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Uranium235

Imaging with the Samyang 135mm f2

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4 minutes ago, Scott said:

Here's a few from a complete newcomer to camera lens imaging

Very nice Scott. It is a joy of a lens to use and I've been very satisfied with the results I have obtained using the ASI1600, my Atik428ex and my Canon 70D.

It's great to see what others have achieved on a variety of targets.

Adrian

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Just now, Knight of Clear Skies said:

What camera did you use please?

Sorry, An Atik 460EX mono

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Adding one more Samyang  image. ( 3 hrs with a Sony A7)

CS

Rush

Image37_ABE.jpg.866907124151afa8f025febadf047bc6.jpg

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Posted (edited)

You will get phase shifting but whether it's an issue or not depends on the filter and where it's mounted.

I guess that at 3nm or 5nm you may have an issue. I've used 5nm Astrodons at f2.8 and all seemed fine to my eyes. A 3nm looses around 20% at f3 http://dosandbox.astrodon.com/wp-content/uploads/2018/05/Astrodon-Narrowband-Filters_FAQ.pdf

There are those who believe that a phase shifted and efficient 5nm filter is still far better than a wider filter that has a low T efficiency.

Dave.

Edit. Just remembered that Baader do an f2 filter set. What the equivalence in FWHM is I don't know. 

Edited by davew
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Ah I use a ZWO set for now at 7nm  with my asi183mm and noticed my frames were soft in Ha detail on NGC7000 but I totally just blamed the poor transparency.  I should stop to F4 and see if I have improvements. I'm sure it will improve but k already regret that loss of light at F4!

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On 20/06/2019 at 16:53, Kaydubbed said:

At F2 would you get phase shifting issues using normal narrowband filters?

It also depends on the bandwidth of the filter.  A standard Baader 7nm filter is fine in my experience, however a 3nm Astrodon would be more inefficient. A 12nm Astronomik on the other hand would fare better.

But hey, youre at f2!! :)  so a slight loss in transmission is no big deal at that speed.

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Got myself one of these lovely lenses for a trip to Ibiza. I was hoping to get a nice shot of Rho Ophiuchi which is always too low for me to shoot. But thanks to a well placed tower crane and light pollution all my data on that target is garbage. Thankfully I took some test shots of the Sadr region in Cygnus. This shot is made up of 5 x 120s exposures of HA and SIII and only 1 x 120s of O, no flats or darks. So I'm pretty pleased with the result. Just wish I'd shot more data on this target but I was only messing around with the setup. Shot using a Samyang 135mm F2, ZWO ASI 1600MM and an ASI Air. 

 

ic1318.thumb.png.82e41abb35d80de35f35139092f94c30.png

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It is entirely possible to get rho ophiuchi from the UK 😊 you just need a dark, unobstructed location, and pick your nights well (no fuzzy skies). 

Now is a good time for it.  But you have to stay up well late for it...lol 

Actually, I'm thinking of getting yet another of these lenses since my new home has such a limited window of opportunity I would need to cram in as much data as possible in just 3 hours... and the only way to do that is to go superfast.

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I took this of Rho back in May with the Samyang from South Wales, bad tracking meant I lost a lot of data so it’s only 16 minutes worth, I’m hoping to top it up! 

 

E586E018-6B38-461B-AE97-92AAD031EFB4.jpeg

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Nice work. Looks pretty good for 14 mins data. Just shows what F2 can do for you, it just hoovers up those photons. 

 

 

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I just discovered by chance that the collar/ring of the William Optics ZenithStar 61, TS-Optics 60ED and similar, also fits the Samyang 135mm perfectly. You simply need to attach it to the area between the focus ring and the aperture ring. Which is conveniently placed near the middle of the imaging train.

This collar has an inner diameter of 70mm. I don't know any other collar for regular lenses that has this diameter, sadly.

Hope that helps! :) 

Pierre

 

IMG_6181.thumb.jpg.e4fb8d8605a4ec951f5155357b2e19c0.jpg

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Posted (edited)
On 20/06/2019 at 20:35, Kaydubbed said:

Ah I use a ZWO set for now at 7nm  with my asi183mm and noticed my frames were soft in Ha detail on NGC7000 but I totally just blamed the poor transparency.  I should stop to F4 and see if I have improvements. I'm sure it will improve but k already regret that loss of light at F4!

Added 3 hrs of Ha and O3 to the Sony DSLR image fully wide open at F2. My eyes cannot see the occilation nor the incoherence of the light signal.

Cant say overall SNR s improved or aggravated the phase distortion by the filters . The colours look different and some of those dust lanes, star colours vanished :( and Nebula itself became more dense. 

Baader 7 nm and Baader F/2 High speed O3 filter were used.

CS

Rush

DSLR image

489919531_Image37_ABEcopy.jpg.ef47876d8454d1424d6cce0b0390bb8d.jpg

N band added.

467109742_HORGB!copy.jpg.d6e706e6cc7ec03148ca1e7d91678557.jpg

 

Edited by Rush
some image uploading error
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I was looking around for a cheap used 135mm sammy, but came across something very interesting this evening. Samyang have released a 135mm cine lens, rated at T2.2 (transmission value, rather than F ratio). Its expensive, but I found that you can get a variant with a fitting  called "Positive Lock". Which gives a much more secure fit than the standard EF springs found on your typical camera mount (as cine lenses are heavy beasts).

A little more digging found that there is a PL - T2 adaptor available, and the flange-chip distance of the lens is a generous 52mm.

Would be nice to see someone with deep pockets give that a go for astro :) but as always, best to keep your powder dry until someone else makes the leap. Its only been released this month, so its yet to get any attention. If its anything like the standard 135, it would be quite special - especially given the secure nature of its mountings.

The price? £1544 .... hahahaha yea right (if I won the lotto) :D:D:D 

Weight? 1.4kg .... lol...

Thats a lot of dough for 135mm (though probably cheap in the world of cine)

https://rokinon.com/xeen/xeen-cine-system/135mm-t22

 

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Posted (edited)
7 minutes ago, Uranium235 said:

I was looking around for a cheap used 135mm sammy, but came across something very interesting this evening. Samyang have released a 135mm cine lens, rated at T2.2 (transmission value, rather than F ratio). Its expensive, but I found that you can get a variant with a fitting  called "Positive Lock". Which gives a much more secure fit than the standard EF springs found on your typical camera mount (as cine lenses are heavy beasts).

A little more digging found that there is a PL - T2 adaptor available, and the flange-chip distance of the lens is a generous 52mm.

Would be nice to see someone with deep pockets give that a go for astro :) but as always, best to keep your powder dry until someone else makes the leap. Its only been released this month, so its yet to get any attention. If its anything like the standard 135, it would be quite special - especially given the secure nature of its mountings.

The price? £1544 .... hahahaha yea right (if I won the lotto) :D:D:D 

Weight? 1.4kg .... lol...

Thats a lot of dough for 135mm.

https://rokinon.com/xeen/xeen-cine-system/135mm-t22

 

Sounds good, as to price a similar Canon version would be 6K+ so its a bargain...... I also suspect most scope manufacturers like TAK would run and hide if they had to get anywhere near f/2 at any price :icon_biggrin:

Alan

Edited by Alien 13

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12 minutes ago, Alien 13 said:

Sounds good, as to price a similar Canon version would be 6K+ so its a bargain......

Alan

Hmmmm.    that PL thingy has got me thinking a bit. It would be so nuch better if there was a custom adaptor that did away with the whole bayonet business  for standard photo lenses, it would hex bolt to the lens (using compression) and be ultra short....lol... I know might be dffiicult to envisage, but given some time and perhaps a test 3d print (before moving on to aluminium), it might be possible.

lol... I wish Samywang made an M48 or T2 fit version... that would be fantastic :D

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1 minute ago, Uranium235 said:

lol... I wish Samywang made an M48 or T2 fit version... that would be fantastic :D

That would be good but not impossible, I can just remember a company in the far east that could swap out the back end of any camera lens (mechanical bits not the glass) to any fitting...

Alan

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Looking at the rear end of a Sammy, it looks like the bayonet can be removed (held on by three screws). It might be possible to engineer something to replace it, but it would need to be precision stuff, not something I could knock up on the kitchen table.

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2 minutes ago, Uranium235 said:

Looking at the rear end of a Sammy, it looks like the bayonet can be removed (held on by three screws). It might be possible to engineer something to replace it, but it would need to be precision stuff, not something I could knock up on the kitchen table.

I found that most old M42 lenses had a back that had three screws too, I did swap out a old lens using a donor one that fitted with no mods so worth taking some measurements and a visit to a few charity shops.....

Alan

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14 hours ago, Alien 13 said:

I found that most old M42 lenses had a back that had three screws too, I did swap out a old lens using a donor one that fitted with no mods so worth taking some measurements and a visit to a few charity shops.....

Alan

Sounds like a plan! I've got a bench drill so I could drill any additional holes that might be required. The M42 donor lens doesnt even have to be working, as im taking it apart for bits.

 

Edit: Patent pending....lol :D

 

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Posted (edited)

I know - M31 again - but this is just 3x60s of R, G and B plus 3x120s of Ha - so 15 minute in total - using the 135mm Samyang with the ASI1600MM-Pro. I had been imaging IC1396 and stopped when it hit the meridian. I noticed M31 was on the way back to Park so thought I'd grab some of that as well but the clouds rolled right on in and that was that!

1889623998_M31_HaRGB_minimalPS.thumb.jpg.dd8789eb3db840b45fc6297ddbb03d9e.jpg

I know it won't win any prizes but it just goes to show what this remarkable lens can do when used on f2 with a CMOS camera.

I am hoping this image of M31 is finally showing that I've managed to largely solve my odd shaped stars problem by finding a way to mount and support the ASI1600+135mm without getting a droop or misalignment. The ZWO ASI1600 mount and ZWO EoS connector works really well, certainly better than the EoS mounts I've used to date.

IMG_9217.thumb.JPG.4626bec56f1b85431ad2cbdd02e73907.JPG

I think I may still have a slight spacing issue but hopefully I'm getting there.

Adrian

 

Edited by Adreneline
Clarification and additional image
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Just a thought..... if im to attempt modding the 135 I will need three measurements (I cant do it myself since I dont currently own a 135). The rear aperture looks quite wide when compared to some M42 lenses, so I need to know exactly what it is before hunting around for an M42 donor lens. If someone could whip out a digital caliper or ruler (for a rough measurement) that would be handy :)  

The three measurements I need are as follows:

16423_main2_1_measure.jpg.6845b562f3ed7a5189bf5731fdedb358.jpg

If I cant find a lens that is suitable, then I know a chap who just might be able to machine something. If I were to go down the custom route, it would probably end up being M48 instead.

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2 hours ago, Adreneline said:

65.00mm

48.33mm

43.53mm

 

Awesome ☺ thanks! 

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