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Archive 2012Canon 24mm T/SII vs ZE/ZF 25mm f2.0
p.4 #1Canon 24mm T/SII vs ZE/ZF 25mm f2.0
Well, the Oly is pretty even across the frame and so is the TSE (unlike Zeiss/Nikon), so that's probably as close as I've got for a first order approximation test. Of course, a Canon 24 vs.Canon 24 TSE would probably be better still.
Edited on Jan 16, 2012 at 11:05 PM · View previous versions
Edited on Jan 16, 2012 at 11:05 PM · View previous versions
Jan 16, 2012 at 11:03 PM
p.4 #2Canon 24mm T/SII vs ZE/ZF 25mm f2.0
RustyBug wrote:
Understood "optically ideal" at designed for specific format size ... i.e. Oly 24/2.8 designed for FF, TSE designed for FF ... both "optically ideal" for FF, yet two different image circles. Would that represent a fair comparison test with both on the same FF sensor?
It should, yes.
Let's put it this way. If you had a crappy (and I mean REALLY crappy) 24mm lens that was soft even at f/8 in the image center, how would that affect your ability to ascertain the image's DOF if you put it in front of a 5D2 sensor? Then consider what happens if you put that same crappy lens in front of an equally crappy sensor, say a hypothetical 0.01 MP full frame sensor (pixels so large they're easily visible to the naked eye)? With such a low-resolution sensor, would it make any difference in terms of resolving spatial detail if you put a TS-E 24/3.5L II in front of it?
Conversely, a lens doesn't have to be a perfect imaging device for you to be able to model the DOF it should produce and empirically validate that model. It just has to be sharp *enough* compared the device you're using to measure it (i.e., the sensor).
Understood "optically ideal" at designed for specific format size ... i.e. Oly 24/2.8 designed for FF, TSE designed for FF ... both "optically ideal" for FF, yet two different image circles. Would that represent a fair comparison test with both on the same FF sensor?
It should, yes.
Let's put it this way. If you had a crappy (and I mean REALLY crappy) 24mm lens that was soft even at f/8 in the image center, how would that affect your ability to ascertain the image's DOF if you put it in front of a 5D2 sensor? Then consider what happens if you put that same crappy lens in front of an equally crappy sensor, say a hypothetical 0.01 MP full frame sensor (pixels so large they're easily visible to the naked eye)? With such a low-resolution sensor, would it make any difference in terms of resolving spatial detail if you put a TS-E 24/3.5L II in front of it?
Conversely, a lens doesn't have to be a perfect imaging device for you to be able to model the DOF it should produce and empirically validate that model. It just has to be sharp *enough* compared the device you're using to measure it (i.e., the sensor).
Jan 16, 2012 at 11:05 PM
p.4 #3Canon 24mm T/SII vs ZE/ZF 25mm f2.0
Well, I've got my choice of using SLR/C or 1D MK II with regard to CoC / resolution. The Oly should be "sharp enough"... since it won the 24mm shootout from 16:9 ... I've been planning on comparing the two anyway.
+1 @ model should be telling, if true.
+1 @ model should be telling, if true.
Jan 16, 2012 at 11:08 PM
p.4 #5Canon 24mm T/SII vs ZE/ZF 25mm f2.0
^ From these samples it does look like the Zeiss was at a closer focus distance.
Jan 17, 2012 at 02:10 AM
p.4 #6Canon 24mm T/SII vs ZE/ZF 25mm f2.0
Thanks, alundeb. The Zeiss looks slightly better at B too, to my eye, though it might just be the longer focal length speaking. The differences are a tad clearer before sharpening.
In any case, accurate and appropriate focus, and subjects known to be stationary, are essential for proper comparison.
In any case, accurate and appropriate focus, and subjects known to be stationary, are essential for proper comparison.
Jan 17, 2012 at 02:15 AM
p.4 #7Canon 24mm T/SII vs ZE/ZF 25mm f2.0
S Dilworth wrote:
In any case, accurate and appropriate focus, and subjects known to be stationary, are essential for proper comparison.
Sure. For publication, quality assurance after the test is also essential. Errors will always happen once in a while, even for the best ones. A close visual inspection, looking for typical errors like focus and motion blur, and then retest if it doesn't look right. In forum discussions, the threshold is lower, as they also serve the function of our common education and we should also have fun alongside. But it is a bit frustrating though that the focus is questioned in the majority of the tests and image comparisons given to us. Too often, it ends up, with "we can't really tell anything from this comparison" The best would be if we also get the definition of focus for the comparison. Center, curvature average or spot focus where field curvature is present, sagittal or tangential where astigmatism is present, optimal sharpness wide open or stopped down where focus shift is present. Did I forget something? I have learned a LOT from theSuede, Toothwalker and Wickerprints and others in this matter, and also apprciate when people like you who are relatively new on the forum bring competence and helpful spirit in here.
In any case, accurate and appropriate focus, and subjects known to be stationary, are essential for proper comparison.
Sure. For publication, quality assurance after the test is also essential. Errors will always happen once in a while, even for the best ones. A close visual inspection, looking for typical errors like focus and motion blur, and then retest if it doesn't look right. In forum discussions, the threshold is lower, as they also serve the function of our common education and we should also have fun alongside. But it is a bit frustrating though that the focus is questioned in the majority of the tests and image comparisons given to us. Too often, it ends up, with "we can't really tell anything from this comparison" The best would be if we also get the definition of focus for the comparison. Center, curvature average or spot focus where field curvature is present, sagittal or tangential where astigmatism is present, optimal sharpness wide open or stopped down where focus shift is present. Did I forget something? I have learned a LOT from theSuede, Toothwalker and Wickerprints and others in this matter, and also apprciate when people like you who are relatively new on the forum bring competence and helpful spirit in here.
Jan 17, 2012 at 04:20 AM
p.4 #8Canon 24mm T/SII vs ZE/ZF 25mm f2.0
alundeb wrote:
But it is a bit frustrating though that the focus is questioned in the majority of the tests and image comparisons given to us. Too often, it ends up, with "we can't really tell anything from this comparison"
It's surprising that people recklessly push on towards a conclusion anyway, even while admitting the test is flawed in ways that preclude a sure conclusion.
This particular thread isn't useless, though it doesn't allow sensible comparison of sharpness. A pragmatic interpretation of the images might suggest that, on the balance of probability, the Zeiss has more field curvature and light fall-off near the corners than the Canon.
We should also keep in mind quite how different these lenses are, though I have no problem with comparing them to each other. The Zeiss is surprisingly compact and 3x brighter than the Canon, which in turn has a much larger angle of view and image circle, not to mention tilt-shift capability.
alundeb wrote:
The best would be if we also get the definition of focus for the comparison. Center, curvature average or spot focus where field curvature is present, sagittal or tangential where astigmatism is present, optimal sharpness wide open or stopped down where focus shift is present.
Agreed. It would be useful to hear some clarification about the focus from photomadnz. It sounds like he was trying to accommodate an expected field curvature, but while the idea may have been sound, the technique was not.
But it is a bit frustrating though that the focus is questioned in the majority of the tests and image comparisons given to us. Too often, it ends up, with "we can't really tell anything from this comparison"
It's surprising that people recklessly push on towards a conclusion anyway, even while admitting the test is flawed in ways that preclude a sure conclusion.
This particular thread isn't useless, though it doesn't allow sensible comparison of sharpness. A pragmatic interpretation of the images might suggest that, on the balance of probability, the Zeiss has more field curvature and light fall-off near the corners than the Canon.
We should also keep in mind quite how different these lenses are, though I have no problem with comparing them to each other. The Zeiss is surprisingly compact and 3x brighter than the Canon, which in turn has a much larger angle of view and image circle, not to mention tilt-shift capability.
alundeb wrote:
The best would be if we also get the definition of focus for the comparison. Center, curvature average or spot focus where field curvature is present, sagittal or tangential where astigmatism is present, optimal sharpness wide open or stopped down where focus shift is present.
Agreed. It would be useful to hear some clarification about the focus from photomadnz. It sounds like he was trying to accommodate an expected field curvature, but while the idea may have been sound, the technique was not.
Jan 17, 2012 at 05:21 AM
p.4 #9Canon 24mm T/SII vs ZE/ZF 25mm f2.0
RustyBug wrote:
The C has a significantly larger image circle ... should account for a shallower DOF, a smoother bokeh and less vignetting.
Rusty, it has already been explained by others, but the larger image circle obviously doesn't affect DOF because the outer rays aren't captured by the sensor. If what you say is true, using a MF or LF lens on a FF sensor would yield extremely shallow DOF, which is not the case at all. You should know this from your experience with your Mamiya 645 glass.
The larger image circle is only utilized when using shift, or when using tilt, to prevent vignetting. Vignetting will be lower because at zero shift/tilt because there is.
The C has a significantly larger image circle ... should account for a shallower DOF, a smoother bokeh and less vignetting.
Rusty, it has already been explained by others, but the larger image circle obviously doesn't affect DOF because the outer rays aren't captured by the sensor. If what you say is true, using a MF or LF lens on a FF sensor would yield extremely shallow DOF, which is not the case at all. You should know this from your experience with your Mamiya 645 glass.
The larger image circle is only utilized when using shift, or when using tilt, to prevent vignetting. Vignetting will be lower because at zero shift/tilt because there is.
Jan 17, 2012 at 07:02 AM
p.4 #10Canon 24mm T/SII vs ZE/ZF 25mm f2.0
Toothwalker wrote:
Gunzorro, an aberration on some Zeiss models where the plane of focus is more of a sphere is not well known. An aberration where the plane of focus is quite flat except for the corners is known to occur---but maybe that is what you mean.
I should add that older Distagon designs may have a bit wavy field, and at close focus anything can happen without countermeasures in the form of floating elements. Anyway, I asked Zeiss about the D2/25 and it has a flat field up to 16 mm, as we could already tell from the MTF charts. Towards the corners the field curves backwards (away from the photographer).
Gunzorro, an aberration on some Zeiss models where the plane of focus is more of a sphere is not well known. An aberration where the plane of focus is quite flat except for the corners is known to occur---but maybe that is what you mean.
I should add that older Distagon designs may have a bit wavy field, and at close focus anything can happen without countermeasures in the form of floating elements. Anyway, I asked Zeiss about the D2/25 and it has a flat field up to 16 mm, as we could already tell from the MTF charts. Towards the corners the field curves backwards (away from the photographer).
Jan 17, 2012 at 11:56 AM
p.4 #11Canon 24mm T/SII vs ZE/ZF 25mm f2.0
No pleasing some! The Zeiss was at infinity. The lens is shipping now so you can buy and conduct your own tests.
Jan 17, 2012 at 02:04 PM
p.4 #12Canon 24mm T/SII vs ZE/ZF 25mm f2.0
photomadnz wrote:
The Zeiss was at infinity.
What does that mean? That you used the infinity mark? It is never reliable.
The Zeiss was at infinity.
What does that mean? That you used the infinity mark? It is never reliable.
Jan 17, 2012 at 02:27 PM
p.4 #13Canon 24mm T/SII vs ZE/ZF 25mm f2.0
Its is a hard stop?! Confirmed with live view as always whilst wide open before stopping down for the shot.
Jan 17, 2012 at 02:31 PM