Imaging with the Samyang 135mm f2

[Space Oddities]

12 hours ago, aleixandrus said:

Love it! May I ask which filters are you using? Thanks

The new Astrodon 3nm Ha and OIII I just received  

[aleixandrus]

Out of my budget! But they seem to perform excellent 😅

[barbulo]

I’ve just ordered one!!! 
Discounted in Am***n. 

[AstroFin]

I've been living in Australia for the last 4 months. While here I've had the opportunity to photograph the southern skies with this lens and my Canon EOS 6D DSLR camera. Here are some of my photos with that setup 🙂 I have a few more in my astrobin!

 

Edited December 17, 2022 by AstroFin

[ollypenrice]

Along with two of my robotic shed clients, Paul Kummer and Peter Woods, I'll be joining this club. We're jointly funding a TS 2600 OSC COS camera, the Samyang, a ZWO focus motor and a lot of bracketery including FLO's adapter for eliminating the tilt-prone bayonet fixing.

We aim to use the system at F2 and, on some targets, enhance regions of interest with higher res panels from the RASA 8 with its 2600 camera as well. I processed some data from another copy of this lens and thought it stunning, especially when using StarXterminator to hold down star sizes ruthlessly.

This is Paul's Samyang data with my telescopic data for the Cone and Rosette applied for enhancement.

Olly

[Space Oddities]

Bienvenue Olly! Your image looks stunning. I'm sure you'll have a lot of fun with this lens!

[geeklee]

I've given up thinking I'll get the OIII to give this the extra data it deserves.  Hopefully next year 🙂.  This is ~5h (108x180s) of Ha across a couple of nights in November.  Conditions weren't great, with another 30-40 subs in the bin.

Samyang 135 (@~F2.6) + ASI 533MM and 6nm Astronomik MaxFR Ha filter.  Thanks for looking.

Edited November 24, 2022 by geeklee

[Laurin Dave]

Here's a couple I've taken over the last week, just over 3 hours on each, f2.8 and ASI2600mc gain zero minus10 300second subs.  Processed in Pixinsight :- calibration, cosmetic correction, debayer, reg, NSG, integration, DBE, Spectrophotometric colour calibration, Starnet, Noise Exterminator and stretching (ArcSinh, HT and GHS)) and Photoshop for colour enhancement, combining various levels of stretch and adding the stars back using Screen mode.

Obviously M42 and the Horsehead region and the Pleiades with a guest appearance from LBN777 The Vulture Nebula at top left

Thanks for looking 

Dave

 

Edited November 26, 2022 by Laurin Dave

[AstroFin]

Superb photos, @Laurin Dave! The IMX571 seems to be a perfect match for this light bucket. I might need to consider upgrading my 183MC at some point... 😁

We had another clear and moonless night here in Victoria. With the help of Bortle 2 skies I managed to get a decent image of the Large Magellanic Cloud! 

253x60s (4h 13min)

Samyang 135mm @ f2.8
Canon EOS 6D (modified)
Star Adventurer 

Larger image in my astrobin.

Edited December 17, 2022 by AstroFin

[ollypenrice]

On 24/11/2022 at 19:49, geeklee said:

I've given up thinking I'll get the OIII to give this the extra data it deserves.  Hopefully next year 🙂.  This is ~5h (108x180s) of Ha across a couple of nights in November.  Conditions weren't great, with another 30-40 subs in the bin.

Samyang 135 (@~F2.6) + ASI 533MM and 6nm Astronomik MaxFR Ha filter.  Thanks for looking.

I'm seeing convincing traces of hydrogen here for the first time and I have enough data on this target to sink a ship. Brilliant. Absolutely brilliant. Can't wait to get started.

Olly

[gorann]

On 24/11/2022 at 19:49, geeklee said:

I've given up thinking I'll get the OIII to give this the extra data it deserves.  Hopefully next year 🙂.  This is ~5h (108x180s) of Ha across a couple of nights in November.  Conditions weren't great, with another 30-40 subs in the bin.

Samyang 135 (@~F2.6) + ASI 533MM and 6nm Astronomik MaxFR Ha filter.  Thanks for looking.

 

51 minutes ago, ollypenrice said:

I'm seeing convincing traces of hydrogen here for the first time and I have enough data on this target to sink a ship. Brilliant. Absolutely brilliant. Can't wait to get started.

Olly

That is nice and sharp Lee! Yes, there is plenty of Ha around. This is 37 x 5 min = 3.1 h taken with a Samyang 135 @ f/2 and an Omegon veTEC571 piggybacking on my dual RASA8 rig. I used the IDAS NBZ filter so not as narrow Ha bandwidth as a pure Ha filter and probably therefore not as detailed. Like you Olly I add a bit of RASA data to the central details.

Cheers, Göran

[gorann]

I had missed this thread (or forgot about it). After having had my Samyang 135 on a shelf for a while it is now piggybacking on my dual RASA8 rig providing me with bonus data and a "wider picture" of what I am aiming at. Here are some of its recent images taken with an Omegon veTEC571 and an IDAS NBZ (Ha+Oiii) filter, with some RASA data added here and there.

Details on the captures can be found on my Astrobin page.

Cheers

Göran

 

Edited November 27, 2022 by gorann

[geeklee]

53 minutes ago, gorann said:

This is 37 x 5 min = 3.1 h taken with a Samyang 135 @ f/2 and an Omegon veTEC571 piggybacking on my dual RASA8 rig. I used the IDAS NBZ filter so not as narrow Ha bandwidth as a pure Ha filter and probably therefore not as detailed.

@gorann Is it just a trait of these dual NB filters that all images come out red so it looks like the background Ha is so strong?  I m pondering on this based on the below structure(s).  How would this structure be clear in my Ha image, but I'm missing all that other "faint Ha"?  Your image has this structure and the one to the left (I think) missing or behind the background Ha?

Here's my raw stack, Auto-STF in PI

 

Edited November 27, 2022 by geeklee

[geeklee]

1 hour ago, ollypenrice said:

I'm seeing convincing traces of hydrogen here for the first time and I have enough data on this target to sink a ship. Brilliant. Absolutely brilliant. Can't wait to get started.

Thanks @ollypenrice I spent some time on Astrobin reviewing other wide and very wide field images to guage how accurate this - hopefully - is.  Dismissing a lot of images along the way.

Super stretching a resampled version of the above hopefully still shows a true - or close to true - picture.

Edited November 27, 2022 by geeklee

[Adreneline]

3 minutes ago, geeklee said:

Super stretching a resampled version of the above hopefully still shows a true - or close to true - picture.

Hi Lee.

That may be the case if the data can take being 'super stretched' in PI. A purely personal view is that we are seeing a great many images that have been 'stretched' beyond their means, whether they are taken with a Samyang, RASA, Takahashi or an iPhone!

There is no substitute for imaging time to reveal data - or that always used to be the case, and certainly the mantra that was preached by so many when I started this mad hobby only six years ago.

I do wonder if in the 'smash and grab' world in which we now seem to be residing with photon hoover scopes and ever more sensitive cmos devices there is too much emphasis on using processing to expose detail that is barely there in the first place because there is insufficient data. It has always been the case that rubbish data produces rubbish images but next to no data surely cannot produce a credible image. The likes of StarX and NoiseX are not the holy grail of imaging if all they do is encourage super-stretching and over-processed images to reveal noise as data/nebulosity. We are kidding ourselves.

Or have I got it all wrong.

Apologies if I have derailed this thread.

Adrian

[geeklee]

31 minutes ago, Adreneline said:

Or have I got it all wrong.

No, I agree.  I wouldn't want to publish the above with the "super stretch" at any "size" beyond that - the data can't back it up.

Resampling data in software obviously provides us with more width to push an image.

You can see from a small snippet above showing an AutoSTF of my master stack that StarX played a very positive role in letting me deal with the nebulosity and stars separately (and really peg back the stars).

Edited November 27, 2022 by geeklee

[Adreneline]

19 minutes ago, geeklee said:

and really peg back the stars

... totally agree.

[gorann]

1 hour ago, geeklee said:

@gorann Is it just a trait of these dual NB filters that all images come out red so it looks like the background Ha is so strong?  I m pondering on this based on the below structure(s).  How would this structure be clear in my Ha image, but I'm missing all that other "faint Ha"?  Your image has this structure and the one to the left (I think) missing or behind the background Ha?

I think that it has to do with the width of the bandpass for Ha. For the NBZ it is around 30 nm (judging from this spectrum) while a Ha only filter is often 3 - 7 nm. It appears to be a general impression that the narrower the bandpass is the more details you can get out which may be an effect of dispersion our atmosphere. That is why some of us are prepared to pay a lot for the 3nm filters. With regard to Oiii, the NBZ filter also picks up quite a lot of blue reflection nebulosity which is blocked by a narrower Oiii filter.

[geeklee]

5 minutes ago, gorann said:

I think that it has to do with the width of the bandpass for Ha. For the NBZ it is around 30 nm (judging from this spectrum) while a Ha only filter is often 3 - 7 nm. It appears to be a general impression that the narrower the bandpass is the more details you can get out which may be an effect of dispersion our atmosphere. 

I'm surprised how this is related as the structures I highlighted look about the same strength & size as those that do appear.

7 minutes ago, gorann said:

That is why some of us are prepared to pay a lot for the 3nm filters.

Yes, ultra narrow band filters are brilliant.  I wish had more than one set!

[gorann]

10 minutes ago, geeklee said:

I'm surprised how this is related as the structures I highlighted look about the same strength & size as those that do appear.

Yes, ultra narrow band filters are brilliant.  I wish had more than one set!

Aha! As I said in my post I also added RASA data to central parts of the image so I think what you see is the edge of the RASA data.

[gorann]

17 minutes ago, geeklee said:

I'm surprised how this is related as the structures I highlighted look about the same strength & size as those that do appear.

Yes, ultra narrow band filters are brilliant.  I wish had more than one set!

Yes, that is it - here is my RASA image (two panels but still not enough to cover it all):

[ollypenrice]

28 minutes ago, Adreneline said:

Hi Lee.

That may be the case if the data can take being 'super stretched' in PI. A purely personal view is that we are seeing a great many images that have been 'stretched' beyond their means, whether they are taken with a Samyang, RASA, Takahashi or an iPhone!

There is no substitute for imaging time to reveal data - or that always used to be the case, and certainly the mantra that was preached by so many when I started this mad hobby only six years ago.

I do wonder if in the 'smash and grab' world in which we now seem to be residing with photon hoover scopes and ever more sensitive cmos devices there is too much emphasis on using processing to expose detail that is barely there in the first place because there is insufficient data. It has always been the case that rubbish data produces rubbish images but next to no data surely cannot produce a credible image. The likes of StarX and NoiseX are not the holy grail of imaging if all they do is encourage super-stretching and over-processed images to reveal noise as data/nebulosity. We are kidding ourselves.

Or have I got it all wrong.

Apologies if I have derailed this thread.

Adrian

Any image can be stretched beyond its useful data content and its noise floor. If we do this we cannot blame anyone but ourselves. The use of a fast system makes it harder, not easier, to stretch too far but every data set has its limits and we should respect them. Looking at Lee's image at the scale presented, I see no evidence at all that it has been pushed too far, but that's me and my perception. (If I were to offer a comment it might be to be a bit more careful about the white point, which may be clipped slightly. However, the faint regions are the best I've ever seen.)

I have to say that StarX and NoiseX may well be the holy grail of imaging from my point of view.  The separation of an image into zones requiring different processing has always been the key to creating a good picture and the separation of stars from background is the most potent-ever expression of this.  It's not just that softly stretched stars can be put back into a hard-stretched image: the imager can see what they are doing while working on the uncluttered nebulosity.  Although I've used StarX on some photon-hoover datasets, most of my time with it has been spent revising older images from slower systems.

StarX is also of particularlu high value to widefield imagers because it overcomes the key weakness of small aperture optics: they give larger stars. Nice as they often were, camera lens images were given away by their large stars. Not any more, though. I've been drawn into the Samyang 135 fold precisely because of this.

Olly

[Adreneline]

2 minutes ago, ollypenrice said:

Looking at Lee's image at the scale presented, I see no evidence at all that it has been pushed too far, but that's me and my perception.

Neither do I, and it was not my intention to imply as such. It was my intention to say, in my opinion, that there is an increasing tendency to push data beyond the limit and I agree with you that the fault is entirely with the individual if that is the case. Recognising when you can push data and just how far is a skill hard learnt and one I have yet to master; I bow to those who have mastered the skill and know exactly how far you can go.

Adrian

 

[geeklee]

7 minutes ago, ollypenrice said:

(If I were to offer a comment it might be to be a bit more careful about the white point, which may be clipped slightly. However, the faint regions are the best I've ever seen.)

Thanks Olly.  I had spotted some clipped nebulosity when I went to look at the data again wondering if I'd been too hasty resampling it (I hadn't). 

In trying to balance the faint stuff so much I made a classic mistake of forgetting another key element of the image.  If there are other points clipped, do call them out so I can review 👍  It was the eastern Veil I was thinking - it has some tricky ranges.

[gorann]

14 minutes ago, ollypenrice said:

Any image can be stretched beyond its useful data content and its noise floor. If we do this we cannot blame anyone but ourselves. The use of a fast system makes it harder, not easier, to stretch too far but every data set has its limits and we should respect them. Looking at Lee's image at the scale presented, I see no evidence at all that it has been pushed too far, but that's me and my perception. (If I were to offer a comment it might be to be a bit more careful about the white point, which may be clipped slightly. However, the faint regions are the best I've ever seen.)

I have to say that StarX and NoiseX may well be the holy grail of imaging from my point of view.  The separation of an image into zones requiring different processing has always been the key to creating a good picture and the separation of stars from background is the most potent-ever expression of this.  It's not just that softly stretched stars can be put back into a hard-stretched image: the imager can see what they are doing while working on the uncluttered nebulosity.  Although I've used StarX on some photon-hoover datasets, most of my time with it has been spent revising older images from slower systems.

StarX is also of particularlu high value to widefield imagers because it overcomes the key weakness of small aperture optics: they give larger stars. Nice as they often were, camera lens images were given away by their large stars. Not any more, though. I've been drawn into the Samyang 135 fold precisely because of this.

Olly

Well spoken Olly! As far as I know you can not stretch an image to create false detail as someone claimed. The problem with false details has more to do with fancy AI filters like Topaz. Stretching too far just creates noise in my experience, and and an ugly image. But with our new fast optics and sensitive CMOS we can reveal structures that have previously been unreachable with slower systems unless you spend weeks of data capture.

Edited November 27, 2022 by gorann