Imaging with the Samyang 135mm f2

[Grant93]

Whats peoples opinions on the T2.2 cine lens version? Can only find this at a reasonable price at the moment! Not too sure whether to buy it.

Grant

[nephilim]

7 minutes ago, Grant93 said:

Whats peoples opinions on the T2.2 cine lens version? Can only find this at a reasonable price at the moment! Not too sure whether to buy it.

Grant

I personally dont know enough about this lens but its more suited to filming, its also for full frame sensors. 

 

[symmetal]

By the price it appears to be the standard lens but fitted with geared focus and aperture rings. True cine lenses are much more expensive than their standard counterparts as they are made to higher standards, being sharp to the corners with much reduced chromatic aberration, and no barrel distortion, vignetting or focus breathing.

Having the geared focus ring would be handy if you wanted to automate the focus as it's a standard pitch gear. The aperture ring is continuous with no click stops and is calibrated in transmission T stops rather than the normal F stops.

Alan

Edited June 6, 2021 by symmetal

[Grant93]

3 hours ago, nephilim said:

I personally dont know enough about this lens but its more suited to filming, its also for full frame sensors. 

 

Might be a stupid question, Never done any sort of DSLR photography before entering astrophotography, but would it still be good on an 800D? As its a crop sensor.

2 hours ago, symmetal said:

By the price it appears to be the standard lens but fitted with geared focus and aperture rings. True cine lenses are much more expensive than their standard counterparts as they are made to higher standards, being sharp to the corners with much reduced chromatic aberration, and no barrel distortion, vignetting or focus breathing.

Having the geared focus ring would be handy if you wanted to automate the focus as it's a standard pitch gear. The aperture ring is continuous with no click stops and is calibrated in transmission T stops rather than the normal F stops.

Alan

By what you've said and what I've previously read, it sounds like the only thing that its bad for is if you try to replicate a previous image because you wouldnt be able to get the exact same aperture, (Or it would atleast be very hard since you haven't got the click stops).

So would this still be perfectly fine for astrophotography compared to a F2 version? I don't want to compromise just because I've seen one at a good price, and they seem to be quite hard to find unless your willing to pay £400-450+.

I've seen this one at a reputable company that I do believe offer a 6 month warranty on purchases for £300, second-hand but 'as new' condition, (I would definitely return it if it doesn't look as new).

Thanks for both replys!

Edit: Ive just seen also you mentioned 'by the price', so I assume you've seen the one I'm looking at? Also I think I've been confused on your reply. What your saying is this isnt a cine lens I'm looking at, its something thats been fitted to make it more 'cine-like'. So new question! Would you buy this given the choice?

Edited June 6, 2021 by Grant93

[symmetal]

4 hours ago, Grant93 said:

Might be a stupid question, Never done any sort of DSLR photography before entering astrophotography, but would it still be good on an 800D? As its a crop sensor.

A lens suitable for full frame will be fine on a smaller sensor, in fact it should appear to perform better, as the full frame edge performance roll off will not be present on a smaller sensor which doesn't cover the same distance from the lens centre axis.

4 hours ago, Grant93 said:

Edit: Ive just seen also you mentioned 'by the price', so I assume you've seen the one I'm looking at? Also I think I've been confused on your reply. What your saying is this isnt a cine lens I'm looking at, its something thats been fitted to make it more 'cine-like'. So new question! Would you buy this given the choice? Or stay away since its been tampered with?

That's right. It will function on a film or TV camera, as it has the gear connections for the servos on a film/TV camera enabling local or remote control of focus and exposure, (and zoom, if it was a zoom lens.) For a film camera it's controlled locally by the cameraman, while for a TV camera the exposure is often controlled remotely. It's the critical zoom performance, maintaining perfect image focus and no image shift or degredation during the zoom which is the main cost of cine lenses. Film companies generally rent cine lenses when required, as the cost of buying them outright can be prohibitive. Here's a good run down on the differences between cine and regular lenses.

Not having click stops on the aperture shouldn't put you off as it will be stiff enough not to move on its own. The T-stop scale is more precise than F-stops with more marked graduations for setting it. T-stops allow different lenses to be used which will give the exact same exposure as long as they are set to the same T-stop setting. That means they have the same light transmission. F-stops are just a mathematical ratio and the light transmission of the lens is not factored in. Here's an explanation of the difference compared to F-stops. The T2.2 Samyang lets in the same light as the F2 Samyang, it's just the light transmission factor of the lens is taken into account when giving the T value.

I'd be happy buying one in place of a standard lens for astrophotography as the settings are all manual, which is what you want anyway, with easier external automation of focus and aperture if required. Optically, in this case, the cine Samyang will be the same as the standard lens version so if you can get it easier I'd go for it. It's not been 'tampered with' as such as both are made by Samyang. 🙂

Alan

Edited June 6, 2021 by symmetal

[Grant93]

12 hours ago, symmetal said:

I'd be happy buying one in place of a standard lens for astrophotography as the settings are all manual, which is what you want anyway, with easier external automation of focus and aperture if required. Optically, in this case, the cine Samyang will be the same as the standard lens version so if you can get it easier I'd go for it. It's not been 'tampered with' as such as both are made by Samyang. 🙂

Alan

Thank you very much for your extensive help and patience, I have decided to purchase and it will be here tomorrow, and apparently clear skies! Touch wood.

Haha I editted out that tampered bit out, sorry! It must of been whilst you were still typing the reply! I realised what I said was stupid, after thinking about it, its just a little mod from samyang to make it more suitable for cine, even though its not a true cine lens. I guess thats why they call it a VDSLR lens?

I think the proper cine 135mm from Samyang is that Xeen one, and I've seen the prices 😱.

Thanks again!

Grant

[symmetal]

As I've talked you into it Grant, I hope you'll be happy with it. 😀

As you say, the Xeen range are true cine lenses. You can imagine the extra cost of their zoom cine lenses. 😬

Alan

[Toaster05]

Hey all,

I've seen it mentioned that a Redcat/Starcat collar will fit a Samyang 135mm. Just wondering if this was correct and did anyone have any feedback if they are using one.

I'm assuming this is the part in question? 

https://www.firstlightoptics.com/william-optics-brand/william-optics-redcat-spacecat-single-mounting-ring-black.html

Kind regards

 

Edited June 7, 2021 by Toaster05
Typo

[Adreneline]

4 minutes ago, Toaster05 said:

Hey all,

I've seen it mentioned that a Redcat/Starcat collar will fit a Samyang 135mm. Just wondering if this was correct and did anyone have any feedback if they are using one.

I'm assuming this is the part in question? 

https://www.firstlightoptics.com/william-optics-brand/william-optics-redcat-spacecat-single-mounting-ring-black.html

Kind regards

 

That is correct. I use one and it works very well.

Adrian

I've recently purchased the RedCat handle to mount the guide scope more securely - and provide a convenient handle!

 

[Toaster05]

@Adreneline Thanks for the reply. 

Can you still access the aperture ring though? It appears slightly covered. Not that it's a deal breaker as I pretty much know what I'll be shooting at night by night, target by target.

Looks really great by the way.

[Victor Boesen]

Be aware that it may just barely fit if you're using the collar and lens with a DSLR. With my Nikon D3300 I need to turn the camera body a certain way to fit the collar under the camera flash housing.

Edited June 7, 2021 by Victor Boesen

[Adreneline]

Just now, Toaster05 said:

Can you still access the aperture ring though?

No - you need to set the aperture before closing the ring.

I have experimented with other mounts that work well with a ZWO1600 or ZWO294 camera - like this one using PrimaLuce Lab 80mm rings.

 

[Toaster05]

13 minutes ago, Victor Boesen said:

Be aware that it may just barely fit if you're using the collar and lens with a DSLR. With my Nikon D3300 I need to turn the camera body a certain way to fit the collar under the camera flash housing.

Yeah, that was going to be my use case. It might just have to be a suck it and see on this one.

[nephilim]

On 05/06/2021 at 23:01, Space Oddities said:

You could use the cheaper dual plate from TS Optics, There should be enough room for an EAF between the lens and the Evoguide: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8315_TS-Optics-Parallelbefestigung---Doppelbefestigung-fuer-Teleskope--Tele-und-Leitfernrohre.html

 

@Space Oddities I've just realised I haven't a clue how to fit this to my mount, will I need a different saddle as otherwise adding to my current saddle will have my set up turned 90 degrees (apologies if this is a daft question 🙂)

[Space Oddities]

21 hours ago, nephilim said:

@Space Oddities I've just realised I haven't a clue how to fit this to my mount, will I need a different saddle as otherwise adding to my current saddle will have my set up turned 90 degrees (apologies if this is a daft question 🙂)

No problem, it's indeed an unusual way to mount your scope!

The dovetail itself is a standard vixen one, so you just attach it to your mount's saddle, like you do with your current setup.

Using this image as a reference:

• On the right side, there's a vixen saddle to which you can mount the Samyang with your existing dovetail (although a shorter one might be better)
• On the left side, the clamp allows you to mount the guide scope, or anything that has a standard finder dovetail (like the ASIAIR Pro)
• In the middle, you can attach the ASIAIR Pro (vertically), using the included 1/4" screw. This should provide a good balance and make the ASIAIR Pro close to everything. As you can see on the picture below, there should be enough room for the ASIAIR.

You do have to rotate manually your mount's saddle by 90°. That's how I did on my AZ-GTi, I'm not sure how this works on other mounts though... But I guess it's as easy as releasing the clutch and rotating the DEC axis 90°  

Below are 2 pictures of the setup I had, hope that helps!

[nephilim]

3 hours ago, Space Oddities said:

No problem, it's indeed an unusual way to mount your scope!

The dovetail itself is a standard vixen one, so you just attach it to your mount's saddle, like you do with your current setup.

Using this image as a reference:

• On the right side, there's a vixen saddle to which you can mount the Samyang with your existing dovetail (although a shorter one might be better)
• On the left side, the clamp allows you to mount the guide scope, or anything that has a standard finder dovetail (like the ASIAIR Pro)
• In the middle, you can attach the ASIAIR Pro (vertically), using the included 1/4" screw. This should provide a good balance and make the ASIAIR Pro close to everything. As you can see on the picture below, there should be enough room for the ASIAIR.

You do have to rotate manually your mount's saddle by 90°. That's how I did on my AZ-GTi, I'm not sure how this works on other mounts though... But I guess it's as easy as releasing the clutch and rotating the DEC axis 90°  

Below are 2 pictures of the setup I had, hope that helps!

That's great news thanks for such a detailed reply.

I had a good long chat with @Adreneline this morning about his set up & mentioned that last night whilst faffing about I accidently over tightened one of the 3D printed mounting rings on the Samyang which resulted in it snapping. This was actually a good thing really as its made me realise its probably not wise trusting a lot of moneys worth off kit on a plastic mounting system.

I hope Adrian doesn't mind me reproducing his photo below  but this what I've decided on & now you've given me the above info I can use the dual mount, have the Asiair in the centre & will also have a good site for a future focuser. At last i've a clear plan of what I want & after finally getting all my gear working together last night I can  move forward.
 

[Space Oddities]

@nephilim My pleasure!  

Yesterday I spent some time trying to polar align my mount on my closed balcony. It is facing east exactly, and therefore I can't see Polaris... I've always wanted to try drift alignment, so I gave it a try yesterday. It wasn't easy, since you need to point the scope south, which i also don't see... and since I can't remove the windows, I had to get creative and drift align through the glass of one of them    But! It actually worked, and I got the mount (very) roughly polar aligned. I was quite surprised to be honest!

I'll try to improve the polar alignment now that I got the hang of it. But even with a rough polar alignment, my guiding was around 1.7"... which sounds like a miracle to me, given the conditions! 

It was also the first light for my ASI2600MC and the new Black Cat mount that I adapted to the Samyang. It worked flawlessly!

I made a few test exposures of the Sadr region, which is conveniently placed in the east right now. With this configuration, I can image targets up to ~60-65° of altitude, before the ceiling appears in the picture. I don't think I can image more than 2 hours in this configuration, but it's better than nothing!  

 

A 20 seconds exposure at gain 0, with the UV/IR cut filter:

Just before the ceiling took over, I switched to the Optolong L-eNhance and made a 2 min exposure. I didn't bother to restart the autofocus, so it's a bit blurry... And the stars aren't pinpoint, the limits of my polar alignment started to show! But I was expecting much worse honestly  So with a refined polar alignment, proper focus and the wide aperture of the Samyang, I'm sure I can make some very nice long exposures now!

If you stand away from your computer screen, these objects might appear more in focus!  

 

[geeklee]

27 minutes ago, Space Oddities said:

Just before the ceiling took over, I switched to the Optolong L-eNhance and made a 2 min exposure.

Nice one @Space Oddities  If that method can make your life easier going forward it was time well spent.

I thought the image above with the roof just in shot was stunning, if not for focus (  ) then for the scale of the shot you get with just a tiny bit of roof showing - felt like I had stuck my head out the window to look up at the sky.

Edited June 14, 2021 by geeklee

[Space Oddities]

Thanks Lee! I wish I took the time to properly refocus, but well it was past midnight and I was exhausted from all the gymnastics I had to do for polar alignment   But yes - focus apart, it looks promising, and I can't wait to try again! 

It will indeed make my life easier (hopefully), I kind of lost the motivation to get out in the public parks... The cold, the curfews and now the sun setting very late aren't good motivators. But I'm getting closer!

I just found a screenshot of the drift alignment, with the frame of my window  I still have no idea how PHD could guide with such a tiny space, and through another window's glass... What an awesome software!

Edited June 14, 2021 by Space Oddities

[Adreneline]

Haha! I think maybe BlackCat mounts are about to get a boost! Nice arrangement Pierre - thanks for sharing!

Adrian

[Space Oddities]

20 minutes ago, Adreneline said:

Haha! I think maybe BlackCat mounts are about to get a boost! Nice arrangement Pierre - thanks for sharing!

Adrian

Yes, they're really nicely made! Compared to the rings used by Steve, I think the main advantage is that everything relies on the more solid William Optics tube ring, rather than 3D printed rings. Better for the peace of mind!

I'm currently beta testing a prototype for the Samyang, which basically is the same as the RedCat but with a different focus ring. It worked great yesterday and helped keep everything compact and tidy. I guess they should be available very soon!  

[david_taurus83]

On 07/06/2021 at 18:13, Toaster05 said:

Yeah, that was going to be my use case. It might just have to be a suck it and see on this one.

This one will fit but its 1mm too big so I used some electrical tape to beef up the lens body. Fitted nice and snug and the bonus is you can still access the aperture ring.

https://www.amazon.co.uk/dp/B07DVKZBXG/ref=cm_sw_r_cp_apa_glt_fabc_T0WDMBR512ZSNGT720GZ

 

[Adreneline]

36 minutes ago, david_taurus83 said:

I used some electrical tape to beef up the lens body.

I've found this stuff is really good for making up gaps in rings. It comes in various thicknesses. I've only used the 2mm thick which compresses nicely to tighten play in rings on my setup.

 

[Toaster05]

@david_taurus83 Thanks for the reply. That could work for my needs, however I'm not so keen on applying tape to the lens itself as I use it for daytime photography too.

Though looking at what @Adreneline has posted I wonder if it would be viable for application on the ring itself?

[Space Oddities]

18 minutes ago, Toaster05 said:

@david_taurus83 Thanks for the reply. That could work for my needs, however I'm not so keen on applying tape to the lens itself as I use it for daytime photography too.

Though looking at what @Adreneline has posted I wonder if it would be viable for application on the ring itself?

I did like Adrenaline on a pair of 80mm ring to make them work on my scope that has 78mm inner diameter. It took a bit of trial and error, but I found the right adhesive felt bands and it works very well!

The advantage over tape, is that you modify the lens collar, not the lens. 

Try looking at the furniture section on Amazon, there are lots of felt pads and tape of any thickness, size, shape... 

To give you an idea, my rings have an 80mm inner diameter and the scope was 78mm. So I needed 2mm. However, I used 3mm thick felt to take the compression of the felt into account. I think another extra 0.5-1mm would have been even better, because with enough force I can still push the scope when the rings are closed. Although it's still secure enough like this.

So if you need 1mm, perhaps a 1.5mm should do the trick, so you have enough compression to hold the lens securely. But then again, some trial and error might be needed!

And of course, the thickness you need must be calculated with the existing felt removed, so you know what you need exactly!

Hope that helps  

Edited June 14, 2021 by Space Oddities