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Author Topic: A comparison of four shift lenses on the A7R  (Read 15263 times)

mjon

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Re: A comparison of four shift lenses on the A7R
« Reply #20 on: September 12, 2014, 09:28:32 am »

The Nikon with an EOS adapter on the HCam is unable to use movements, because there is no shift mechanism !

I see. I thought, there was an EOS adapter including a shift mechanism :-(

Thanks!

mjon



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narikin

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Re: A comparison of four shift lenses on the A7R
« Reply #21 on: September 13, 2014, 01:45:21 pm »

As Torger mentioned the 60XL is the wonder lens.  I can take this lens to 25mm of shift (yes 25mm).  I use the CF on mine which helps on the light fall off and I have started to use a CF on my 40mm Rodenstock.  

Tried the 60XL on my Alpa setup and thought it just ok in its resolution, certainly inferior in the center to the Roddy 60mm f4 Digaron-S, but then that is not a stitching/shifting lens.  I want it to be good, so believe me, am not a 'knocker' of other people's gear, but it has problems for me - sharpness I just mentioned, and that vignetting. Having to put a CF on a back working at ISO50, means incredibly slow effective ISO, and therefore long exposures. I need to freeze sidewalk action sometimes, and even distant people will blur at slower shutter speeds. That CF is not without cost.

I would love to see a shutter solution for the tech market that allows 1/3 or even 1/2 stops since the copols are so rigid in their stops.    
Paul

The Alpa FPS has been out for nearly 2 years now! 1/3, 1/2, 1/4, or whole stops. whatever you wish.
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Paul2660

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Re: A comparison of four shift lenses on the A7R
« Reply #22 on: September 13, 2014, 04:12:24 pm »

Good points.  Who knows, you might have a bad copy of the 60XL, it can happen.  Most find it very sharp on 60 or 80MP backs.  Mine is.  

I didn't really overlook the FPS, as it's limited to Alpa mount only, as an Arca user I guess I am looking for a more universal solution.  Something like the current electronics on the market, but with more range in speeds.  What little that was per-released on the DHW version seemed to show promise, but the 2K cost per shutter, was not going to work for many. 
 
Also I know the FPS has a a lot of lens mount options, but with the 28 Rod and 35 SK can you still have tilt?  I just don't know enough about it.  

No doubt right now for more variety in shutter speed options is seems to currently about the only game in town, and if I had already made the investment in Arca R mount, I would be definitely looking at one.  I could have kept my 17mm and 24mm TS-E lenses!  

Hopefully Arca and Cambo are working on something similar (frankly I am surprised neither has), but with maybe a more realist cost of entry, i.e. less than 8.5K.  (that was the FPS price last time I checked).

Paul




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Paul Caldwell
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marc aurel

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Re: A comparison of four shift lenses on the A7R
« Reply #23 on: September 14, 2014, 06:57:07 am »

Thanks everybody for the input.

Bart - I forgot mentioning stitching as an option. And I know some people get great results with that technique. But for me it is not useful. I work as a professional architecture photographer and go through lot's of images. Often I combine more than one exposure for interiors because of harsh contrasts - even with the high dynamic range of the A7R. I just can't stitch with the amount of images I need. And I like to see the final composition in what ever kind of viewfinder.

Stefan - I like the idea of your shift adapter for the Nikon 14-24mm a lot. I am curious how the image quality of that lens is when you use it outside of the "official" image circle (it is great within) on the A7R. A problem I see for my kind of shooting with this solution: how can I correct images for distortion? You have a lot of variables: the varying distortion depending on the focal length you use. And the different amount of rise / fall / shift you use. As far as I know none of this information can be recorded and saved in exif. So I do not see a chance to create profiles for correction of distortion. Maybe not a problem in a lot of cases for landscapes, but for architecture it is.    

The new Alpa Adapters with movements for Hasselblad H and Contax 645 look interesting to me. That could be a way of using wide retrofocus MF-lenses on a 44x33mm-chip. No LCCs and eventually (hopefully) no problems with crosstalk too. Does anybody know the image circles of Hasselblad H or Contax 645 lenses. How much shift would lenses with 28mm or wider allow on a 44x33mm-chip? Would it be more than just a few millimeters? Hopefully they will create profiles for correction of distortion for their Alpa plugin software. But it looks as if they don't record the amount of used movements in exif which would be great.

Marc
« Last Edit: September 14, 2014, 08:57:46 am by marc aurel »
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Aphoto

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Re: A comparison of four shift lenses on the A7R
« Reply #24 on: September 14, 2014, 03:23:35 pm »


Stefan - I like the idea of your shift adapter for the Nikon 14-24mm a lot. I am curious how the image quality of that lens is when you use it outside of the "official" image circle (it is great within) on the A7R. A problem I see for my kind of shooting with this solution: how can I correct images for distortion? You have a lot of variables: the varying distortion depending on the focal length you use. And the different amount of rise / fall / shift you use. As far as I know none of this information can be recorded and saved in exif. So I do not see a chance to create profiles for correction of distortion. Maybe not a problem in a lot of cases for landscapes, but for architecture it is.    

With PT-Lens it is possible to correct for example the distortion of my great Pentax 645 A 35mm lens, shifted to any position.
So, in theory, you "only" need a lens profile and the knowledge of the focal lens and the horizon in your image.
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marc aurel

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Re: A comparison of four shift lenses on the A7R
« Reply #25 on: January 17, 2016, 12:46:19 am »

Update on the performance of the TS-E 24mm L II in the shifted corner:

Since in another thread people refer to this test I wanted to give a short update: when I did this test I did not know that my copy of the TS-E 24 needed adjustment. The sharpness in the shifted corners in my original test is much worse than usual with the lens. Here are crops and full image on a different copy on the 5DsR with 12mm of shift. Sorry it is not on the same subject and for the grey low-contrast weather conditions, but I think one can clearly see the difference.

Marc
« Last Edit: January 17, 2016, 01:00:28 am by marc aurel »
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ErikKaffehr

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Re: A comparison of four shift lenses on the A7R
« Reply #26 on: January 17, 2016, 11:41:21 am »

Thanks for the info!

Best regards
Erik

Update on the performance of the TS-E 24mm L II in the shifted corner:

Since in another thread people refer to this test I wanted to give a short update: when I did this test I did not know that my copy of the TS-E 24 needed adjustment. The sharpness in the shifted corners in my original test is much worse than usual with the lens. Here are crops and full image on a different copy on the 5DsR with 12mm of shift. Sorry it is not on the same subject and for the grey low-contrast weather conditions, but I think one can clearly see the difference.

Marc
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Theodoros

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Re: A comparison of four shift lenses on the A7R
« Reply #27 on: January 17, 2016, 02:41:38 pm »

   

The new Alpa Adapters with movements for Hasselblad H and Contax 645 look interesting to me. That could be a way of using wide retrofocus MF-lenses on a 44x33mm-chip. No LCCs and eventually (hopefully) no problems with crosstalk too. Does anybody know the image circles of Hasselblad H or Contax 645 lenses. How much shift would lenses with 28mm or wider allow on a 44x33mm-chip? Would it be more than just a few millimeters? Hopefully they will create profiles for correction of distortion for their Alpa plugin software. But it looks as if they don't record the amount of used movements in exif which would be great.

Marc

Without having any further research on the subject than posts on the web, it seems that Contax lenses have significantly larger image circles than the respective Hasselblad H ones, because H lenses where designed as to cope with the maximum of 37x49mm sensors that where the largest ones when the line first appeared.

On the Alpa site one can find examples of the Contax 35mm and 140mm lenses, which should be the two ones with the narrower image circle since the 35mm is the wider one and the 140, the one with the longest minimum focusing distance (1.3m!!!), the 35mm (according to Alpa) allows 6mm of shifts on an IQ-180 and the 140 is able to to do full 12mm shifts (on ALPA FPS) with the same back... It seems that Contax lenses will prove able to cope well not only with 33x44 sensors, but with up to 37X49mm ones too...

The matter is of particular interest to me too as I own the whole series (but the 350) of the C645 lenses, but it seems to me (by examining the lenses mechanically) that the 45-90mm vario-sonnar zoom, should prove a pleasant surprise if used with a view camera and the same should apply to the 120mm APO micro lens...
I'm now heavily converting a Rollei X-Act 2 camera which will end up having Contax 645 lens interface control and one will be able to use both Sony α7 cameras and multishot MFDBs on it without having to convert the rear standard (there is "special" care taken to avoid the recess that the α7 handgrip causes and rotation is retained with both the α7 or an MFDB). I'll soon be able to examine the image circle of all C645 lenses and will post the results...
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yashima

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Re: A comparison of four shift lenses on the A7R
« Reply #28 on: January 20, 2016, 08:04:43 am »

Hi Theodoros, any particular reason for choosing the Rollei-Xact for this purpose?
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JaapD

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Re: A comparison of four shift lenses on the A7R
« Reply #29 on: January 20, 2016, 08:28:25 am »

I find many shift lenses really horrible in their edge and corner performance. Wouldn’t it be much better if we don’t apply shift lenses anymore?

Why not use normal lenses, tilt the complete camera, leave sufficient space for cropping and make our corrections in post? It’s what I do in C1.

These days with high megapixel sensors the resolution after correction in post seems still more than sufficient, and it is at least more than what we get with shift lenses.

Am I missing something here?

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torger

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Re: A comparison of four shift lenses on the A7R
« Reply #30 on: January 20, 2016, 08:32:21 am »

I find many shift lenses really horrible in their edge and corner performance. Wouldn’t it be much better if we don’t apply shift lenses anymore?

Why not use normal lenses, tilt the complete camera, leave sufficient space for cropping and make our corrections in post? It’s what I do in C1.

These days with high megapixel sensors the resolution after correction in post seems still more than sufficient, and it is at least more than what we get with shift lenses.

Am I missing something here?

I'm quite sure the good shift lenses still outperform cropping and keystone correction. But indeed it would be interesting to make a side-by-side comparison of the two methods.
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Theodoros

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Re: A comparison of four shift lenses on the A7R
« Reply #31 on: January 20, 2016, 09:19:53 am »

Hi Theodoros, any particular reason for choosing the Rollei-Xact for this purpose?

Yes there is.... The camera is used for testing purposes only, as the end product will have different mechanisms design that will lead to even smaller overall size and greater range of movements, so the important thing for testing purposes was to use a camera as a base that would be easy to convert the plates of the standards and additionally would allow (again by relatively simple modification) for the front and rear standard plates to come as close as possible to each other... The Rollei X-act2 allows the front and rear standard plates to collide (with out a bellows on and after a relatively simple conversion of the rear standard only) yet retaining the yaw free design of the original design. With a WA bellows on, the total  of the rear standard plate width + (sqeezed) bellows + front standard plate width adds up to only 24mm.  Additionally, there are plenty of lens mounts available from Novoflex which are easily interchangeable to each other.

EDIT: An other requirement that the x-act-2 can be modified to fullfill, is that after the rear standard modification the rear standard's surface is completely flat...
« Last Edit: January 20, 2016, 09:32:57 am by Theodoros »
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marc aurel

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Re: A comparison of four shift lenses on the A7R
« Reply #32 on: January 20, 2016, 09:48:15 am »

I find many shift lenses really horrible in their edge and corner performance. Wouldn’t it be much better if we don’t apply shift lenses anymore?

Why not use normal lenses, tilt the complete camera, leave sufficient space for cropping and make our corrections in post? It’s what I do in C1.

These days with high megapixel sensors the resolution after correction in post seems still more than sufficient, and it is at least more than what we get with shift lenses.

Am I missing something here?

There is more to a shift lens than just the question of resolution. I prefer to compose my image in the viewfinder.

But if you only have the question of resolution and sharpness in mind:

For longer focal lengths the loss introduced by keystone correction is not too much. I don't see too much difference between my TS-E 90mm at full shift and my 85mm 1.8 with keystone correction.
But that is not true fur the wide lenses - especially as wide as 35, 24 or even 17mm. The resolution loss through keystone correction can be quite extreme - especially when you shift much.
Another effect reduces sharpness when you do not use a tilt-shift lens: if you want to take a photo of a facade and use a normal lens you have to tilt camera and lens to have everything in your frame. That means that your plane of focus is tilted too, parts of the facade are out of focus - and depth of field is not always deep enough to compensate for this.

A lens as good as the TS-E 24mm II will win against a keystone corrected normal lens.
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Theodoros

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Re: A comparison of four shift lenses on the A7R
« Reply #33 on: January 21, 2016, 04:07:19 am »

The widest Solution for the HCam with anIQ250 is our new cut 2,8/14-24mm Nikon AF-S G-ED .
You will be able to see this on Photokina on the Novoflex booth in hall 2.1 Booth A40

Greetings from Germany
Stefan
Hi Stefan, have you tried the Nikkor 17-35mm f2.8 instead of the 14-24mm one? How the image circle behaves at respective focal lengths with this lens? I think it may have wider image circle at 24mm?  ...how does it behave at 28mm and 35mm?
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