Imaging with the Samyang 135mm f2

[groberts]

Thanks Adrian, much appreciated.  Still yet to decide the way forwards but I have the Samyang lens now, so will need to move forwards on the rest soon.

I've long been thinking about which way to go next and in life and so astronomy, generally like to see and understand the big picture - the Samyang widefield images look just the job.  Great thread, thanks to everyone's input which I've been reading avidly before pushing the button.

Graham      

Edited February 28, 2020 by groberts

[Adreneline]

1 minute ago, groberts said:

the Samyang widefield images look just the job

I started with a 600mm ED80 but rapidly got tired of taking images of tiny galaxies; there was never any prospect of buying a bigger or longer focal length telescope. I can be up and imaging in less than 15 minutes now and packed away in less than five and it's all down to a smaller mount, the 135mm/1600 combo and the wonderful ASIair.

I also like to see these nebula in their context and am happy to trade a wider FoV for less detail.

Good luck with the Samyang once you get it up and running and I look forward to seeing your images.

Adrian

[Craney]

Here is my limited attempt at the Sphagetti Nebula.....always wanted to have a go at this and at the moment Taurus is going behing the neighbours house.

2 pane mosaic ( Ha-O3 Bi Colour, although there isn't much O3)   Samyang 135mm @ F2, 48mins Ha, 24 Mins O3.  3mins subs    Atik 414ex Mono  EFW2.

It was clear, but a bit murky. Occaisonal passing cloud.

Sean.

[Adreneline]

3 minutes ago, Craney said:

Here is my limited attempt at the Sphagetti Nebula

That's a good start Sean - definitely something to build on. It is such a difficult target and I too only get a limited window of opportunity as it passes between the neighbours trees and the neighbours roof - my neighbour has got a lot to answer for when it comes to my astroimaging! Thanks for sharing

Adrian

[Craney]

Thanks Adrian.    So much to learn when it comes to multi-pane compositions.  You can definitely tell on the subs that the top half was done later than the bottom half. 

< lots of PS witchcraft gone into the blend >

For now I am happy that I can actually pick the nebula out from the sky glow and create 'something'.   Oh for a tree-less South horizon, no Moon and no nearby halogen lit car-lot.

The beauty of the 135mm is that it is so portable and fast, that a possible dark skies journey may be scheduled in the future to capture similar beasts.

 

sean.

[Adreneline]

5 minutes ago, Craney said:

The beauty of the 135mm is that it is so portable and fast, that a possible dark skies journey may be scheduled in the future to capture similar beasts.

Exactly why I have gone for the iOptron CEM25-EC + ASIair to use with my Samyang/1600 combo. I can be setup and ready to image in less than 15 minutes and the ASIair plate solving is a godsend when it comes to repeatability to build up an image databases for these feint target. All I need now is the portable 12V supply and I am good to go. Question is which 12V power pack to go for?

 

[Adreneline]

Thursday night was quite fruitful in many respects.

This is a two pane mosaic of the Rosette and Cone taken with the 135/1600 combo. Lens at f2.4 : camera at gain 139, offset 50, temp -20 degrees. Each pane is Ha, 10 x 180s unguided. Preprocessed and stitched together in APP; background extracted and histogram stretched in PI.

Adrian

 

[Craney]

My present wide field rig.

Great for those annoying clear nights of late that have been significantly gusty.  Quite a small profile and large FOV, so the shakes are minimal.

Here is the Atik 414ex with EFW2.  In the background is my general guide scope  ( Bresser 102mm F4.6 refractor with ZWO120mm).

The lens mounting system is from  AstroKraken   ( a French astro accessories firm).  The middle ( none-orthogonal ring  Oops!!)  is the micro-focus adjust.   It actually seems to work very well and has produced encouraging results on the second night of operation.

This all sits on an EQ6, but hopefully I will escape the garden and try for some darker, less cluttered skies with a smaller platform..... EQ3  or Ioptron.

 

Sean.

[Craney]

Latest  image for y'all.     Rosette in Hubble palette.

Fickle cloud  not allowing any great exposure runs so i was limited to 15mins Ha , 5 mins  O3 and S2.    All one minute subs.

Atik 414ex  on Eq6.    Phd2 guiding with 102mm bresser refractor.

Clear night tonight but  the Moon is lurking near to any sizeable targets.    May go for the Witches Head .

[Adreneline]

Used my Samyang 135mm and ASI1600 with my new 2" Astronomik 6nm Ha filter for the first time last night (delivery of new filter and clear night on the same day!). The results, to me, seem very encouraging. Had the usual game of finding the exact spacing to give star focus with the focus mark in the middle of the 'L' but I got there in the end. This is just Ha with very minimal edge cropping. The image is stacked in APP and processed in PI with minimal final noise reduction in PS.

I also took a few frames of OIII with my Baader 2" filter. The focus point for the Baader was significantly different to the Astronomik and well before the 'L' mark on the lens. This is pure HOO. I combined the images in PixelMath before stretching. Light Vortex recommends stretching and then combining but that in one respect seems counter-intuitive to me. Having applied LinearFit to equalize the background it then seems right to combine. If I apply Histogram Stretch and then combine the chances of the backgrounds being the same are slim and I am sure I read LF works best on linear images. Anyway, here it is:

Adrian

 

[carastro]

Looking very good Adrian.

Carole 

[carastro]

I must admit I do tend to process my Ha, Oiii and Sii separately before combining.

Carole 

[Craney]

Well the Dolphin Nebula attempt sunk into the murky waters  of the local car-lot Halogen light-bath last night.   Then the Witches Head failed to register above the ambient Moonlight.

Best option was to turn away from the South West and pick out an object over to the North East.   Not much narrow band over there,  so I plumped for a HaLRGB  of the M81 M82 region as the clouds started to mass on the western horizon.

Not having the option to auto-focus at the moment I set a general mid-point focus and hoped it wouldn't show too much on the integration.

Looking at what the top imagers have achieved with this region I learned about the IFN  (Integrated Flux Nebula), that threads its way around these galaxies.  Very faint and a real challenge.

Not sure I have got it.... probably the Integrated Cloud Stack   ..... although there is some variation in the background....but it is something to aim for in future days.

This is 30mins per channel,  I think I will need about 10 hours !!!!!

[Adreneline]

10 hours ago, carastro said:

I must admit I do tend to process my Ha, Oiii and Sii separately before combining.

Ha and OIII processed separately and with added synthetic luminance with help from vlaiv.

 

[carastro]

Hmmm, I think I prefer your first method.  Maybe I need to go back and take a look at a few of mine and do it that way round lol

Carole 

[carastro]

I've just received my Astrokraken dove tail and microfocusser.  I am impressed with the kit and as a bonus it has a bracket on top for my finderguider which I wasn't expecting.

I just need to sort out whether I am going to use the Geoptik adapter where the foot gets in the way of the EFW when I try to screw them together, and if I add an adapter (to clear the foot) it makes the distance too big, or whether to wait for Modern Astronomy's EOS to to CCD camera adapter (he's out of stock at the moment with the shut downs in China).  Apparently that gives the correct spacing

In the meantime I could use the Geoptik adapter with an inserted filter instead of the EFW.

Looking on top at the microfocusser and Finderguider bracket:

 

With finderguider on top.

Getting there.

Carole 

 

Edited March 5, 2020 by carastro

[Craney]

Looking good Carole.    Hope you can get it sorted for the next clear night.     

Remember not to put too much strain on those focus ring adjustment screws, they can bend alarmingly.

 

[Space Oddities]

6 hours ago, carastro said:

I've just received my Astrokraken dove tail and microfocusser.  I am impressed with the kit and as a bonus it has a bracket on top for my finderguider which I wasn't expecting.

I just need to sort out whether I am going to use the Geoptik adapter where the foot gets in the way of the EFW when I try to screw them together, and if I add an adapter (to clear the foot) it makes the distance too big, or whether to wait for Modern Astronomy's EOS to to CCD camera adapter (he's out of stock at the moment with the shut downs in China).  Apparently that gives the correct spacing

Carole,

I might be wrong but it looks to me that the foot can be removed. TS Optics sells a copy of the Geoptik adapter, and in their product pictures I can see 2 hex bolts under the foot. Have you tried removing them, to see if it solves the issue with your filter wheel?

You might even be able to mount it back, in reverse position, to install red dot finder for instance.

Hope that helps!  

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p7835_TS-Optics-CCD-Kamera-Adapter-mit-T2-Anschluss-fuer-Canon-EOS-Objektive.html

 

Edited March 5, 2020 by Space Oddities

[Rush]

This is a new attempt with Samy 135mm fully open and Canon 5D . Processed without cali frames, laziness amazes me.

CS

Rush

[Adreneline]

Another iteration on my setup. Decided to utilise my EvoGuide50ED alongside my Samyang 135mm as I have found it really difficult to achieve a good level of focus with my ZWO mini guide scope. This combination/setup works a treat although it is more difficult to handle and place on the mount. The guide graph stayed with +/- 2" - could be better I suppose but that may have been less than ideal seeing.

The ASIair continues to perform faultlessly and has transformed an imaging session for me. There are a few things I'd change but the ease of focussing with a BM and the iPad pinch-zoom display is amazing; APP reported every sub with FWHM of ~1.25. Plate solving and mount syncronisation saves so much time and gaurantees repeatability in seconds!

Testing meant yet another session on the Heart & Soul - it's the only target I can see now from my garden and even then I only get an hour before it disappears behind the roof.

Adrian

 

Edited March 16, 2020 by Adreneline
Typo & clarification

[groberts]

The new rig looks very nice Adrian + the quality of the resulting image speaks for itself - pity about your sight lines though, I know what you mean!

I've decided to go with the off-the-shelf AstroKraken rig to get me going with a modded DSLR - if I can remember how it works still - it's been a while since using DSLR for AP.  However, I'm still battling with what to do about a guidescope.  Something small and light apeals for now but your experience with the ZWO mini guider is of some concern and I am now drawn towards a similar version by RVO which apprently has better / longer focus travel.  Of course with all the current problems it's not in stock now.

However, assuming all goes well my end game is to use this lens with my ZWO1600MM-C at which point a more comprehensive rig seems likely.  If it's not inconvenient, would appreciate another picture to show how the equioment is now loaded from below / the front.  Your experience with the ASIair etc is also very compelling + I see you're now using their autofocus too?

Look forwards to seeing more from your new set-up.

Graham  

    

 

[Adreneline]

41 minutes ago, groberts said:

would appreciate another picture to show how the equioment is now loaded from below / the front.

Hi Graham,

Here's a couple of photos I hope you and maybe others may find useful.

I'll PM you regarding the ASIair and mini guider so as not to send this 135mm thread too much off track.

Adrian

[Adreneline]

Here's my latest effort with the new setup - IC1396 in Ha only. If the forecast is to be believed I might get lucky and get some OIII in the coming nights.

This is 40 x 180s of Ha taken between 00.30 and 04.00 last night, all unguided. I took 60 in total but discarded the first 20 as IC1396 was so low in the sky.

All calibrated and integrated in APP followed by ABE, HT, LHE and HDRM in PI and finally a little bit of noise reduction in PS.

The Garnet star is looking a bit dodgy but on the whole the others don't look too bad.

Thanks for looking.

Adrian

[carastro]

Got my rig all set up (photo pre cables):

My first two images:

Jellyfish:

First light with Samyang 135mm F2 lens imaging at F2.8
Atik460EX
Newly Rowan belt modded HEQ5

Ha 12 x 600 secs
RGB 17 x 150 secs
Oiii 10 x 300secs (but doesn't really add to the image)
Bortle 8

NAN and Pelican in Ha 16 x 600secs (planning to add colour)

 

Really pleased with this lens and the microfocusser is a dream to use.  I also have a Lonely Speck Lens bahtinov mask i bought for my previous lenses, so adapted that with a collar to go over the Samyang lens and find it fits perfectly snug inside the Dew shield, so don't even have to take it off. 

Carole 

[Adreneline]

45 minutes ago, carastro said:

Got my rig all set up

Glad you're up and running Carole; it's all looking very good and the results speak for themselves.

Adrian