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What are best 85mm to 200mm lenses for milky way panoramas?

astrophotography dslr
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#26 garret

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Posted 04 July 2020 - 12:44 AM

 

They say it is fantastic and the best of its focal length.  Yet I know that the 85mm f/1.4 Zeiss Otus shows "flock of seagull" stars at the edges at f/1.4 because I own the lens!

In the MTF chart the tan and the sag lines should be as close together as possible.

For the 85mm Otus, already from 12mm distance, they are far apart of each other; coma and seagulls is the result (wide open)


Edited by garret, 04 July 2020 - 12:45 AM.


#27 robbieg147

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Posted 04 July 2020 - 04:44 AM

 

for 85mm

-------------

Zeiss Otus is bad at f/1.4 - not sure about f/2

Zeiss Milvus f/1.4 - I doubt it it is good if Otus isn't

 

Samyang/Rokinon 85mm f/1.4  - not good at f/1.4.  I don't havegood test photos at f/2

 

Samyang/Rokinon 85mm f/1.2 SP/XP  - not sure

Sigma Art 85mm f/1.4  - not sure

 

Canon 85mm f/1.4 - not good in any version (but a good daytime lens)

 

 

Have you looked at the Canon 85mm F1.2 for DSLR's, stop it down to F1.4 will still be twice as fast as the Canon 200 F2



#28 rfe3

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Posted 04 July 2020 - 06:37 AM

The best advice on DSLR Lenses at a reasonable cost I got from this Forum 4 or 5 years ago, and they were great purchaces and make great photos at a reasonable price. In fact, because I shoot with up to 4 DSLR"s at a time I own multiple  of each (except the Nikkor in the Article) I have 2 of the 300mm Zeiss's, 2 of the 200mm Takumar's, 4 of the 135mm Asahi Pentax's, and additionaly 2 of the old  85mm Nikkor AI's @ f2 and all for under maybe 1300 Euros. I use the Stepdown rings exactly as the Article says and I"ve been more than happy with them.

 

https://www.cloudyni...otography-r2993


Edited by rfe3, 04 July 2020 - 06:38 AM.

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#29 nathanm

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Posted 04 July 2020 - 11:25 AM

I have the Canon 85mm f/1.2 lens, for daytime use.   It is a great lens, but lots of coma wide open.   I haven't tested it to see exactly what f-stop the coma dies down.  

 

There is also the Samyang/Rokinon 85mm f/1.2 SP / XP  lens, but I haven't seen shots from it.

 

Its come to my attention that Samyang/Rokinon recently announced a set of new lenses that for the most part have not shipped yet.    

 

Some of these seem to be autofocus versions of previous lenses that were only available as manual.

 

But there are are also new manual focus lenses.   There is a 14mm f/2.8 Series II, and  an 85mm f/1.4 Series II.    The announcement says that they both have a focus lock feature - which is nice for astrophotography, and (for me) would replace the gaffer's tape I use for that purpose.

 

There also is a new 85mm f/1.4 lens with Canon RF mount (and also one for Nikon mirrorless mount).



#30 robbieg147

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Posted 04 July 2020 - 01:08 PM

You must be a very keen photographer to have the 85mm 1.2 it is a special lens, I am a bit surprised it has coma I wonder at what F stop it disappears?

 

I see the 200mm F2 has a rear filter drawer.



#31 erictheastrojunkie

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Posted 04 July 2020 - 01:19 PM

The new Rokinon lenses use the same optics as the old so there won't be any difference there, just AF mechanisms integrated. If your goal is maximum sharpness with minimal aberrations then skip the Rokinon, for the most part they will have minimal aberrations but none will come close to the sharpness offered by the Art lenses.

As was mentioned, and as far as I'm concerned, the best at the 85mm and 105mm are the Art lenses. At 135mm you can bring the Zeiss App Sonar and the Rokinon into the conversation, at 200mm the Canon.

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#32 nathanm

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Posted 04 July 2020 - 03:01 PM

erictheastrojunke, I think you are correct that the AF Samyang/Rokinon lenses are the same as previous, but they do claim new designs for the "Series 2".

 

Also, it is clearly a new design for the 85mm f/1.2 SP / XP since it is f/1.2 and the previous design was f/1.4.    That lens has only been out since 2017 and I haven't found much in the way astrophotos shot wide open with it to judge.   

 

With respect to your list, the actual test shots I have seen on line for Sigma 85 and 105 art lenses are not great, but lots of people here on the list seem to swear by them.

 

The 135mm Samyang/Rokinon is 135mm Zeiss Apo Sonnar seem to be clearly good, by all of the images I have seen.

 

Ditto for the Canon 200mm f/2.   

 

The Nikon 200mm f/2, isn't relevant for me but I its images look very good in the corner also.  https://www.flickr.c...pin/6868664316/



#33 nathanm

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Posted 04 July 2020 - 03:15 PM

Garret:    I didn't realize that one could predict coma from MTF charts.   

 

How well can you predict it?  Does distance between tan and sag lines tell you how much coma there will be ?   



#34 sharpstar

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Posted 05 July 2020 - 04:14 AM

http://www.askarlens...class1/179.html

 

World's first 200mm F/4 APO Flat-Field Astro Camera Lens will be released in this month



#35 DanielJStein

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Posted 05 July 2020 - 10:42 AM

In my own testing, I have found both the Canon 70-200 f/2.8L II, Sigma 85 f/1.4 ART, Sigma 105 f/1.4 ART, and Rokinon 135 f/2 lenses to be chart toppers in corner and edge to edge performance. I have not tested all of the others however. 

 

I think the most notable one is the Canon 70-200 f/2.8L II. As a zoom, you wouldn't think it would perform as well as it does, but it certainly surprised me. 

 

Here is an unedited shot at 70mm with my Nikon Z6 astro mod, wide open at 2.8.

 

ZrHbPfN.jpg

 

Here is a 1:1 crop at center:

 

RtNypaJ.jpg

 

And of course, 1:1 at the corner:

 

HMOScGl.jpg

 

Here is another test. This time zoomed to 122 but stopped to f/4. 1:1 crop at center then corner:

 

7dQFzvW.jpg

 

Corner:

 

AO9XRfW.jpg

 

The reason why I love this lens so much is because I use it for daytime landscapes. The fact that I can then use it at night and be a great performer is just the icing on the cake with the cherry on top!


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#36 garret

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Posted 05 July 2020 - 11:07 AM

That lens is indeed a very, very good zoomlens.

For AP the Canon 100-400 mk2 is also a very good zoomlens, this review show some AP and interferometrical results: http://interferometr...sm-ii-tele.html


Edited by garret, 05 July 2020 - 11:12 AM.


#37 nathanm

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Posted 05 July 2020 - 11:30 AM

I tried the Canon 85mm f/1.2 last night and it has strong coma from f/1.2 down, with some residual coma even at f/2.8


Edited by nathanm, 05 July 2020 - 11:40 AM.


#38 fritz k

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Posted 05 July 2020 - 12:26 PM

Rokinon 135 mm f/2 manual focus vs Zeiss 135 mm f/2 Apo Sonnar:

 

I had a chance to compare the above two lenses this Spring 2020 in early April.  In terms of sharpness, I found both to live up to their reviews.  They are very sharp in the center, even at f/2, and sharp enough in the corners.  However I found an important critical difference.  Testing was done on a stationary tripod, pointed at Polaris, with exposures of only a few seconds.  I moved Polaris around from the center to all the edges and corners.  In both cases the lenses were supported with a Bogen 3420 Telephoto Lens Support.  The lenses were taken from inside (T = 70’s F) to outside (T = 40’s F).  The Rokinon held focus as I moved Polaris thru all the test positions; say ten minutes.  The Zeiss, however, changed focus to grossly out of focus after just a few minutes.  It was continuing to drift even after half an hour outside.  During a night of falling temperatures I would say the Zeiss is un-usable for astrophotography.
I offer two possible explanations for this behavior.  The Zeiss has a metal lens barrel while the Rokinon is ‘plastic’.  I would expect the latter to be less temperature sensitive.   Secondly, the Zeiss changes length when focusing while the Rokinon does not.  Changing length is problematic when the lens is being held by the Bogen 3420 lens support as the lens is held by both the camera mount and by the nose of the lens.
I only had a chance to perform this test one evening as I had to decide which lens to keep and which to send back.

In summary, I found both sharp, but the Zeiss too temperature sensitive.  And the tests were only done on a single evening (with several repeats); sorry.

 

(The fine print:  The Zeiss lens was a used lens which appeared in every way to be in excellent optical shape with only slight cosmetic damage to the barrel.  Thus, for instance, the performance in all four corners was very similar.  Secondly, I shot with a Canon 6D full frame camera.  The Rokinon lens was a Canon mount lens.  The Zeiss lens was a Nikon mount lens with a FotoDiox adapter (pro model).  This was the right choice for me as the Nikon version of this lens has manual aperture control while the Canon version has automatic aperture control.  In the latter case I would not be able to control the aperture with my Canon mount gear lacking electrical contacts.)

 

Fritz K


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#39 nathanm

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Posted 05 July 2020 - 02:37 PM

The temperature dependence is very interesting!

 

I don't think that the difference is metal versus plastic, because plastic in general has much higher coefficients of thermal expansion than metals.

 

See https://www.engineer...ients-d_95.html

 

ABS plastic has a coefficient of 72 - 108.   The units work out to microns per meter per degree C.

 

So, a 1 meter rod of ABS ought to expand by 72 to 108 microns if heated one degree C.

 

Acrylic is 68 - 75 in these units.   Epoxy and fiberglass is 36.  Nylon is 50-90.  Polycarbonate is 65-70.

 

Meanwhile, aluminum is 21 - 24 in the same units.   FAR less than the plastics.

 

Steel is 10.8 to 12.5.  Stainless steel is 9.9- 17.3 depending on the alloy.

 

I find this very counterintuitive, but it is the case.   Note that the plastic used in most 3D printers is ABS and it is very bad - even worse than the 72-108 listed above.

 

Normally speaking stability under temperature is something that lens designers worry about because glass in very different than either the plastics or the metals they are mounted in.    Glass is 4 to 9 in those units, so far less than the others.


Edited by nathanm, 05 July 2020 - 05:26 PM.

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#40 nathanm

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Posted 11 July 2020 - 02:28 PM

I have tested the Canon 200mm f/2 and Zeiss Milvus 135mm f/2,  both wide open at f/2.   The stars in the corners are good.  

 

I haven't been able to test the Sigma 85mm Art or 105mm Art.


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