Ray,
To take the discussion further you need to post images that proves your point. Here's an experiment for you:
1. Mount the camera on a tripod, point it at some area with geometric objects, like a playground or similar
2. Shoot two photographs with one wide angle and one longer focal length (or use a zoom). Do not move the camera or change its direction.
3. Make sure that you apply distortion correction in your raw converter so the lenses render as close as possible to perfect rectilinear
4. Crop the wide angle so it has the exact same FOV as the longer focal length
5. Compare.
If I understand you correctly you claim that there will be some more difference apart from lower resolution. I have not been able to understand what difference that would be from all your long posts. Can you describe in a short way what you mean the difference between cropping a wider and using a longer focal length would be?
I can give you a lead: the experiment above will show that there is no difference to be found.
Torger, I
have posted images relating to this issue in other threads. I own a Nikkor 14-24 so I'm very familiar with the effect of moderately distant objects, such as mountains in the background, appearing really tiny in relation to the much larger objects in the foreground which seem closer to their normal size, or the size one might expect them to be.
I also know very well that cropping a wide angle shot to the same FoV as a shot from a longer lens, from the same position, results in images with the same perspective, provided that resolution is sufficient for one to be able to recognize the elements in the cropped image.
For me, this issue is about describing a phenomenon or image characteristic clearly, precisely and logically so that the statement holds true in all situations. If there are exceptions, then the theory cannot be claimed to be true, in the absence of other explanations for the anomalies.
All I'm asking is for some bright spark to provide the explanation for these obvious exceptions and inconsistencies, as in the following example which highlights the problem and perhaps even proves that people like JJJ and Bart are wrong on this issue. I never accuse people of being wrong unless I'm also able to provide reasons and evidence for their being wrong.
In view of the categorical statement from JJJ that "Cropping has zero effect on perspective, nor does print/sensor size or viewing distance and the biggest myth of all, focal length", then why have you required the act of cropping, in procedure # 4 above, in order to demonstrate that cropping has no effect on perspective?
If two images taken with different focal lengths of lens
appear to have the same perspective, and after cropping one of the images, the perspective is still the same, then that would demonstrate that cropping has no effect on perspective, provided one repeated the cropping a few times with different images just to be sure there were no exceptions.
However, if all images taken from the same position, without exception,
appear to have the same perspective, whatever focal lengths of lens was used, then what is the purpose of cropping, in your experiment as described above? Are you with me so far?
Is it reasonable for me to assume that you recognise that the image from the wider-angle shot
only appears to have a different perspective and that you have cropped the wider-angle shot in order to demonstrate that this
apparent difference is a mere illusion?
Now this is what I suspect is going on here. People like JJJ and Bart, and others, are trying to claim that images taken with wide-angle lenses
only appear to have a different perspective as a result of various lens distortions, and that cropping removes such distortions to reveal the
true perspective which is determined only by lens position.let's examine this argument to see if it makes sense. It's true that wide-angle lenses tend to produce a type of distortion known as Volume Anamorphosis, which editing programs from DXO can correct reasonably well, and it is now commonplace for image editing programs such as ACR and Lightroom to correct for various types of lens distortions, provided there's a profile available for the lens.
But let's take this a step further and claim that despite such distortion corrections in programs from DXO and Adobe, the images from the wider-angle lenses are still distorted and this is the only reason why the wider-angle shots appear to have a different perspective.
If this statement is true, then it would follow that in any comparison of shots taken with different focal lengths of lens,
the longer focal length would always provide the truer perspective. In other words, the shot from the 14mm lens appears to have a different perspective to the same scene shot with a 35mm lens,
only because the 14mm lens is plagued by uncorrectable distortions. Also. we would have to claim that the shot from the 35mm lens compared with another shot from an 85mm lens only appears to have a different perspective because 35mm lenses are inherently more prone to distortions than 85mm lenses.
We could apply the same comparisons of 85mm lenses with 200mm lenses, 200mm with 400mm lenses and 400mm lenses with 1,000mm lenses and so on. With each comparison between longer and longer focal lengths of lenses, we would eventually arrive at the situation where the longest focal length of lens that it is possible to manufacture would provide the truest perspective and that any differences in perspective that may appear in images taken with shorter focal lengths, are merely illusions.
Is this what you believe, Torger?