Imaging with the Samyang 135mm f2

[kirkster501]

Bunnies on the lens front surface will be so out of focus you won't see evidence of them on the flats.

[Rza]

On 05/04/2019 at 10:15, Scooot said:

I use this fine focuser, it’s very helpful, if not a bit fiddly to put on.

http://www.astrokraken.fr/samyang-135mm-f-2-bracket-micro-focuser-a145773756

Edit

just noticed he does a hinged ring version which looks better

http://www.astrokraken.fr/micro-focuser-with-hinged-rings-for-dslr-telephoto-lens-a145773206

Has anyone bought the hinged version for the Samyang 135mm? If so what size did you get?

[Space Oddities]

Yes, and it was not a good quality. The rings didn't close properly, and couldn't hold my lens.

I went with the one from Astrojolo.com, definitely better quality printing, and cheaper too  

[Rza]

12 hours ago, Space Oddities said:

Yes, and it was not a good quality. The rings didn't close properly, and couldn't hold my lens.

I went with the one from Astrojolo.com, definitely better quality printing, and cheaper too  

The one that goes around the focus ring with the little tab sticking up?

[TareqPhoto]

This is very nice thread, i liked the results here from this lens.

Unfortunetly i have 135mm lens but from Canon itself, not Samyang or Rokinon, and i keep trying to find a suitable ring to attach for this lens and then mount it, i did buy that ZWO adapter ring they have for ASI1600mm which is 78mm i think, i tried that ring on my QHY163M and it wasn't tight enough, need like 1mm less, something like 77mm i think will be fine, or even 76mm and it will tight it perfectly, with an adapter on camera i can mount any Canon lens then, while if i go with lens then i will need many adapter rings at different sizes, so hopefully i can find something for 135mm Canon lens or QHY163M camera[76-77mm].

[Space Oddities]

On 08/12/2019 at 03:45, TareqPhoto said:

This is very nice thread, i liked the results here from this lens.

Unfortunetly i have 135mm lens but from Canon itself, not Samyang or Rokinon, and i keep trying to find a suitable ring to attach for this lens and then mount it, i did buy that ZWO adapter ring they have for ASI1600mm which is 78mm i think, i tried that ring on my QHY163M and it wasn't tight enough, need like 1mm less, something like 77mm i think will be fine, or even 76mm and it will tight it perfectly, with an adapter on camera i can mount any Canon lens then, while if i go with lens then i will need many adapter rings at different sizes, so hopefully i can find something for 135mm Canon lens or QHY163M camera[76-77mm].

Teleskop Services sells a couple rings with that diameter:

https://www.teleskop-express.de/shop/product_info.php/info/p981_Orion-Rohrschellen---Aluminium---fuer-Tuben-mit-D-76-mm.html

https://www.teleskop-express.de/shop/product_info.php/info/p10216_TS-Optics-Fotostativadapter---Haltering-fuer-Astro-Kameras-D-74-76-mm.html

I believe they are the same, but it depends if you need 1 or 2   No idea if they fit the Canon 135mm though, since this lens isn't designed to have a tripod collar.

There's also the Geoptik adapter for Canon EOS lenses: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2836_Geoptik-CCD-Kamera-Adapter-mit-T2-Anschluss-fuer-Canon-EOS-Objektive.html

The consensus is that this adapter is the most solid option for attaching heavy lenses to astro cameras.

Hope that helps!

[TareqPhoto]

1 hour ago, Space Oddities said:

Teleskop Services sells a couple rings with that diameter:

https://www.teleskop-express.de/shop/product_info.php/info/p981_Orion-Rohrschellen---Aluminium---fuer-Tuben-mit-D-76-mm.html

https://www.teleskop-express.de/shop/product_info.php/info/p10216_TS-Optics-Fotostativadapter---Haltering-fuer-Astro-Kameras-D-74-76-mm.html

I believe they are the same, but it depends if you need 1 or 2   No idea if they fit the Canon 135mm though, since this lens isn't designed to have a tripod collar.

There's also the Geoptik adapter for Canon EOS lenses: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2836_Geoptik-CCD-Kamera-Adapter-mit-T2-Anschluss-fuer-Canon-EOS-Objektive.html

The consensus is that this adapter is the most solid option for attaching heavy lenses to astro cameras.

Hope that helps!

WOW, excellent, i didn't know about those, sounds the second one is the one, thank you very much 😊

[Uranium235]

Its been a while, what with work, Christmas, and endless cloud getting in the way of things. But I've gotten a few images out of the modified lens now

The only downside, this particular lens is not quite on par with the two Ive had previously - so Ive had to stop it down a bit. The following images are all fairly short runs, just over an hour for each, and absolutely no calibration:

[TareqPhoto]

5 hours ago, Uranium235 said:

Its been a while, what with work, Christmas, and endless cloud getting in the way of things. But I've gotten a few images out of the modified lens now

The only downside, this particular lens is not quite on par with the two Ive had previously - so Ive had to stop it down a bit. The following images are all fairly short runs, just over an hour for each, and absolutely no calibration:

Very nice results!

So, which camera did you use for those? and at what F number did you use the lens?

[Uranium235]

23 hours ago, TareqPhoto said:

Very nice results!

So, which camera did you use for those? and at what F number did you use the lens?

 

Thanks

Its the QSI683ws camera (KAF8300), and the lens was stopped down to f4.

[Davey-T]

Good to see you've managed to get out under the stars Rob 

Dave

[Uranium235]

Quick update chaps, the Samyang mod will be available from FLO shortly.... watch this space

[TareqPhoto]

20 hours ago, Uranium235 said:

Quick update chaps, the Samyang mod will be available from FLO shortly.... watch this space

What is Samyang mod?

[Davey-T]

23 minutes ago, TareqPhoto said:

What is Samyang mod?

It's on the previous page.

Dave

[Uranium235]

Samyang mod now available from FLO

https://www.firstlightoptics.com/adapters/astro-essentials-samyang-lens-to-m48-adapter.html

Product discussion thread here:

From what it seems after discussion, is that there is a good chance it will also work with the manual 85, 50, 35 and 14mm lenses (canon fit). Hopfully someone can verify this over time.

[PeterCPC]

Did this one the other night. Was 65 subs at 60 secs 800 iso plus 25 subs at 60 secs 1600 iso. I also used a Haida Clear-Night Filter and I am quite impressed by it. Aquired with Canon 1200d modded. No guiding.

Heart and Soul.

Peter

[Mark1489]

I went for an Orion wide field with the Samyang recently, it was difficult for me to get the processing right and could do with more data but here it is! 
 

 

Edited February 7, 2020 by Mark1489

[geordie85]

Here is my 2 panel mosaic of orion using my QHY183C at F2.

Less than an hours data altogether. Compressed for uploading here. It would be nearly 200mb otherwise

I hope you like it

[Craney]

Saw a lot of the excellent photos taken on here with the Samyang  and found that I could not resist when one came up for sale recently.

This is the first shot I got with it  under an 80%+  Moon which was lurking somewhere nearby in Taurus a few days ago.     This is with a modded 600D using a clip-in Astronomik Ha filter   (it's the 12nm one) , but the plan is to get my cooled mono involved when  the Moon, Storms and work clears off.

On the left is the Moonlight "influenced" shot.   On the right is the same data with a bit of processing in PS.  (10x300secs...ISO 800)

 

What a great lens.

 

Sean.

Edited February 25, 2020 by Craney

[Adreneline]

We can't have this thread languishing on Page 3 so here's an image - not a great or even memorable image by any means but an image taken with a Samyang 135mm combined with a ZWO-ASI1600MM-Pro and ZWO-EFW.

I decided that it was time to give my Canon 200mm a rest and reinstate the Samyang back on the mount, this time equipped with the Astrojolo M42 adapter to replace the EoS end plate. It took a bit of experimentation but then I finally found that the M42 adapter + ZWO 16.5mm spacer and 0.75mm of ZWO spacers plus the EFW gave me focus exactly in the middle of the infinity range marker on the lens.

Decent targets are now pretty much out of sight from my location so I decided to go for a star test with M67. This is 600s of R, G and B pre-processed in APP and the post processed in PI with both Histogram and Arcsinh stretch. The two images were layer combined in PS followed by a little bit of noise reduction. Since fitting a Hoya UV filter on the lens (and on my Canon) my bloated blue and OIII stars are now largely tempered and the focus positions are very similar for all seven filters. APP reported very similar FWHM on all filters; if anything the red is now bloating. I've cropped off the very edges of the image so there is some coma type star distortion in the corners - best not to zoom in too much!

Plate solved and annotated in PI:

Thanks for looking.

As ever any advice on how to improve are gratefully received.

Adrian

P.S. A few more images of my current setup showing the spacing and focus arrangements.

 

Edited February 25, 2020 by Adreneline
Clarification

[Craney]

I agree.....

There is so much this lens can offer for the astro-photographers amongst us.   

A stiff breeze would normally wreck a FL=1000mm Galaxy imaging session with my big Newtonian, so you would think I would be OK with a 135mm of small stature.... Alas, not... the wind has been so consistently strong EVERY time it has been clear, with scattered showers as well !!!!.....it is just not worth the inevitable frustration....

[Adreneline]

Set up to do some imaging last night with varying degress of success.

First up was Sh2-264 in Ha and OIII, 60 mins of each before it disappeared behind a neighbouring roof; it is proving really difficult to process.

Next was an Ha mosaic from the Rosette to the Cone (10 s 180s on each) which worked surprisingly well but I've done it before.

This was a single 60s test shot of the Seagull Nebula IC 2217 - no processing at all - it is a screen grab off my iPad using the ASIair interface. Using the lens at f2.4 with 1.25" Baader filters and ASI1600MM-Pro at gain 139, offset 50 and -20 degrees.

What is interesting to me is the the star shapes are pretty good right into the corners (excluding where the neighbour's roof is!). I've rotated the image 90 degrees CCW so (going by my previous stacked images) I would expect to see some significant coma shaped stars in what is now the top left hand corner but in fact they are not too bad.

If I have a small amount of corner coma in individual subs does/could stacking exacerbate the problem?

The nebula was below 30 degrees and well in the light pollution zone so I am surprised it is visible at all.

Thanks for looking.

Adrian

 

[groberts]

Adrian, I am faced with establishing a similar rig and would be interested to know:

• What's the ring size on your rig?
• What's the autofocus equipment you're using?
• What's your experience with the  ZWO Mini Guider like?
• What's the backfocus for the ZWO 1600MM with this lens? 

Thanks, Graham 

[Adreneline]

Hi Graham,

29 minutes ago, groberts said:

What's the ring size on your rig?

I bought the rings from TS Optics in German - they are somewhat overkill but they also make it easy/easier to mount anciliary equipment. 

37 minutes ago, groberts said:

What's the autofocus equipment you're using?

I  use the ZWO EAF but the ASIair does not support autofocus. I have determined the focus positions for each filter using a Bahtinov mask and I manually change the focus between filter changes. (I have used the autofocus system in SGPro but never successfully - probably due to my ineptness! I have wasted so much time trying to get autofocus to work that in the end I just gave it up as a bad job.)

40 minutes ago, groberts said:

What's your experience with the  ZWO Mini Guider like?

Not that great so far. I initially found it very difficult to focus the mini guidescope/mini 120 combination. I have now achieved an acceptable focus and the guiding system works well in the ASIair. Having said that the iOptron CEM25-EC tracks so well that I don't really need to guide unless I want to dither. It does work well and it is excellent for a light-weight setup.

41 minutes ago, groberts said:

What's the backfocus for the ZWO 1600MM with this lens?

The backfocus on the ASI1600 is 6.5mm. The ZWO EFW is 20mm and I have had to add the 16.5mm ZWO spacer and 0.75mm of spacer rings. I believe the Astojolo M42 replacement end plate adds 3mm. So that gives 40.25 + 6.5 end of lens to sensor. The 'infinity' focus position is as shown at f2.4 :

HTH

Adrian

[Adreneline]

I know I've broken all the rules but this is just a bit of fun lest we get too serious.

In my defence I did use the Samyang 135mm.

Sh2-264. In theory they are kissing angel fish but they could be kissing gourami fish!

In some respects this image could be a metaphor for life.

Adrian