rig based on Samyang 135/2. Finally, the pieces come together. And I noticed something unexpected.

The following are some photos of my setup. The payload at camera mount side includes QHY294m, CFW3s-us, CTU M48 and a custom-made CAA. 

If I push the tail of the camera downwards, I can see there is a very small play (flexure) between the imaging payload and the lens. It's not the M48 plate used to replace the bayonet - initially I suspected that and retightened all 3 screws. When I release the pressure from the camera, the tiny play "bounces" back. 

There is a picture with a YELLOW arrow to show where the flexure happens. 

Does anybody experience similar thing, or I got a bad copy?

Thanks in advance! 

-Min from Coppell, Texas

 

Nice setup here a lot of people have had issues with this lens if you scroll back through the thread with stars that are elongated in one corner. However as we know this lens does perform incredibly in picking up those photons. I tend to ensure when shooting I check which side my bad corner is and position the DSO out the way so I can crop the bad stuff! There are some others that have upgraded to better connections to stop flex which I have not tried and it looks like you have this adapter already? This makes me wonder if it is actually flex? Last thing you could try is some additional rings around the camera in order to reduce the stress and flex if that turns out to be the case? 
 

and welcome to SGL!

Edited October 29, 2021 by Simon Pepper

[mxcoppell]

Thanks for the kind words, Simon!

Yes, I have the M48 adapter to replace the original EF bayonet mount. The part I feel is not solid is not the M48 adapter - it connects to the end element of the lens securely. 

The flexure is between the end element and the lens barrel after I loaded the imaging gears. I don't feel it's really that solid. Not sure how the end element (after removing the bayonet mount to expose it) is connecting to the main body of the lens inside the barrel. I tried to Google this matter to see if anybody has experience to disassemble the Samyang 135/f2 lens, but didn't find any. 

 

[powerlord]

With the crap weather, no new data. But here's a reframing and reprocessing of cygnus data from August.

I think I prefer the no stars version.

 

 

 

[AstroGee]

I like some of the images in this thread. I started from the beginning and started to work my way through. I can't say it reads intuitively from an astro noob point of view. There's so much minimalist jargon going on that is a faff to decipher... Is there a getting started with Getting Started with Imaging section?

[Adreneline]

2 hours ago, AstroGee said:

I like some of the images in this thread. I started from the beginning and started to work my way through. I can't say it reads intuitively from an astro noob point of view. There's so much minimalist jargon going on that is a faff to decipher... Is there a getting started with Getting Started with Imaging section?

How about the very first thread in this topic area?

 

[kirkster501]

 

Here are two images I have done with my Samyang 135mm and two different cameras.  Not contributed to this thread so sharing for first time.  An amazing lens.  I have to stop my example down a few stops though or else I lose my stars in the corners but that's fine and easily corrected by upping the exposures a bit.  It is the widefield I am after with this lens.

Sadr Region with Samyang 135mm lens and Moravian G2-8300 | SK Astro

North American Nebula in a wide field with Samyang 135mm and QHY268C camera | SK Astro

 

[kirkster501]

..as stated elsewhere, weather been diabolical in recent months so opportunities to use the new Samyang/QHY268C setup and its massive wide field have been almost none-existant for months.

[tomato]

Just on the lens flexing issue, I went the budget option and purchased a SY135 with the Sony mount. The bespoke adapter is attached to the lens body by 3 original tiny screws and they could not cope with a Moravian G2-8300 hanging off it. A separate bracket was made that picks up off the lens clamp, this has eliminated flexing at this point.

[nephilim]

6 hours ago, AstroGee said:

I like some of the images in this thread. I started from the beginning and started to work my way through. I can't say it reads intuitively from an astro noob point of view. There's so much minimalist jargon going on that is a faff to decipher... Is there a getting started with Getting Started with Imaging section?

Welcome to AP, a whole world full of jargon, frustration & faff.........But its very much worth it.

[nephilim]

Due to the incessant rain & cloud swamping Cumbria forever I decided to process this & post it. The framing is awful as i'd only just got the Asiair Pro & wasnt sure how to use it properly. Next time i'll get both the Heart & Soul in there. It was a while back so i'm unsure of the integration time but it was around 5hrs, taken with the gear in my signature.

Thanks for looking

Steve

[kirkster501]

The Heart Nebula is an object worth imaging in its own right.  It does not always need to be with The Soul Nebula.

Your image is super but there is a lot more faint nebulosity around the Heart (and Soul for that matter) that I can tell your data contains but you haven't quite pulled out as yet.

Edited October 31, 2021 by kirkster501

[nephilim]

2 minutes ago, kirkster501 said:

The Heart Nebula is an object worth imaging in its own right.  It does not always need to be with The Soul Nebula.

Your image is super but there is a lot more faint nebulosity around the Heart (and Soul for that matter) that I can tell your data contains but you haven't quite pulled out as yet.

Thanks. I'm still getting my head around PI so its an image i'll definitely go back to.

[kirkster501]

8 hours ago, AstroGee said:

I like some of the images in this thread. I started from the beginning and started to work my way through. I can't say it reads intuitively from an astro noob point of view. There's so much minimalist jargon going on that is a faff to decipher... Is there a getting started with Getting Started with Imaging section?

Astro imaging is a complex field in both hardware and software.  There are plenty of books on the subject.  You cannot distill such a complex topic into an easily digestible set of steps any more than you can learning to play the piano or guitar or learning a language.  You need experience and need to feel your way a bit.  Ask questions in the beginners imaging section and people here will gladly assist you.

Edited October 31, 2021 by kirkster501

[kirkster501]

3 minutes ago, nephilim said:

Thanks. I'm still getting my head around PI so its an image i'll definitely go back to.

A lot of it comes down to the stretching process and overly aggressive background extraction.  People go way too aggressively and end up cutting out much of the data they spent so long in collecting.

[powerlord]

11 hours of imaging last night with the 135mm and asi1600 !!! after forecasts all said was was crap and probably rain..

anyway, one hour of it spent on Orion in Ha (filter wheel fitted too). Surprises how well it turned out considering it was also blowing 45mph winds.

I plan to continue tonight with S and Oiii, but here it is processed in mono. Click and zoom in. lots of detail.

[kirkster501]

^^^^Fabulous

[powerlord]

I'm on a SY135 run at the mo, so here's the 3 shot and finished so far in last few days in one place (also posted in DSO imaging). Definately glad I bought this wee lens.