Questions reg. Samyang 12mm f/2.0 NCS CS lens

[crowley213]

Yesterday I received my Samyang 12mm f/2.0 NCS CS lens. I purchased the lens mainly for astrophotography, an area I want to explore a little further.

As this lens is often stated for this specific genre in photography and B&H had the lens on sale for $249 I finally ordered it.

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

- Is it normal that the lens does not show the aperture value on my X-T3, the value is always "0"?

- What would be the best method (reliable, easy to do) to check if the lens is okay regarding sharpness, potential de-centering, etc.? As I have read and understand there seem to be sample variations and I would like to make sure I have an acceptable sample.

- What would be the best method to check where is infinity focus, as this point seems not to be always / automatically at the infinity focus hard stop of the lens.

Any advice, tips and tricks are very welcome!

Herbert

 

[Morris0]

This is a totally manual lens and there is no connection to the camera electronics. The camera will not no what lens is mounted, can not know the aperture set and can not focus it.

Unless you want to frustrate your self photographing test charts, use the lens and enjoy it. If images are disappointing, then investigate or simply return.

Morris

 

[Jerry-astro]

Yesterday I received my Samyang 12mm f/2.0 NCS CS lens. I purchased the lens mainly for astrophotography, an area I want to explore a little further.

Many people will argue that it's pretty well the best lens out there for wide field astrophotography. You chose well.

As this lens is often stated for this specific genre in photography and B&H had the lens on sale for $249 I finally ordered it.

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

- Is it normal that the lens does not show the aperture value on my X-T3, the value is always "0"?

The lens doesn't have the necessary logic to communicate with the camera in the same manner that a native Fujifilm lens does. As such, EXIF information will not be valid, but the aperture you set on the lens will operate as marked. You should be fine shooting wide open (but stop down a bit after setting critical focus if you're seeing IQ issues).

- What would be the best method (reliable, easy to do) to check if the lens is okay regarding sharpness, potential de-centering, etc.? As I have read and understand there seem to be sample variations and I would like to make sure I have an acceptable sample.

A starscape is arguably one of the most challenging things you can shoot to test the optics of a lens. Once you've established critical focus (see below), then look for IQ defects towards the edges (such a coma, which makes a point light source such as a star look a bit more like a comma -- no pun intended). You might see a bit of this at the very edges, but those sorts of issues should be minimal and only visible on the very edges (and are easily cropped out in post if necessary).

- What would be the best method to check where is infinity focus, as this point seems not to be always / automatically at the infinity focus hard stop of the lens.

There are some tools out there that can be used to find critical focus, however, the easiest way to get started would be to simply set focus to infinity, take a shot, pixel peep by magnifying in-camera for sharpness, adjust the focus dial just a bit, then repeat until you get pinpoint stars. The actual point is not always exactly where's it's marked on the barrel. Once you've established the critical focus point, you can likely place a mark on the barrel so you can avoid having to go through all that every time you go out to shoot with the lens.

Any advice, tips and tricks are very welcome!

Hope this helps.

--
Jerry-Astro

 

[McWoodley]

Hi Herbert,

As Morris pointed out its fully manual, no electronics to pass aperture info to the camera.

I'll defer to others on sharpness test but generally agree with Morris. Take a few shots and if nothing is glaringly amiss have fun with the lens, its a great one.

Infinity seems to be different on all of them. Use focus peaking, red seems to work bet for me. Do a few test shots and confirm on your computer. I took a white paint pen and placed a dot for true infinity. That said when shooting astro I always focus on a bright star without peaking on using my dot as a starting point its usually real close but always good to double check.

For astro I usually stop down one to two click from wide open. ISO 1600 or 3200 and try to keep shutter as low as possible ususally use T with 15 to 20 seconds. Usually use the 2 second times but recently realized how bad my tripos shakes even after 2 seconds will start using a remote trigger again until i can buy a better tripod. even then will probably use a remote.

For general shooting stop down between f5-8 and hyperfocal works really well. I wish they would put hyperfocal markers on the lens but not really needed. Usually focusing about 3 feet in from will give you great results.

Enjoy the lens, one of the best bang for your buck you can get.

 

[Tom Schum]

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

If this is your first third party non-electronic lens, you need to set "shoot without lens" to "ON".

It might be a good idea to explore manual focusing with one of your Fuji lenses. There are several features that should make this easy. The main one is magnification. Read the manual to find out how to do it, and you want it to show you the place where you have set the focus square. Use maximum magnification.

A tripod test can verify basic operation. Put it on a tripod, manually focus on something not too far away (20ft or so). Take a picture. When viewing the result you should be able to zoom in quite a bit before softness takes over.

Focus on infinity, watching to see that the focusing action optically is about the same as your first test. If the infinity stop is not properly set, you might find that infinity focus does not give you maximum clarity. Or, you might not be able to be absolutely sure that you are getting maximum clarity because the infinity stop actually prevents you from making sure. This can be a problem! Best situation is for the lens to focus slightly beyond infinity, so you can be sure to get the best out of the lens. I'm not sure how you might re-adjust the infinity stop because my 12mm F2 is focusing adequately.

If you have significant distortion or variations of sharpness across the field, it might work better to set the focusing square somewhat off center, for example 1/2 of the distance between center and edge of the image. Just a little trick that might help. Or not.

I've only used my 12mm F2 for earthbound shooting, not astro. You can always put a scratch into the focus ring to mark proper infinity focus for astro, once you have figured it out.

It's a great lens. Good luck!

--
Tom Schum
Copper: Mankind's favorite electrical conductor

 

[davidnbb]

I'd make a couple of suggestions about this lens.

First, the hyperfocal distance is not infinity, it's about 3 metres. So measure out a distance of 3m from a strongly-defined object, stand at the 3m mark and carefully focus. Mark that point on lens in line with the focus dot on the red ring using a thin strip of electrical tape or a dot of Tippex or marker pen. That way you don't need to worry too much about focussing if the lens is stopped down to 5.6 or so because evrthing between about 50cm and infinity will be in focus. This is obviously not useful for astro work at F2, however!.

Second, watch out for flare. If the sun is in your frame (or even close to the edge of the frame), you'll likely get some artefacts.

The rear lens cap will probably be loose and keep falling off. Solution is to use a little piece of electrical tape about 1cm wide (stick it on the flat part of the mount and bend it up and round the barrel about 5mm to secure it. Not pretty, but it really works (if you use red tape, it would probably look intentional). Seems to have no effect on mounting or demounting the lens, but it does keep the rear cap in place.

Finally, Adobe Camera Raw (and I'd assume C1, too) have lens corrections for the Samyang that make a significant difference to the final output, but they have to be applied manually when converting RAWs since there's no exif to tell the converter which corrections to use.

 

[crowley213]

This is a totally manual lens and there is no connection to the camera electronics. The camera will not no what lens is mounted, can not know the aperture set and can not focus it.

Unless you want to frustrate your self photographing test charts, use the lens and enjoy it. If images are disappointing, then investigate or simply return.

Morris

Okay, got it regarding aperture values not shown!

No intention here to do excessive tests with test charts, I totally agree. Nevertheless I would like to make some basic tests to see if there is a major flaw with the lens.

Returns are a little bit complicated for me, living down here in Mexico and ordering the stuff from B&H always means customs and that gets even more difficult with returns!

Herbert

 

[crowley213]

Yesterday I received my Samyang 12mm f/2.0 NCS CS lens. I purchased the lens mainly for astrophotography, an area I want to explore a little further.

Many people will argue that it's pretty well the best lens out there for wide field astrophotography. You chose well.

As this lens is often stated for this specific genre in photography and B&H had the lens on sale for $249 I finally ordered it.

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

- Is it normal that the lens does not show the aperture value on my X-T3, the value is always "0"?

The lens doesn't have the necessary logic to communicate with the camera in the same manner that a native Fujifilm lens does. As such, EXIF information will not be valid, but the aperture you set on the lens will operate as marked. You should be fine shooting wide open (but stop down a bit after setting critical focus if you're seeing IQ issues).

- What would be the best method (reliable, easy to do) to check if the lens is okay regarding sharpness, potential de-centering, etc.? As I have read and understand there seem to be sample variations and I would like to make sure I have an acceptable sample.

A starscape is arguably one of the most challenging things you can shoot to test the optics of a lens. Once you've established critical focus (see below), then look for IQ defects towards the edges (such a coma, which makes a point light source such as a star look a bit more like a comma -- no pun intended). You might see a bit of this at the very edges, but those sorts of issues should be minimal and only visible on the very edges (and are easily cropped out in post if necessary).

- What would be the best method to check where is infinity focus, as this point seems not to be always / automatically at the infinity focus hard stop of the lens.

There are some tools out there that can be used to find critical focus, however, the easiest way to get started would be to simply set focus to infinity, take a shot, pixel peep by magnifying in-camera for sharpness, adjust the focus dial just a bit, then repeat until you get pinpoint stars. The actual point is not always exactly where's it's marked on the barrel. Once you've established the critical focus point, you can likely place a mark on the barrel so you can avoid having to go through all that every time you go out to shoot with the lens.

Any advice, tips and tricks are very welcome!

Hope this helps.

Thanks Jerry, I will do as mentioned.

By the way, the very basic tests I would not do with night sky but during the day, that would already give me some ideas if I may have a major flaw in the lens.

Herbert

 

[crowley213]

Hi Herbert,

As Morris pointed out its fully manual, no electronics to pass aperture info to the camera.

I'll defer to others on sharpness test but generally agree with Morris. Take a few shots and if nothing is glaringly amiss have fun with the lens, its a great one.

Infinity seems to be different on all of them. Use focus peaking, red seems to work bet for me. Do a few test shots and confirm on your computer. I took a white paint pen and placed a dot for true infinity. That said when shooting astro I always focus on a bright star without peaking on using my dot as a starting point its usually real close but always good to double check.

For astro I usually stop down one to two click from wide open. ISO 1600 or 3200 and try to keep shutter as low as possible ususally use T with 15 to 20 seconds. Usually use the 2 second times but recently realized how bad my tripos shakes even after 2 seconds will start using a remote trigger again until i can buy a better tripod. even then will probably use a remote.

For general shooting stop down between f5-8 and hyperfocal works really well. I wish they would put hyperfocal markers on the lens but not really needed. Usually focusing about 3 feet in from will give you great results.

Enjoy the lens, one of the best bang for your buck you can get.

Thanks a lot for your response, I will do so as mentioned.

In regards to the final objective of astrophotography:

- Tripod is not (should not be) an issue at all, I think here I am settled with a really stable one (FLM CP38-L4II)!

- I have as well a simple remote trigger as also a more sophisticated external intervalometer, these topics are also covered.

- Last but no least, I also purchased a "beginners" star tracker to really get deeper into this fascinating genre of photography.

So a lot to learn...!

Herbert

 

[crowley213]

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

If this is your first third party non-electronic lens, you need to set "shoot without lens" to "ON".

It might be a good idea to explore manual focusing with one of your Fuji lenses. There are several features that should make this easy. The main one is magnification. Read the manual to find out how to do it, and you want it to show you the place where you have set the focus square. Use maximum magnification.

A tripod test can verify basic operation. Put it on a tripod, manually focus on something not too far away (20ft or so). Take a picture. When viewing the result you should be able to zoom in quite a bit before softness takes over.

Focus on infinity, watching to see that the focusing action optically is about the same as your first test. If the infinity stop is not properly set, you might find that infinity focus does not give you maximum clarity. Or, you might not be able to be absolutely sure that you are getting maximum clarity because the infinity stop actually prevents you from making sure. This can be a problem! Best situation is for the lens to focus slightly beyond infinity, so you can be sure to get the best out of the lens. I'm not sure how you might re-adjust the infinity stop because my 12mm F2 is focusing adequately.

If you have significant distortion or variations of sharpness across the field, it might work better to set the focusing square somewhat off center, for example 1/2 of the distance between center and edge of the image. Just a little trick that might help. Or not.

I've only used my 12mm F2 for earthbound shooting, not astro. You can always put a scratch into the focus ring to mark proper infinity focus for astro, once you have figured it out.

It's a great lens. Good luck!

Tom, thank you very much for your response, I will do so as proposed.

I already knew about the topic reg. shooting without lens, I used a manual K&F adapter for my Nikon glass in the past.

I also already use manual focusing with my Fuji lenses, so I know the features in here the X-T3 is offering. In general it works great, but such specific topics like focusing an uwa at night will again need some learning.

Herbert

 

[crowley213]

I'd make a couple of suggestions about this lens.

First, the hyperfocal distance is not infinity, it's about 3 metres. So measure out a distance of 3m from a strongly-defined object, stand at the 3m mark and carefully focus. Mark that point on lens in line with the focus dot on the red ring using a thin strip of electrical tape or a dot of Tippex or marker pen. That way you don't need to worry too much about focussing if the lens is stopped down to 5.6 or so because evrthing between about 50cm and infinity will be in focus. This is obviously not useful for astro work at F2, however!.

Second, watch out for flare. If the sun is in your frame (or even close to the edge of the frame), you'll likely get some artefacts.

The rear lens cap will probably be loose and keep falling off. Solution is to use a little piece of electrical tape about 1cm wide (stick it on the flat part of the mount and bend it up and round the barrel about 5mm to secure it. Not pretty, but it really works (if you use red tape, it would probably look intentional). Seems to have no effect on mounting or demounting the lens, but it does keep the rear cap in place.

Finally, Adobe Camera Raw (and I'd assume C1, too) have lens corrections for the Samyang that make a significant difference to the final output, but they have to be applied manually when converting RAWs since there's no exif to tell the converter which corrections to use.

Hi David, thank you very much or your suggestions. I will do so as proposed!

I definitely need to check LR and C1 regarding the lens profiles, a good hint!

Herbert

 

[pifilos]

Yesterday I received my Samyang 12mm f/2.0 NCS CS lens. I purchased the lens mainly for astrophotography, an area I want to explore a little further.

As this lens is often stated for this specific genre in photography and B&H had the lens on sale for $249 I finally ordered it.

My questions now, as I neither used any third party lens with Fuji mount on my X-T3 until now and I am not a specialist reg. UWA lenses:

- Is it normal that the lens does not show the aperture value on my X-T3, the value is always "0"?

- What would be the best method (reliable, easy to do) to check if the lens is okay regarding sharpness, potential de-centering, etc.? As I have read and understand there seem to be sample variations and I would like to make sure I have an acceptable sample.

- What would be the best method to check where is infinity focus, as this point seems not to be always / automatically at the infinity focus hard stop of the lens.

Any advice, tips and tricks are very welcome!

Herbert

The other members have covered your questions pretty much so I will only speak about the infinity part.

From my experience the 2 copies I tried both had issues regarding focusing to infinity. More specifically, the focusing ring reached the hard stop before the lens could reach infinity. So it was physically impossible to actually focus on stars. I didn't have issues shooting other stuff like interiors or buildings but since I bought the lens specifically for astrophotography and landscapes it was kinda useless for me. I am sure that I was just unlucky but after 2 copies I didn't want to struggle more and asked for a refund.

As long as it works properly I am pretty sure you will enjoy it a lot.

 

[Rightsaidfred]

Hi Herbert

Here I've described a simple and quick test for decentering:

https://www.dpreview.com/forums/post/63756500

BR,

Martin