70 replies to this topic

[nhmorgan79]

I'd say it's better than the Sigma in this comparison, definitely in terms of vignetting and edge performance. Looks like your sensor has a bit of tilt going on, the stars on the left side with both lenses are elongated and softer compared to those on the right side. 

I noticed that too. I initially did this test with a z6ii and it displayed the same thing. I use the z6ii a lot for astro and it doesn't show up with other lenses, so I'm thinking that it may be on both lenses. On both the Z6ii and Z8 the Plena showed issues on the left side, especially toward the bottom. 

[lucutes]

https://nikonrumors....xTlBEMeYeqfiEa4

 

 

Here's a second review of the Nikkor 135mm Z Plena for astrophotography. 
 

[lucutes]

Traded my 70-200 for this puppy. Looking forward to the test results.

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[lucutes]

I was able to test out the Plena and the Z6ii(a) for the first time. Conditions were clear but the target was low on the horizon. Also some wind didn't help matters with the SkyGuiderPro. Overall I am happy but there is some issues in the corners. I purchased the arca-swiss collar for the 105MC which is the same as the 135mm Z 1.8 and that should help keep the connection true to the mount as the lens is almost double the weight of camera.

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[vidrazor]

I was able to test out the Plena and the Z6ii(a) for the first time. Conditions were clear but the target was low on the horizon. Also some wind didn't help matters with the SkyGuiderPro. Overall I am happy but there is some issues in the corners. I purchased the arca-swiss collar for the 105MC which is the same as the 135mm Z 1.8 and that should help keep the connection true to the mount as the lens is almost double the weight of camera.

I hope you didn't buy that lens strictly for astrophotography. Otherwise I'd say your money would've been better spent on a lightweight strainwave mount and a decent scope.

[whwang]

I was able to test out the Plena and the Z6ii(a) for the first time. Conditions were clear but the target was low on the horizon. Also some wind didn't help matters with the SkyGuiderPro. Overall I am happy but there is some issues in the corners. I purchased the arca-swiss collar for the 105MC which is the same as the 135mm Z 1.8 and that should help keep the connection true to the mount as the lens is almost double the weight of camera.

Hi,

 

Is the image you attached shot at F1.8 or a smaller aperture?  I see that the stars in the lower-left corners appear somewhat bigger, but I can't be sure whether they are just brighter, or they are distorted by the optics.  Do you mind sharing a larger version of the image, or crops of the corners and center?

[lucutes]

Yes it's true. I basically got this lens used mind you just for Astro. 
 

yes it is shot at 1.8. 
The previous articles showed much better corners than this example. But Dominque did use a lens collar to help with mount sag. This is just using Arca Swiss on the base of the camera. Not ideal. 
I hope to get some more testing and I will try my other two Z mount cameras to ensure it's not sensor tilt. I will post soon the enlarged corners. More tests to come. 

[vidrazor]

Yes it's true. I basically got this lens used mind you just for Astro.

Well, it's your money, but for the price of that lens you could have a Skywatcher Wave100i strain wave mount and an Askar FMA135 triplet if you want that field of view, or an ASKAR FMA180Pro triplet for a bit more reach. The Plena is simply not that great for astrophotography, especially at it's price.
 

[lucutes]

I am not advocating that people spend this kind of money on a 135mm lens. However if you are invested in Nikon Z and want another use for your expensive Plena then this is a good reason. The above mentioned lenses shoot at 4.5 not 1.8 which is another reason to use the Plena. As I learned with the RASA it is extremely hard to shoot fast optics without some kind of tilt or vignetting. This is a simple Mirrorless setup which you can set up quickly and get fantastic results. Your above gear doesn't include the camera which for full frame cool would be mega bucks.

I look forward to using this setup again and trying the collar in no wind conditions. Let you know when I get some results.

[vidrazor]

I am not advocating that people spend this kind of money on a 135mm lens. However if you are invested in Nikon Z and want another use for your expensive Plena then this is a good reason. The above mentioned lenses shoot at 4.5 not 1.8 which is another reason to use the Plena. As I learned with the RASA it is extremely hard to shoot fast optics without some kind of tilt or vignetting. This is a simple Mirrorless setup which you can set up quickly and get fantastic results. Your above gear doesn't include the camera which for full frame cool would be mega bucks.

Well, the aperture isn't as imperative when you have an accurately tracking mount like a Wave 100i. It's easy enough to mount a Nikon body to any optic.

 

But if you want to forge ahead with that setup, I wish you the best.

 

Wind is a problem with any rig, at any size. Explore Scientific sells tent you can use to protect from the wind, but unfortunately they've been holding off on stock due to the tariffs, so it's anyone's guess when it will finally be available again.. Barring that, you may want to look at room dividers, but you will need to make sure they are well weighed down or well spiked into the ground so they are not tipped over by large gusts.

[erictheastrojunkie]

Ya, quick perusal of the various 135mm's, including the newish Viltrox 135mm f1.8....really hard to justify the $2,300 price tag for the Plena when you can get the Sigma Art for ~$1,200 (or much less, used) or even the Viltrox for $900 brand new. Even the Rokinon 135mm is a serious contender given the vast 3rd part options available for astro. The test results from the Viltrox that I see are actually very impressive given the price point, Dustin Abbott has a couple astro tests on his website from that lens:

https://dustinabbott...1-8-vcm-review/

 

Comparing MTF test charts and actual test results shows nearly no difference between the Sigma Art 135mm:

https://www.ephotozi...rt-review-31257

 

And the Plena:

https://www.ephotozi...ns-review-36710

 

And given the capabilities of software like RC-astro's BlurX in PixInsight, there's just no way I could recommend someone plop down that kind of money for the Plena from a strictly astro use case. Buy the Viltrox or the Sigma, then buy yourself a good mount like the SW 100i or ZWO AM3 for portability.  

[whwang]

Among all the Sigma Art lenses that I have used and/or have seen enough, the 135 is the one with largest sample variance.  Just a moderately bad luck can lead you to a bad copy.  Of course, you may return and get a replacement if you buy from a vendor with good return policy.  But this process takes time, and who knows if you are going to get clear sky to test the lens before the return period expires?  The same goes for Rokinon, and likely it's much worse.

 

Of course, budget is an important consideration.  For those who can afford this test-and-return game, getting a Rokinon one is indeed a reasonable choice, and this does save some substantial money.  Sigma is the next choice if you want to move away from the extreme end of the spectrum.  It's more expensive, and probably less (but certainly not zero) chance of getting a bad copy.  Then the Nikon is at the other end of the spectrum.  It's obviously much more expensive (but not outrageously expensive).  If it offers some certainty on the quality (little chance of getting a bad copy), I would still be happy to give it a serious consideration.  Question is, does it?  I don't know.  

[lucutes]

Ya, quick perusal of the various 135mm's, including the newish Viltrox 135mm f1.8....really hard to justify the $2,300 price tag for the Plena when you can get the Sigma Art for ~$1,200 (or much less, used) or even the Viltrox for $900 brand new. Even the Rokinon 135mm is a serious contender given the vast 3rd part options available for astro. The test results from the Viltrox that I see are actually very impressive given the price point, Dustin Abbott has a couple astro tests on his website from that lens:

https://dustinabbott...1-8-vcm-review/

 

Comparing MTF test charts and actual test results shows nearly no difference between the Sigma Art 135mm:

https://www.ephotozi...rt-review-31257

 

And the Plena:

https://www.ephotozi...ns-review-36710

 

And given the capabilities of software like RC-astro's BlurX in PixInsight, there's just no way I could recommend someone plop down that kind of money for the Plena from a strictly astro use case. Buy the Viltrox or the Sigma, then buy yourself a good mount like the SW 100i or ZWO AM3 for portability.  

 

I highly doubt the Sigma Art 135mm 1.8 for DSLRs a (2017) design is anywhere close to the quality you will get with the Nikkor 135 Plena. I have the Rokinon f-mount and it's ok if you slap a cooled camera on "APS" but the corners are horrible. Here you have a lens designed for round balls corner to corner and little to no vignetting on a full frame at f/1.8 !

Sorry this is a niche lens because it can't be used on Astro cooled cameras so far but on modded Z camera this is a pretty cool piece of kit. I will keep my Rokinon for other applications but this is so much fun.  

 

Another thing to note for people trying to reach focus on this lens or something similar, Nikon have an option to make the lens focus pull non linear and in this case using a bahtinov mask you can fine tune the focus without blowing through it.  

[dan_hm]

Don’t Nikon cameras universally suffer from concentric ring artifacts? Why would anyone buy this for astro given that?

[erictheastrojunkie]

I highly doubt the Sigma Art 135mm 1.8 for DSLRs a (2017) design is anywhere close to the quality you will get with the Nikkor 135 Plena. I have the Rokinon f-mount and it's ok if you slap a cooled camera on "APS" but the corners are horrible. Here you have a lens designed for round balls corner to corner and little to no vignetting on a full frame at f/1.8 !

Sorry this is a niche lens because it can't be used on Astro cooled cameras so far but on modded Z camera this is a pretty cool piece of kit. I will keep my Rokinon for other applications but this is so much fun.  

 

Another thing to note for people trying to reach focus on this lens or something similar, Nikon have an option to make the lens focus pull non linear and in this case using a bahtinov mask you can fine tune the focus without blowing through it.  

Well, I'd say you'd be surprised, the Sigma 135mm is an excellent lens (I know Wei-Hao has mentioned sample variation, but honestly I feel that pretty much applies to every lens and manufacturer these days). I already gave you MTF testing comparisons between the Plena and the Art 135mm showing virtually zero difference from those kinds of numbers, here's another much more extensive review from Roger Cicala who I consider among the best lens testers:

https://www.lensrent...nd-the-curtain/

 

And if all else fails you can judge results for yourself from others who have used the lens for astro purposes, of course:

https://app.astrobin...-f18-dg-hsm-art

 

There's a plethora of very good lenses in the 100 to 135mm focal range, across the entire spectrum of price ranges as well. I used the Voigtlander 110mm for a few years to accomplish this large Milky Way mosaic, it's also a very good option, but a bit slower at f2.5: https://www.astrobin.com/xvn3fi/

 

It's up to each person to decide their budget for equipment based on needs and expectations/wants, for me I'd put the Plena at the far end of value spectrum when it comes to factoring in the cost of the lens vs the results that could be had with a variety of alternatives. 

 

You mentioned the focus mechanics, I'll just say that after using Nikon Z7 and Z6 cameras and various S-line lenses over multiple years (not to mention many other cameras and lenses from Sony, Canon, Sigma, Voigtlander, etc) that Nikon's focus-by-wire is among the most frustrating implementations of such mechanisms in the photography world. It's actually one of the reasons I rid myself of the Z cameras and S-line lenses, I now shoot a Sigma Fp with a couple Sigma Contemporary lenses (35mm and 65mm) for my Milky Way stuff. Sony also had some rocky implementation of FBW in lenses which made focusing abysmal and difficult, but improved dramatically in that area over time. Hopefully the Plena 135mm is better than the S-line lenses in that regard. 

[dan_hm]

Does this lens exhibit an “inverted lighthouse” artifact on bright stars when used wide open? If not, that puts it above the other options alone - that is, if an astrocamera adapter is ever made for the Z mount.

[erictheastrojunkie]

Does this lens exhibit an “inverted lighthouse” artifact on bright stars when used wide open? If not, that puts it above the other options alone - that is, if an astrocamera adapter is ever made for the Z mount.

An adapter wouldn't help anyways, as far as I know every Nikon made lens is now focus by wire, requiring electrical control by the camera to make any adjustments to focus and aperture.

It's part of why I switched away from Nikon, but the Voigtlander APO lenses are a spectacular option for astro given they are entirely manual. The only negatives are pretty heavy vignetting and a short focus throw at infinity.

[dan_hm]

An adapter wouldn't help anyways, as far as I know every Nikon made lens is now focus by wire, requiring electrical control by the camera to make any adjustments to focus and aperture.

It's part of why I switched away from Nikon, but the Voigtlander APO lenses are a spectacular option for astro given they are entirely manual. The only negatives are pretty heavy vignetting and a short focus throw at infinity.

The lens has a focus ring. If someone made a belt drive for it, it could be focused with something like an EAF. As for iris control, that’s every modern lens. The Rokinon is the only one I can think of that has manual iris control. With electronic ones most people just set it in a DSLR or mirrorless and leave it locked at that f-stop.

But my specific problem is for the Rokinon and Sigma when used at min aperture anyway.

Edited by dan_hm, 10 June 2025 - 07:40 PM.

[lucutes]

Going back to my previous post about focusing with the Plena. Nikon through firmware updates have made it possible to adjust focus non-linearly up to 1080 degrees rotation if need be. This makes fine focus adjustments very easy considering it's f/1.8 . I don't think you would need to bother with an EAF with this setup because at f 1.8 you will not need the entire night or multiple nights to collect enough data. 30 sec subs might even be overkill. 

[dan_hm]

Going back to my previous post about focusing with the Plena. Nikon through firmware updates have made it possible to adjust focus non-linearly up to 1080 degrees rotation if need be. This makes fine focus adjustments very easy considering it's f/1.8 . I don't think you would need to bother with an EAF with this setup because at f 1.8 you will not need the entire night or multiple nights to collect enough data. 30 sec subs might even be overkill.

Depends on if you are using filters. I also like to use autofocus because it’s hard to determine where the CFZ is with manual focus at very fast focal ratios.

[whwang]

Wait.  Let's make sure one thing.  Can this lens really focus without a Nikon Z camera?  Dan mentioned that it has a focusing ring.  But this doesn't mean the ring can work without a camera.  

 

My GFX lenses all have focusing rings.  But the rings are not connecting to any of the lens elements.  The rings send the focus command (by sensing user's focusing motion) to the camera, and then the camera issues focusing command to the lens to change focus.  When the lenses are detached from the camera, no matter how you turn the rings, nothing would happen.

 

Before you consider putting this Nikon lens on any camera other than a Nikon Z, you better make sure it can focus.  Just having a focus ring doesn't guarantee this.

 

Also, Nikon Z mount has the smallest flange-back distance among all mirrorless cameras, as far as I know.  That means no adapters can exist to adapt this camera to other mirrorless cameras.  You will have difficulty even with astro cameras.  There isn't much room between the lens mount and the sensor.

[dan_hm]

Wait. Let's make sure one thing. Can this lens really focus without a Nikon Z camera? Dan mentioned that it has a focusing ring. But this doesn't mean the ring can work without a camera.

My GFX lenses all have focusing rings. But the rings are not connecting to any of the lens elements. The rings send the focus command (by sensing user's focusing motion) to the camera, and then the camera issues focusing command to the lens to change focus. When the lenses are detached from the camera, no matter how you turn the rings, nothing would happen.

Before you consider putting this Nikon lens on any camera other than a Nikon Z, you better make sure it can focus. Just having a focus ring doesn't guarantee this.

Also, Nikon Z mount has the smallest flange-back distance among all mirrorless cameras, as far as I know. That means no adapters can exist to adapt this camera to other mirrorless cameras. You will have difficulty even with astro cameras. There isn't much room between the lens mount and the sensor.

Well, that would make this a fairly useless lens for astro unless there’s a Nikon Z camera free of concentric ringing, star eating, and other artifacts.

[erictheastrojunkie]

The lens has a focus ring. If someone made a belt drive for it, it could be focused with something like an EAF. As for iris control, that’s every modern lens. The Rokinon is the only one I can think of that has manual iris control. With electronic ones most people just set it in a DSLR or mirrorless and leave it locked at that f-stop.

But my specific problem is for the Rokinon and Sigma when used at min aperture anyway.

No, you're not understanding, focus by wire literally means the lens cannot be focused at all without electrical input and communication with a camera body. A Z camera must be connected to the lens otherwise the focus ring does nothing, when the body is attached the communication protocols between the camera and lens allow the focus assist motors to move and the lens to be focused. It's a major annoyance in modern lens engineering, something that is entirely pointless in my opinion, it's why I always recommend lenses like the Voigtlander APO's over the Nikon S lenses for astro because you genuinely have pure manual control over everything with the lens and they are exceptionally sharp and well corrected. Focus by wire is one of those camera industry blunders that took off and should have been smacked back out of existence. 

[erictheastrojunkie]

Wait.  Let's make sure one thing.  Can this lens really focus without a Nikon Z camera?  Dan mentioned that it has a focusing ring.  But this doesn't mean the ring can work without a camera.  

 

My GFX lenses all have focusing rings.  But the rings are not connecting to any of the lens elements.  The rings send the focus command (by sensing user's focusing motion) to the camera, and then the camera issues focusing command to the lens to change focus.  When the lenses are detached from the camera, no matter how you turn the rings, nothing would happen.

 

Before you consider putting this Nikon lens on any camera other than a Nikon Z, you better make sure it can focus.  Just having a focus ring doesn't guarantee this.

 

Also, Nikon Z mount has the smallest flange-back distance among all mirrorless cameras, as far as I know.  That means no adapters can exist to adapt this camera to other mirrorless cameras.  You will have difficulty even with astro cameras.  There isn't much room between the lens mount and the sensor.

As far as I know all modern Nikon lenses are focus by wire requiring electrical control by a Nikon camera, so no it cannot be focused at all without mounting the lens on a Z camera. 

 

The Z-mount flange focal distance is 16mm, there's a few relatively obscure other mount types which are smaller (like CS mount, for instance): https://en.wikipedia..._focal_distance

 

Theoretically you can mount the Z-mount lenses on an astro camera, smaller ZWO cameras are 6.5mm back focus distance, larger ZWO cameras are 12.5mm without the tilt plate. I worked with Jinux to develop an adapter that allows Sony E-mount lenses to be used with the larger ZWO cameras, at first Jinux designed a replacement tilt plate with a E-mount flange, but I found the margin of error to be too great with the 3D printed tilt plate. So I changed the design such that you mounted the M54 tilt plate on the ASI2600mc (in my case) and then I designed an externally M54 threaded Sony E-mount adapter that let me attach an E-mount lens to that camera. That's how I used the Voigtlander 110mm APO on my ASI2600mc Pro to do that Milky Way mosaic I posted up in post #40. This is the adapter I designed: https://www.cloudyni...ras/?p=11848098

 

You could potentially do the same for the Z-mount, but you would not be able to use the stock tilt plate, you'd have to design a tilt plate with the Z-flange and it'd have to be 3.5mm thick. Additionally, I'm not sure how long the Z-mount flange "arms" are or if they'd be too thick, thus preventing you from actually mounting the lens to the bigger ZWO cameras even with a custom tilt plate. That was the benefit of using the Sony E-mount lenses, they have 18mm flange focal distance, meaning even with the stock tilt plate on the larger ZWO cameras you still had 0.5mm wiggle room (back focus distance of larger ZWO cameras with stock tilt plate is 17.5mm). 

[whwang]

Thanks.  That's what I thought, possible but very difficult.  I would say just use good DSLR lenses if one wants to use an astro camera.