Hi everyone. I just made an account, specifically to ask this question, though I am sure I will be posting more in the future.
Anyways.
So, I just ordered this lens. I will use it for a variety of things, but I bought it specifically for architectural photography. As you all know, having low distortion is very important for architecture photography, due to lines and such. So, I was wondering if anyone had any information concerning the distortion levels of this lens, or perhaps someone could take a picture at around f5.6(what I normally shoot at) of straight lines, or a building, just so I can have an idea. Previously, I was shooting with the 35 f1.4, and loves the almost nonexistant distortion, but thought the lens wasn't wide enough for my uses. Hopefully this can be a suitable replacement. Thanks!
Gunzorro wrote:
grasmuch -- Excellent images! The best I've seen from this lens. Night and day compared to Wayne's sample and other test shots I've seen.
It is normal for this purpose for two reasons:
- the size of the details are very big so that may be employed large number of pixels in them.
- the fringes of the CAS, that are little but are, are corrected in ACR.
You should not compare with samples Wayne´s or mine with purposes of landscape.
wayne seltzer wrote:
You can see the difference in depth of field and amount of bokeh blur between f1.4 and f2 at 3ft distance and see the sharpness of both wide open (f1.4 and f2). This was in terribly bright harsh midday lighting.
In those pictures the sun is at eight (clock), if you do the photos at ten (clock), right on the corner of the hood, and f/ 8, for example, you will see the difference of the level of contrast and saturation between the two and possible flare (video).
'I was wondering if anyone had any information concerning the distortion levels of this lens'
Illithid Dude, first welcome to this corner of the webosphere.
Looking up the two lenses distortion data in the MTF data sheets, I doubt you will be disappointed with the 25/2. Zeiss had a bit to say about addressing the criticism some users level at the distortion of the 21/2.8, though I think it mostly concerns the shape of the distortion in image space, due to the change in the direction of the distortion curve in the outer parts of the frame. You cannot please some people.
In any case, both the 35/1.4 and 25/2 show maximum distortion levels of around 2%. The 35/1.4 (presuming you refer to the ZE) has a steady increase over image height - and the 25/2 levels out at image height of 18mm then rises just a fraction to extreme corners. You won't notice this change in images.
Some extremists, generally seen checking that walls are straight enough to photograph, believe anything over 1% is an abomination, but for normal people 1-2% or so is excellent. People even use the Samyang 14mm lens with its 5% plus of barrel distortion.
You would want better for macro lenses (these can get close to zero distortion).
Note that both the 28/2 and the 25/2.8 show higher distortion levels than the 25/2, for an 'apples to apples' comparison. Hope you like it...
philip_pj wrote:
'I was wondering if anyone had any information concerning the distortion levels of this lens'
In any case, both the 35/1.4 and 25/2 show maximum distortion levels of around 2%. The 35/1.4 (presuming you refer to the ZE) has a steady increase over image height - and the 25/2 levels out at image height of 18mm then rises just a fraction to extreme corners. You won't notice this change in images.
Some extremists, generally seen checking that walls are straight enough to photograph, believe anything over 1% is an abomination, but for normal people 1-2% or so is excellent. People even use the Samyang 14mm lens with its 5% plus of barrel distortion.
You would want better for macro lenses (these can get close to zero distortion).
Note that both the 28/2 and the 25/2.8 show higher distortion levels than the 25/2, for an 'apples to apples' comparison. Hope you like it......Show more →
For a distance of 2,5 meters the amount distortion provided is -0,58%
, the value of 2% must be for a frame of 1.2 meters of width.
As happens with distance placement of MTF charts, calculate the distortion with distance approaches to so low habitual not represent the habitual performance of the lens. On the other side either the % of distortion is linear, that way can not extrapolate the distortion of a distance of 6 meters knowing the % of 0,6 meters.
The final reverse of the trajectory (mustache) ios more low than the 21/2,8 Distagon.
The Zeiss-supplied graphic representation of the lens' distortion is just about the only useful way to describe it. Quoting percentages alone is nearly meaningless, since the amount of distortion varies with the image height, as well as with the focused distance. Even Zeiss doesn't seem to specify at what focused distance their distortion readings are taken. I've always assumed it is infinity, but...?
Keith B. wrote:
The Zeiss-supplied graphic representation of the lens' distortion is just about the only useful way to describe it. Quoting percentages alone is nearly meaningless, since the amount of distortion varies with the image height, as well as with the focused distance. Even Zeiss doesn't seem to specify at what focused distance their distortion readings are taken. I've always assumed it is infinity, but...?
is made with minimum of 24 sampling points, as they say, is to infinity. In the graph you can see the change of course and the end. The lower end is logically but we are interested in architecture and the expected and the maximum. In the habitual test only given one value (end or expected).
The figure of 2% to infinity indicating I not agree with my results obtained to 2,5 meters. Is easy calculate the distance for this 2%, I think that will be more small. Will make the picture with a pattern that can be measured more pints. This type of test is the most easy can be performed and in which the data are 100% reliable. Calculate the % difference of radio is simple and in the processing not interfere other issues such as MTF values.
Well, They are already assembled four of the 10 photo-tests that I did the past Monday. I no cut a crop on the central area becasue no are difference between all the AF modes.
The first three photos have an exchange images mousing over them, the fourth you must to select the focus mode in the down texts.
The method is always the same for all: the first with live view focus and that is exchanged with the MF ring full of top-infinity.
regards
Hi G. Pierre, I'm looking forward to the rest of the tests and hope to see some distant detail at the borders or corners. These you have posted look great but, of course, all the border/ corner detail is at a very close distance.
Tariq Gibran wrote:
Hi G. Pierre, I'm looking forward to the rest of the tests and hope to see some distant detail at the borders or corners. These you have posted look great but, of course, all the border/ corner detail is at a very close distance.
Well, I just change the Zeiss 25/2 for a Cannon 24-70, before return it I´ll make another sample focusing the sky or undergronud that in a normal photo of landscape i think that is inusual, is the only way for put the corner in infinite. Until now I´d centered in make the focus at infinite in conditions of the middle horizon.
G. Pierre wrote:
Well, I just change the Zeiss 25/2 for a Cannon 24-70, before return it I´ll make another sample focusing the sky or undergronud that in a normal photo of landscape i think that is inusual, is the only way for put the corner in infinite. Until now I´d centered in make the focus at infinite in conditions of the middle horizon.
regards
There are a number of situations in actual shooting where distant detail can show up in the corners. Waynes seascape and pier shot are examples where the bottom corners are at a very far distance. Mountains shot from a lower position (or anything similar) is another where you can easily end up with important detail at the upper borders. The test for this is pretty easy with your distant mountain scene from the high vantage point as all you have to do is tilt the camera down until the mountains are framed at the top edge and go into the corners.
Tariq Gibran wrote:
There are a number of situations in actual shooting where distant detail can show up in the corners. Waynes seascape and pier shot are examples where the bottom corners are at a very far distance. Mountains shot from a lower position (or anything similar) is another where you can easily end up with important detail at the upper borders. The test for this is pretty easy with your distant mountain scene from the high vantage point as all you have to do is tilt the camera down until the mountains are framed at the top edge and go into the corners. ...Show more →
the buildings of the lower left are a lot more distance that the bottom corner of the sea photo Wayne´s. In ane case not are problem, I´ll make various photos in this conditions, maybe the problem that I have is that the bigs mountains are far from Barcelona. The day of the series I´m thinking in corners-angles very close.
the buildings of the lower left are a lot more distance that the bottom corner of the sea photo Wayne´s. In ane case not are problem, I´ll make various photos in this conditions, maybe the problem that I have is that the bigs mountains are far from Barcelona. The day of the series I´m thinking in corners-angles very close.
I appreciate all of your tests and if you can't get to it, I completely understand.
the buildings of the lower left are a lot more distance that the bottom corner of the sea photo Wayne´s. In ane case not are problem, I´ll make various photos in this conditions, maybe the problem that I have is that the bigs mountains are far from Barcelona. The day of the series I´m thinking in corners-angles very close.
I appreciate all of your tests and if you can't get to it, I completely understand.
No problem, just a matter of time, there are available to do it.
is made with minimum of 24 sampling points, as they say, is to infinity. In the graph you can see the change of course and the end. The lower end is logically but we are interested in architecture and the expected and the maximum. In the habitual test only given one value (end or expected).
The figure of 2% to infinity indicating I not agree with my results obtained to 2,5 meters.
How do you determine the initial radius (Radio Inicial under Cálculo)?
When I estimate the distortion at 25 cm from your test result, I obtain -2.5% and not the -1.17% that you list.
Toothwalker wrote:
How do you determine the initial radius (Radio Inicial under Cálculo)?
When I estimate the distortion at 25 cm from your test result, I obtain -2.5% and not the -1.17% that you list.
I take the front line that get full across the top of the frame and calculate the deviation from the starting point that is the central axis, the deviation if the line had continued straight. This value is the height of a right triangle rectangle, the base is parallel to the plane and the hypotenuse is the difference of the radio.
If you are interested I send the original of the shot at 25 cms. measuring with the sketch.
Attention, the method calculates SMIA what otherwise but then is not the difference of radio. The values calculated with SMIA always given higher results.
G. Pierre wrote:
I take the front line that get full across the top of the frame and calculate the deviation from the starting point that is the central axis, the deviation if the line had continued straight. This value is the height of a right triangle rectangle, the base is parallel to the plane and the hypotenuse is the difference of the radio.
If you are interested I send the original of the shot at 25 cms. measuring with the sketch.
Attention, the method calculates SMIA what otherwise but then is not the difference of radio. The values calculated with SMIA always given higher results.
The shooting distance to try to make them the focal X100. ...Show more →
The last sentence on that page says it all: What a mess.
Anyway, if I understand your explanation correctly you are not using the same definition as Zeiss so comparisons between your results and Zeiss data sheets are not meaningful. The weakness of your approach is that your reference value (the initial radius) is already distorted. You compare a corner point, displaced by distortion, with a border point, also displaced by distortion. Thus you find smaller distortion values than Zeiss, who use the image point in the absence of distortion as the reference value (i.e. according to this figure from the link you provided).
Thanks guys for the help with distortion. Looks like I won't be having a problem with that! One more question: where are you getting the lens? I ordered it three weeks ago, and the store I ordered it at still isn't getting it for at least another week. Are you ordering it online?
