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Author Topic: 24mm T/S lenses... which has the largest image circle on MF sensor?  (Read 1444 times)

Theodoros

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If one has tested between FF 24mm lenses for image circle size and sharpness, but with no shifts or tilts applied on the lens and the circle projected on an MFDB (on a view camera) please share your experience....

I am only interested on which lens projects larger/sharper image circle without any shifts or tilts applied on the lens... This is due to the fact that the rear element of the Nikon is mechanically blocked by a flange in the lens (don't know if the same happens to Canon) which causes some image circle blocking if the lens is shifted more than 6mm... please only results observed on a tech camera with no movements applied on the lenses body... Your experience will be highly appreciated.
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Theodoros

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #1 on: January 15, 2016, 11:12:44 am »

Please... if anyone has information related to the subject his contribution will be highly appreciated....
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alan_b

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #2 on: January 15, 2016, 12:56:23 pm »

Alpa has some comparison shots w/ the Canon, Nikon & Samyang 24mm (among others) on an IQ180 here:
http://www.alpa.ch/en/site/a-vast-choice-of-lenses-with-the-alpa-12-fps

Not the whole image circle, but you can see sharpness falloff & field curvature differences, even if the focus point is a bit different between lenses.
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Theodoros

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #3 on: January 15, 2016, 01:44:08 pm »

Alpa has some comparison shots w/ the Canon, Nikon & Samyang 24mm (among others) on an IQ180 here:
http://www.alpa.ch/en/site/a-vast-choice-of-lenses-with-the-alpa-12-fps

Not the whole image circle, but you can see sharpness falloff & field curvature differences, even if the focus point is a bit different between lenses.

Alan... you are a life savior! It seems that the best 24mm for a 37x49 sensor is the ...Samyang? ...it's clearly the sharpest in the corners (of 37x49) although it is stopped down to f16 (the Canon to f11, the Nikon to f8) which should mean that it is diffraction limited more than the other two... no? It also seems to have the largest image circle out of the three since it has less vignetting...

EDIT: Just noticed that there is something wrong with the ALPA example of the Canon 24mm... the lens is a mess at the right corner and sharp to the left corner?
« Last Edit: January 15, 2016, 02:00:57 pm by Theodoros »
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Paul2660

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #4 on: January 15, 2016, 02:30:30 pm »

The Samyang is the weakest shift I have tried in 35mm
I can't see it holding up to a larger MF sensor.   It was hoped that Samyang would be able equal the Canon TSEII or Coke close but they did not. Lensrentals.com did a very good work up on the Samyang 24mm a while back.

Reviews of this lens also show that when shifted past 5mm the results are less than stellar.

The Canon 24 TSE II is an excellent optic vastly superior to the older Canon 24 or the new Samyang.  It has been shown to work well with the IQ250 and 180. Canon has some sample variation but a good lens will not disappoint.

Alpa has tested the 17mm Canon also.

You might get some more responses if you posted over on Getdpi. Gerald has done some amazing work with the Canons on several Phase backs.

Paul C
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Paul Caldwell
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www.photosofarkansas.com

Theodoros

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #5 on: January 15, 2016, 03:13:10 pm »

The Samyang is the weakest shift I have tried in 35mm
I can't see it holding up to a larger MF sensor.   It was hoped that Samyang would be able equal the Canon TSEII or Coke close but they did not. Lensrentals.com did a very good work up on the Samyang 24mm a while back.

Reviews of this lens also show that when shifted past 5mm the results are less than stellar.

The Canon 24 TSE II is an excellent optic vastly superior to the older Canon 24 or the new Samyang.  It has been shown to work well with the IQ250 and 180. Canon has some sample variation but a good lens will not disappoint.

Alpa has tested the 17mm Canon also.

You might get some more responses if you posted over on Getdpi. Gerald has done some amazing work with the Canons on several Phase backs.

Paul C

Paul, I'm aware on what happens with 35mm... As I said before I'm not interested at all on what happens if the lens is shifted as it is designed to do since the lens isn't needed for that kind of use, nor the shifting on 35mm equivalent image areas can be reliable of how a "free" image circle behaves... This is because the Samyang has the most recessed rear element and the Nikon, although a little less recessed, has an additional "flange" of lower diameter than the mount... As a result, both lenses (perhaps the Canon too) image circle is mechanically "obstructed" when shifted on their own frame... A proof for that, is that the Nikon presents severe vignetting if shifted at more than 9mm (I now own the lens), while on the ALPA examples, it only vignettes (not severely) to the furthest corners of a 54x40.5 sensor...
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voidshatter

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #6 on: January 15, 2016, 03:47:44 pm »

This might be relavent: http://forum.luminous-landscape.com/index.php?topic=93273.0

According to my experience with the 17mm TS-E, the sharpness fall off is severe in the corners when it's shifted to the extreme (which is the case for usage on a larger sensor even not shifted much). In order to offset that you would need to stop down the lens to f/16 but diffraction would kick in and hammer the sharpness of the whole picture.
« Last Edit: January 15, 2016, 03:53:49 pm by Yunli Song »
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Craig Magee

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #7 on: January 16, 2016, 09:57:18 am »

My Canon 24mm is certainly not a great, its softer to the left and bottom corners. Sharper at the top. Its dependant on distance also, from about 3m and closer its much more even across the frame. Thats all at F11. Keep meaning to find a better version. Canon quote 67.2mm for the image circle if thats any help.Though I would say its bigger, but havent done any specific testing.
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Theodoros

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Re: 24mm T/S lenses... which has the largest image circle on MF sensor?
« Reply #8 on: January 16, 2016, 01:32:14 pm »

My Canon 24mm is certainly not a great, its softer to the left and bottom corners. Sharper at the top. Its dependant on distance also, from about 3m and closer its much more even across the frame. Thats all at F11. Keep meaning to find a better version. Canon quote 67.2mm for the image circle if thats any help.Though I would say its bigger, but havent done any specific testing.

It seems that those lenses (all of them, out of all makers) have additional calibration problems to the usual ones that have to do with lens elements assembly/alighnment... This is explainable as the shift/tilt mechanisms involve different metal parts with low tolerances between them, but the different parts of the mechanisms are also affected for size (and therefore calibration) by enviromental temprature, friction & ware of use... Other than that, as ALPA's examples show,  http://www.alpa.ch/en/site/a-vast-choice-of-lenses-with-the-alpa-12-fps  ,the mechanical design of the lens itself limits the optical system of it from exposing its full potential... Partly the reason why in the O/P I ask on the lens behavior with no movements applied, as I believe that it is best for one to use a small view camera and mirrorless (or MFDB) combination with a lens that has wide image circle, but offers no movements on its barrel...
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