Imaging with the Samyang 135mm f2

[Uranium235]

1 hour ago, Simon Pepper said:

Was this with a dslr or dedicated? Thanks 

KAF8300 sensor (just a little smaller than APS-C)  22mm diagonal

[Uranium235]

2 hours ago, powerlord said:

very nice. is that with the asi ? I shot the same target/comp basically last night with my 6d +135. Not looked at subs yet but no way as good as that.

Old skool CCD mate   QSI583 - KAF8300 sensor. Had to limit my exposure length to 7.5min due to where it was (I have a very limited window on it), at least that way I could generate a stack just big enough to average out some of the noise.

[powerlord]

I shot two targets last night - elephant trunk and orion. Here's elephant trunk.

For me, old skool is my Canon 6D - not used it in months, but nice FF gets me some wide views with the 135mm. L-extreme of course. There's life in the old 6D yet I reckon - came out ok for 80 mins of subs.

[powerlord]

And here's my Orion - Canon 6D and 135mm/Lextreme again.

About 60 mins of subs.

With and Without stars.

[Uranium235]

Pixel peepers delight

16x600 (Ha)

(corners @ 200%)  

[powerlord]

Even @vlaiv will struggle to find fault with that. 😀 well done!

stu

[powerlord]

A late M42. I shot a similar wide view In November, but in NB with my asi1600. Same sort of view, but this time with the asi533 and L-extreme.

Of course, colours a bit different, etc but still an interesting comparison? Far more detail in the asi1600 version, but then that's to be expected with 12mp of active pixels vs 1/4 of 9mp on the asi533

first is asi533/L-extreme, second is asi1600 and SHO.

 

[Adreneline]

This great thread is languishing down on Page 3 and in danger of slipping on to Page 4 - and that will never do!

So here is IC410 et al taken on a full Moon night with an Astronomik 6nm Ha filter - 29 x 300s with an ASI183MM-Pro, gain 111, -20 degrees using a 49mm step-down-ring on the lens.

Calibrated, registered and integrated in APP and then processed in PI.

Don't you just love the Samyang 135mm lens.

[woldsman]

I recently bought a printed micro focuser for the Samyang 135 but am disappointed with the fit and operation of it. Have a ZWO focuser attached to a scope and am reluctant to buy another or to transfer the unit between two rigs. 

Any recommendations? If possible, images of how the micro focuser is attached would also be appreciated. Thanks!

[Adreneline]

12 minutes ago, woldsman said:

I recently bought a printed micro focuser for the Samyang 135 but am disappointed with the fit and operation of it. Have a ZWO focuser attached to a scope and am reluctant to buy another or to transfer the unit between two rigs.

My experience exactly; it wasn't just the fit - the operation was far from easy - frustrating in fact. In the end I decided to buy a second EAF as I too did not want to disrupt my RedCat setup.

I did try an old SW DC focuser I had going spare but as I wanted to use the ASIair that was not really a workable solution.

Sorry I cannot offer any alternative suggestions.

😐

 

[woldsman]

3 minutes ago, Adreneline said:

My experience exactly; it wasn't just the fit - the operation was far from easy - frustrating in fact. In the end I decided to buy a second EAF as I too did not want to disrupt my RedCat setup.

I did try an old SW DC focuser I had going spare but as I wanted to use the ASIair that was not really a workable solution.

Sorry I cannot offer any alternative suggestions.

😐

 

Thanks! - at least I already have the Redcat unit on my setup. Noticed you seem still to have the 11mm attachment on your ZWO camera plus what seems to be a ZWO eos adapter. You also have a filter wheel in there. Could I ask what your back focus is? The Samyang may be a Nikon fit which I think gives more tolerance but even so you have managed to put together what looks like an interesting imaging train.

[geeklee]

31 minutes ago, woldsman said:

Any recommendations? If possible, images of how the micro focuser is attached would also be appreciated. Thanks!

Very similar to @Adreneline (same ring for the belt on the lens).  Link to post within this thread below.

 

Edited April 18, 2022 by geeklee

[Adreneline]

23 minutes ago, woldsman said:

Noticed you seem still to have the 11mm attachment on your ZWO camera plus what seems to be a ZWO eos adapter. You also have a filter wheel in there. Could I ask what your back focus is? The Samyang may be a Nikon fit which I think gives more tolerance but even so you have managed to put together what looks like an interesting imaging train.

Yes, I use the 11mm ZWO ring but no ZWO EoS adapter. I replaced the EoS lens fitting with an Astrojolo 42mm threaded connection as it is much more rigid and less prone to 'droop'.

I have spent what seems like a very long time getting the spacing as close as possible to ideal and I can achieve focus with the foot of the 'L' on the lens when I use my Astronomik Ha, SII and L2 filters. If I use my Baader OIII the focus point moves to about 3mm before the 'L' due to the Baader filters being thicker (2mm as opposed to 1mm for the Astronomik).

The spacing is very sensitive - the additon (or removal) of a 0.1mm spacer will have a profound effect on the focus position.

HTH

Adrian

P.S. I use a TS Optics manual filter drawer for 2" filters.

Edited April 18, 2022 by Adreneline
Clarification

[Bibabutzemann]

On 06/02/2022 at 00:24, powerlord said:

And here's my Orion - Canon 6D and 135mm/Lextreme again.

About 60 mins of subs.

With and Without stars.

 

Wow, the perfomance of this lens, even in edges of a 6d, is amazing. Which f ratio was used?

[woldsman]

My imaging train is away being repaired with the scope (misaligned optics). Passing the time pairing the Samyang 135 with a no-frills Canon 100d (modded) & Optolong L-eNhance. This is another Elephant’s Trunk at f2.8 & ISO 400 taken over a weekend (124 x 120”) guided on a HEQ5. Managed to keep the noise down by dithering every frame and waiting 30” for the sensor to cool down a bit.

Edited - this time stacked the calibration frames for each session separately, tweaked the processing, and applied some noise reduction software.

 

Edited May 12, 2022 by woldsman

[900SL]

Edited

 

Edited May 6, 2022 by 900SL

[900SL]

M31 D5600 S135 FLT2 tracker

[900SL]

I read somewhere that it wasn't recommended to use a dual narrowband Ha/Oiii filter on an OSC astro camera with the Samyang 135 because one or other of the channels will be 'soft'. I can't find the original post now, so wondered if any of you Sammie's had encountered this in use? 

[woldsman]

On 18/04/2022 at 16:37, Adreneline said:

Yes, I use the 11mm ZWO ring but no ZWO EoS adapter. I replaced the EoS lens fitting with an Astrojolo 42mm threaded connection as it is much more rigid and less prone to 'droop'.

I have spent what seems like a very long time getting the spacing as close as possible to ideal and I can achieve focus with the foot of the 'L' on the lens when I use my Astronomik Ha, SII and L2 filters. If I use my Baader OIII the focus point moves to about 3mm before the 'L' due to the Baader filters being thicker (2mm as opposed to 1mm for the Astronomik).

The spacing is very sensitive - the additon (or removal) of a 0.1mm spacer will have a profound effect on the focus position.

HTH

Adrian

P.S. I use a TS Optics manual filter drawer for 2" filters.

Hi, Things have moved on for me. I’ve a new scope and am happy with its manual focus. So am thinking of redeploying the EAF to the Samyang 135 widefield rig. Could I ask where you sourced the belt drive and the red attachment that you put on the Samyang focus ring? 

[woldsman]

NGC 7822. Just a quick session: 36 x 136” lights with 11 x 136” darks, 31 x 3” flats & 31 x 3 dark flats. Canon DSLR 100d (modded) at iso 400.  Optolong L-eNhance filter. Guided and dithered.  Stacked in Affinity Photo and processed using Startools. 

Edited May 22, 2022 by woldsman

[Adreneline]

15 minutes ago, woldsman said:

Hi, Things have moved on for me. I’ve a new scope and am happy with its manual focus. So am thinking of redeploying the EAF to the Samyang 135 widefield rig. Could I ask where you sourced the belt drive and the red attachment that you put on the Samyang focus ring? 

The EAF (or similar) is essential for the Samyang 135. I bought my belts and HTD gears from Motionco.co.uk . The red ring was 3D printed from an existing design intended for a RedCat 51. Prior to the red gear ring I used a section from a second belt which I attached to the lens using a double sided tape purchased off Amazon - that arrangement worked really well considering it was so simple. You don’t need to cover the whole circumference - just enough for the drive belt to engage to ensure good registration. I tried using the drive belt alone on the focuser ring but unless you employ excessive tension the drive belt will slip or ‘process’ and you won’t get repeatability in absolute focus position from the EAF.

HTH

Adrian

[woldsman]

5 minutes ago, Adreneline said:

The EAF (or similar) is essential for the Samyang 135. I bought my belts and HTD gears from Motionco.co.uk . The red ring was 3D printed from an existing design intended for a RedCat 51. Prior to the red gear ring I used a section from a second belt which I attached to the lens using a double sided tape purchased off Amazon - that arrangement worked really well considering it was so simple. You don’t need to cover the whole circumference - just enough for the drive belt to engage to ensure good registration. I tried using the drive belt alone on the focuser ring but unless you employ excessive tension the drive belt will slip or ‘process’ and you won’t get repeatability in absolute focus position from the EAF.

HTH

Adrian

Thanks! Do you use a guide camera? Just wondering where it would go. Having the EAF mounted below on the dovetail would free up a perch for a guide scope on top. 

[Adreneline]

Rarely imaged Sh2-150 and Sh2-145 in Cepheus.

Really happy with the corner star shapes. 

[Adreneline]

2 minutes ago, woldsman said:

Thanks! Do you use a guide camera? Just wondering where it would go. Having the EAF mounted below on the dovetail would free up a perch for a guide scope on top. 

No. Fortunately I don’t need to guide with the CEM25-EC. Mounting the EAF below the Samyang would allow a small guide-scope to piggyback above I suppose. 

[Adreneline]

10 minutes ago, Adreneline said:

No. Fortunately I don’t need to guide with the CEM25-EC. Mounting the EAF below the Samyang would allow a small guide-scope to piggyback above I suppose. 

 

Edited May 22, 2022 by Adreneline